Language：English   Publishing type：Research paper (scientific journal)   Publisher：BMC  

Background Severe complications, such as eye damage and dysfunciton of salivary glands, have been reported after radiotherapy among patients with head and neck cancer. Complications such as visual impairment have also been reported after proton therapy with pencil beam scanning (PBS). In the case of PBS, collimation can sharpen the penumbra towards surrounding normal tissue in the low energy region of the proton beam. In the current study, we examined how much the dose to the normal tissue was reduced by when intensity-modulated proton therapy (IMPT) was performed using a multi-leaf collimator (MLC) for patients with maxillary sinus cancer. Methods Computed tomography findings of 26 consecutive patients who received photon therapy at Okayama University Hospital were used in this study. We compared D2% of the region of interest (ROI; ROI-(D2%)) and the mean dose of ROI (ROI-(mean)) with and without the use of an MLC. The organs at risk (OARs) were the posterior retina, lacrimal gland, eyeball, and parotid gland. IMPT was performed for all patients. The spot size was approximately 5-6 mm at the isocenter. The collimator margin was calculated by enlarging the maximum outline of the target from the beam's eye view and setting the margin to 6 mm. All plans were optimized with the same parameters. Results The mean of ROI-(D2%) for the ipsilateral optic nerve was significantly reduced by 0.48 Gy, and the mean of ROI-(mean) for the ipsilateral optic nerve was significantly reduced by 1.04 Gy. The mean of ROI-(mean) to the optic chiasm was significantly reduced by 0.70 Gy. The dose to most OARs and the planning at risk volumes were also reduced. Conclusions Compared with the plan involving IMPT without an MLC, in the dose plan involving IMPT using an MLC for maxillary sinus cancer, the dose to the optic nerve and optic chiasm were significantly reduced, as measured by the ROI-(D2%) and the ROI-(mean). These findings demonstrate that the use of an MLC during IMPT for maxillary sinus cancer may be useful for preserving vision and preventing complications.

DOI： 10.1186/s13014-019-1405-y

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Adenoid cystic carcinoma (ACC) is a rare epithelial tumor of the head and neck region, and one of the most common malignant tumors of the salivary glands. ACC is a slow-growing tumor characterized by perineural invasion and often has a high-recurrence rate. We describe a case of oropharyngeal ACC invading the mandibular bone through the mandibular foramen that showed a rare pattern of origin and invasion. A 70-year-old woman complained of noise and pain around the right temporomandibular joint. Osteomyelitis was suspected on the initial imaging examinations, although the findings were slightly atypical. However, a mass was observed in the right oropharyngeal wall on subsequent imaging examinations, and mandibular bone invasion, rather than osteomyelitis, was additionally suspected. The mass in the right oropharyngeal wall and right mandible was surgically excised. On postoperative histopathological examination, the mass was finally diagnosed as ACC. As tumor cells were also observed around the inferior alveolar nerve, mandibular bone invasion through the mandibular foramen was suspected. An oropharyngeal ACC invading the mandibular bone through the mandibular foramen is extremely rare. The present case suggests that bone invasion should be considered carefully with several imaging examinations when a malignant tumor such as ACC is observed around the jaw bone.

DOI： 10.1007/s11282-018-0359-3

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OKAYAMA UNIV MED SCHOOL  

We used image-processing software to analyze the setup errors at the skin surface position of breast cancer patients (n=66) who underwent post-operative whole breast irradiation at our hospital in 2014-2015. The sixty-six digital reconstructed radiographs (DRR) were created at the treatment planning for each patient. The lineacgraphies (n=377) were taken after the patients' setup during radiotherapy. The lineacgraphies and DRR were superimposed at the skin surface position for each patient with the image-processing software. We measured the deviations of the isocenters for the nipple-lung (X) direction and craniocaudal (Y) direction and the deviation of the rotation angle of the XY axes between the lineacgraphy and DRR on the superimposed images. The systematic error (mu, Sigma) and random error (sigma) were calculated from the X and Y deviations and rotation angle deviation. The mu of X, Y, and rotation angle were 0.01 mm, -1.2 mm, and 0.05 degrees, respectively. The Sigma of X, Y, and rotation angle were 1.8 mm, 1.5 mm, and 0.9 degrees, respectively. The s of X, Y, and rotation angle were 2.0 mm, 1.5 mm, and 1.0 degrees, respectively. Our analyses thus revealed that evaluations using image-processing software at the skin surface position in routine breast radiotherapy result in sufficiently small setup errors.

DOI： 10.18926/AMO/56167

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Language：Japanese   Publisher：Japan Society for Head and Neck Cancer  

The purpose of this study was to analyze the risk factors for osteoradionecrosis （ORN） of the mandible after radiotherapy for treatment of oral or oropharyngeal cancers. Sixty patients with oral or oropharyngeal cancers who had undergone external radiotherapy from January 2011 to December 2016 were retrospectively reviewed. Seven patients （12%） had ORN, and the median time to the development of ORN was 15 months （range, 1-53 months）. In the analysis of the whole mandible, univariate analysis revealed that tooth extractions within one month before radiotherapy （p<0.001）, the mean dose of radiotherapy to the mandible （p=0.04）, and the volume of mandible receiving doses of 40Gy （p=0.02） and 50Gy （p=0.04） were significant risk factors for ORN. In the analyses of the right and left sides of the mandible, the mean dose of radiotherapy to the mandible and the volume of mandible receiving a dose of 40Gy were significant risk factors （p=0.04 for each）. In the multivariate analysis, tooth extractions in the analysis of the whole mandible was the only significant risk factor for ORN （p<0.01）. Incorporation of both mean dose constraints to the mandible in addition to maximal dose constraints might be needed to reduce the occurrence rate of ORN.

DOI： 10.5981/jjhnc.44.57

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The usefulness of dental approaches, such as oral management, has gained recognition among patients treated for head and neck cancer. In particular, oral management plays a very important role before, during, and after treatment in patients undergoing radiotherapy, or a combination of both. However, specialized dentistry knowledge and techniques that are useful for patients undergoing radiotherapy for head and neck cancer have yet to be reported. Therefore, in this review article, our aim is to introduce dental approaches in radiotherapy for patients with head and neck cancer that have been developed and are currently being used at our institute. (C) 2016 The Author(s). Published by Elsevier Ltd on behalf of Japanese Association for DentalScience.

DOI： 10.1016/j.jdsr.2016.09.003

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Salivary gland carcinomas are rare tumors, representing similar to 0.5% of all malignancies. Myoepithelioma is also uncommon, representing similar to 1% of all salivary gland tumors. Myoepithelial carcinoma (MC) is even rarer, representing 0.2 to 0.6% of all salivary gland tumors. We herein report a case of MC with multiple metastases arising from a submandibular gland in a 71-year-old male patient and present the associated imaging findings. The patient was considered to have a de novo type of myoepithelial carcinoma, which is reportedly associated with higher malignancy than the transformation type of the disease (i.e., a malignant change from pleomorphic adenoma or myoepithelioma). This was reflected in the multiple lung and bone metastases sites and strong positivity for p53 and Ki-67.

DOI： 10.3892/ol.2017.5783

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Language：Japanese   Publisher：日本口腔顎顔面技工学会  

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Language：Japanese   Publisher：岡山歯学会  

2000年4月〜2014年3月に一次治療を行った舌扁平上皮癌Stage I・II症例93例(Stage I 40例、Stage II 53例)を対象に、一次治療終了以降に転移が判明した症例(後発転移)の頻度とそれに影響を及ぼす臨床因子、後発転移発現までの期間、生存率について検討した。後発転移は全93例中23例(24.7%)に認められた。ステージ別ではStage I 40例中6例(15.0%)、Stage II 53例中17例(32.1%)、治療法別では手術群81例中17例(21.0%)、放射線療法群12例中6例(50.0%)にそれぞれ後発転移が発現した。後発転移の有無は、分化度、浸潤様式、原発巣の厚みと相関していたが、放射線療法を行った症例ではStage IIで原発巣の厚みが5mm以上であることが強く影響していた。後発転移への期間は、手術群で平均8.1ヵ月、中央値6ヵ月、放射線療法群で平均5ヵ月、中央値6ヵ月で、治療法による有意差は認められなかった。生存率と関連する臨床因子を検討したところ、有意な影響が認められた因子は後発転移のみであった。

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Bisphosphonates (BPs) are useful drugs for the management of osteoporosis and metastatic bone disease, and are used to prevent skeletal-related events. However, the side effects of BPs, bisphosphonate-related osteonecrosis of the jaw (BRONJ), sometimes severely impairs patient quality of life. Here we report a case of severe BRONJ in the maxilla, which caused Le Fort I-type fracture-like bone fracture due to formation of a large sequestrum in the maxilla. (C) 2015 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved.*

DOI： 10.1016/j.ajoms.2015.10.001

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Language：Japanese   Publisher：(一社)日本頭頸部癌学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BIOMED CENTRAL LTD  

Background: High-dose-rate (HDR) brachytherapy using the mold technique is a less invasive treatment for early lip and oral cavity cancer. However, limited reports exist regarding the feasibility of this method. In this retrospective study, we evaluated the outcome of this therapy and investigated its feasibility for lip and oral cavity tumors.Methods: Between May 2002 and December 2010, 17 patients (median age, 80.0 years) with histologically confirmed squamous cell carcinoma of the lip or oral cavity were treated by means of HDR brachytherapy using the mold technique after external beam radiotherapy (EBRT). Tumor sites included the buccal mucosa in eight cases, the gingiva in three cases, the lips in two cases, the floor of the mouth in two cases, and the hard palate in two cases. For all patients, EBRT (30 Gy/15 fractions), was performed before HDR brachytherapy. Two 6-Gy fractions were delivered twice daily for 2 days a week with an interval of 6 hours between the fractions. The total HDR brachytherapy dose was 24 Gy. Prior to EBRT, two patients with neck metastasis underwent neck dissection, and one patient with an exophytic tumor underwent tumor resection.Results: The median follow-up period was 53.4 (range, 4.8-83.4) months. Of the 17 patients, 14 (82.4%) achieved a complete response, and three (17.6%) displayed a partial response. The overall 3-and 5-year survival rates were both 68.8%, the 3-and 5-year disease-specific survival rates were both 86.7%, and the 3-and 5-year local control rates were both 54.1%. Seven patients developed local recurrence at a median time of 3.4 (range, 1.7-29.1) months after treatment. Nodal and lung metastases occurred separately in two patients. By the end of the follow-up period, two patients had died of the primary disease and four patients had died of other causes.Conclusions: Although there is a need to improve the technical aspects of the treatment protocol, HDR brachytherapy using the mold technique might be a therapeutic option for superficial lip or oral cavity tumors, especially in older patients who have a poor performance status or are in poor physical condition.

DOI： 10.1186/s13014-015-0390-z

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Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare type of odontogenic carcinoma arising from the jawbone. Odontogenic cysts are true cysts that arise from the dental epithelium, which is associated with tooth formation. The epithelial lining of odontogenic cysts has the potential to transform into various types of odontogenic tumor; however, this transformation from an odontogenic cyst to a malignant tumor is rare. The definitive diagnosis for PIOSCC generally requires the observation of either features of squamous cell carcinoma (SCC) within the jawbone that are distinct from direct invasion from the surface oral epithelium, or evidence of SCC arising from odontogenic epithelium and from tumors that have metastasized to the jawbone from distant sites. In the present study, a case of PIOSCC of the maxilla is presented, which, based on the results of computed tomography and the clinical course, was hypothesized to have originated from an infected residual cyst.

DOI： 10.3892/ol.2014.2644

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Language：Japanese   Publisher：日本口腔顎顔面外傷学会  

症例は53歳男性で、飲酒後に数人から殴打され、救命救急科へ搬送された。X線で左上顎洞後壁、蝶形骨翼状突起基部から眼窩底部に骨折を認め、下顎骨ではオトガイ部骨折および切痕から左顎関節突起基底部に骨折線がみられた。下顎骨骨折については咬合偏位が著明で、抗凝固療法中であることより早期の手術を計画した。眼窩下壁骨折は眼科で左眼窩底部骨片圧迫による下直筋障害を指摘され、手術適応と判断された。下直筋障害増悪を認めたため、第6病日に下顎骨骨折および眼窩骨折の整復術を施行した。眼窩下壁骨折は、上顎洞後壁が前方に偏位し外眼筋を圧迫していたため、経結膜切開による眼窩アプローチを選択し、眼窩前方から骨折部を明示して眼窩内に偏位していた骨片を整復した。良好な眼球運動機能改善が得られ、眼窩底部の再建は行わなかった。術後経過良好で、複視症状や咬合不全も改善した。

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPANDIDOS PUBL LTD  

The aim of this study was to create a new phantom for a 3 Tesla (3T) magnetic resonance imaging (MRI) device for the calculation of the apparent diffusion coefficient (ADC) using diffusion-weighted imaging (DWI), and to mimic the ADC values of normal and tumor tissues at various temperatures, including the physiological body temperature of 37 C. The phantom was produced using several concentrations of sucrose from 0 to 1.2 M, and the DWI was performed using various phantom temperatures. The accurate ADC values were calculated using the DWIs of the phantoms, and an empirical formula was developed to calculate the ADC values of the phantoms from an arbitrary sucrose concentration and arbitrary phantom temperature. The empirical formula was able to produce ADC values ranging between 0.33 and 3.02x10(-3) mm(2)/sec, which covered the range of ADC values of the human body that have been measured clinically by 3T MRI in previous studies. The phantom and empirical formula developed in this study may be available to mimic the ADC values of the clinical human lesion by 3T MRI.

DOI： 10.3892/ol.2014.2187

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It is known that the magnetic resonance (MR) imaging features of dentigerous cysts (DCs) are the same as those of other cysts. The cavities of DCs generally show low signal intensity (SI) on T1-weighted imaging (T1WI). However, in our experience, DCs often show high SI on T1WI, rendering them difficult to distinguish from keratocystic odontogenic tumors (KCOTs). In this study, we evaluated seven cases of DC and 23 cases of KCOT to assess whether MR imaging can provide additional information for the differential diagnosis of DC and KCOT.Two trials were evaluated. The first trial was an analysis of the cystic cavity SI on T1WI. To compare the SI between patients, we performed T1WI with contrast (T1c). The second trial analyzed the SI uniformity (U (I )) pound on T1WI, T2-weighted imaging (T2WI), and short inversion time inversion recovery (STIR) images of the cystic cavity, because it has been reported that an MR imaging feature of KCOT is heterogeneous SI. Statistical analyses were performed using the Mann-Whitney U test and a receiver operating characteristic (ROC) curve.The T1c values of DCs were significantly higher than those for KCOTs. The U (I ) pound values on T1WI and STIR images were significantly higher for DCs than for KCOTs. The T1c cutoff values (0.66 and 0.84) and U (I ) pound cutoff values for T1WI (82.1 %) and STIR images (79.8 %) were determined from the ROC analyses.T1c and U (I ) pound values provide useful additional information for the differential diagnosis of DC and KCOT.

DOI： 10.1007/s11282-013-0128-2

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We previously reported that dynamic contrast-enhanced MRI parameters and time-signal intensity curves (TICs; also known as contrast index curves) are useful for the differential diagnosis of jawbone lesions. In particular, odontogenic fibroma and ossifying fibroma, which possess similar histopathological features (i.e., a mixture of hard and soft tissue components), display unique TIC patterns, and we consider that the TIC patterns of these lesions reflect their hard and soft tissue components. Therefore, fibrous dysplasia, which contains fibrous tissue and immature isolated trabeculae composed of woven bone, is expected to display an interesting TIC. The purpose of this study was to assess the utility of TICs for differentiating between the abovementioned lesions, which have similar histopathological components.

DOI： 10.1007/s11282-013-0137-1

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OKAYAMA UNIV MED SCHOOL  

It is well known that many tumor tissues show lower apparent diffusion coefficient (ADC) values, and that several factors are involved in the reduction of ADC values. The aim of this study was to clarify how much each factor contributes to decreases in ADC values. We investigate the roles of cell density, extracellular space, intracellular factors, apoptosis and necrosis in ADC values using bio-phantoms. The ADC values of bio-phantoms, in which Jurkat cells were encapsulated by gellan gum, were measured by a 1.5-Tesla magnetic resonance imaging device with constant diffusion time of 30 sec. Heating at 42 degrees C was used to induce apoptosis while heating at 48 degrees C was used to induce necrosis. Cell death after heating was evaluated by flow cytometric analysis and electron microscopy. The ADC values of bio-phantoms including non-heated cells decreased linearly with increases in cell density, and showed a steep decline when the distance between cells became less than 3 mu m. The analysis of ADC values of cells after destruction of cellular structures by sonication suggested that approximately two-thirds of the ADC values of cells originate from their cellular structures. The ADC values of bio-phantoms including necrotic cells increased while those including apoptotic cells decreased. This study quantitatively clarified the role of the cellular factors and the extracellular space in determining the ADC values produced by tumor cells. The intermediate diffusion time of 30 msec might be optimal to distinguish between apoptosis and necrosis.

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DOI： 10.1016/j.oooo.2012.03.025

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Objectives: To evaluate the diagnostic value of MRI for odontogenic tumours. Materials and methods: 51 patients with odontogenic tumours were subjected to preoperative MRI examinations. For tumours with liquid components, i.e. ameloblastomas and keratocystic odontogenic tumours (KCOTs), the signal intensity (SI) uniformity of their cystic components (US) was calculated and then their US values were compared. For tumours with solid components that had been examined using dynamic contrast-enhanced MRI (DCEMRI), their CI max (maximum contrast index), Tmax (the time when CImax occurred), CIpeak (CImax×0.90), Tpeak (the time when CIpeak occurred) and CI300 (i.e. the CI observed at 300 s after contrast medium injection) values were determined from CI curves. We then classified the odontogenic tumours according to their DCE-MRI parameters. Results: Significant differences between the US values of the ameloblastomas and KCOT were observed on T1 weighted images, T2 weighted images and short TI inversion recovery images. Depending on their DCE-MRI parameters, we classified the odontogenic tumours into the following five types: Type A, CIpeak > 2.0 and Tpeak < 200 s; Type B, CIpeak < 2.0 and Tpeak < 200 s; Type C, CI 300 > 2.0 and Tmax < 600 s; Type D, CI300 > 2.0 and Tmax > 600 s; Type E, CI300 < 2.0 and Tmax > 600 s. Conclusion: Cystic component SI uniformity was found to be useful for differentiating between ameloblastomas and KCOT. However, the DCE-MRI parameters of odontogenic tumours, except for odontogenic fibromas and odontogenic myxomas, contributed little to their differential diagnosis. © 2013 The British Institute of Radiology.

DOI： 10.1259/dmfr.20120265

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER ACAD PEDIATRIC DENTISTRY  

Purpose: The purpose of this study was to evaluate the radiological and histopathological findings of 11 patients with unerupted first molars to verify the factors obstructing spontaneous eruption. Methods: The patients' clinical, radiological, and histopathological data were evaluated retrospectively to determine histopathological diagnosis, radiographic findings, methods of surgical management, and postoperative course. Results: This study involved 4 male and 7 female patients (mean age=9.5 years old). Nine cases involved the mandible. The patients' histopathological diagnoses included 3 odontogenic tumors, 2 odontogenic cysts, and 6 hyperplastic dental follicles. Radiographically, 10 cases showed characterless enlargement of the follicular space, while only 1 displayed radiopaque bodies. One patient with a tumor underwent enucleation, and 1 with a cyst underwent cystectomy and tooth extraction. The others underwent wide excision or partial excision of the surrounding tissue at the top of the impacted tooth. Tumor relapse was observed in 3 cases. Conclusion: Surgeons should perform aggressive treatment for patients with unerupted teeth because spontaneous eruption is rare in cases involving non-neoplastic lesions such as hyperplastic dental follicles.

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Language：Japanese   Publisher：岡山歯学会  

「歯科放射線学分野」の講義試験としてe-learning(WebClassシステム)によるPCを用いた試験を試み、受験生56名に試験後アンケート調査を行ってその有用性について検討した。肯定的回答(大変そう思う・そう思う)の割合は、PC使用試験については「共用試験CBTの予行として役立つ」100%、「試験解説がすぐに受けられる」93%、「試験結果がすぐに公表される」78%で、低かったのは「試験に集中しやすい」46%、「システムの使用が難しい」49%であった。試験会場については「席による不公平がない」91%、「講義室からの移動が面倒」71%であった。視覚素材については、「あると問題が理解しやすい」96%、「問題が難しくなる」52%であった。試験内容(選択問題)については、「国家試験、CBTの予行になる」「採点結果が明確」100%、「理解度をアピールしにくい」72%、「楽だ」35%、「語彙力、理解力低下につながる」47%であった。共用試験CBT後のアンケートではPC使用試験が「予行として役立った」98%であった。

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Objectives: To evaluate the diagnostic value of dynamic contrast-enhanced MRI (DCE-MRI) for differentiating between benign and malignant tumors in the palate.Materials and methods: 26 patients with submucosal palatal tumors were preoperatively examined using DCE-MRI. Their maximum contrast index (CImax), time of CImax (Tmax), and washout ratios (WR300 and WR600) were determined from contrast index curves. The submucosal palatal tumors were divided into two groups according to their Tmax values: the early enhancement group (Tmax < 300 s) consisted of 9 malignant tumors and 6 benign tumors, while the late enhancement group (Tmax >= 300 s) included one malignant tumor and 10 benign tumors. We compared the following DCE-MRI parameters between the benign and malignant tumors: CImax and Tmax in all cases and CImax, Tmax, and the washout ratios in the early enhancement group. In addition, we performed a regression analysis of the relationships between tumor size and DCE-MRI parameters; i. e., CImax, Tmax, and washout ratios, among the malignant salivary gland tumors and pleomorphic adenomas.Results: In all cases and the early enhancement group, significant differences in Tmax were detected between the benign and malignant tumors (P < 0.001 and P < 0.05, respectively), and the optimal Tmax cutoff value for differentiating between them was found to be 165 s. None of the other parameters displayed significant differences between the benign and malignant tumors. Only the WR600 of the pleomorphic adenomas was significantly correlated with tumor size (R-2 = 0.92, P < 0.001).Conclusions: Tmax is a useful parameter for distinguishing between benign and malignant submucosal palatal tumors. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.ejrad.2012.04.009

