Acceleration of Double Inversion Recovery Sequences in Multiple Sclerosis With Compressed Sensing.

OBJECTIVE: The aim of this study was to assess the performance of double inversion recovery (DIR) sequences accelerated by compressed sensing (CS) in a clinical setting.

MATERIALS AND METHODS: We included 106 patients with MS (62 female [58%]; mean age, 44.9 ± 11.0 years) in this prospective study. In addition to a full magnetic resonance imaging protocol including a conventional SENSE accelerated DIR, we acquired a CS DIR (time reduction, 51%). We generated subtraction maps between the two DIR sequences to visualize focal intensity differences. Two neuroradiologists independently assessed these maps for intensity differences, which were categorized into definite MS lesions, possible lesions, or definite artifacts. Counts of focal intensity differences were compared using a Wilcoxon rank sum test. Moreover, conventional lesion counts were acquired for both sequences in independent readouts, and agreement between the DIR variants was assessed with intraclass correlation coefficients.

RESULTS: No hyperintensity that was rated as definite lesion was missed in the CS DIR. Two possible lesions were only detected in the conventional DIR, one only in the CS DIR (no significant difference, P = 0.57). The conventional DIR showed significantly more definite artifacts within the white matter (P = 0.024) and highly significantly more at the cortical-sulcal interface (P < 0.001). For both readers, intraclass correlation coefficient between the lesion counts in the two DIR variants was near perfect (0.985 for reader 1 and 0.981 for reader 2).

CONCLUSIONS: Compressed sensing can be used to substantially reduce scan time of DIR sequences without compromising diagnostic quality. Moreover, the CS accelerated DIR proved to be significantly less prone to imaging artifacts.