Improving the detection sensitivity of pH-weighted amide proton transfer MRI in acute stroke patients using extrapolated semisolid magnetization transfer reference signals.

ABSTRACT: PURPOSETo quantify amide protein transfer (APT) effects in acidic ischemic lesions and assess the spatial-temporal relationship among diffusion, perfusion, and pH deficits in acute stroke patients.METHODSThirty acute stroke patients were scanned at 3?T. Quantitative APT (APT# ) effects in acidic ischemic lesions were measured using an extrapolated semisolid magnetization transfer reference signal technique and compared with commonly used MTRasym (3.5ppm) or APT-weighted parameters.RESULTSThe APT# images showed clear pH deficits in the ischemic lesion, whereas the MTRasym (3.5ppm) signals were slightly hypointense. The APT# contrast between acidic ischemic lesions and normal tissue in acute stroke patients was more than three times larger than MTRasym (3.5ppm) contrast (-1.45?±?0.40% for APT# versus -0.39?±?0.52% for MTRasym (3.5ppm), P?CONCLUSIONSThe quantitative APT study using the extrapolated semisolid magnetization transfer reference signal approach enhances APT MRI sensitivity to pH compared with conventional APT-weighted MRI, allowing more reliable delineation of an ischemic acidosis in the penumbra. Magn Reson Med 78:871-880, 2017. © 2017 International Society for Magnetic Resonance in Medicine.

SUBMITTER: Heo HY 

PROVIDER: S-EPMC5561454 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature