Abstract：
For precise delineation of glioma extent, amino acid PET is superior to conventional MR imaging. Since metabolic MR sequences such as chemical exchange saturation transfer (CEST) imaging and MR spectroscopy (MRS) were developed, we aimed to evaluate the diagnostic accuracy of combined CEST and MRS to predict glioma infiltration. Eighteen glioma patients of different tumor grades were enrolled in this study; 18F-fluoroethyltyrosine (FET)-PET, amide proton transfer CEST at 7 Tesla(T), MRS and conventional MR at 3T were conducted preoperatively. Multi modalities and their association were evaluated using Pearson correlation analysis patient-wise and voxel-wise. Both CEST (R = 0.736, p < 0.001) and MRS (R = 0.495, p = 0.037) correlated with FET-PET, while the correlation between CEST and MRS was weaker. In subgroup analysis, APT values were significantly higher in high grade glioma (3.923 ± 1.239) and IDH wildtype group (3.932 ± 1.264) than low grade glioma (3.317 ± 0.868, p < 0.001) or IDH mutant group (3.358 ± 0.847, p < 0.001). Using high FET uptake as the standard, the CEST/MRS combination (AUC, 95% CI: 0.910, 0.907−0.913) predicted tumor infiltration better than CEST (0.812, 0.808−0.815) or MRS (0.888, 0.885−0.891) alone, consistent with contrast-enhancing and T2-hyperintense areas. Probability maps of tumor presence constructed from the CEST/MRS combination were preliminarily verified by multi-region biopsies. The combination of 7T CEST/MRS might serve as a promising non-radioactive alternative to delineate glioma infiltration, thus reshaping the guidance for tumor resection and irradiation.
摘要：
为了精确描绘神经胶质瘤的范围，氨基酸PET优于常规MR成像。由于已开发出代谢MR序列，例如化学交换饱和转移（CEST）成像和MR光谱（MRS），我们旨在评估CEST和MRS联合预测胶质瘤浸润的诊断准确性。18例不同肿瘤等级的神经胶质瘤患者纳入本研究；18F-氟乙基酪氨酸（FET）-PET，酰胺质子转移CEST在7特斯拉（T），术前在3T进行MRS和常规MR。使用Pearson相关性分析患者和体素评估多模式及其关联。CEST(R=0.736,p<0.001)和MRS(R=0.495,p=0.037)均与FET-PET相关,而CEST与MRS的相关性较弱。在亚组分析中，高级别胶质瘤（3.923±1.239）和IDH野生型（3.932±1.264）组的APT值明显高于低级别胶质瘤（3.317±0.868，p＆lt;0.001）或IDH突变组（3.358±0.847，p＆lt;0.001）。使用高FET吸收作为标准，CEST/MRS组合(AUC，95％CI：0.910，0.907-0.913）预测肿瘤浸润优于单独的CEST（0.812，0.808-0.815）或MRS（0.888，0.885-0.891），与对比度增强和T2高强度区域一致。通过多区域活检初步验证了由CEST/MRS组合构建的肿瘤存在的概率图。7TCEST/MRS的组合可能作为描绘神经胶质瘤浸润的有希望的非放射性替代方案，从而重塑肿瘤切除和放疗的指导。
