Sirin Selma, Kathemann Simone, Schweiger Bernd, Hahnemann Maria L, Forsting Michael, Lauenstein Thomas C, Kinner Sonja
From the *Department of Diagnostic and Interventional Radiology and Neuroradiology, and †Clinic for Pediatrics II, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Invest Radiol. 2015 Jan;50(1):32-9. doi: 10.1097/RLI.0000000000000092.
Magnetic resonance colonography (MRC) is a well-accepted, noninvasive imaging modality for the depiction of inflammatory bowel disease. Diffusion-weighted imaging (DWI) is very helpful to display inflammatory lesions. The aim of this retrospective study was to assess whether intravenous contrast is needed to depict inflammatory lesions in bowel magnetic resonance imaging if DWI is available.
Thirty-seven patients (23 females, 14 males; mean age, 14.6 years) underwent MRC on a 1.5-T scanner (MAGNETOM Avanto; Siemens). Contrast-enhanced T1-weighted (ce-T1-w) sequences and DWI sequences in axial and coronal planes (b = 50, 500, 1000) were acquired. Two reviewers evaluated (1) DWI, (2) ce-T1-w MRC, as well as (3) DWI and ce-T1-w MRC concerning lesion conspicuity. The preferred b value was assessed. Colonoscopy was performed within 1 week, including biopsies serving as the reference standard. Sensitivities and specificities were calculated, and interobserver variability was assessed.
Mean sensitivity and specificity of the 2 readers for the depiction of inflammatory lesions were 78.4%/100% using ce-T1-w MRC, 95.2%/100% using DWI, and 93.5%/100% combining both imaging techniques compared with colonoscopy including results of the histopathological samples. In 6 patients, inflammatory lesions were only detected by DWI; in another 6 patients, DWI detected additional lesions. The κ values for the 2 readers were excellent (k = 0.92-0.96). The preferred b value with the best detectability of the lesion was b1000 in 28 of the 30 patients (93.3%) with restricted diffusion.
Diffusion-weighted imaging of the bowel identified inflammatory lesions with high accuracy and revealed lesions that were not detectable with ce-T1-w imaging alone. A b value of 1000 showed the best lesion detectability.
磁共振结肠成像（MRC）是一种被广泛接受的用于描绘炎症性肠病的非侵入性成像方式。扩散加权成像（DWI）对显示炎症性病变非常有帮助。这项回顾性研究的目的是评估在有DWI的情况下，肠道磁共振成像描绘炎症性病变是否需要静脉注射造影剂。
37例患者（23例女性，14例男性；平均年龄14.6岁）在1.5-T扫描仪（MAGNETOM Avanto；西门子）上接受MRC检查。采集轴位和冠状位的对比增强T1加权（ce-T1-w）序列以及DWI序列（b = 50、500、1000）。两名阅片者评估（1）DWI，（2）ce-T1-w MRC，以及（3）DWI和ce-T1-w MRC关于病变的显见度。评估了最佳b值。在1周内进行结肠镜检查，包括活检作为参考标准。计算敏感性和特异性，并评估观察者间的变异性。
与包括组织病理学样本结果的结肠镜检查相比，两名阅片者使用ce-T1-w MRC描绘炎症性病变的平均敏感性和特异性分别为78.4%/100%，使用DWI为95.2%/100%，两种成像技术联合使用为93.5%/100%。在6例患者中，炎症性病变仅通过DWI检测到；在另外6例患者中，DWI检测到额外的病变。两名阅片者的κ值极佳（k = 0.92 - 0.96）。在30例扩散受限的患者中，有28例（93.3%）病变检测最佳的首选b值为b1000。
肠道的扩散加权成像能高精度识别炎症性病变，并揭示单独ce-T1-w成像无法检测到的病变。b值为1000时病变检测效果最佳。
