54例累及颅底的鼻咽癌、脊索瘤及垂体瘤的MRI影像

MRI analyses in 54 cases of basicranial nasopharyngeal carcinoma,chordoma and pituitary adenoma

目的:探讨累及颅底的鼻咽癌、脊索瘤和垂体瘤MRI影像特点,以期提高对其鉴别诊断水平。方法:搜集经病理证实的累及颅底的28例鼻咽癌、10例脊索瘤及16例垂体瘤,比较分析其MRI表现。结果:本组鼻咽癌在T1WI上有10例表现为等信号,18例表现为稍低信号;在T2WI上10例表现为等信号,18例表现为稍高信号,形态不规则,边界不清。脊索瘤10例在T1WI上均表现为信号欠均匀,以低信号为主,混杂有等信号,其中有1例伴有斑片状高信号影;T2WI上均表现为不均匀明显高信号,为分叶状肿块,边界较为清楚。垂体瘤16例在T1WI上表现为均匀等信号或稍低信号,边界清楚,其中4例肿瘤内有出血。28例鼻咽癌的肿瘤中心部位均位于一侧的鼻咽侧壁;脊索瘤10例中有9例肿瘤的中心部位在颅底中线处的斜坡,1例肿瘤的中心部位在左侧枕骨、颞骨交界区;16例垂体瘤的肿瘤中心部位位于蝶鞍。结论:根据MRI信号特点、肿瘤中心点部位和边缘情况,大多数累及颅底的鼻咽癌、脊索瘤和垂体瘤可以作出正确诊断。

Aim： To appraise the value of differential diagnosis with MRI in nasopharyngeal carcinoma,chordoma and pituitary adenoma involved in skull base. Methods： Twenty-eight nasopharyngeal carcinomas, 10 chordomas and 16 pituitary adenomas confirmed pathologically were collected, to analyze and compare their MRI findings. Results： Of 28 nasopharyngeal carcinomas, 10 cases showed iso-intense signal and 18 cases showed slighdy hypo-intense signal on T1WI while 10 cases showed iso-intense and 18 cases showed slight hyper-intense with irregular shape and ill-defined margin on T2WI. Of 10 chordomas,9 cases displayed inhomogeneous signal with hypo-or iso-intense signal on T1WI and 1 case accompany hyper-intense on T1WI while inhomogeneous hyper-intense signal with well-defined margin on T2WI. Sixteen cases of pituitary adenoma showed iso-intense or slight hypo-intense signal on TIWI with well-defined margin and 4 cases accompany hemorrhage. The central position of nasopharyngeal carcinoma of 28 cases was located on the nasopharyngeal lateral wall. The central position of chordoma of 9 cases was located on the clivus of the skull base while 1 case was located on the boundary of the left occipital and temporal bone. The central position of pituitary adenoma of 16 cases was located in sella turcica. Conclusion： Based on the MRI signal features, central position and margin, correct diagnosis can be made for most of the basicranial nasopharyngeal carcinoma、chordoma and pituitary adenoma.