Comparison of MR neurography of the brachial plexus with unidirectionally encoded diffusion-weighted imaging with background signal suppression and enhanced three dimensional short inversion time inversion recovery sampling perfection with application optimized contrasts using different flip angle evolutions / 中华放射学杂志

ABSTRACT

Objective To evaluate two different MRI techniques , enhanced 3D STIR SPACE and unidirectionally-encoded DWIBS MR Neurography in visualizing the brachial plexus.Methods Twenty healthy volunteers underwent MR scanning by the procedures of unidirectionally -encoded DWIBS and enhanced 3D STIR SPACE sequence of the brachial plexus.Original images were reconstructed with coronal maximum intensity projection ( MIP ).The image quality was assessed by comparing the visualization of various parts of the brachial plexus and the suppression ratio of image background.The degree of visualization was compared via χ2-test of paired data , and comparison of background suppression scores was performed using a nonparametric Wilcoxon signed rank sum test.Results The successful rate of visualizing the brachial plexus supraclavicular section ( C5-T1 ) was 84% ( 167/200 ) and 99% ( 198/200 ) , respectively, for the DWIBS and enhanced 3D STIR SPACE, and the rate for the infraclavicular section was 33%( 13/40 ) and 95% ( 38/40 ).The differences between these two techniques were statistically significant (χ2 value was 28.18 and 31.15 respectively, P <0.01).In all images, the scores of grade (Ⅰ-Ⅳ) of background suppression were 0, 0, 4 and 16 for unidirectionally-encoded DWIBS, respectively;while they were 15, 4, 1 and 0 for enhanced 3D STIR SPACE.There was significant difference between the two techniques ( Z =3.96,P <0.01).Conclusions High-quality MR neurography of the brachial plexus can be obtained using the enhanced 3D STIR SPACE sequence.It offers a complete anatomical coverage of the brachial plexus , and thus demonstrates a better capacity in depicting the anatomy of brachial plexus as compared with the unidirectionally-encoded DWIBS.