Yamashita Rikiya, Isoda Hiroyoshi, Arizono Shigeki, Furuta Akihiro, Ohno Tsuyoshi, Ono Ayako, Murata Katsutoshi, 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, Osaka Red Cross Hospital, 5-30 Fudegasaki-cho, Tennoji-ku, Osaka, 543-8555, Japan.
Eur J Radiol. 2017 Jan;86:52-57. doi: 10.1016/j.ejrad.2016.10.034. Epub 2016 Nov 2.
To evaluate the potential of readout-segmented echo-planar diffusion-weighted magnetic resonance neurography (RS-EPI DW-MRN) for the selective visualization of pelvic splanchnic nerve and pelvic plexus in healthy male volunteers.
Institutional review board approval and written informed consent were obtained. RS-EPI DW-MRN images were acquired from thirteen healthy male volunteers aged 25-48 years between September 2013 and December 2013. For RS-EPI DW-MRN, the following parameters were used: spatial resolution, 1.1×1.1×2.5mm; b-value, 250s/mm; number of readout-segments, seven; and acquisition time, 7min 45s. For qualitative assessment, two abdominal radiologists independently evaluated the visibility of the pelvic splanchnic nerves and pelvic plexuses bilaterally in each subject on oblique coronal thin-slab 10-mm-thick maximum intensity projection images and scored it with a 4-point grading scale (excellent, good, fair, poor). Both readers scored twice at 6-month intervals. Inter-observer and intra-observer variability were evaluated using Cohen's quadratically weighted κ statistics. Image artifact level was scored on a 4-point grading scale by other two abdominal radiologists in order to evaluate the correlation between the nerve visibility and the severity of imaging artifacts using the Spearman's correlation coefficient.
Qualitative grading showed the following success rate (number of nerves qualitatively scored as excellent or good divided by total number of nerves): reader 1 (first set), 73% (19/26); reader 2 (first set), 77% (20/26); reader 1 (second set), 81% (21/26); and reader 2 (second set), 77% (20/26). Inter-observer agreement between readers 1 and 2 was excellent: κ=0.947 (first set) and 0.845 (second set). Intra-observer agreement was also excellent: κ=0.810 (reader 1) and 0.946 (reader 2). The visibility of pelvic splanchnic nerve and pelvic plexus showed a moderate correlation with the image artifact level (ρ=0.54, p=0.004).
This study demonstrated that RS-EPI DW-MRN is a promising approach for selectively visualizing the pelvic splanchnic nerve and pelvic plexus.
评估读出分段回波平面扩散加权磁共振神经成像（RS-EPI DW-MRN）在健康男性志愿者中选择性显示盆内脏神经和盆腔神经丛的潜力。
获得机构审查委员会批准和书面知情同意。于2013年9月至2013年12月期间，对13名年龄在25 - 48岁的健康男性志愿者进行RS-EPI DW-MRN成像。对于RS-EPI DW-MRN，采用以下参数：空间分辨率1.1×1.1×2.5mm；b值250s/mm²；读出分段数7个；采集时间7分45秒。为进行定性评估，两名腹部放射科医生在斜冠状面10mm厚的最大强度投影图像上独立评估每个受试者双侧盆内脏神经和盆腔神经丛的可视性，并采用4分制评分（优秀、良好、中等、差）。两位阅片者均每隔6个月进行两次评分。采用Cohen二次加权κ统计量评估观察者间和观察者内的变异性。另外两名腹部放射科医生采用4分制对图像伪影水平进行评分，以使用Spearman相关系数评估神经可视性与成像伪影严重程度之间的相关性。
定性分级显示成功率如下（定性评为优秀或良好的神经数量除以神经总数）：阅片者1（第一组），73%（19/26）；阅片者2（第一组），77%（20/26）；阅片者1（第二组），81%（21/26）；阅片者2（第二组），77%（20/26）。阅片者1和阅片者2之间的观察者间一致性极佳：κ = 0.947（第一组）和0.845（第二组）。观察者内一致性也极佳：κ = 0.810（阅片者1）和0.946（阅片者2）。盆内脏神经和盆腔神经丛的可视性与图像伪影水平呈中度相关（ρ = 0.54，p = 0.004）。
本研究表明RS-EPI DW-MRN是一种选择性显示盆内脏神经和盆腔神经丛的有前景的方法。
