联合磁敏感加权成像及多体素质子波谱成像对脑星形细胞瘤分级诊断的研究

摘要

Purpose To evaluate the grading effectiveness of combined MR T2 star weighted angiography (SWAN) and 'H- MR spectroscopy 3D multi-voxel imaging in patients with astrocytoma. Materials and Methods 57 patients with primary astrocytoma underwent pre-operative MR examination. The astrocytomas were graded as low or high based on conventional MR imaging findings and compared to histopathologic grading. The sensitivity and specificity of conventional MR examination for identifying high-grade astrocytoma were calculated. These patients also underwent SWAN and 3D multi-voxel 'H-MRS examination on a 1.5T scanner (GE, HD) for grading and compared to histopathologic grading. Receiver operating characteristic analyses were performed to determine optimum thresholds for astrocytoma grading. The sensitivity and specificity were the combined SWAN and MRS imaging for identifying high-grade astrocytoma were calculated. Results Sensitivity and specificity for determining high-grade astrocytoma using conventional MR were 75.3% and 70.8%. A threshold value of grade two of intratumor susceptibility signal intensity on SWAN had sensitivity and specificity of 84.8% and 90.9% in determining high-grade astrocytoma. A threshold value of Cho/NAA=2.35 provided sensitivity and specificity of 86.4% and 81.2%. The combination of Cho/ NAA and the degree of intratumor susceptibility signal intensity on SWAN resulted in sensitivity and specificity of 93.2% and 81.0% respectively. Conclusion Compared with conventional MR imaging, combined Cho/NAA and the degree of intratumoral susceptibility signal intensity on SWAN can significantly increase sensitivity and decrease false negative rate in grading astrocytoma.%目的 探讨联合磁敏感加权成像和多体素质子波谱成像对脑低、高级星形细胞瘤的鉴别诊断价值.资料与方法 57例星形细胞瘤患者术前行MR平扫+增强扫描作出分级诊断,并与病理分级对照,计算敏感度、特异度;行磁敏感加权成像(SWAN)检查、1H-磁共振波谱(MRS) 3D多体素检查,两种技术联合筛检,与MR平扫+增强的诊断效能进行比较.结果 MR平扫+增强诊断高级别星形细胞瘤的敏感度为75.3％,特异度为70.8％.SWAN评分≥2级时,高级别星形细胞瘤的诊断敏感度为84.8％,特异度为90.9％;Cho/NAA=2.35时,高级别星形细胞瘤的诊断敏感度为86.4％,特异度为81.2％.SWAN、1H-MRS 3D多体素两种技术联合筛检对高级别星形细胞瘤的诊断敏感度为93.2％,特异度为81.0％.结论 SWAN、1H-MRS 3D多体素两种技术联合应用较MR平扫+增强能大幅提升高级别星形细胞瘤的诊断敏感度,降低假阴性率.