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare malignant odontogenic tumor arising from odontogenic epithelial remnants within the jawbones. PIOSCC is histopathologically divided into 3 types: solid-type carcinoma, carcinoma derived from a keratocystic odontogenic tumor, and carcinoma derived from an odontogenic cyst. In this article, we report a case of solid-type PIOSCC involving reactive bone formation in the mandible in a 60-year-old female patient together with its histopathological and imaging findings. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:e71-e77)

DOI： 10.1016/j.oooo.2012.05.019

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Ossifying fibroma (OF), a rare nonodontogenic tumor, is defined as a bone-related jawbone lesion. The main histopathological feature of OF is the replacement of bone by benign connective tissue. Ossifying fibroma usually occurs in the second to fourth decades of life and shows a predilection for females. Ossifying fibroma most commonly occurs in the mandible, and OF arising from the anterior part of the maxilla is rare. Ossifying fibromas display various radiographic findings, including varying degrees of radiolucency and radiopacity, depending on the proportions of their soft and hard tissue components. Depending on their components, it can be difficult to distinguish OF from other fibroosseous lesions and some odontogenic tumors by using conventional radiographs, computed tomography, and magnetic resonance imaging (MRI). We report a case of OF in the anterior maxilla in a 56-year-old man, together with its histopathological and imaging findings including the dynamic MRI findings. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:e139-e146)

DOI： 10.1016/j.oooo.2012.04.015

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Objective: To evaluate the diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for minor salivary gland tumors in the oral cavity.Materials and methods: Thirty-two patients with minor salivary gland tumors were examined preoperatively using DCE-MRI. Their maximum contrast index (CImax), time of CImax (Tmax), Tpeak; i.e., the time that corresponded to the CImax x 0.90, and washout ratios (WR300 and WR600) were determined from contrast index (CI) curves. We compared these parameters between benign and malignant tumors and among the different histopathological types of minor salivary gland tumors. Then, we categorized the patients' CI curves into four patterns (gradual increase, rapid increase with high washout ratio, rapid increase with low washout, and flat).Results: Statistically significant differences in Tmax (P = 0.004) and Tpeak (P = 0.002) were observed between the benign and malignant tumors. Regarding each histopathological tumor type, significant differences in Tmax (P < 0.001), Tpeak (P < 0.001), and WR600 (P = 0.026) were observed between the pleomorphic adenomas and mucoepidermoid carcinomas. It was difficult to distinguish between benign and malignant tumors using our CI curve classification because that two-thirds of the cases were classified into the same type (gradual increase).Conclusion: The DCE-MRI parameters of minor salivary gland tumors contributed little to their differential diagnosis compared with those for major salivary gland tumors. During the diagnosis of minor salivary gland tumors, Tmax is useful for distinguishing between benign and malignant tumors. (c) 2011 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.ejrad.2011.11.005

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Adenoid cystic carcinoma (ACC) of the head and neck region is an uncommon epithelial tumor of the major and minor salivary glands. In the oral region, although ACC arising from the minor salivary glands is the second most commonly found tumor in the tongue base, its occurrence in the anterior part of the tongue is rare. Histopathologically, ACC is categorized into three growth patterns (tubular, cribriform, and solid types) and three histologic grades (I-III) that are based on the proportions of these patterns. According to this classification, tubular- and cribriform-type ACCs are considered to be lower grade lesions, while solid-type ACCs are considered to be higher grade lesions. A fourth histopathological type has recently been reported by some authors, namely, dedifferentiation or high-grade transformation of ACC. However, very few studies have focused on the imaging features of these ACCs. We report here the case of a 63-year-old female patient with ACC of the tongue with dedifferentiated components, together with the radiological images and pathological features of this ACC.

DOI： 10.1007/s11282-012-0097-x

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Lymphoepithelial cysts, which are also known as branchial cleft cysts, commonly occur in the lateral cervical region. Lymphoepithelial cysts arising in the parotid gland are rare and must be distinguished from parotid gland tumors. Magnetic resonance imaging (MRI) is useful for diagnosing parotid gland lesions, and MR images of lymphoepithelial cysts typically display a cystic mass that appears homogeneously hypointense on T1-weighted images and homogeneously hyperintense on T2-weighted images. However, some parotid gland tumors that retain fluid in their inner sections show similar MRI findings to lymphoepithelial cysts. Furthermore, lymphoepithelial cysts are sometimes modified by inflammation, and these cases are hard to diagnose. We report the case of a 59-year-old female with a lymphoepithelial cyst that arose in the parotid gland. The cyst had been affected by inflammation and displayed atypical imaging findings, i.e., heterogeneous signal intensity of the liquid component and the presence of a well-enhanced capsule-like structure surrounding the liquid component. In addition, we compare the MRI findings of this case with those of two other cervical lymphoepithelial cysts.

DOI： 10.1007/s11282-012-0086-0

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Odontogenic fibroma (OF) is a rare nonepithelial benign tumor arising from the odontogenic mesenchymal tissue in the jawbone. OFs are topographically categorized into 2 types, the central type and peripheral type, and are histopathologically divided into the epithelium-poor type and epithelium-rich type. The radiological findings of central OF commonly include a uni- or multilocular radiolucent area with a well-defined margin, which are similar to those of cysts and other benign tumors of the jawbone. Therefore, it is difficult to distinguish OF from these jawbone lesions on radiographs because of their noncharacteristic radiological findings. In this article, we report the cases of 2 patients with central OF who underwent magnetic resonance (MR) examinations and describe the usefulness of dynamic contrast-enhanced MR imaging for diagnosing OF. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:e51-e58)

DOI： 10.1016/j.oooo.2011.12.013

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OKAYAMA UNIV MED SCHOOL  

The roles of cell density, extracellular space, intracellular factors, and apoptosis induced by the molecularly targeted drug rituximab on the apparent diffusion coefficient (ADC) values were investigated using bio-phantoms. In these bio-phantoms, Ramos cells (a human Burkitt's lymphoma cell line) were encapsulated in gellan gum. The ADC values decreased linearly with the increase in cell density, and declined steeply when the extracellular space became less than 4 gm. The analysis of ADC values after destruction of the cellular membrane by sonication indicated that approximately 65% of the ADC values of normal cells originate from the cell structures made of membranes and that the remaining 35% originate from intracellular components. Microparticles, defined as particles smaller than the normal cells, increased in number after rituximab treatments, migrated to the extracellular space and significantly decreased the ADC values of bio-phantoms during apoptosis. An in vitro study using bio-phantoms was conducted to quantitatively clarify the roles of cellular factors and of extracellular space in determining the ADC values yielded by tumor cells and the mechanism by which apoptosis changes those values.

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It is sometimes difficult to differentiate cysts and pseudocysts from tumors in the jawbone on the basis of conventional radiographs. Moreover, cysts and pseudocysts that arise in soft tissue can not be detected on radiographic images without the use of contrast agents. Therefore, additional information is sometimes required to diagnose these lesions. Computed tomography and magnetic resonance imaging (CT; MRI) have been demonstrated to be very useful for depicting normal structures and pathological processes in the oral and maxillofacial region. Whereas CT is best for depicting bone structures, MRI is superior to CT at evaluating soft tissue. The contents of bone lesions might also be better visualized on MRI. In this chapter, among the variety of lesions that occur in the oral and maxillofacial region, we would like to focus on those arising in the jaw or adjacent soft tissue. We present their representative CT and MRI findings and discuss the imaging characteristics that most contribute to their differential diagnosis. © 2012 by Nova Science Publishers, Inc. All rights reserved.

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Objective. High-dose-rate (HDR) brachytherapy using a customized mold is a minimally invasive treatment for oral cancer; however, it is difficult to use this technique for buccal and lip cancers involving the commissura labiorum, owing to its anatomic form. The purpose of this study was to introduce an improved customized mold consisting of 2 pieces to allow the fixation of molds to these sites.Study design. Five patients with buccal carcinoma and 1 patient with lip carcinoma were treated with this technique after external beam radiotherapy. One patient with neck metastasis underwent both neck dissection and partial tumor resection before HDR brachytherapy.Results. At the end of the follow-up period, 5 patients had no tumor recurrence, and 1 patient had suffered local recurrence.Conclusions. Our technique is a viable therapeutic option for patients with buccal and lip carcinomas for whom the therapeutic modalities are limited by age, performance status, and other factors. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:118-125)

DOI： 10.1016/j.tripleo.2011.06.038

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Objective. The purpose of this study was to evaluate the diagnostic value of magnetic resonance imaging (MRI), especially dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), in extranodal non-Hodgkin lymphoma (NHL) of oral and maxillofacial regions.Study design. Thirteen cases with extranodal NHL were examined using MRI. T1-weighted images (T1WI) and T2-weighted images (T2WI) or short TI inversion recovery (STIR) images were obtained in all cases. Contrast-enhanced images and DCEM-RI were acquired in 10 and 7 cases, respectively. On DCE-MRIs, we analyzed the parameters as follows: contrast index at maximal contrast enhancement (CImax), maximum contrast index (CI) gain/CImax ratio, and washout ratios (WR300, WR600, and WR900) at 300, 600, and 900 seconds after contrast medium injection.Results. The signal intensity of all lesions was hypointense to isointense on T1WIs and showed variable contrast enhancement patterns. On T2WIs and STIR images, the signal intensity was isointense to hyperintense in almost all cases. Analysis of DCE-MRI parameters in extranodal NHLs resulted in the identification of 4 types of CI curves according to CImax and WR: (1) CImax greater than 2.0 and WR900 greater than 40%, (2) CImax greater than 2.0 and WR900 less than 40%, (3) CImax less than 1.5 and WR900 greater than 40%, and (4) CImax less than 1.5 and WR900 greater than 40%.Conclusions. The signal intensities on MRI were not specific to extranodal NHL and resembled those of other tumor types. When CImax was less than 1.5 or WR900 was less than 40%, these parameters contributed to diagnosis in extranodal NHLs. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012; 113: 126-133)

DOI： 10.1016/j.tripleo.2011.07.038

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Language：Japanese   Publisher：岡山歯学会  

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角化嚢胞性歯原性腫瘍(KCOT)の診断におけるMRIのT1強調像の有用性について検討した。顎骨の歯原性腫瘍あるいは歯原性嚢胞の画像診断で外科的手術を施行し、KCOTと病理診断し、生検前にMRI検査を受けていた22例に対して後ろ向き調査を行った。T1強調像における嚢胞内容物が正のコントラストを示した症例は18例、4例のみが負のコントラストを示した。単房性と多房性のコントラストの差は有意ではなかった。コントラストと近遠心径の間とコントラストと頬舌径の間に相関関係は認めなかった。

