Furuta Akihiro, Isoda Hiroyoshi, Yamashita Rikiya, Ohno Tsuyoshi, Kawahara Seiya, Shimizu Hironori, Shibata Toshiya, Togashi Kaori
Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Eur J Radiol. 2014 Sep;83(9):1626-30. doi: 10.1016/j.ejrad.2014.06.003. Epub 2014 Jun 17.
To compare monopolar (MP) and bipolar (BP) diffusion weighted imaging (DWI) in detecting small liver metastases.
Eighty-eight patients underwent 3-T MRI. The signal-to-noise ratios (SNR) of the liver parenchyma and lesions, the lesion-to-liver contrast-to-noise ratios (CNR), and the detection sensitivities were compared. The lesion distortion was scored (LDS) from 4 (no distortion) to 1 (excessive distortion), dichotomised as no-distortion and distortion, and the association between detected lesions for each reader in the MP or BP DWI group and the dichotomised lesion distortion degree was assessed.
Forty-six hepatic metastases were confirmed. The CNR with BP images showed significantly higher values than with MP (P=0.017). The detection sensitivities of the three readers were higher in the BP sequence than in MP, and one reader detected significantly more hepatic lesions with BP images (P=0.04). LDS was significantly improved with BP sequence (P=0.002). In the no-distortion group, excluding the MP DWI assessments of one reader, detection sensitivities were significantly higher than in the distortion group (P<0.001 and P=0.002, respectively).
Reduced lesion distortion improves the detection of small liver metastases, and BP is more sensitive in detecting small liver metastases than MP DWI.
比较单极(MP)和双极(BP)扩散加权成像(DWI)检测肝脏小转移灶的效果。
88例患者接受了3-T磁共振成像检查。比较肝实质和病灶的信噪比(SNR)、病灶与肝脏的对比噪声比(CNR)以及检测灵敏度。对病灶变形程度进行评分(LDS),范围从4分(无变形)到1分(过度变形),分为无变形和变形两组,并评估MP或BP DWI组中每位阅片者检测到的病灶与二分法病灶变形程度之间的关联。
共确诊46个肝转移灶。BP图像的CNR值显著高于MP图像(P = 0.017)。三位阅片者在BP序列中的检测灵敏度高于MP序列,且一位阅片者用BP图像检测到的肝病灶明显更多(P = 0.04)。BP序列的LDS有显著改善(P = 0.002)。在无变形组中,排除一位阅片者的MP DWI评估,检测灵敏度显著高于变形组(分别为P < 0.001和P = 0.002)。
减少病灶变形可提高肝脏小转移灶的检测率,且BP在检测肝脏小转移灶方面比MP DWI更敏感。