Evaluation of optimized b -value sampling schemas for diffusion kurtosis imaging with an application to stroke patient data

Abstract Diffusion kurtosis imaging (DKI) is a new method of magnetic resonance imaging (MRI) that provides non-Gaussian information that is not available in conventional diffusion tensor imaging (DTI). DKI requires data acquisition at multiple b -values for parameter estimation; this process is usually time-consuming. Therefore, fewer b -values are preferable to expedite acquisition. In this study, we carefully evaluated various acquisition schemas using different numbers and combinations of b -values. Acquisition schemas that sampled b -values that were distributed to two ends were optimized. Compared to conventional schemas using equally spaced b -values (ESB), optimized schemas require fewer b -values to minimize fitting errors in parameter estimation and may thus significantly reduce scanning time. Following a ranked list of optimized schemas resulted from the evaluation, we recommend the 3b schema based on its estimation accuracy and time efficiency, which needs data from only 3 b -values at 0, around 800 and around 2600 s/mm2 , respectively. Analyses using voxel-based analysis (VBA) and region-of-interest (ROI) analysis with human DKI datasets support the use of the optimized 3b (0, 1000, 2500 s/mm2 ) DKI schema in practical clinical applications.