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Malignant lymphoma is the second-most common malignancy in the head and neck region. Waldeyer's ring is the most common site of extranodal Hodgkin's lymphoma (NHL) in that region, and a small percentage of primary extranodal NHL occurs in the oral cavity. The most common sites of extranodal NHL in the oral region are the palate and maxilla, and nearly half of extranodal NHL cases arise from bone. It is difficult to diagnose extranodal NHL because of the variety of its radiological features. We report a case of primary extranodal NHL of the maxilla in a 68-year-old female patient with atypical imaging findings, along with the results of analysis of dynamic magnetic resonance imaging (MRI). (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 112: e59-e69)

DOI： 10.1016/j.tripleo.2011.02.052

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Ameloblastic carcinoma is a rare malignant odontogenic carcinoma that has metastatic potential, and because of its rare incidence, there are few reports focusing on its radiologic imaging. If it shows aggressive appearances, it can be diagnosed as malignant tumor. But in case of negative appearance, it is difficult to distinguish ameloblastic carcinoma from ameloblastoma. We report a case of ameloblastic carcinoma of the maxilla in a 76-year-old female patient with radiologic images and pathologic features. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 112: e40-e47)

DOI： 10.1016/j.tripleo.2011.01.023

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Language：Japanese   Publisher：岡山歯学会  

2008年1月〜2010年9月にインプラント治療を希望して受診しパノラマX線撮影が行われた患者500例を対象に、患者背景やX線所見について統計学的に検討した。性別は男性192例(38%)、女性308例(62%)であった。年齢は17〜87歳(平均57.4歳)で、50〜60歳代が多く69%を占めていた。インプラント希望歯数は、1本の患者が125例(25%)、2本が114例(23%)、3本が79例(16%)、4本が54例(11%)、5本以上が128例(26%)であった。インプラント希望部位を年齢別にみると、若年層で前歯部が多く、高齢者で臼歯部が多いという特徴が認められた。X線で歯欠損以外の異常所見を認めたものが325例(65%)あり、内訳は歯根膿瘍307例(61%)、歯根膿瘍と他の異常所見が重複しているもの24例(5%)、歯根膿瘍以外の所見18例(4%)であった。歯根膿瘍は1患者平均2.05本認め、インプラント希望部位の隣在歯に認めたものが79例(16%)あった。

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Typical MR images of ameloblastomas on T2-weighted image (WI) or short inversion time inversion-recovery (STIR) show multiple bright high-signal-intensity loci on a high-signal-intensity background. Unilocular cystic-type ameloblastomas show homogeneously bright high signal intensity on T2WI or STIR as a water-like signal intensity. Therefore, it is difficult to distinguish unilocular cystic-type ameloblastoma from other cystic lesions such as keratocystic odontogenic tumors, radicular cysts (residual cysts) and dentigerous cysts only on the basis of MRI signal intensity. In the present study, we evaluated whether contrast-enhanced (CE)-T1WI and dynamic CE-MRI (DCE-MRI) could provide additional information for differential diagnosis in unilocular cystic-type ameloblastoma. Images from 12 cases of suspected unilocular cystic-type ameloblastoma were evaluated in the present study. Of them, 5 had areas suspected of indicating a solid component on T1WI and T2WI (or STIR). Ten had undergone additional CE-T1WI and DCE-MRI. On 5 of 10 cases of CE-T1WI, a tiny enhancement area was detected. On 6 of 10 DCE-images, a time-course enhanced area which was suspected to be a solid component was detected. CE-T1WI was helpful in the diagnosis of ameloblastoma because the tiny enhanced areas were taken to indicate possible solid components. Moreover, the rim-enhancement area on CE-T1WI could be divided into small regions of interest, and some of these showed slightly increased enhancement on DCE-MRI, which was taken to indicate a solid component and/or intramural nodule with focal invasion of ameloblastoma tissue. DCE-MRIs of the four remaining cases, which provided no clues to the diagnosis of ameloblastoma in the manner of the above descriptions, showed thicker rim enhancement than odontogenic cysts. Thus, CE-T1WI and DCE-MRI were helpful in the differential diagnosis of unilocular cystic-type ameloblastomas with homogeneously bright high signal intensity on T2WI or STIR. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.oraloncology.2010.11.009

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

Aneurysmal bone cysts (ABCs) are classified as bone-related lesions based on the 2005 World Health Organization histological classification of odontogenic tumors. Most ABCs are diagnosed using a combination of conventional radiography, computed tomography, magnetic resonance imaging (MRI), and digital subtraction angiography. ABCs should be differentiated from true cysts or other pseudocysts because their treatment is different. Additionally, unlike other cysts, ABCs pose a hemorrhagic risk in surgery; thus, preoperative evaluation of intralesional blood flow is required. Here we report a case of a mandibular ABC in a 39-year-old woman and focus on its dynamic contrast-enhanced MRI (DCE-MRI) features. On DCE-MRI, the lesion was divided into two areas according to the enhancement pattern: the blood-pooling and blood-flow areas. The series of DCE-MR images of the blood-pooling area showed marked enhancement of the margin, but no enhancement in the inner part of the cavity. Additionally, the time-signal intensity curve (TIC) demonstrated no change in the signal intensity (SI) until approximately 15 min after gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) administration. In contrast, the series of DCE-MR images of the blood-flow area exhibited marked enhancement in the cyst cavity in the early phase. The TIC showed a rapid increase in SI in the early phase, followed by a rapid decrease until 150 s, and finally a gradual decrease until approximately 15 min after Gd-DTPA administration. Thus, in the current patient, preoperative DCE-MRI clearly delineated the vessel-rich area within the lesion.

DOI： 10.1007/s11282-010-0048-3

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MOSBY-ELSEVIER  

Introduction. It can be difficult to differentiate simple bone cysts (SBCs) from true cysts in the jaw when these lesions appear unilocular. The present study reports the MR imaging of subjects with SBCs and describes the diagnostic value of the MRI findings.Materials and methods. Ten subjects with SBCs in the jaw were examined using MRI. T1- and T2-weighted images (T1WI, T2WI) were obtained, and contrast-enhanced images and dynamic contrast-enhanced MRI (DCE-MRI) were acquired.Results. In all cases, the contrast-enhanced T1WI acquired approximately 6 minutes after the administration of GdDTPA showed marked enhancement of the margin and slight enhancement of the inner part of the cyst cavity. In all cases, the time-signal intensity (SI) curves show a gradual increase in the SI until approximately 15 minutes after the administration of Gd-DTPA. These findings might not be observed on the DCE-MRIs of the other true cysts with epithelial lining that show no enhancement in a cavity.Conclusion. MRI, especially DCE-MRI, can provide useful information for distinguishing SBCs from other cysts. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:364-369)

DOI： 10.1016/j.tripleo.2010.05.001

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Language：Japanese   Publisher：岡山歯学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPANDIDOS PUBL LTD  

In recent years, magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) has seen wide clinical use, such as for early detection of cerebrovascular diseases and whole body screening for tumors. The apparent diffusion coefficient (ADC) standard phantom, which mimics the ADC values of several lesions in the body, is indispensable for the development of new pulse sequences for DWI, such as diffusion-weighted whole-body imaging with background body-signal suppression (DWIBS). However, information on the ADC values of the previously reported ADC standard phantoms is limited, because these phantoms were made using only a few different materials at a limited range of concentrations, and the ADC values were measured only at certain temperatures. It has been considered difficult, if not impossible, to create a phantom that provides arbitrary ADC values, because it is difficult to calculate the concentrations of the materials and the temperature at ADC measurement. In this study, we used polyethylene glycol (PEG) as a phantom material, and developed an empirical formula to calculate the PEG concentration at any measurement temperature to obtain arbitrary ADC values of the phantom. DWI images of phantoms made using seven different PEG concentrations were taken under heating from 17 to 46 degrees C at 1 degrees C intervals. Using ADC values calculated from these DWI images, we developed two empirical formulas: i) an empirical formula to calculate the ADC values of phantoms made using any PEG concentration at any measurement temperature; and ii) an empirical formula to calculate PEG concentrations to obtain arbitrary ADC values at any measurement temperature. We inspected the accuracy of these empirical formulas by newly made PEG phantoms. A comparison between the ADC values calculated with the empirical formulas and the measured ADC values confirmed the high accuracy of these formulas. PEG phantoms are safe, inexpensive and easy to make, compared with the previously reported ADC standard phantoms. Our empirical formulas enable us to calculate PEG concentrations that provide arbitrary ADC values at any measurement temperature. The empirical formulas could be used within a range of ADC values from 0.37x10(-3) to 3.67x10(-3) mm(2)/s, PEG concentrations from 0 to 120 mM, and measurement temperatures from IS to 45 degrees C. Using these formulas, it would be possible to make standard phantoms that mimic the ADC values of any clinical lesions. The PEG phantom might thus be an excellent new ADC standard phantom for MRI with DWI.

DOI： 10.3892/ijo_00000404

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPANDIDOS PUBL LTD  

Diffusion-weighted magnetic resonance imaging (MRI) is frequently used clinically, and is available for the whole-body screening for tumors. The exact mechanism by which the apparent diffusion coefficient (ADC) value decreases in tumorous tissue remains unclear, although various theories have been proposed, including intracellular and extracellular factor theories. It is impossible to distinguish each factor in the intracellular and extracellular spaces as the source of MR signal generation by means of conventional comparison between MR images and pathological specimens. Other factors which have been reported to affect ADC include cellularity and cellular edema of human tissues, and temperature of phantoms at the time of measurement. We employed a new technique that enables cellular MR imaging using a newly developed bio-phantom containing a living culture tumor cell line, Jurkat-N1. We investigated possible reasons for observed decreases in ADC values for tumors, and we considered the contribution of both the intracellular and extracellular space to such a decrease. The ADC values of the bio-phantom increased with increasing heat exposure from 27 to 45 degrees C. ADC values also increased after the destruction by sonication of tumor cell membranes. ADC values decreased as cellularity increased in the bio-phantorn. ADC values decreased due to cellular edema caused by a low salt concentration in the bio-phantom. Changes in pressure in the bio-phantom had no effect on the observed ADC values. We calculated both the intracellular ADC and extracellular ADC values using the ADC values, cellularity, and cellular volume of Jurkat-N1 cells in the bio-phantom. The extracellular ADC values in the bio-phantom were estimated to be lower than the ADC value of distilled water. These results indicate that not only intracellular ADC values, but also extracellular ADC values contribute to the determination of the ADC values of bio-phantoms. This is the first report to have examined the contribution of intracellular and extracellular space on the ADC values of bio-phantoms containing cultured tumor cells.

