垂体大腺瘤的MRI诊断

目的：分析垂体大腺瘤的MRI表现及其生长特点。材料与方法：搜集68例经手术病理证实的垂体大腺瘤，使用GE Vectra 0.5T MR扫描机，行SE序列常规矢状位T1WI、冠状位T1WI、T2WI及质子加权成像，必要时再作轴位扫描。42例作了增强扫描。结果：实质性肿瘤T1WI为中等或稍低信号，T2WI及质子加权像为稍高或高信号。囊变为T1WI低信号、T2WI高信号，出血为T1WI、T2WI均高信号。增强后有均匀或不均匀强化。其生长特点多向鞍外发展：鞍隔突破，视交叉、三脑室受压；鞍底受侵下陷，部分肿瘤突入蝶窦；颈内动脉包绕、海棉窦受累等。结论：MRI具有对不同组织有较好的分辨率和三维成像的特点，可以反映肿瘤向各个方向的生长情况，对临床制定治疗方案、判断预后具有重要的指导意义。

MRI Diagnosis of Pituitary Macroadenoma

Purpose:To study MRI features and growth character of pituitary macroadenoma.Materials and Methods:68 patients with pituitary macroadenoma proved by surgical pathologic were imaged with sagittal (T 1WI) and coronal (T 1WI,T 2WI and proton density weighted),SE sequences,using a GE Vectra 0 5T MRI scanner. 42 patients were scaned after Gd-DTPA enhancement.Results:The MRI features of substance tumor were intermediate or slightly low signal intensity on T 1WI and equal or slightly high signal intensity on T 2WI.The MRI features were T 1WI and T 2WI increased signal intensity when tumor hemorrhage while T 1WI low signal intensity and T 2WI high signal intensity when tumor cystic.Contrast enhancement MRI appearance were even or non-even enhancement of the tumor.The growth character of pituitary Macroadenoma was often extrasellar developed:invasion suprasellay,Opticus nervus and third ventricle,invasion of the sella turcica and adjacent bones,involvement of sphenoid sinus and cavernous sinus,encasement of internal carotid artery,etc.Conclusion:MRI has a good positive resolution to the different tissues and capability of three-dimensional imaging,can provide morphological feature of the adenoma before surgery,which played an important role in deciding clinical therapy and prognosis.