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

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 ). 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 values were compared among groups and components using a linear mixed model.

Results: MTR 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 values among components was not significantly different between tumour and non-tumour groups. MTR in acute haemorrhage was significantly higher than those in the other regions regardless of underlying pathology.

Conclusions: Acute haemorrhages showed high MTR regardless of the underlying pathology, whereas subacute haemorrhages showed lower MTR 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 values than subacute haemorrhages. • MTR is higher in acute haemorrhage than in enhancing tumour tissue. • MTR in haemorrhage does not differ between tumorous and non-tumorous lesions.