Amide Proton Transfer Imaging for Differentiation of Glioblastoma from Brain Metastasis

Objective: To evaluate the difference in amide proton transfer (APT)-weighted imaging between glioblastoma and brain metastasis.

Materials and Methods: Fourteen patients including eight males and six females, with age ranging between 46 and 75 years old, were included in the present study. Ten patients with glioblastomas and four patients with brain metastases underwent preoperative brain 3T-MRI with APT-weighted sequence. The magnetization transfer ratio asymmetry (MTRasym) and normalized magnetization transfer ratio asymmetry (nMTRasym) values in enhancing solid portion, peritumoral non-enhancing hyperintense FLAIR area, and contralateral normal appearing white matter (CNAWM) in glioblastomas and brain metastases were obtained and compared for statistical analyses. Final diagnosis was validated by pathological results.

Results: The MTRasym and nMTRasym in enhancing solid portion and peritumoral non-enhancing hyperintense FLAIR area of glioblastomas were significantly greater than that of the brain metastases. By visual assessment, the APTw color map also showed higher signal at the perilesional edema in glioblastomas than the metastasis.

Conclusion: As a non-invasive imaging method, APT-weighted MR imaging might be helpful to distinguish glioblastomas from brain metastasis.

Keywords: Amide proton transfer weighted imaging; Glioblastomas; Brain metastasis