Brain abscess and necrotic or cystic brain tumor: discrimination with dynamic susceptibility contrast perfusion weighted MRI

Abstract

Introduction: Differentiating between cerebral ring enhancing lesions such as brain abscesses, high-grade gliomas, and metastases is often difÏcult with conventional MRI. DSC perfusion MRI is an advanced MR technique that measures T2*-weighted signal intensity loss, and from which relative cerebral blood volume (CBV), relative cerebral blood flow (rCBF), and relative mean transit time (rMTT) can be computed. On DSC perfusion MRI, the enhancing rims of abscesses typically demonstrate CBV that is lower than those of glioblastomas and metastases. Aim of study:The aim of this study was to evaluate the diagnostic utility of perfusion MRI to differentiate between these pathologies. Materials and Methods: MRI was performed in 31 patients with rim-enhancing brain lesions. Relative cerebral blood volume (rCBV) ratios, relative cerebral blood flow (rCBF) ratios and relative mean transit time (rMTT) ratios were obtained via the values of the capsular portions of the lesions and the normal white matter. We compared the rCBV max/ rCBVmean values, rCBFmax/rCBFmean values and rMTTmax/rMTTmean values of abscesses and tumors with the independent t-test. P<0.05 was considered statistically significant. Statistical analysis was performed using SPSS version 25.0 for Windows. Results: The difference between abscesses and cystic tumors was statistically significant with rCBVmax, rCBVmean and rCBFmax, rCBFmean values (P = 0.001). There was no statistically significant difference between the two groups with rMTTmax and rMTTmean values (p > 0.05). Conclusion: Perfusion MRI may allow the differentiation of brain abscess from cystic brain tumors, making it a strong additional imaging modality in the early diagnosis of these two entities.