Improved Motion-Sensitized Driven Equilibrium–Prepared Inversion Recovery TSE Sequence for Ulnar Nerve MR Neurography

BACKGROUND AND PURPOSE: Conventional inversion recovery TSE for ulnar neuropathy has limited venous and muscle suppression, requiring contrast agents. Improved motion-sensitized driven equilibrium (iMSDE) utilizes T2 magnetization preparatory pulse and diffuse gradient field to suppress venous and muscle signal. This study aimed to evaluate ability of inversion recovery TSE with iMSDE for visualizing ulnar neuropathy. MATERIALS AND METHODS: Twenty-nine patients (52.3 ± 15.8 years; 17 men) with suspected ulnar neuropathy at the elbow underwent 3T MRI including non-contrast, contrast-enhanced, iMSDE inversion recovery TSE. A four-point Likert scale was used to evaluate overall image quality, nerve visualization, muscle/fat/vein suppression, and diagnostic confidence. The SNR contrast-to-noise ratio for nerve-to-background, and contrast ratio for nerve-to-background were calculated. The nerve cross-sectional area was evaluated between MR and ultrasound. RESULTS: The iMSDE inversion recovery TSE yielded the highest subjective muscle suppression scores and greatest nerve-to-muscle contrast ratio (p p p > 0.05). The iMSDE inversion recovery TSE showed excellent agreement with ultrasound cross-sectional area measurements. The cross-sectional area values correlated moderately with compound muscle action potential amplitudes (r = −0.679, p = 0.02). CONCLUSIONS: The iMSDE inversion recovery TSE can clearly visualize the morphology and pathologic changes of ulnar nerve, providing a feasible alternative method to detect ulnar neuropathy.