用MRI选择大型垂体腺瘤手术入路

目的 :探索用 MRI对直径 >2 cm的大型垂体腺瘤手术入路的选择。　方法 :收集 1 992～ 1 996年间经本院MRI诊断并手术证实的大型垂体腺瘤 5 0例 ,根据 T2 加权成像 (T2 WI)将肿瘤信号分别与脑灰质、白质信号比较 ,预测肿瘤的软硬度。肿瘤为等信号者质地一般坚硬 ,高信号者质地较软。T1 和 T2 加权均为高信号或密集颗粒状高低混杂信号者则可能为瘤卒中。最后均与手术所见进行比较研究。　结果 :可参与比较的 47例 ,以在 T2 WI上肿瘤信号与脑灰质信号比较 ,获得的信号强度所预测肿瘤的质地 ,和手术所见相符者为 42例 (89% ) ,肿瘤信号与白质比较 ,以其信号强度预测肿瘤质地和手术所见相符者 40例 (85 % ) ,二者无统计学差异。　结论 :1 MRI影像上 T2 WI肿瘤信号可作为术前大型垂体腺瘤质地预测的重要参考 ;2以 T2 WI上肿瘤信号与灰质信号比较所获得的肿瘤信号强度预测肿瘤质地更接近手术所见 ;3大型垂体腺瘤如果在 T2 WI上为等信号 ,应选择经额下入路为宜

MRI-guided choice of surgical approach to large pituitary adenoma

Objectives: To explore the significance and value of MRI in guiding the choice of surgical approach to large pituitary adenoma with diameter more than 2 cm. Methods: Fifty cases of large pituitary adenoma demonstrated by MRI and operated upon in our hospital were analyzed retrospectively. The tumor intensity was compared respectively with the intensity of cerebral gray and white matter in T 2 weighted MRI to predict the consistence of tumor. It was presumed that isointensity indicated hard consistence of tumor, hyperintensity soft consistence, and hyperintensity or dense granular mixed intensity in both T 1 and T 2 weighted MRI indicated tumor apoplexy. The preoperative presumed tumor consistence was compared with the surgical findings. Results:Compared results were obtained in 47 cases, of whom 42 cases (89%) showed identical consistence with surgical findings if tumor intensity was compared with intensity of gray matter in T 2 weighted MRI, and 40 cases (85%) with identical consistence compared with the intensity of white matter in T 2 weighted MRI. There was no significant difference between the sensitive predictive results using the intensity of gray and white matter in T 2 weighted MRI as markers for comparison. Conclusions: Tumor intensity in T 2 weighted MRI was an important factor to predict preoperatively the consistence of large pituitary adenoma. The presumed consistence was more close to the surgical findings using the intensity of gray matter in T 2 weighted MRI as compared with tumor intensity. Subfrontal approach should be considered for large pituitary adenoma with isointensity in T 2 weighted MRI.