Sakai F, Sone S, Kiyono K, Kawai T, Maruyama A, Ueda H, Aoki J, Honda T, Morimoto M, Ishii K
Department of Radiology, School of Medicine, Shinshu University, Matsumoto, Japan.
AJR Am J Roentgenol. 1992 Apr;158(4):751-6. doi: 10.2214/ajr.158.4.1546586.
MR images in 17 patients with surgically proved thymomas (12 malignant and five benign) were reviewed and compared with pathologic specimens. In nine cases, MR images of excised specimens also were made and evaluated. On T2-weighted images, 11 of 12 malignant thymomas had an inhomogeneous signal intensity, half with and half without a lobulated internal architecture. None of the five benign thymomas had a lobulated internal architecture, and they all had a moderately or slightly inhomogeneous signal. Cystic regions and/or hemorrhage were noted pathologically, and corresponded to areas of inhomogeneous high signal intensity seen on T2-weighted images. Examination of the excised specimens in malignant thymomas showed that the lobulated configuration seen in the tumors was caused by thick fibrous septa. Our experience suggests that, although calcification cannot be identified, MR is helpful in making a differential diagnosis of mediastinal tumors and in determining malignancy of thymoma.
对17例经手术证实的胸腺瘤患者（12例恶性，5例良性）的磁共振成像（MR）进行回顾，并与病理标本进行比较。其中9例还对切除标本进行了MR成像并评估。在T2加权图像上，12例恶性胸腺瘤中有11例信号强度不均匀，其中一半有分叶状内部结构，一半没有。5例良性胸腺瘤均无分叶状内部结构，信号均呈中度或轻度不均匀。病理检查发现有囊性区域和/或出血，对应于T2加权图像上信号强度不均匀的高信号区域。对恶性胸腺瘤切除标本的检查显示，肿瘤中所见的分叶状结构是由厚纤维间隔引起的。我们的经验表明，虽然无法识别钙化，但MR有助于纵隔肿瘤的鉴别诊断以及胸腺瘤恶性程度的判定。
