Characterizing amide proton transfer imaging in haemorrhage brain lesions using 3T MRI

Abstract

OBJECTIVES: The aim of this study was to characterize amide proton transfer (APT)-weighted signals in acute and subacute haemorrhage brain lesions of various underlying aetiologies.

METHODS: Twenty-three patients with symptomatic haemorrhage brain lesions including tumorous (n = 16) and non-tumorous lesions (n = 7) were evaluated. APT imaging was performed and analyzed with magnetization transfer ratio asymmetry (MTR asym ). Regions of interest were defined as the enhancing portion (when present), acute or subacute haemorrhage, and normal-appearing white matter based on anatomical MRI. MTR asym values were compared among groups and components using a linear mixed model.

RESULTS: MTR asym values were 3.68 % in acute haemorrhage, 1.6 % in subacute haemorrhage, 2.65 % in the enhancing portion, and 0.38 % in normal white matter. According to the linear mixed model, the distribution of MTR asym values among components was not significantly different between tumour and non-tumour groups. MTR asym in acute haemorrhage was significantly higher than those in the other regions regardless of underlying pathology.

CONCLUSIONS: Acute haemorrhages showed high MTR asym regardless of the underlying pathology, whereas subacute haemorrhages showed lower MTR asym than acute haemorrhages. These results can aid in the interpretation of APT imaging in haemorrhage brain lesions.

KEY POINTS: Acute haemorrhages show significantly higher MTR asym values than subacute haemorrhages. • MTR asym is higher in acute haemorrhage than in enhancing tumour tissue. • MTR asym in haemorrhage does not differ between tumorous and non-tumorous lesions.