肌内黏液瘤的CT及MRI表现

目的 分析肌内黏液瘤的CT及MRI表现,并与病理结果对照.方法 回顾性分析5例经手术病理证实的肌内黏液瘤患者的影像资料,其中4例接受MR检查(其中3例接受增强扫描),1例接受CT检查(平扫和增强扫描).结果 5例肌内黏液瘤患者中,股内侧肌内黏液瘤2例,腓肠肌内黏液瘤1例,腓骨长肌内黏液瘤1例,胸锁乳突肌后方肌内黏液瘤1例.MR平扫肌内黏液瘤旱与肌肉走行一致的椭圆形3例,呈不规则片状1例,均呈T1WI低信号、T2WI高信号;4例接受增强扫描,3例呈不均匀渐进性强化,1例呈厚壁强化并可见结节.CT平扫肿瘤呈液性低密度肿块;增强后动脉期病灶边缘环形强化,内部呈轻度不均匀强化,静脉期及延迟期病灶边缘及内部渐进性强化.结论 肌内黏液瘤的影像学表现具有特征性,但部分影像学表现不典型,MR增强扫描与病理具有较好的一致性.

CT and MRI appearances of intramuscular myxomas

Objective To evaluate the CT and MRI characteristics of intramuscular myxomas compared with pathologic findings. Methods Five patients with intramuscular myxomas confirmed pathologically were retrospectively reviewed. Four patients underwent MR scanning (3 obtained after the intravenous administration of a gadolinium chelate), 1 patient underwent CT (noncontrast and enhancement scan). Results Intramuscular myxomas located in the vastus medialis muscle in 2 patients, in the gastrocnemius musculus, the peroneus longus musculu and behind the sternocleidomastoideus in one patient, respectively. The tumors were oval-like, with long axis consistent with muscle fiber in 3 patients, and was irregular flake in 1 patient, which were markedly low signal intensity on T1WI and high signal intensity on T2WI. Contrast enhancement MR scanning showed heterogeneity and progressive enhancement in 3 patients and peripheral (thick wall) enhancement with nodules in 1 patient. Low attenuation was found in plain CT in 1 patient. After contrast injection, ring like peripheral enhancemwnt in arterial phase, mild heterogeneity and progressive enhancement in the venous and delay phase were detected on CT. Conclusion Imaging manifestation of intramuscular myxomas have some special characteristics, but in some patients are not typical. The finding of MRI has well consistency with the pathology for intramuscular myxomas.