DOI： 10.3892/or_00000484

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

We evaluated the relationship between histopathological prognostic factors, tumor proliferation microvessel density (MVD), and enhancement parameters in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in oral squamous cell carcinoma (SCC). Twenty-eight T2 and T3 patients with primary oral SCC underwent DCE-MRI using three-dimensional fast imaging with a steady-state precession sequence. Tumor cell proliferation and MVD of all surgical specimens were evaluated using immunohistochemical staining with CD34 and the antibody for proliferating cell nuclear antigen (PCNA). Regression analysis was used to statistically analyze the relationship between the PCNA labeling index or MVD and each of three DCE-MRI parameters: maximum CI (CI-max), maximum CI gain (CI-gain) and the CI-gain / CI-max ratio. The PCNA labeling index and MVD showed significant correlations with the CI-gain/CI-max ratio (P = 0.0012, r = 0.581 and P = 0.00141, r = 0.574, respectively). The assessment of DCE-MRI parameters may prove to be a valuable non-invasive method for assessing tumor cell proliferation and MVD of patients with oral cancer. (C) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.oraloncology.2008.09.003

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Language：Japanese   Publisher：岡山歯学会  

9歳女児。左側下顎乳臼歯のう蝕を主訴に近医を受診した。その際のX線検査によって、左側下顎側切歯遠心部における過剰歯の萠出、ならびに左側下顎第二小臼歯の先天的欠如の可能性を指摘された。左側下顎犬歯および第一小臼歯は未萠出で、将来同歯が正常に萠出するか不安を抱いたため、紹介受診した。左側切歯部に、切歯状を呈する歯が3本存在し、その3本のうち、過剰歯が1本存在していると考えられた。しかし、同歯を含む左側下顎切歯3本について、歯冠形態および萠出状態に差異はなく、また、若干黄ばんだ色調からも永久歯と思われ、いずれの歯が過剰歯か判然としなかった。パノラマX線写真による画像所見として、左側下顎前歯部の3本の切歯全てにおいて、エナメル質、象牙質、歯髄腔の区別ができ、歯冠形態および歯根の形成に差異はなく、また、根尖も同様に閉鎖、完成していることから、いずれの歯が過剰歯かは判然としなかった。

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OBJECTIVES: To compare MRI manifestations according to gender and age and to identify correlations between clinical manifestations and MRI findings in patients with temporomandibular disorder (TMD) as based on a large series. MATERIALS AND METHODS: Fat suppressed oblique sagittal images of the open and closed mouth were acquired, and MRI scanning parameters were applied. RESULTS: The patients consisted of 946 females (average, 36.6 years old), and 319 males (average, 34.3 years old). In all TMD patients, 945 had symptoms in the unilateral temporomandibular joint (TMJ) and 320 in the bilateral TMJ. There were significant differences in the distribution of disk positions based on age, regardless of gender, in the unilaterally and bilaterally symptomatic groups; however, the results were not significant in the asymptomatic group. There were significant differences with respect to the distribution of disk positions between males and females in asymptomatic group and in the unilaterally symptomatic group, although the bilaterally symptomatic group did not show significant differences in this regard. As regards the disk positions in the joints of the three groups (asymptomatic group, unilaterally and bilaterally symptomatic groups), there were significant interactive effects of disk positions, regardless of gender. There were statistically significant age-related differences in disk deformities in all symptom groups, regardless of gender, except for in the group of males lacking symptoms in either joint. As regards disk deformities among the three groups studies here, there were significant interactive effects for disk positions, regardless of gender.

DOI： 10.2174/1874210600903010001

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Language：Japanese   Publisher：(一社)日本口腔診断学会  

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2006年4月〜2008年9月にPET撮影を行った頭頸部悪性腫瘍患者121名173例(男68名、女53名、年齢29〜89歳)を対象に検討した。半年毎の患者数は22例、32例、42例、38例、39例と推移し、術後の割合が36.4%、46.9%、57.1%、60.5%、64.1%と増加傾向を示した。原発巣は術前78例中73例(93.6%)にFDGの異常集積を認め、偽陰性5例は4例が上皮内癌からT1の表在性の悪性腫瘍で、1例が高血糖であった。術後94例中16例(17.0%)に異常集積を認め、表在性の悪性腫瘍1例は偽陰性であった。リンパ節は術前初発症例78例中24例(30.8%)、術後では94例中19例(20.2%)に異常集積を認め、偽陰性3例(1.7%)は高血糖1例、内部壊死を起こした2例であった。遠隔転移は7例で、2例は胸部CTで既に疑われており、5例はPET検査で認識でき、重複癌である多臓器原発の悪性腫瘍2例、原発性肺癌2例を認めた。以上より原発巣、所属リンパ節転移、遠位転移、重複癌の検出にPETの有用性が示されたが偽陰性も少なからずあることから、他のモダリティとの組み合わせにより診断能を向上させることが必要と考えた。

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OBJECTIVES: To examine oral and maxillofacial lesions other than those related to the chief complaint in panoramic radiographs taken at the department of paediatric dentistry at our hospital. METHODS: We retrospectively reviewed all 1092 patients who had visited the department of paediatric dentistry at our hospital and had a panoramic radiograph taken between August 1999 and October 2004. The following information was obtained from the patients' files and panoramic radiographs: gender, age, chief complaints and the presence or absence of lesions. RESULTS: Lesions were observed in 140 of the 1092 panoramic radiographs (12.8%). Among the 140 patients discovered to have lesions in the panoramic radiographs, 66 (47.1%, or 6.05% of the entire group of 1092 patients) had different lesions from those underlying the chief complaint. These 66 patients ages ranged from 3 years to 14 years and the lesions involved 39 (59.1%) missing teeth, 20 (30.3%) mesiodentes, 4 supernumerary teeth, 1 odontoma, 1 radicular cyst and 1 impacted tooth. The missing teeth were observed in the central and lateral incisor, canine, and first and second premolar positions of both jaws, especially in the lower lateral incisor and upper central incisor positions. CONCLUSIONS: We were able to detect incidental lesions at a rate of 6.05% (66 of 1092 patients) and at a relatively early age (mean 6.8 years) in the present study. Early treatment of these lesions could avoid maxillofacial deformity and other complications.

DOI： 10.1259/dmfr/31214423

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Language：Japanese   Publisher：岡山歯学会  

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Language：Japanese   Publisher：岡山歯学会  

症例1:52歳男性。舌癌で放射線治療適応となり、組織内照射約70Gyを行った後、口腔乾燥を訴えるようになった。ガムテストでは6.2cc/10min.であった。放射線治療後の口腔乾燥症として塩酸ピロカルピン15mg/day投与と、齲蝕予防のために1〜2ヵ月に1回のフッ素塗布、連日のフッ素洗口を開始した。さらに家庭においてフッ化物配合歯磨剤を用いたブラッシングを勧めた。症例2:63歳男性。舌癌で放射線治療を希望し、外照射20Gyの後、組織内照射約70Gyを行った後、口腔乾燥を訴えるようになった。ガムテストでは5cc/10min.であった。放射線治療後の口腔乾燥症として塩酸ピロカルピン15mg/day投与と、齲蝕予防のために3週間に1回のフッ素塗布を開始した。さらに家庭においてフッ化物配合歯磨剤を用いたブラッシングを勧めた。症例1では自覚的にも他覚的にも口腔乾燥を脱し、副作用発現なく投与10週後に中止した。症例2では副作用の頻尿感などで投与10日後に中止となったが、2週間後には自覚的にも他覚的にも口腔乾燥感の改善がみられた。ともに齲蝕のコントロールは良好である。

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

To evaluate the diagnostic value of dynamic contrast-enhanced MRI (DCE-MRI) in salivary gland tumors, thirty-five patients (47 lesions) who underwent MR examinations and were histopathologically diagnosed with salivary gland tumors in Okayama University Hospital, between April 1998 and March 2005, were entered in the present study. The parameters included CImax300 or CImax6003 which was the contrast index (CI) at maximal contrast enhancement upon 300 s or 600 s, and T-max, which was the time that corresponded to the CImax300. Washout ratio (WR300 or WR600) was defined as follows: CImax300 - CI300s/CImax300 or CImax600 - CI600s/CImax600 X 100 (%), where CI300 or CI600 was the CI at 300 s or 600 s after contrast medium administration. We obtained the following results from the analysis of DCE-MRI parameters; (a) The salivary gland tumors were categorized into three Cl curve types according to Tmax and WR300; Pleomorphic adenoma; Tmax > 210 s and WR300 < 10%, Warthin tumor; Tmax < 60 s and WR300 > 40%, and malignant tumor; 60 s < Tmax < 210 s and 10% < WR300 < 30%; (b) On the basis of the relationship between Tmax and CImax or WR, all pleomorphic adenomas were successfully differentiated from Warthin tumor lesions. Of the 20 pleomorphic adenomas, 18 (90.0%) were successfully differentiated from malignant tumors. All Warthin tumor lesions were successfully differentiated from pleomorphic adenomas and malignant tumors. Of 12 the malignant tumors, 11 (91.7%) were successfully differentiated from pleomorphic adenomas. All malignant tumors were successfully differentiated from Warthin tumors. Thus, DCE-MRI parameters are useful in diagnosing salivary gland tumors on the basis of the combined assessment of Tmax and CImax or WR. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.oraloncology.2006.11.009

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Objectives. We rarely find multiple cystic lesions in the jaw in panoramic radiographs. Most reports of multiple cystic lesions have described keratocystic odontogenic tumors (KOTs) in patients with basal cell nevus syndrome. In this study, we performed radiographic and clinical examinations of patients with multiple cystic jaw lesions found during their first visit to our department to determine the proportion of basal cell nevus syndrome among multiple cystic lesions. Methods. Patients who had a panoramic radiograph taken at Okayama University Hospital between 1993 and 2000 were examined. Twenty-three patients with multiple cystic jaw lesions on a first panoramic radiography examination were entered into this study. Results. Of the 23 patients, 12 (52.2%) were diagnosed with basal cell nevus syndrome and 11 (47.8%) were not. Of the 14 patients with multiple KOTs, 12 (85.7%) were diagnosed as having basal cell nevus syndrome. Of the nine remaining patients with multiple cystic jaw lesions, only seven had multiple dentigerous cysts and two had multiple simple bone cysts. Cleft palate was observed in four of the 12 patients (33.3%) with basal cell nevus syndrome. Conclusion. Diagnosing basal cell nevus syndrome based on multiple cystic jaw lesions carries a high risk of misdiagnosis. A strong possibility exists that patients with multiple jaw KOTs have basal cell nevus syndrome. Furthermore, cleft palate should be considered an important oral finding in basal cell nevus syndrome because its occurrence was relatively frequent in our study. © 2007 Japanese Society for Oral and Maxillofacial Radiology Springer-Verlag.

