Low Russell N, Chen Sloane C, Barone Robert
Department of Radiology, Sharp Memorial Hospital and Sharp and Children's MRI Center, 7901 Frost St, San Diego, CA 92123, USA.
Radiology. 2003 Jul;228(1):157-65. doi: 10.1148/radiol.2281020728.
To retrospectively evaluate the features of benign versus malignant bowel obstruction on unenhanced and gadolinium-enhanced spoiled gradient-echo magnetic resonance (MR) images in patients with malignancy.
Forty-eight patients with malignancy and bowel obstruction underwent abdominal and pelvic MR imaging. Two blinded radiologists independently evaluated each study for dilated bowel, transition point, level of obstruction, obstructing mass, mural thickening and enhancement, and peritoneal disease. Benign obstruction was recorded if no mass was present and if mural thickening (when present) was segmental or diffuse. Malignant bowel obstruction was recorded if there was a mass, a disseminated abdominal tumor, or focal mural thickening. MR images were compared with surgical findings, follow-up imaging studies, and clinical outcome. chi2 test and Fisher exact test were used to assess the relationship between the MR features and benign versus malignant obstruction.
Bowel obstruction had a benign cause in 19 patients and a malignant cause in 29 patients. Observer 1 correctly characterized benign bowel obstruction in 17 of 19 patients and malignant bowel obstruction in 27 of 29 patients. The sensitivity of observer 1 for characterizing malignant obstruction was 93%, specificity was 89%, and accuracy was 92%. Observer 2 correctly characterized benign bowel obstruction in 18 of 19 patients and malignant bowel obstruction in 26 of 29 patients. The sensitivity of observer 2 for characterizing malignant obstruction was 90%, specificity was 95%, and accuracy was 92%. Malignant bowel obstruction was present in 24 of 25 patients with an obstructing mass (P <.001). All 16 patients with focal mural thickening had malignant obstruction. Benign obstruction was present in four of five patients with diffuse mural thickening. Segmental mural thickening occurred in four patients with serosal metastases and in 11 patients with benign bowel obstruction. More extensive peritoneal thickening and enhancement correlated with malignant obstruction.
In patients with malignancy who have symptoms indicative of bowel obstruction, gadolinium-enhanced MR imaging can help distinguish benign from malignant causes of bowel obstruction.
回顾性评估恶性肿瘤患者中，未增强及钆增强的扰相梯度回波磁共振（MR）图像上良性与恶性肠梗阻的特征。
48例患有恶性肿瘤并伴有肠梗阻的患者接受了腹部和盆腔MR成像检查。两名盲法放射科医生独立评估每项研究中的肠管扩张、移行点、梗阻水平、梗阻性肿块、肠壁增厚及强化情况以及腹膜病变。若未发现肿块且肠壁增厚（若存在）为节段性或弥漫性，则记录为良性梗阻。若存在肿块、弥漫性腹部肿瘤或局限性肠壁增厚，则记录为恶性肠梗阻。将MR图像与手术结果、随访成像研究及临床结局进行比较。采用卡方检验和Fisher精确检验来评估MR特征与良性及恶性梗阻之间的关系。
19例患者的肠梗阻为良性病因，29例为恶性病因。观察者1在19例患者中的17例正确判断为良性肠梗阻，在29例患者中的27例正确判断为恶性肠梗阻。观察者1判断恶性梗阻特征的敏感性为93%，特异性为89%，准确性为92%。观察者2在19例患者中的18例正确判断为良性肠梗阻，在29例患者中的26例正确判断为恶性肠梗阻。观察者2判断恶性梗阻特征的敏感性为90%，特异性为95%，准确性为92%。25例有梗阻性肿块的患者中有24例存在恶性肠梗阻（P <.001）。所有16例局限性肠壁增厚的患者均为恶性梗阻。5例弥漫性肠壁增厚的患者中有4例为良性梗阻。4例有浆膜转移的患者及11例良性肠梗阻患者出现节段性肠壁增厚。更广泛的腹膜增厚及强化与恶性梗阻相关。
对于有提示肠梗阻症状的恶性肿瘤患者，钆增强MR成像有助于区分肠梗阻的良性与恶性病因。
