Zaike Toshiyuki, Kotaki Shinya, Takahashi Shogo, Yoshida Asami, Saito Shigeyoshi, Takatsu Yasuo
Diagnostic Imaging Center, Osaka Dental University Hospital.
Department of Oral Radiology, Osaka Dental University.
Nihon Hoshasen Gijutsu Gakkai Zasshi. 2021;77(10):1196-1202. doi: 10.6009/jjrt.2021_JSRT_77.10.1196.
This study aims to evaluate the fat suppression effect on images of the head and neck region using chemical shift selective (CHESS), and iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL).
A self-made phantom containing oil around the simulated bone marrow and muscle was scanned. The signal-to-noise ratio (SNR) was calculated using the National Electrical Manufacturers Association (NEMA) subtraction and pixel shift methods. Thereafter, the fat suppression effect and SNR were calculated in clinical images using the pixel shift method.
In both phantom and clinical images, the fat suppression effect was higher using IDEAL. In addition, the SNR of the NEMA subtraction method and the pixel shift method in phantom images was higher in the simulated bone marrow than in the simulated muscle. The SNR of the vertebral body was higher than that of the tongue in the clinical images using IDEAL, and the same tendency was observed in the phantom image evaluation. However, there was a difference in SNR between the phantom and clinical images.
In the head and neck region, fat-suppressed images using IDEAL showed the same higher fat-suppressing effect as that in a previous study. The SNR for the phantom and the clinical images was different. The SNR calculated using the pixel shift method for the phantom images with IDEAL and the clinical images showed the same tendency. Although there is a difference between the SNRs of phantom and clinical images calculated by the pixel shift method, it is suggested that the method can be used to compare the SNR between tissues such as the vertebral body and the tongue.
本研究旨在评估使用化学位移选择法（CHESS）以及水脂迭代分解与回波不对称和最小二乘估计法（IDEAL）对头颈部区域图像的脂肪抑制效果。
扫描一个自制的含有围绕模拟骨髓和肌肉的油的体模。使用美国国家电气制造商协会（NEMA）减法和像素移位法计算信噪比（SNR）。此后，使用像素移位法在临床图像中计算脂肪抑制效果和SNR。
在体模和临床图像中，使用IDEAL的脂肪抑制效果更高。此外，在模拟骨髓中，体模图像中NEMA减法和像素移位法的SNR高于模拟肌肉中的SNR。在使用IDEAL的临床图像中，椎体的SNR高于舌头的SNR，在体模图像评估中也观察到相同趋势。然而，体模和临床图像之间的SNR存在差异。
在头颈部区域，使用IDEAL的脂肪抑制图像显示出与先前研究相同的更高脂肪抑制效果。体模和临床图像的SNR不同。使用像素移位法计算的IDEAL体模图像和临床图像的SNR显示出相同趋势。尽管通过像素移位法计算的体模和临床图像的SNR之间存在差异，但建议该方法可用于比较椎体和舌头等组织之间的SNR。
