Søvik E, Lien H H, Tveit K M
Department of Diagnostic Radiology, Norwegian Radium Hospital, Oslo, Norway.
Acta Radiol. 1993 Nov;34(6):573-6.
MR images of 45 patients who had received radiation therapy for carcinoma of the anus or recurrent carcinoma of the rectum were reviewed with regard to postirradiation changes of the pelvic wall. High signal intensity in bone marrow on T1-weighted images due to fatty replacement was almost always observed. Presacral edema occurred in 7 of 36 patients who were examined 4 to 6 weeks after the end of irradiation and was more frequent at later studies. The pelvic wall muscles showed high signal intensity on T2-weighted images compatible with edema. This finding was most frequent on studies performed more than 6 weeks after the end of irradiation. The changes subsided more than a year after radiation therapy. To avoid an erroneous diagnosis of tumor infiltration into the pelvic wall, it is important to be familiar with the normal postirradiation changes of the presacral space and the muscles.
回顾了45例因肛门癌或直肠癌复发接受放射治疗患者的盆腔壁放疗后变化的磁共振成像（MR）图像。几乎总能观察到T1加权图像上骨髓因脂肪替代而出现的高信号强度。36例患者在放疗结束后4至6周接受检查，其中7例出现骶前水肿，且在后期检查中更常见。盆腔壁肌肉在T2加权图像上显示与水肿相符的高信号强度。这一发现最常见于放疗结束后6周以上进行的检查。放疗一年多后这些变化消退。为避免错误诊断肿瘤浸润至盆腔壁，熟悉骶前间隙和肌肉的正常放疗后变化很重要。
