原发性脑内淋巴瘤的MRI诊断

目的 总结原发性脑内淋巴瘤的MRI特点,以提高诊断的正确性. 资料与方法 回顾分析19例经手术病理证实的原发性脑内淋巴瘤的MRI资料. 结果 单发18例,多发1例;幕上16例,幕下3例.幕上14例位于大脑半球深部近或中线区,2例以宽基底靠近脑表面,幕下2例位于小脑半球,1例位于第四脑室.T1WI呈等信号13例,稍低信号6例,T2WI呈稍高信号3例,等信号10例,稍低信号6例.增强后9例呈明显均匀强化的团块状,5例呈内伴小囊变区的团块状,2例呈散在絮状强化,1例呈花环状强化,1例呈不均匀团状强化.1例位于胼胝体的病灶呈胼胝体的均匀强化.2例病变可见邻近室管膜的强化,1例可见"脑膜尾征".瘤周水肿轻度6例,中度10例,重度3例. 结论 原发性脑内淋巴瘤大多具有较典型的MRI特征,少数表现亦可多样,只要结合临床资料认真分析病变,误诊是可以明显减少的.

MRI Diagnosis of Primary Intracranial Lymphoma

Objective To discuss the MRI features of primary intracranial lymphoma,and improve the accuracy of diagnosis.Materials and Methods MR findings of 19 patients with primary brain lymphoma confirmed by operation and pathology were analyzed retrospectively.Results18 patients with single lesion were found and 1 patient with multiple lesions.The lesions of 16 patients were located at supratentorial region with lying deep in the hemicerebrum adjacent to the middle line of cerebrum in 14 cases and adjacent to the encephalic surface with a wide base in 2 cases.3 patients located at infratentorial region,2 cases had the lesions found in the cerebellar hemisphere and 1 case in the fourth ventricle.The lesions demonstrated isointensity signal(13 cases)or slightly hypointensity signal(6 cases)on T1WI,and slightly hyperintensity signal(3 cases),isointensity signal(10 cases)or slightly hypointensity signal(6 cases)on T2WI.After Gd-DTPA injection,obvious homogeneous mass-like enhancement,homogeneous mass-like enhancement with small cystic degeneration and dispersive flocculent enhancement were showed in 9,5 and 2 cases respectively,and chaplet-like and asymmetry enhancement were showed respectively in 1 case.1 patient had lesion located in the corpus callosum,and the lesion demonstrated obvious homogeneous enhancement in the corpus callosum.2 patients had adjacent ependyma enhancement and 1 patient had obvious dural enhancement.Slight para-tumorous edema was found in 6 patients,moderate edema in 10 patients and marked edema in 3 patients.Conclusion Most of primary intracranial lymphomas have typical MRI features,but various features are also demonstrated in some cases.Misdiagnosis can be reduced greatly if enough attention is paid to the analysis of the MRI features.