The role of parallel imaging technique in decreasing geometric distortion artifact in diffusion weighted imaging of the brain

Abstract

IntroductionThe purpose of this study was to evaluate the role of parallel imaging technique in obtaining a more accurate geometric representation of the studied anatomy and how far this technique can reduce the pixel displacement and increase resolution in echo planner imaging- diffusion weighted (EPI-DW) images of the brain. Patients & methodsThe study was done on 6 patients, they were subjected to routine brain MRI examination for different symptoms, examination was done on 1.5 T scanner, the degree of geometric distortion was measured in the phase encoding direction (from anterior to posterior (A/P) in the used sequence) in both DWI sequence acquired without and with parallel imaging technique respectively and was compared with T2-FSE sequence which has no geometric distortion as in EPI. ResultsParallel imaging technique reduced artifact (pixel displacement) in frontal and occipital lobes in addition to increasing resolution for EPI-DWI for the brain. This technique reduced pixel displacement in the frontal lobe by 47 ± 11.7% and 47.3 ± 11% reduction in the occipital lobe. ConclusionParallel imaging technique can be used with EPI-DWI to increase resolution and decrease geometric distortion artifact to acquire more accurate geometric representation of the acquired anatomy.