Nakahara N, Uetani M, Hayashi K
Department of Radiology, Nagasaki University, School of Medicine.
Nihon Igaku Hoshasen Gakkai Zasshi. 1995 Apr;55(5):281-8.
Seven patients with sacral insufficiency fractures and seven patients with sacral metastasis were studied with MR imaging. The diagnoses were confirmed with other imaging modalities and clinical follow-up. The insufficiency fractures appeared as bands of abnormal signal: low signal intensity on T1-weighted images and slightly low to iso signal intensity on T2-weighted images. The lesions were delineated better on T1-weighted images than on T2-weighted images. The sacral alae were involved in all patients; five patients had bilateral lesions. The lesions that run across the sacral body were seen in three cases. Inclined coronal images were useful in demonstrating the pattern of distribution of the sacral insufficiency fractures. In three patients with follow-up MR studies, the lesions were markedly reduced or disappeared. The sacral metastatic tumors were of low signal in density on T1-weighted images and iso to high signal in density on T2-weighted images. The extent and distribution patterns of the lesions were various. It is possible to differentiate sacral insufficiency fractures from sacral metastases based on their distribution patterns on MRI. However, if the diagnosis is uncertain or if the symptoms persist or become worse, follow-up MR studies may be necessary.
对7例骶骨应力性骨折患者和7例骶骨转移瘤患者进行了磁共振成像（MR）研究。通过其他成像方式及临床随访对诊断进行了确认。应力性骨折表现为异常信号带：在T1加权像上呈低信号强度，在T2加权像上呈略低至高信号强度。病变在T1加权像上比在T2加权像上显示得更清晰。所有患者的骶骨翼均受累；5例患者为双侧病变。3例可见贯穿骶骨体的病变。斜冠状位图像有助于显示骶骨应力性骨折的分布模式。在3例接受随访MR研究的患者中，病变明显减轻或消失。骶骨转移瘤在T1加权像上呈低密度信号，在T2加权像上呈等信号至高信号。病变的范围和分布模式各不相同。根据MRI上的分布模式，有可能区分骶骨应力性骨折和骶骨转移瘤。然而，如果诊断不确定，或者症状持续或加重，则可能需要进行随访MR研究。
