Practical Aspects of Shortening Acquisition Time in Brain MR Susceptibility-Weighted Imaging.

Magnetic resonance susceptibility-weighted imaging (SWI), a novel 3D gradient echo MRI sequence exploiting phase and magnitude data for post-processing, is able to detect blood, iron, calcification and deoxygenated hemoglobin content for brain. SWI has been widely used to evaluate cerebral vascular disorders, trauma, multiple sclerosis, and tumors. We have also used SWI to evaluate acute stroke patients to identify thrombosis and possible penumbra. The acquisition was too long for examining acute stroke patients due to motion from agitation and mental changes. We have altered the parameters of phase resolution, voxel size, matrix size and partial Fourier to shorten the acquisition time to improve the diagnostic quality of SWI for acute stroke patients. The result was to reduce the acquisition time from 3:46 min to 2:14 min thereby providing a helpful tool in screening stroke patients.