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

Abstract

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.

Lesion load assessment among multiple sclerosis patient using DIR, FLAIR, and T2WI sequences

“…So, the greater the extent of the artifacts at the cortico-sulcal interface, the greater likelihood of counting misinterpreted cortical lesions. Therefore, a significant reduction of such artifacts will increase the quality of the diagnosis [18,34,35].…”

“…Since there are no gaps between the slices, so 3D scans can easily keep the image quality in term of contrast-to-noise ratio (CNR) providing greater spatial resolution. Three-dimensional MRI sequences, due to the use of smaller slice thicknesses, detect smaller size MS plaques especially cortical lesions more precisely and less flow artifacts compared to two-dimensional sequences [34,36].…”

“…There are no artifacts of blood flow and CSF in 3-D sequences because of non-selective inversion pulses. Three-dimensional MRI is crucial for the diagnosis of cerebral atrophy and evaluation of the cortical lesions load that cause more cognitive impairment and physical disability than white matter [34,35].…”

Clinical feasibility of ultrafast intracranial vessel imaging with non-Cartesian spiral 3D time-of-flight MR angiography at 1.5T: An intra-individual comparison study

“…Two sequences had an identical geometric resolution (voxel size: 0.82 x 0.82 x 1.2 mm 3 ); First the Cartesian CS 3.5 sequence (used routinely at our and other institutions [9]) relying on the Compressed SENSE acceleration technique with a variable density Poisson disk-sampling scheme followed by iterative reconstruction (Compressed SENSE factor 3.5, scan duration 03:06 min). Details concerning the Compressed SENSE technique can be found elsewhere [13,19,20,21,22,23]. Second a prototypical non-Cartesian Spiral-TOF (abbreviated Spiral) based on a stack of spirals with an in-plane spiral-out readout scheme (spiral interleaves 27, spiral acquisition window 10 ms, scan duration 01:32 min).…”

AI in Radiology: Where are we today in Multiple Sclerosis Imaging?

“…In Projekten, die unmittelbar auf dieser Technologie basieren, konnte gezeigt werden, dass eine Kontrastmittelgabe nicht mehr zu einer weiteren Sensitivitätssteigerung in der Detektion neu aufgetretener Läsionen im Verlauf beitragen kann [12]. Außerdem wurden Subtraktionskarten verwendet, um die Gleichwertigkeit einer neuartig beschleunigten Double-Inversion-Recovery (DIR) -Sequenz mit einer konventionell akquirierten DIR-Sequenz zu zeigen [13].…”