Combine contrast-enhanced 3D T2-weighted short inversion time inversion recovery MR neurography with MR angiography at 1.5 T in the assessment of brachial plexopathy

Abstract

To explore the benefits of using a single injection of contrast agent at a 1.5T system to perform both contrast-enhanced MR angiography (MRA) and 3D-T2-STIR MR neurography (MRN) to assess of brachial plexopathy. In this prospective study, 27 patients with suspected brachial plexopathy, received an imaging procedure composed sequentially of non-enhanced 3D-T2-STIR, CE-MRA, and contrast-enhanced 3D-T2-STIR, using a 1.5T MR scanner. Signal intensities and contrast ratios were compared with and without contrast agent. The non-enhanced and contrast-enhanced 3D-T2-STIR images were mixed for two experienced radiologists to rate image diagnostic quality in a blind manner. 3D images of MRN and MRA were merged to reveal the spatial relation between brachial plexopathy and concomitant vascular disorders. By comparing the non-enhanced with contrast-enhanced 3D-T2-STIR images, it revealed that the use of the contrast agent in 3D-T2-STIR MRN could significantly suppress the background signals contributed by small vein (P < 0.001), lymph node (P < 0.001), muscle (P < 0.001) and bone (P < 0.001). This improved the contrast ratios between the brachial plexus and its surrounding tissues (P < 0.001) and boosted the image's quality score (P < 0.01). Examining both CE-MRA and 3D-T2-STIR images revealed a relatively high incidence of concurrent vascular dysfunction in brachial plexopathy, with 39% of confirmed cases accompanied with subclavian and axillary vessel abnormalities. Combining contrast-enhanced 3D-T2-STIR MRN with MRA at a 1.5T system significantly suppresses background signals, improves brachial-plexus display, and provides a direct assessment for both brachial plexus lesion and surrounding vascular injury.