ABSTRACT
Objective To optimize the parameters for the diffusion tensor imaging (DTI)of the ulnar nerve in elbow.Methods 5 groups of DTI sequences with different b values and numbers of diffusion gradient directions (NDGDs)were used to collect ulnar nerve images from 13 volunteers,and then the diffusion tensor tractography (DTT)was established.The fractional anisotropy (FA),apparent diffusion coefficient (ADC),length of ulnar nerve fiber and DTI image quality were compared under different imaging parameters. Results DTI results for 18 normal ulnar nerves were included in the study.Under different imaging conditions,FAs showed no significant differences.With constant NDGDs,increasing b value decreased both image quality and ADCs of the ulnar nerve.NDGDs had no significant effects on ADCs or image quality.When b=1 000 s/mm2 and NDGDs=20,the length of the ulnar nerve fiber was the longest and DTT had the best subjective scoring in image quality.Conclusion b=1 000 s/mm2 and NDGDs=20 is recommended for DTI of elbow ulnar nerve,so as to obtain high image quality and stable observing targets.