DOI： 10.1007/s11282-007-0059-x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPANDIDOS PUBL LTD  

We attempted to find a specific antigen of oral squamous cell carcinoma (SCC) cells that could be safely applied to gene therapy in the conservative clinical treatment of oral cancer. We performed subtraction using normal human keratinocyte cells, followed by selection using four oral SCC cell lines. We isolated three clones from poorly differentiated SCC cells and four from well-differentiated SCC cells. These seven clones adsorbed to the oral SCC cells at rates 10-100 times those of normal human keratinocyte cells. The three clones from the poorly differentiated SCC cells showed the same peptide sequence (LAPRTHP). Of the four clones from the well-differentiated SCC cells, three showed the same peptide sequence (FGTLPGT) and the fourth showed a different one (VTPNSTP). Each peptide sequence may recognize the material that exists specifically on the oral SCC cell cortex. We can expect applications not only for tumor-targeting treatment using a gene therapy virus vector but also for diagnosis using, as a tumor marker, the peculiar SCC surface material that these peptides recognize.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER IRELAND LTD  

Purpose: To examine whether the signal intensity of dynamic contrast-enhanced MRI (DCE-MRI) is altered by test injection of 1 ml of contrast medium, and if so, whether this change affects the DCE-MRI analysis.Materials and methods: Six healthy volunteers were examined by DCE-MRI using a Magnevist syringe and/or an Omniscan syringe for the injection of contrast medium. Each scan was performed 10 times using steady-state free precession (3D-FISP), a sequence for DCE-MRI, before and after intravenous injection of 1 ml of the contrast medium. The internal pterygoid muscle, masseter muscle, tongue, parotid gland, submandibular gland, bone marrow of the mandible, subcutaneous adipose tissue, and common carotid artery were determined to be regions of interest (ROI), and the ROI internal average signal intensity was measured. The 10 data sets obtained before or after contrast medium administration for each ROI were evaluated using the paired t-test.Results: The test injection increased the signal intensities of six of eight ROIs, with all 20 experiments in the submandibular gland showing significant differences. There was no significant difference in the two ROIs corresponding to the carotid artery and subcutaneous adipose tissue of the cheek.Conclusions: The enhanced signal intensity in the tissue might have been caused by the small amount of contrast medium in the test injection. To eliminate this discrepancy caused by the test injection, a pre-contrast scan should be performed when the average signal intensity of an ROI is measured. We therefore believe that the data obtained before a test injection may be important in the analysis of DCE-MRI. (C) 2006 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.ejrad.2006.03.017

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The radiographic features of unicystic ameloblastoma (UA) are typically unilocular and round area of radiolucency. Therefore, this type of lesion is often misdiagnosed as an odontogenic keratocyst or a dentigerous cyst. UA should be differentiated from odontogenic cysts because the former have a higher rate of recurrence than the latter. In the present study, we performed contrast enhanced-MRI (CE-MRI) to diagnose 13 cases of unilocular, round radiolucent lesions visualized on panoramic radiograph and/or CT. In the cases of UA, low signal intensity was observed on T1-weighted images (WIs), and a markedly high signal intensity was observed on T2-WIs; moreover, relatively thick rim-enhancement with/without small intraluminal nodules was observed upon CE-T1 WIs. CE-MRI was considered useful in the diagnosis of UA, as characteristic features of this type of Lesion i.e., thick enhancement of the tumor wall and small intraluminal nodules were detected only by CE-MRI in the present study. (c) 2005 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.oraloncology.2005.10.001

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Language：Japanese   Publisher：岡山歯学会  

病理組織学的に好酸球肉芽腫と診断した4例を対象とした.主訴は4例中2例が腫脹,1例が疼痛,1例がX線撮影時に偶然発見されたものであった.臨床的・X線学的に4例中2例は悪性腫瘍,1例は骨髄炎と診断され,1例は不明であった.最終的には病理組織学的に全例,好酸球肉芽腫と診断した.X線学的には,顎骨内に生じた14病巣はび漫性のX線透過像を示した.処置は8病巣で掻爬あるいは辺縁骨切除などの外科処置,4病巣で放射線照射,3病巣で化学療法,2病巣で外科処置と放射線照射,3病巣で放射線照射と化学療法を行った.いずれの処置に対してもよく反応したが,化学療法に関しては悪性リンパ腫の診断の基に行ったもので,反応は悪かった.外科処置のみを行った4病巣に再発を生じたが,放射線照射および外科処置と放射線照射の併用によって制御された

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We retrospectively evaluated magnetic resonance images (MRI) and dynamic contrast-enhanced MRI (DCE-MRI) of ameloblastomas. MRI and DCE-MRI were performed for 10 ameloblastomas. We obtained the following results from the MRI and DCE-MRI. (a) Ameloblastomas can be divided into solid and cystic portions on the basis of MR signal intensities. (b) Ameloblastomas show a predilection for intermediate signal intensity on T1WI, high signal intensity on T2WI, and well enhancement in the solid portion; they also show a homogeneous intermediate signal intensity on T1WI and homogeneous high signal intensity on T2WI, and no enhancement in the cystic portion. (c) The mural nodule or thick wall can be detected in ameloblastomas lesions. (d) CI curves of ameloblastomas show two patterns: the first pattern increases, reaches a plateau at 100-300 s, then sustains the plateau or decreases gradually to 600-900 s, while the other increases relatively rapidly, reaches a plateau at 90-120 s, then decreases relatively rapidly to 300 s, and decreases gradually thereafter. There was no difference in the CI curve patterns among primary and recurrent cases, a case with glandular odontogenic tumor in ameloblastoma or among histopathological types such as plexiform, follicular, mixed, desmoplastic, and unicystic type.

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Language：Japanese   Publisher：(NPO)日本歯科放射線学会  

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The radiographical differentiation of adenomatoid odontogenic tumor (AOT) from dentigerous cysts, calcifying odontogenic cysts, calcifying epithelial odontogenic tumors, odontogenic keratocysts and amelobastomas is sometimes difficult. We attempted to differentiate AOT from other lesions similar to AOT in radiographic findings using MRI. The MRI features of AOT in our three cases included homogeneous low SI in the cystic portion and homogeneous intermediate SI in the solid portion on T1WI, homogeneous high SI in the cystic portion and intermediate to slightly high SI in the solid portion on T2WI and enhancement of only the solid portion on CE-T1WI although none of the sequences included SI of calcifications. The contrast index curves in the three cases of AOT showed a gradual increase to 300 s, which signified a benign tumor. These MRI features were characteristic features of AOT and might be a basis for differentiating AOT from the above possible lesions in radiographic examinations.

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Because malignant lymphoma, the second most common malignant tumor of the head and neck, and squamous cell carcinoma (SCC), the most common malignant tumor of the head and neck, require different treatments, it is important to be able to differentiate them. In the present study, we attempted to differentiate malignant lymphomas from SCCs using dynamic contrast-enhanced MRI (DCE-MRI). Seventeen lesions (in 8 cases) of malignant lymphoma and 30 cases of SCC were compared by DCE-MRI. Thirteen of 17 malignant lymphomas (76.5%) showed the maximum contrast index (CI) at 90-180 s, while 26 of 30 SCCs (86.7%) showed the maximum CI at a much faster 60-105 s. There was a statistically significant difference between SCC and malignant lymphoma in the time needed reach the maximum CI (p = 0.0177). There was also significant difference between SCC and malignant lymphoma in their maximum CIs (p < 0.001), with the maximum CIs of 29/30 SCCs (96.7%) above 2.0, while 12/17 malignant lymphomas (70.6%) showed CIs of less than 2.0. We consider these findings to be useful for distinguishing lymphomas from SCCs.

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OBJECTIVES: To examine mesiodens with regard to their status, their influence on adjacent teeth and their alteration during the follow-up period. METHODS: From retrospective reviews of all patients who visited our institution from 1990-2001, we identified 200 patients (256 mesiodentes) who were shown to have mesiodentes on the basis of a periapical radiograph, a panoramic radiograph or an axial radiograph. RESULTS: The number of supernumerary teeth was one in 146 cases (73%), two in 52 cases (26%) and three in 2 cases (1%). Of 256 mesiodentes, the direction of the crown of the mesiodens was inverted in 172 (67%), in a normal direction in 69 (27%) and in a horizontal direction with regard to the tooth axis in 15 (6%). Of the 147 mesiodentes for which axial radiography was performed, 131 (89%) were located at a palatal site against the dental arch, 16 (11%) overlapped the dental arch and none were at a labial site. Of our 200 cases, a delay of eruption of the permanent central incisor was seen in 12 (6%), malposition or rotation of the central incisor in 5 (2.5%) and dentigerous cyst formation arising from mesiodens in 22 (11%). Marked movement of the mesiodens was seen in 10 cases during the follow-up period of 5-7 years. Some complication arising from mesiodens was seen in 19.5% of all cases in our research. CONCLUSION: Although mesiodentes are not caused by malocclusion, they may cause it. A long period of impaction of mesiodentes may bring about dentigerous cyst formation or movement of the mesiodentes.

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Objectives: To examine radiographically the relationship between the deciduous tooth and dentigerous cyst of the permanent successor during the transitional dentition. Methods: From a retrospective review of all patients who visited our institution from April 1988 to August 2001, 70 patients under 16 years of age who had histologically confirmed dentigerous cysts that had developed from the central incisor to the second premolar were identified. These 70 patients were investigated using panoramic and periapical radiographs. Results: In most cases (54 cases; 77.1%) the cyst was in the premolar region. Of the 54 premolars with dentigerous cysts, the overlying deciduous tooth had already been lost in 7 cases. Of the 47 remaining premolars with associated deciduous tooth, 35 (74.5%) had bone resorption of the periapical or bifurcation region, or irregular resorption of the associated deciduous tooth. Of the remaining 12 deciduous teeth with no periapical lesions, 9 had been treated with root canal therapy. Thus, 44 of these 47 cases (93.6%) had the possibility of inflammation at the deciduous tooth associated with the dentigerous cyst. Evidence from one case in the present study suggesting the process by which cyst development occurs is also given. Conclusion: Inflammatory change at the apex of the deciduous tooth may bring on a dentigerous cyst of the permanent successor. © 2004 The British Institute of Radiology.

