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

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.

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.

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.

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.

• 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.