A brain phantom for motion-corrected PROPELLER showing image contrast and construction similar to those of in vivo MRI

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• 作者：Kousaku Saotome^a ; ^b ; ^{saotome84@gmail.com} ; Akira Matsushita^a ; ^c ; ¹ ; ² ; Koji Matsumoto^d ; ³ ; Yoshiaki Kato^e ; ⁴ ; Kei Nakai^c ; ² ; Koichi Murata^f ; ⁵ ; Tetsuya Yamamoto^c ; ² ; Yoshiyuki Sankai^a ; ^g ; ¹ ; ⁵ ; Akira Matsumura^c ; ²
• 关键词：Propeller ; Phantom ; Brain ; Motion correction ; 3-D prototyping technology
• 刊名：Magnetic Resonance Imaging
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：36
• 期：Complete
• 页码：32-39
• 全文大小：1183 K
• 卷排序：36

文摘

A fast spin-echo sequence based on the Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction (PROPELLER) technique is a magnetic resonance (MR) imaging data acquisition and reconstruction method for correcting motion during scans. Previous studies attempted to verify the in vivo capabilities of motion-corrected PROPELLER in real clinical situations. However, such experiments are limited by repeated, stray head motion by research participants during the prescribed and precise head motion protocol of a PROPELLER acquisition. Therefore, our purpose was to develop a brain phantom set for motion-corrected PROPELLER.Materials and methodsThe profile curves of the signal intensities on the in vivo T2-weighted image (T2WI) and 3-D rapid prototyping technology were used to produce the phantom. In addition, we used a homemade driver system to achieve in-plane motion at the intended timing. We calculated the Pearson's correlation coefficient (R2) between the signal intensities of the in vivo T2WI and the phantom T2WI and clarified the rotation precision of the driver system. In addition, we used the phantom set to perform initial experiments to show the rotational angle and frequency dependences of PROPELLER.ResultsThe in vivo and phantom T2WIs were visually congruent, with a significant correlation (R2) of 0.955 (p < .001). The rotational precision of the driver system was within 1 degree of tolerance. The experiment on the rotational angle dependency showed image discrepancies between the rotational angles. The experiment on the rotational frequency dependency showed that the reconstructed images became increasingly blurred by the corruption of the blades as the number of motions increased.ConclusionsIn this study, we developed a phantom that showed image contrasts and construction similar to the in vivo T2WI. In addition, our homemade driver system achieved precise in-plane motion at the intended timing. Our proposed phantom set could perform systematic experiments with a real clinical MR image, which to date has not been possible in in vivo studies. Further investigation should focus on the improvement of the motion-correction algorithm in PROPELLER using our phantom set for what would traditionally be considered problematic patients (children, emergency patients, elderly, those with dementia, and so on).