MRS在脑内占位病变诊断中的应用

目的评价MRS对颅内占位性病变的临床应用价值。方法采用3DPRESS序列,结合MRI对52例经手术/立体定向活检或临床随诊证实的脑内占位及肿瘤术后复发患者进行扫描。结果52例患者中,肿瘤38例,诊断正确率为89.5%(34/38),14例非肿瘤病变,诊断正确率为78.6%(11/14)。胶质瘤的MRSI表现为Cho升高,NAA消失或明显降低,肿瘤实质及中央坏死区Lac升高,周围脑组织有相似改变;转移瘤MRS表现为Cho明显升高,NAA及Cr消失或明显降低,Lac升高,而瘤旁脑组织MRS波形正常或有轻度改变;淋巴瘤显示Cho升高,NAA中度降低,Lac升高,Lip峰的出现为其特征,瘤周MRS正常;脱髓鞘病变NAA轻至中度降低,Lac出现,而Cr无明显变化。放疗后反应MRS各代谢峰明显降低或消失,Cho下降幅度较NAA及Cr为小,随时间延长下降幅度明显增加,至放射性坏死时,各波峰均消失。脑脓肿MRS表现为Lac升高,在2.0ppm出现复合峰,NAA峰消失,Cho及Cr降低,而脓肿旁脑组织MRS正常。结论MRS作为无创性的诊断手段,对脑内病变的鉴别诊断及病变范围的确定有重要作用。

Application of Magnetic Resonance Spectroscopy in Diagnosis of Intracranial Lesions

Objective To evaluate the clinical value of MR spectroscopy in intracranial neoplasm. Methods 52 cases with brain neoplasm or recurrent neoplasm or non-tumor lesion confirmed by pathology were undergone proton MRS before stereotactic biopsy, or operation. Results Of 52 cases, 38 were neoplasm and 14 were nonneoplastic lesion, 34 of 38 brain tumor, 11 of 14 nonneoplastic lesion were diagnosed correctly. The characteristics on MRS of glioma were remarkable Cho increase and NAA decrease, Lac in the tumors and the central necrotic area was elevated. Metastasis: Cho increased,NAA disappeared or obviously decreased and Lac increased, but the peritumoral region was normal. Lymphoma: Cho increased, NAA decreased moderately, Lip presented, but the peritumoral region was normal. Demyelination lesion: slight or median decreased NAA and normal Cr, Lac increased slightly. All metabolism decreased or disappeared in radiation necrosis, Cho was relative high compared with NAA. Brain abscess: Lac increased in the centre of abscess and perilesion was normal.Conclusion MRS has significant value in detecting and differentiating brain lesions.