Applying protein-based amide proton transfer MR imaging to distinguish solitary brain metastases from glioblastoma

Objectives To determine the utility of amide proton transfer-weighted (APTw) MRimaging in distinguishing solitary brain metastases (SBMs) from glioblastomas (GBMs). Methods Forty-five patients with SBMs and 43 patients with GBMs underwent conventional and APT-weighted sequences before clinical intervention. The APTw parameters and relative APTw (rAPTw) parameters in the tumour core and the peritumoral brain zone (PBZ) were obtained and compared between SBMs and GBMs. The receiver-operating characteristic (ROC) curve was used to assess the best parameter for distinguishing between the two groups. Results The APTw(max), APTw(min), APTw(mean), rAPTw(max), rAPTw(min) or rAPTw(mean) values in the tumour core were not significantly different between the SBM and GBM groups (P = 0.141, 0.361, 0.221, 0.305, 0.578 and 0.448, respectively). However, the APTw(max), APTw(min), APTw(mean), rAPTw(max), rAPTw(min) or rAPTw(mean) values in the PBZ were significantly lower in the SBM group than in the GBM group (P < 0.001). The APTw(min) values had the highest area under the ROC curve 0.905 and accuracy 85.2% in discriminating between the two neoplasms. Conclusion As a noninvasive imaging method, APT-weighted MR imaging can be used to distinguish SBMs from GBMs.