请选择 进入手机版 | 继续访问电脑版

胸腺上皮肿瘤MRI表现

已有 22 次阅读2019-12-3 14:26 |个人分类:TET学习|系统分类:医学科学

胸腺上皮肿瘤MRI表现
Magnetic resonance imaging of thymic epithelial tumors.

Abstract
The authors review their experience with magnetic resonance imaging (MRI) of the thymus and discuss the appearance of thymic epithelial tumors where MRI is clinically useful. Detailed descriptions of MRI findings in benign thymomas, invasive thymomas, and thymic carcinomas are provided. 

Most benign (noninvasive) thymomas appear with a slightly higher signal intensity than that of muscle on T1-weighted images. On T2-weighted images, thymomas have an increase in signal intensity on both T1- and T2-weighted images. Neither fibrous septa nor lobulated internal architecture can be detected on MRI. Gd-DTPA-enhanced MR images show homogeneous enhancement. 

On the other hand, invasive thymomas show the same signal intensity as benign thymomas, both on T1- and T2-weighted images. However, invasive thymomas appear inhomogeneous in signal intensity on T2-weighted images. T2-weighted images also show a lobulated border, fibrous septa, and lobulated internal architecture, characteristic of most invasive thymomas. Irregularity of tumor margins indicating invasion into surrounding structures is noted in some cases of invasive thymomas. Exceptionally minute thymomas (< 1 cm in diameter) show a different signal intensity on MRI as compared to those of usual thymomas: both T1- and T2-weighted MR images show a low signal intensity mass with irregular or unclear borders. Histopathologically, these minute thymomas contain numerous tiny cysts and/or abundant collagenous tissues

Generally, thymic carcinomas, except carcinoid tumors, appear with a relatively low signal intensity on T1- and T2-weighted MR images in comparison to those of thymomas.

In particular, well-differentiated squamous cell carcinomas appear with a low signal intensity on both T1- and T2-weighted images. Abundant collagenous tissue may be a causative factor for the low signal intensity on T2-weighted MR images. Thymic carcinomas appear slightly inhomogeneous on both T1- and T2-weighted images. Neither fibrous septa nor lobulated internal architecture can be detected in any thymic carcinoma. If MRI is performed on a patient with anterior mediastinal tumors, thymic carcinoma may be precisely diagnosed when characteristic MR findings are demonstrated.

Kushihashi T, Fujisawa H, Munechika H. Magnetic resonance imaging of thymic epithelial tumors. Crit Rev Diagn Imaging. 1996 Aug;37(3):191-259. Review. PubMed PMID: 8872410.

路过

鸡蛋

鲜花

握手

雷人

评论 (0 个评论)

facelist

您需要登录后才可以评论 登录 | 立即注册

返回顶部