de Lange E E, Fechner R E, Wanebo H J
Department of Radiology, University of Virginia Medical Center, Charlottesville 22908.
Radiology. 1989 Feb;170(2):323-8. doi: 10.1148/radiology.170.2.2911656.
Eleven patients who underwent abdominoperineal resection for rectosigmoid carcinoma were examined with magnetic resonance (MR) imaging for suspected recurrent tumor in the presacral space. There were 12 suspected masses in the 11 patients. Ten lesions were malignant, and in two lesions only nonneoplastic inflammatory tissue was found. The signal intensity (SI) of each lesion relative to that of muscle was determined visually and correlated with the histologic findings at surgery or biopsy. The SIs of malignant and benign lesions were indistinguishable. All lesions showed areas of high SI that correlated with carcinoma and tumor necrosis or with non-neoplastic inflammation and edema. Areas of low SI corresponded to reactive fibrous tissue (desmoplastic reaction) with small islands of tumor or to nonneoplastic fibrosis. MR imaging can be useful in determining the extent of suspected tumors, but SIs on T2-weighted images do not permit histologic diagnosis. In particular, distinction of benign from malignant tissue is difficult in tumors with a desmoplastic reaction.
11例因直肠乙状结肠癌接受腹会阴联合切除术的患者因怀疑骶前间隙肿瘤复发而接受了磁共振（MR）成像检查。11例患者中有12处疑似肿块。10处病变为恶性，2处病变仅发现非肿瘤性炎性组织。通过视觉确定每个病变相对于肌肉的信号强度（SI），并将其与手术或活检时的组织学结果相关联。恶性和良性病变的SI无法区分。所有病变均显示出高SI区域，这些区域与癌、肿瘤坏死或与非肿瘤性炎症和水肿相关。低SI区域对应于伴有小肿瘤岛的反应性纤维组织（促纤维增生性反应）或非肿瘤性纤维化。MR成像有助于确定疑似肿瘤的范围，但T2加权图像上的SI无法进行组织学诊断。特别是，在有促纤维增生性反应的肿瘤中，区分良性和恶性组织很困难。