DOI： 10.1259/dmfr/24148363

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In this study, we attempted to diagnose malignant lymphoma on the basis of magnetic resonance imagings (MRIs) and dynamic contrast-enhanced MRI (DCE-MRI). Eighteen lesions (in eight patients), all of which had been proven histopathologically, were detected on MRI. The eight patients included five patients with diffuse large B-cell lymphoma, one with B-cell low-grade MALT lymphoma, one with follicular lymphoma, and one with Hodgkin's lymphoma. Nine lesions were located in the submandibular region, three in the buccal region, two in the orbit region, two in the submental region, and one each in the palatal and tonsil regions. The diameter of the lesions ranged between 9 and 42.2 mm (average: 22.4 mm). The signal intensities (SIs) of the 18 lesions were examined on T1-weighted (T1WI), T2WI, and gadopentetate (Gd)-T1WI. One lesion in case 8 was excluded from DCE-MRI findings, i.e., the regions of interest could not be adequately set on DCE-MRIs. The contrast index (CI) curves of the remaining 17 lesions were prepared. All 18 lesions showed almost the same images on T1WI, T2WI, and Gd-T1WI, although they represented four types of lymphoma. The images showed homogeneous SI that was intermediate to slightly high SI on T1WI, slightly high SI on T2WI, and moderately enhanced on Gd-T1WI. Thus, the cases of malignant lymphoma in this study showed relatively characteristic features based on MRI; however, these features might be non-specific. The CI curves in this study showed a relatively rapid increase, reaching a maximum CI at 45-120 s, and a relatively rapid decrease in most lesions (14/17; 82.4%); on the other hand, the curves of 3 of the 15 lesions (17.6%) showed relatively rapid increase, sustenance of a plateau, and a gradual decrease thereafter. These patterns of CI curves may indicate characteristic features useful for distinguishing malignant lymphomas from other lesions.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

We describe a case of angioleiomyoma in the buccal space, and discuss its magnetic resonance imaging (MRI) features with histopathological correlation, with particular emphasis on the usefulness of using dynamic contrast-enhanced MRI (DCE-MRI) to differentiate other possible tumors. Angioleiomyoma of the buccal space in this case corresponded clinically and histopathologically to the previous reports. The characteristic findings of angioleiomyoma were a very high signal intensity on T2WI, and extremely high enhancement on Gd-T1WI. The inner aspect of this lesion was homogeneous on both T1WI and T2WI. However, the histopathological findings included tumor substance, mucous degeneration, and mature adipose cells, and these findings were reflected only on the DCE-MRI. Furthermore, the CI-Curve of the angioleiomyoma showed a characteristic pattern, which might differentiate it from other tumors. © 2003 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/s1571-4675(03)00080-4

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We evaluated magnetic resonance images (MRI) and the value of dynamic contrast enhanced MRI (DCE-MRI) of pleomorphic adenomas retrospectively. MRI was performed for 18 pleomorphic adenomas, including 11 cases with DCE-MRI. We obtained the following results on the MRI and DCE-MRI. (a). Pleomorphic adenomas showed a predilection for homogeneous intermediate signal intensity on T1-weighted images (T1WI), heterogeneous high signal intensity on T2-weighted images, and heterogeneous enhancement on Gd-T1WI. (b). Of 11 contrast index (CI) curves of pleomorphic adenomas, nine CI curves (81.8%) increased gradually to 600 s or increased gradually, reached a plateau, and sustained the plateau to 600 s. The remaining two (18.2%) increased gradually and decreased gradually thereafter. (c). CI curves reached the maximum CI index at 135-300 s.

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We examined the frequency of incidentally found or unexpected tumors discovered at the time of magnetic resonance imaging (MRI) examinations in the temporomandibular joint (TMJ) region for patients with suspicion of TMJ arthrosis. Five MR images (T1-weighted transverse scout image and proton density and T2-weighted oblique sagittal images at the open and closed mouth) were acquired. In 2776 MRI examinations of TMJ arthrosis, two tumors were discovered. They consisted of an adenoid cystic carcinoma in the deep portion of the parotid gland, and a malignant tumor extending from the infratemporal fossa to the parapharyngeal space. The rate of incidentally founded or unexpected tumors in TMJ examinations was low (0.072%), but the two tumors found were malignant tumors, and therefore, scout image should be carefully examined, not only used for positing the slice.

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Lesions that can produce divergence of the roots of teeth in the mandible include odontogenic cysts (odontogenic keratocysts, lateral periodontal cysts and radicular cysts), ameloblastomas, odontogenic myxomas, central giant cell granulomas, adenomatoid odontogenic tumors and aneurismal bone cysts, and other tumors. Moreover most benign jaw lesions can do this occasionally. However, when lesions--which show interradicular tear-shaped radiolucencies--are small it is often difficult to interpret them radiographically, because they do not show characteristic radiographic features. We describe a comparison of radiographic and magnetic resonance (MR) features of a root-diverging odontogenic myxoma, with discussion of the differential diagnosis of lesions likely to move roots. In addition, we discuss radiographic and MR features of possible lesions, which show similar radiographic findings to odontogenic myxoma.

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We investigated the relationship between the enhanced patterns acquired by dynamic MRI and the tumor cell proliferation estimated by immunostaining proliferating cell nuclear antigen (PCNA) in oral squamous cell carcinoma (SCC). Thirty patients with primary oral SCC underwent dynamic contrast enhanced (DCE)-MRI using a three-dimensional fast imaging with steady-state precession sequence. Tumor cell proliferation of all surgical specimens was evaluated using immunohistochemical staining with the anti-PCNA antibody. The relationship between the dynamic MRI parameters (maximum CI and maximum CI gain) and the PCNA labeling index was statistically analyzed using regression analysis. The time contrast index curves of all cases showed a rapid and high uptake pattern. The PCNA labeling index showed a significant correlation with maximum CI and maximum CI gain (P<0.0001, r=0.866 and P=0.0019, r=0.544, respectively). The assessment of DCE-MRI parameters may provide valuable information for tumor cell proliferation of the patients with oral cancer.

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We examined effects of recombinant p53-expressing adenovirus combined with thermoradiotherapy in 8 head and neck squamous cell carcinoma (SCC) cell lines to improve the outcomes of the threatment of advanced head and neck cancer. The p53 gene therapy did not improve the discrepancy between thermoradiosensitivities among the 8 SCC cell lines. However, p53 gene therapy improved the effects of thermoradiotherapy in all 8 cell lines, and there were significant differences in four situations of the HSC4 44°C (p=0.032), SAS at 44°C (p=0.029), the KB at 43°C (p=0.025), and the Ca9-22 43°C (p=0.020). In comparing the survival rates of thermoradiotherapy with those of thermotherapy and radiotherapy, thermoradiotherapy demonstrated actual survival rates less than theoretical survival rates based on the survival rates of thermotherapy multiplied by the survival rates of radiotherapy in almost all treatments of thermoradio-gene therapy of the 8 SCC cell lines. These results demonstrate that thermoradiotherapy combined with p53 gene therapy may be a useful tool in treating SCC cells.

DOI： 10.3892/or.10.2.415

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Aneurysmal bone cyst (ABC) is a relatively rare, non-neoplastic expansile lesion of bone. Bleeding may occur during an operation or biopsy for ABC, as this cyst is an aneurys with numerous pools of blood. Therefore, it is necessary to diagnose ABC before treatment or biopsy. In the present report, we describe the characteristic computed tomography (CT) and magnetic resonance imaging (MRI) features of ABC in the mandible. Based on the literature and on our own experiences, we compare with the features of ABC with the corresponding features of other lesions showing similar conventional radiographic appearances. In the present case, bone-targeting CT showed the characteristic feature, which reflected the histopathological appearance of a partially cystic meshwork divided by coarse septa. MRI showed almost homogeneous intermediate signal intensity, including a partial slight low-signal-intensity area on the T1-weighted image, and homogeneous high signal intensity, which showed a 'bubbly' appearance, on T2-weighted image. On the enhanced T1-weighted image, the intermediate signal intensity areas apart from the areas that showed slight low-signal intensity on the non-enhanced T1-weighted image, were well enhanced. This creates a 'honeycomb' appearance. The 'meshwork' appearance on bone-targeting CT, the 'bubbly' appearance on the T2WI and the 'honeycomb' appearance on Gd-T1WI may be the characteristic features of ABC.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Spandidos Publications  

In the present study, we attempted to diagnose and detect the extent of tumors in the sublingual region using magnetic resonance imaging (MRI) and dynamic MRI. MRI with or without gadopentetate dimeglumine (Gd-DTPA)-enhancement in seven lesions of the sublingual regions was performed. The seven lesions included four cases of mucoepidermoid carcinoma (mucoepidermoid Ca), two cases of adenoid cystic carcinoma (ACC), and one case of squamous cell carcinoma (SCC). Whether the tumor was malignant or benign, as well as the differential diagnosis, could not be determined on the basis of the MR signals, even when enhancement was performed. Dynamic MRI was performed in five cases, two cases of ACC, two cases of mucoepidermoid Ca, and one case of SCC. The dynamic MRI showed a rapid enhancement at 30-45 sec in all five cases before the normal sublingual gland began to be enhanced. The early phases at 30-45 sec of the dynamic MRI in five cases showed marked enhancement before the normal sublingual glands were enhanced, and therefore could clearly show the extent of the lesions. In conclusion, the dynamic MRI may be useful in differentiating malignant from benign tumors, and in detecting the extent of the tumors in the sublingual carcinomas.

DOI： 10.3892/or.9.6.1283

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Thermoradiosensitivity of 8 cell lines of head and neck squamous cell carcinoma (HO-1-u-1, HSC2, HSC3, HSC4, SAS, KB, Hep2, and Ca9-22) was investigated. The differences of radiosensitivity between the cell line with the highest radiosensitivity and the cell line with the lowest radiosensitivity were 1.7-, 7.7-, and 41-fold at 2, 6 and 8 Gy, respectively. The differences between the cell line with the highest thermosensitivity and the cell line with the lowest thermosensitivity were 2.4-, 6.2- and 34.4-fold at 43 degrees C for 40, 60 and 100 min, and 2.6-, 4.9- and 127-fold at 44 degrees C for 20, 30 and 50 min, respectively. These findings indicated that there were large differences in both radiosensitivity and thermosensitivity among the 8 cell lines. There was a negative relationship between radiosensitivity and thermosensitivity (43 degrees C: r=-0.600, 44 degrees C: r=-0.848) in 7 of 8 cell lines, the exception being the HSC4 cell line, which was resistant to both therapies. Four of the 8 cell lines at 43 degrees C and 5 at 44 degrees C in the radiotherapy combined with thermotherapy showed actual survival rates smaller than the theoretical survival rates. Thus, thermoradiotherapy was deemed effective in the head and neck carcinoma cell lines, although 1 of 8 cell lines was resistant to both radiotherapy and thermotherapy.

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It is often difficult to radiographically distinguish odontogenic myxomas from ameloblastomas. In the present study, we tried to differentiate odontogenic myxomas from ameloblastomas using dynamic magnetic resonance imaging (dynamic MRI). Two cases of ameloblastoma with cystic components and two cases of odontogenic myxoma were compared by dynamic MRI. The dynamic MRI features of solid areas of ameloblastomas showed a rapid enhancement, reaching maximum contrast at 45-60 s, and maintained these enhancement levels or showed a gradual wash-out to 600 s thereafter; in contrast, those of the cystic areas of ameloblastomas showed no enhancement. The dynamic MRI features of the whole area of odontogenic myxomas (we considered the whole area to be the tumor substance in the odontogenic myxomas, as based on histopathological examinations) showed a gradual increase in enhancement at 500-600 s. The central portions of the odontogenic myxomas, which did not appear to be enhanced on Gd-T1 weighted images also showed a gradual increase in enhancement at 500-600 s, though the increase was minimal. These results indicate that the dynamic MRI features of odontogenic myxomas are different from those of ameloblastomas. Therefore, dynamic MRI may be a useful tool for diagnosis of myxoma.

