記述言語：英語   掲載種別：研究論文（学術雑誌）  

This study proposes the use of the inversion recovery T1-weighted turbo field echo (IR-T1TFE) sequence for myocardial T1 mapping and compares the results obtained with those of the modified Look-Locker inversion recovery (MOLLI) method for accuracy, precision, and reproducibility. A phantom containing seven vials with different T1 values was imaged, thereby comparing the T1 measurements between the inversion recovery spin-echo (IR-SE) technique, MOLLI, and the IR-T1TFE. The accuracy, precision, and reproducibility of the T1-mapping sequences were analyzed in a phantom study. Fifteen healthy subjects were recruited for the in vivo comparison of native myocardial T1 mapping using MOLLI and IR-T1TFE sequences. After myocardium segmentation, the T1 value of the entire myocardium was calculated. In the phantom study, excellent accuracy was achieved using IR-T1TFE for all T1 ranges. MOLLI displayed lower accuracy than IR-T1TFE (p =0.016), substantially underestimating T1 at large T1 values (> 1000 ms). In the in vivo study, the first mean myocardial T1 values ± SD using MOLLI and IR-T1TFE were 1306 ± 70 ms and 1484 ± 28 ms, respectively, and the second were 1297 ± 68 ms and 1474 ± 43 ms, respectively. The native myocardial T1 obtained with MOLLI was lower than that of IR-T1TFE (p < 0.001). The reproducibility of native myocardial T1 mapping within the same sequence was not statistically significant (p = 0.11). This study demonstrates the utility and validity of myocardial T1 mapping using IR-T1TFE, which is a common sequence. This method was found to have high accuracy and reproducibility.

DOI： 10.1007/s12194-024-00795-w

PubMed

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

Background

Arterial spin-labeling (ASL) imaging is currently the most useful method for diagnosing mitochondrial encephalomyopathy, lactic acidosis, and stroke-like attack syndrome (MELAS). However, ASL is often an optional feature of standard MRI systems. Therefore, not all MRI systems can perform ASL imaging. In contrast, fluid-attenuated inversion recovery (FLAIR) imaging is one of the common sequences in brain MRI because FLAIR imaging can be performed regardless of the specifications of the equipment. This study aimed to compare the diagnostic performance of quantitative analysis of signal intensity obtained from fluid-attenuated inversion recovery (FLAIR) images with ASL images for MELAS with recurrent stroke-like episodes (SLEs). A total of 68 cases with normal magnetic resonance imaging findings and 25 cases diagnosed MELAS with recurrent SLEs were included. We evaluated the frontal lobe and cuneus as target areas and compared the regional cerebral blood flow (rCBF) values obtained from ASL images with the normalized signal intensity (nSI) obtained from FLAIR images.

Results

The sensitivity and specificity for diagnosing MELAS from linear discriminant analysis (LDA) obtained from the rCBF values were 0.84 and 0.941, respectively, and those of nSI were 0.8 and 0.897, respectively. The area under the ROC curves (AUC) calculated from the receiver operating characteristic (ROC) curve analysis using rCBF values and nSI were 0.889 and 0.804, respectively.

Conclusion

Quantitative analysis using the signal intensity of the FLAIR image could have a diagnostic performance equivalent to that of rCBF values obtained from ASL images.

DOI： 10.1186/s43054-023-00232-4

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その他リンク： https://link.springer.com/article/10.1186/s43054-023-00232-4/fulltext.html

記述言語：日本語   出版者・発行元：(一社)日本コンピュータ外科学会  

著者らは、術者の被ばく量低減を目的として、遠隔操作型のCT透視ガイド下針穿刺ロボット(Zerobot)の研究開発を開始している。今回、動物実験のCT画像をもとに術者である医師がロボットを遠隔操作してブタの体内にある標的に対して穿刺を行う場合に、針と標的との位置関係によってどのように針の軌道修正の作業を行うのか調査した。Zerobotを用いて、X軸、Y軸、Z軸の三つの直動軸で三次元方向の並進運動を行い、針の位置を決定した。A軸、B軸の二つの回転軸で回転運動を行い、針の姿勢を決定した。調査に使用したデータはブタを用いた穿刺精度試験で得られたものであった。ロボットを医師が遠隔操作することによる穿刺において、針が標的に近づくにつれ修正回数は指数的に増加していることが分かった。なお、残りの穿刺深さが約10mmとなるのをピークに、それ以降はA軸とB軸の修正回数は減少し、一方で刺し直し回数が増加している様子が観察された。合計60回の穿刺のうち、A軸の修正は110回、B軸の修正は66回、刺し直しは37回であった。自動穿刺シミュレーションの結果、穿刺経路と針との距離と角度がゼロに収束しており、針先を三次元的な穿刺経路に追従させることができることを確認した。針が標的に近づくにしたがって穿刺速度が減速していることが示された。

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その他リンク： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2020&ichushi_jid=J03729&link_issn=&doc_id=20200207210002&doc_link_id=10.5759%2Fjscas.22.14&url=https%3A%2F%2Fdoi.org%2F10.5759%2Fjscas.22.14&type=J-STAGE&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00007_2.gif

掲載種別：研究論文（学術雑誌）   出版者・発行元：The Japan Society of Computer Aided Surgery  

DOI： 10.5759/jscas.22.14

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00330-019-06477-1

Web of Science

PubMed

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総ページ数：xiii, 643p   記述言語：日本語

CiNii Books

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記述言語：英語   出版者・発行元：RADIOLOGICAL SOC NORTH AMERICA  

Purpose: To evaluate the accuracy of the remote-controlled robotic computed tomography (CT)-guided needle insertion in phantom and animal experiments.
Materials and Methods: In a phantom experiment, 18 robotic and manual insertions each were performed with 19-gauge needles by using CT fluoroscopic guidance for the evaluation of the equivalence of accuracy of insertion between the two groups with a 1.0-mm margin. Needle insertion time, CT fluoroscopy time, and radiation exposure were compared by using the Student t test. The animal experiments were approved by the institutional animal care and use committee. In the animal experiment, five robotic insertions each were attempted toward targets in the liver, kidneys, lungs, and hip muscle of three swine by using 19-gauge or 17-gauge needles and by using conventional CT guidance. The feasibility, safety, and accuracy of robotic insertion were evaluated.
Results: The mean accuracies of robotic and manual insertion in phantoms were 1.6 and 1.4 mm, respectively. The 95% confidence interval of the mean difference was 20.3 to 0.6 mm. There were no significant differences in needle insertion time, CT fluoroscopy time, or radiation exposure to the phantom between the two methods. Effective dose to the physician during robotic insertion was always 0 mSv, while that during manual insertion was 5.7 mSv on average (P&lt;.001). Robotic insertion was feasible in the animals, with an overall mean accuracy of 3.2 mm and three minor procedure-related complications.
Conclusion: Robotic insertion exhibited equivalent accuracy as manual insertion in phantoms, without radiation exposure to the physician. It was also found to be accurate in an in vivo procedure in animals. (C) RSNA, 2017

DOI： 10.1148/radiol.2017162856

Web of Science

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種別：出前授業

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