心脏黏液瘤影像学特征的探讨

Imaging features of cardiac myxoma

目的探讨心脏黏液瘤的影像学特征及诊断价值。方法回顾性分析手术证实的22例心脏黏液瘤病例。心脏X线片检查行正侧位。心脏CT采用美国ImatronXPC-150型电子束CT。心脏MR采用德国Siemens1.5TMagnetomVision超导成像仪。结果①17例左房黏液瘤,14例(82.3%)心脏X线照片表现为左房压力增大。5例右房黏液瘤病,3例(60%)表现为右心房增大。②电子束CT扫描提示18例(81.8%)类圆形的黏液瘤整体密度低于心肌,而4例(19.1%)为等密度。3例(13.6%)可见片状或结节样钙化。所有病例均提示不均强化。除1例巨大右房肿瘤外,其他病例CT均显示肿瘤与房间隔附着点,并为外科手术证实。电影序列显示肿瘤跨房室瓣运动情况。③MR扫描提示19例(86.3%)不均匀信号强度,3例(13.7%)为均等信号。T1WI呈稍高或等信号,T2WI呈高信号,GRE呈低信号。增强后黏液瘤病例都有强化。除上述1例巨大右房肿瘤外,所有病例MR均显示肿瘤与房间隔附着点。结论心脏黏液瘤病例的心脏X线典型表现为二尖瓣梗阻征象,电子束CT和MR多提示肿物附着于房间隔。后两种检查能够较好提示黏液瘤的大小、位置、数目和附着,对肿瘤的定性诊断有重要价值。

Objective To study the imaging features of cardiac myxoma and their diagnostic values. Methods Twenty-two patients with cardiac myxoma were reviewed retrospectively for the clinical, pathologic, and radiologic findings. Posteroanterior and lateral chest radiographs, American Imatron C-150 XP Electron Beam CT examination, and Germany Siemens 1.5T Magnetom Vision MR scan were performed on every patient. Results （1） Radiographs of 17 patients with left atrial myxoma showed evidence of mitral valve obstruction in 14（82.3%）, radiographs of 5 patients with right atrial myxoma demonstrated right atrium enlargement in 3（60%） respectively.（2） CT scans of 22 myxomas demonstrated 18 （81.8%） lesions were hypoattenuated and 4 （19.1%） were isoattenuated relative to the myocardium. Calcification or ossification was seen in 3 patients. All myxomas apart from massive one were found attaching to the atrial septum. Movie mode could display the movement of myxoma across the atrioventicular valves.（3） MRI studies of 22 myxomas showed 19 （86.3%） heterogeneous signal intensity and 3 （13.7%） homogeneous. They exhibited slight high or homogeneous signal intensity with both T1- and T2-weighted sequences, and low signal intensity with cine gradient recalled echo sequences. Point of attachment was visible in 21 （95.4%） cases. Conclusion The typical radiograph sign of cardiac myxomas is mitral valve obstruction, CT and MR can demonstrate intracavitary lobular masses attacthing to artrial spetum. The latter two kinds of examinations not only provide accurate assessment of the size, location, and attachment point of these lesions, but also have important qualitative diagnostic advantage.