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We examined three patients with multiple synchronous Warthin's tumors in the bilateral parotid and described the value of using dynamic MRI. The time course of the contrast index (CI curves) was calculated from a dynamic series. Warthin's tumors showed intermediate signal intensity on T1WI, heterogeneous high and intermediate signal intensity on T2WI and a slight enhancement on Gd-T1WI. Warthin's tumors of CI curves showed specific findings. CI curves in each lesion showed the same pattern. It was difficult to diagnose masses as Warthin's tumors using only MR images on T1, T2 and Gd-T1WI. Dynamic MRI can distinguish Warthin's tumors from other possible tumors except for oncocytoma. Therefore, the use of dynamic MRI is recommended as a diagnostic method for Warthin's tumors in multiple synchronous lesions of the parotid gland.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PROFESSOR D A SPANDIDOS  

We report on thermochemotherapy in a human salivary gland adenocarcinoma cell line. Hyperthermia reduced the survival rate to 50 and 20% by heating at 43degreesC for 40 and 60 min, respectively, and is by itself useful in human salivary gland carcinoma treatment. Adriamycin, cisplatin, and mitomycin C can possible be used clinically, while bleomycin and 5-fluorouracil cannot, to treat this carcinoma. The optimal temperature was considered to be 41degreesC in adriamycin, 42degreesC in cisplatin, 37degreesC in mitomycin C, and 42degreesC in bleomycin in the thermochemotherapy. Thermochemotherapy is a useful tool in the treatment of human salivary gland carcinoma cells, but it is necessary to select the best anticancer drugs and the optimal temperature for optimal success using this treatment.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：INT INST ANTICANCER RESEARCH  

In this study, we examined the inhibitory effects on cell growth and the effects of quercetin on intracellular accumulation of adriamycin (ADR) in wild type Ehrlich ascites tumor cells (wild EAT cells) and their ADR-resistant strain. Quercetin strongly inhibited growth in both strains. Cell growth reached a plateau at 3.5 days in the wild type EAT cells and at 7 days in the ADR-resistant strain. The inhibitory concentration in 50% of the ADR-resistant cells on day 7 (24 mu M) was twice that of the wild type EAT cells on day 4 (12 mu M) after continuous treatment with quercetin. Quercetin decreased the ADR accumulation in the wild type cells but did not affect it in the ADR-resistant cells. Further quercetin did not affect the retention of ADR in either strain. These results indicated that qeurcetin decreased ADR accumulation without extruding ADR in the wild type EAT cells. ADR accumulation in the ADR-resistant cells treated with quercetin for 7 days was increased with increasing concentrations of quercetin. Moreover ADR accumulation in the ADR-resistant cells treated with 50 mu M quercetin for 7 days, increased to 186.6% and to 181.9% of that in untreated cells after 60 minutes and 120 minutes incubation, respectively, whilst it ina-eased to 70% from 37.5% of that in the wild type EAT cells after 60 minutes incubation. These findings indicated that quercetin might reverse ADR-resistance.

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Language：Japanese   Publisher：岡山歯学会  

上顎は,歯胚形成が進むにしたがって萠出角度は垂直方向となる傾向にあった.下顎は,歯胚形成が歯冠に限局した時期に既に近心傾斜する傾向にあり,歯根3分の1以上形成された段階以降に近心に46度以上傾斜している症例は更に傾斜する

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：INT INST ANTICANCER RESEARCH  

In this study, we observed the influence of bovine calf serum (BCS) on the intracellular accumulation of adriamycin (ADR) in Ehrlich ascites tumor cells (wild type EAT cells) and their ADR-resistant strain. The ADR accumulation treated in the medium not containing BCS was S-fold of that containing 10% BCS. ADR incorporated into cells was not effluxed in the absence of the BCS, while it was rapidly effluxed for 30 minutes to about 20% of the amount incorporated into the cells in the presence of 20% BCS in both strains. This suggests that BCS remarkably decreases the ADR accumulation due to the promotion of ADR efflux. Further; the ADR accumulation dea eased with increasing concentrations of BCS in both strains. This indicates that BCS promotes the ADR efflux, dependeing on its concentrations. BCS was heated at 100 degrees C for 7 minutes and its protein contents were degenerated. Irs influence in the ADR accumulation of wild type and ADR-resistant strain was apparent. The ADR accumulation decreased with increasing concentrations of heated BCS in both strains, as well as in the untreated BCS. Thus, the protein content of the BCS did not affect ADR accumulation. Therefore, it is necessary to investigate which components of BCS affect the promotion of ADR efflux.

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Language：Japanese   Publisher：岡山歯学会  

1)本病変は全て下顎に発症し,平均年齢は22.0歳であった. 2)X線写真上の特徴は,弱い辺縁を持つX線透過像を示し,頬舌的な膨隆は1例のみで認められた. 3)上方部辺縁が歯根に接する12症例中10例では,いわゆる"帆立貝状"を呈しており,下方辺縁が下顎骨下縁に達する3例では皮質骨の菲薄化が認められた. 4)生検のみを施行した3例も外科処置を施行した10例と同様に治癒傾向を示し再発を認めなかった.したがって,単純性骨嚢胞の処置は生検により確定診断を得た後に経過観察を行うことが有用な方法であると考えられた

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Language：Japanese   Publisher：岡山歯学会  

自験例では全ての症例にCa,Pの代謝異常に起因する腎性骨異栄養症を反映した歯周組織及び顎骨の様々な特徴的なX線像上の変化を認めた.したがって,歯科臨床上,患者の病歴,他疾患併発の可能性に留意すると共に本症発現に伴うX線写真上の顎骨変化も十分認識しておく必要がある

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Language：Japanese   Publisher：岡山歯学会  

Synovial osteochondromatosisが疑われた6例及び病理組織学的に確定した2例について全例でX線撮影,8例中4例でCT検査,8例中3例でMRI検査を行った.X線所見では全例で遊離体がみられ,関節腔の拡大は3例,運動制限は5例,関節表面の不整や骨硬化像は各5例に認められた.CT所見では4例中2例でerosionと骨硬化像,1例でerosionのみ,1例で骨硬化像のみが認められ,全4例で翼突筋の圧迫偏位像を認めた.MRI所見では3例中2例においてT2強調像で翼突筋の信号が高くなり,1例では筋の信号の亢進はなかった.又,遊離体は3例共T1強調像で低信号を示したが,T2強調像では2例が高信号,1例が低信号であった

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Language：Japanese   Publisher：(公社)日本医学放射線学会  

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(公社)日本口腔外科学会  

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(NPO)日本口腔科学会  

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(公社)日本口腔外科学会  

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(公社)日本口腔外科学会  

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Language：Japanese   Publisher：岡山歯学会  

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Language：Japanese   Publisher：(公社)日本口腔外科学会  

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

We investigated the relationship between the enhanced patterns acquired by dynamic MRI and the tumor cell proliferation estimated by immunostaining proliferating cell nuclear antigen (PCNA) in oral squamous cell carcinoma (SCC). Thirty patients with primary oral SCC underwent dynamic contrast enhanced (DCE)-MRI using a three-dimensional fast imaging with steady-state precession sequence. Tumor cell proliferation of all surgical specimens was evaluated using immunohistochernical staining with the anti-PCNA antibody. The relationship between the dynamic MR1 parameters (maximum CI and maximum CI gain) and the PCNA labeling index was statistically analyzed using regression analysis. The time contrast index curves of all cases showed a rapid and high uptake pattern. The PCNA labeling index showed a significant correlation with tnaxitnutn CI and maximum CI gain (P&lt;0.0001, r=0.866 and P=0.0019, r=0.544, respectively). The assessment of DCE-MRI parameters may provide valuable information for tumor cell proliferation of the patients with oral cancer. (C) 2003 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S1368-8375(02)00119-7

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Language：English   Publisher：Elsevier BV  

Introduction: It might be difficult to differentiate solitary bone cysts (SBCs) from other cysts and tumors when the lesion occurs at an unusual location and/or shows atypical radiographic features. Magnetic resonance imaging (MRI) is the most useful modality for evaluating the internal structure of lesions and may have the ability to distinguish SBCs from other lesions. However, few studies exist regarding MRI of SBCs in the oral region. The present study reports on the MR imaging of nine patients with SBCs and describes the diagnostic value of the MRI findings. Materials and methods: Nine patients with SBCs in the mandible were examined using MRI. In all patients, T1- and T2-weighted images (T1-WI, T2-WI) were obtained and contrast enhanced images and dynamic MRI were performed in four cases. Results: MR findings revealed homogeneous intermediate signal intensities (SI) on T1-WI and high SI on T2-WI in all cases. These SI indicated that the SBCs included homogeneous liquid. On the dynamic MRIs in all cases, the SBCs were enhanced from the margin to the inner part, indicating a gradual exudation of the contrast agent from the surrounding medullae to the inner part. These phenomena were not observed on the dynamic MRIs of the other true cysts with epithelial lining. Conclusion: MRI, especially dynamic MRI, can provide useful information for distinguishing SBCs from other cysts or tumors. Furthermore, dynamic MRI findings suggested that the liquid components of SBCs might have infiltrated from the surrounding medullae. © 2002 Elsevier Science Ireland Ltd. All rights reserved.

DOI： 10.1016/S1571-4675(03)00021-X

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

We examined three patients with multiple synchronous Warthin's tumors in the bilateral parotid and described the value of using dynamic MRI. The time course of the contrast index (CI curves) was calculated from a dynamic series. Warthin's tumors showed intermediate signal intensity on T1WI, heterogeneous high and intermediate signal intensity on T2WI and a slight enhancement on Gd-T1WI. Warthin's tumors of CI curves showed specific findings. CI curves in each lesion showed the same pattern. It was difficult to diagnose masses as Warthin's tumors using only MR images on T1, T2 and Gd-T1WI. Dynamic MRI can distinguish Warthin's tumors from other possible tumors except for oncocytoma. Therefore, the use of dynamic MRI is recommended as a diagnostic method for Warthin's tumors in multiple synchronous lesions of the parotid gland. (C) 2002 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S1368-8375(01)00073-2

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Language：English   Publisher：ELSEVIER SCI IRELAND LTD  

We describe the magnetic resonance (MR) features of two cases of nasopalatine duct cyst (NPDC), including the first presentation of TI-weighted images (WI). The signal intensity of the cases of NPDC showed homogeneous high signal intensity on both on T1 and T2WI, although most cysts of maxillofacial regions demonstrate low to intermediate signal intensity on T1WI. NPDC may commonly be of high signal intensity on T1WI, which is consistent with keratin and viscous fluids. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.

DOI： 10.1016/S0720-048X(01)00279-0

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Event date： 2022.12.17 - 2022.12.18

Presentation type：Oral presentation (general)  

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Event date： 2022.2.14 - 2022.3.13

Presentation type：Symposium, workshop panel (nominated)  

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Event date： 2021.6.17 - 2021.6.18

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2021.5.12 - 2021.5.14

Language：Japanese   Presentation type：Poster presentation  

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Event date： 2021.4.17 - 2021.4.18

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2020.12.5 - 2020.12.6

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Event date： 2020.12.5 - 2020.12.6

Presentation type：Poster presentation  

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Event date： 2019.11.30 - 2019.12.1

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Event date： 2019.11.30 - 2019.12.1

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Event date： 2019.11.16

Presentation type：Oral presentation (general)  

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Event date： 2019.9.14 - 2019.9.16

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Event date： 2019.8.28

Presentation type：Poster presentation  

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Event date： 2019.6.13 - 2019.6.14

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Poster presentation  

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