Compressed Sensing Real-Time Cine Reduces CMR Arrhythmia-Related Artifacts

Cardiac magnetic resonance (CMR) is a key tool for cardiac work-up. However, arrhythmia can be responsible for arrhythmia-related artifacts (ARA) and increased scan time using segmented sequences. The aim of this study is to evaluate the effect of cardiac arrhythmia on image quality in a comparison of a compressed sensing real-time (CS_rt) cine sequence with the reference prospectively gated segmented balanced steady-state free precession (Cine_ref) technique regarding ARA.

A total of 71 consecutive adult patients (41 males; mean age = 59.5 ± 20.1 years (95% CI: 54.7-64.2 years)) referred for CMR examination with concomitant irregular heart rate (defined by an RR interval coefficient of variation >10%) during scanning were prospectively enrolled. For each patient, two cine sequences were systematically acquired: first, the reference prospectively triggered multi-breath-hold Cine_ref sequence including a short-axis stack, one four-chamber slice, and a couple of two-chamber slices; second, an additional single breath-hold CS_rt sequence providing the same slices as the reference technique. Two radiologists independently assessed ARA and image quality (overall, acquisition, and edge sharpness) for both techniques.

The mean heart rate was 71.8 ± 19.0 (SD) beat per minute (bpm) (95% CI: 67.4-76.3 bpm) and its coefficient of variation was 25.0 ± 9.4 (SD) % (95% CI: 22.8-27.2%). Acquisition was significantly faster with CS_rt than with Cine_ref (Cine_ref: 556.7 ± 145.4 (SD) s (95% CI: 496.7-616.7 s); CS_rt: 23.9 ± 7.9 (SD) s (95% CI: 20.6-27.1 s); p < 0.0001). A total of 599 pairs of cine slices were evaluated (median: 8 (range: 6-14) slices per patient). The mean proportion of ARA-impaired slices per patient was 85.9 ± 22.7 (SD) % using Cine_ref, but this was figure was zero using CS_rt (p < 0.0001). The European CMR registry artifact score was lower with CS_rt (median: 1 (range: 0-5)) than with Cine_ref (median: 3 (range: 0-3); p < 0.0001). Subjective image quality was higher in CS_rt than in Cine_ref (median: 3 (range: 1-3) versus 2 (range: 1-4), respectively; p < 0.0001). In line, edge sharpness was higher on CS_rt cine than on Cine_ref images (0.054 ± 0.016 pixel^-1 (95% CI: 0.050-0.057 pixel^-1) versus 0.042 ± 0.022 pixel^-1 (95% CI: 0.037-0.047 pixel^-1), respectively; p = 0.0001).

Compressed sensing real-time cine drastically reduces arrhythmia-related artifacts and thus improves cine image quality in patients with arrhythmia.