성인 diffuse glioma 의 조직병리학적 등급 평가에 대한 amide proton transfer imaging 의 가치 : dynamic susceptibility contrast-enhanced MRI 및 diffusion weighted imaging 과의 비교 및 이에 대한 추가적 가치

의과대학/박사Purpose Amide proton transfer (APT), a subtype of chemical exchange saturation transfer, is a novel technique to detect concentration of endogenous peptide or protein without exogenous contrast agent administration. We investigated the difference in APT values according to histopathological grades, and compared the diagnostic value of APT with relative cerebral blood volume (rCBV) from dynamic susceptibility contrast-enhanced (DSC) MRI and apparent diffusion coefficient (ADC) from diffusion weighted imaging (DWI) for histopathological grades in adult diffuse gliomas. We also investigated the incremental value of APT over ADC and rCBV for discriminating high grade and low grade gliomas. Material and Methods The study cohort consisted of 39 adult patients with histopathologically proven diffuse glioma who underwent preoperative APT imaging, with 34 patients available for preoperative DSC MRI and DWI. Regions of interest were obtained from circles manually placed at the area with high signal in APT and rCBV map, and low signal in ADC map. APT signal was compared according to WHO grade or low vs high grade of glioma. Diagnostic ability to discriminate high grade glioma from low grade glioma were compared between APT, ADC, and rCBV by using Receiver operative characteristic (ROC) analysis, and incremental diagnostic value of APT over ADC and rCBV were assessed by using integrated discrimination index. Also, the correlation between APT values and Ki-67 labeling index (LI) was assessed by linear regression. Results The APT SI values were 0.82 ± 0.36% in grade II gliomas, 1.73 ± 0.86% in grade III, and 2.62 ± 0.78% in grade IV gliomas, which showed significant difference between grade II and III (p=0.018), III and IV (p = 0.010), as well as II and IV (p 0.05 for each comparison) Incremental diagnostic value of APT was significant over ADC (p = 0.003), and not significant over rCBV (p=0.066). APT signals were significantly correlated with Ki-67 LI. (p=0.001, R2 = 0.26) Conclusion APT imaging can be useful, and have incremental value over ADC for predicting the histopathological grades of adult diffuse gliomas. APT SI can be correlated with Ki-67 LI.ope