髓母细胞瘤的MRI诊断及临床分析

Medulloblastoma:the role of MRI and its clinical analysis

目的:分析髓母细胞瘤的临床特点、磁共振成像(MRI)征象及其诊断价值。方法:收集经手术与病理证实的髓母细胞瘤4 6例,全部病例均行MRI检查。结果:髓母细胞瘤主要临床表现为头痛、恶性、呕吐及行走不稳。肿瘤位于小脑蚓部4 2例,小脑半球4例。MRI上,病灶在T1WI为低信号者占81% (33/ 4 6 ) ,混杂信号者占19% (13/ 4 6 ) ;T2 WI上为高信号者81% (33/ 4 6 ) ,混杂信号者占19% (13/ 4 6 ) ;Gd DTPA增强扫描显示病灶呈均匀强化者占75 % (34/ 4 6 ) ,不均匀强化者占2 0 % (9/ 4 6 ) ,有5 % (3/ 4 6 )的病灶显示环状强化,瘤周有不同程度的水肿及伴有不同程度脑积水表现。MRI对髓母细胞瘤检出率、定位及定性诊断正确率分别为10 0 %、96 %、90 %。结论:髓母细胞瘤的MRI表现具有一定特征性。MRI检查多方位、多序列成像,对其诊断、治疗及术后随访等有重要作用,因此髓母细胞瘤的检查应首选MRI。

Objective:The purposes of this study were to analyze clinical characteristic and its signs on images of magnetic resonance imaging and diagnosis values of MRI.Methods:There were forty-six patients with medulloblastoma. The diagnosis of all patients had confirmed by operation and pathology. In these patients, the male were thirty-three and the female were thirteen. The age of these patients ranged from five to forty-two years old, mean thirteen years old. All patients had checked by MRI.Results:The main clinical manifestations of medulloblastoma were headache, nausea, vomit and instable walk. The tumor located vermis of cerebellum in forty-two patients, and located cerebellar hemisphere in four patients. In these patients, male children were majority. On MRI, in forty-six patients, tumors were low-signal-intensity in thirty-three patients (81%) and were intermix signal intensity in thirteen patients(5%) on T_1-weighted images; tumors were high-signal-intensity in thirty-three patients (81%) and were intermix signal intensity in thirteen patients(5%) on T_2-weighted images; after injecting Gd-DTPA, the tumors in thirty-four patients were showed homogeneous enhancement and in nine patients were heterogeneous enhancement, there were three patients that their tumors were showed circular enhancement. In some patients, the tumors were occurred cystic change, hemorrhage, calcification. In peripheral of tumor were showed in some degree edema. In all patients, hydrocephalus was showed in some degree on MRI. The detectable rate, correct rate of location and qualitative diagnosis were respectively 100%, 96% and 90%.Conclusion:The findings of medulloblastoma on MRI had some characteristic. MRI were much orientation and sequences, so it were very important for the diagnosis, the choice of treatment methods and followed-up survey after operation of medulloblastoma. MRI were the first method in patients with medulloblastoma.