Comparison of FSE and EPI with Brain MR Imaging

Cho, Yun Ku; Chang, Kee Hyun; Choi, Guk Myeong; Won, Hyung Jin; Kim, Hong Dai; Yu, In Kyu; Han, Moon Hee

Abstract

PURPOSE
To compare the usefulness of echo-planar imaging (EPI) and fast spin-echo (FSE) in routine brain MR imaging.
MATERIALS AND METHODS
Twenty-five patients with various intracranial diseases were prospectively examined with T2-weighted MR imaging on a 1.5T unit using FSE, spin echo singl-shot EPI (SS-EPI) and multi-shot EPI (MS-EPI) techniques. For qualitative assessment, overall image quality, discrimination between cortical gray-white matter and between basal ganglia-white matter, lesion conspicuity, image distortion and artifacts (motion, ghost, flow, and susceptibility) were all evaluated using a subjective scoring system ranging from 1 to 4 (1 for the worst and 4 for the best). For quantitative assessment, contrast and contrast-to-noise ratio (CNR) were calculated for cortical gray-white matter, basal ganglia-white matter, and lesion-white matter.
RESULTS
Overall image quality, discrimination between cortical gray-white matter, basal ganglia-white matter, and lesion-white matter, lesion conspicuity, image distortion and susceptibility artifacts showed the highest value in FSE and the lowest in SS-EPI. Motion artifacts were seen only in FSE, while flow and ghost artifacts were most commonly seen in SS-EPI. Contrast and CNR of anatomical and pathologic structures showed the highest value in FSE, especially for cortical gray-white matter and basal ganglia-white matter .
CONCLUSION
With regard to overall image quality, image distortion, susceptibility artifacts, contrast and CNR, EPI is far inferior to FSE. In routine brain MR imaging., the usefulness of EPI techniques would therefore be very limited.