脑神经胶质瘤磁敏感加权成像与病理分级之间的关系

Relationship between magnetic susceptibility-weighted imaging and pathologic grading of brain gliomas

目的:探讨磁敏感加权成像(magnetic susceptibility-weighted imaging,MSWI)在评估脑神经胶质瘤病理分级中的价值。方法:对60例病理学证实为脑神经胶质瘤的患者行磁共振(magnetic resonance,MR)快速自旋回波(turbo spin echo,TSE)和双回波快速小角度激发(fast low angle shot,FLASH)-T2*WI(TE为15和35ms)磁敏感序列扫描。比较这3种序列所产生的磁敏感伪影(magnetic susceptibility artifact,MSA)的差异。对MSA[个数、最大直径和最低信噪比(signal-to-noise ratio,SNR)]与WHO病理分级和Ki-67的表达进行相关性分析。结果:多样本秩和检验和独立样本方差分析FLASH-T2*WI(TE为15和35ms)和TSE序列这3种序列的MSA差异有统计学意义(χ2=21.331,P=0.001;F=44.517和6.839,P<0.001)。Pearson相关分析显示,WHO病理分级与MSA的个数、最大直径和SNR均相关(r分别为0.737、0.624和-0.528,P=0.000);Ki-67的表达与MSA的个数、最大直径和SNR也均相关(r分别为0.687、0.577和-0.533,P=0.000)。结论:应用MSWI可有效地评价术前脑神经胶质瘤的病理分级,且利用延长TE时间所产生的MSA可以更好地对脑神经胶质瘤的病理分级进行评估。

Objectives： To estimate the value of magnetic susceptibility-weighted imaging （MSWI） in the pathologic grading of gliomas. Materials：Sixty patients with confirmed gliomas proved by pathological examination were prospectively examined. They were scanned by magnetic resonance （MR） turbo spin echo （TSE） T1-weighted imaging （WI） and dual fast low angle shot （FLASH）-T2 ^＊ WI imaging with TE of 15 and 35 ms, respectively. The difference in the magnetic susceptibility artifact （MSA） induced by the various sequences was compared. The correlation of MSA [ number, maximal diameter, and signal to noise ratio （SNR） ] with WHO pathological grade and Ki-7 values were analyzed. Results： Multiplicity rank sum test and variance analysis indicated that there was a statistical difference in MSA between the three sequences, 15-ms FLASH-T2＊ WI, 35-ms FLASH-T2^＊ WI, and TSE （X2 = 21. 331, P = 0. 001; F =44.517 and 6.839 ,P 〈0.001 ）. Pearson correlation analysis suggested that WHO pathological grade correlated with MSA parameters including number, maximal diameter and SNR （r = 0.737, 0. 624 and - 0. 528, P = 0.000） ; the expression level of Ki-67 also correlated with MSA parameters including number, maximal diameter and SNR （r =0.687, 0. 577, and -0.533, P =0.000）. Conclusions： MSWI is helpful in the evaluation of preoperative pathologic grade of brain gliomas. MSA produced by longer TE FLASH （35 ms） is better than that produced by shorter TE FLASH （ 15 ms） to evaluate the pathologic grade of brain gliomas.