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

Background And Objective: 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) cine sequence with the reference prospectively gated segmented balanced steady-state free precession (Cine) technique regarding ARA.

Methods: 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 sequence including a short-axis stack, one four-chamber slice, and a couple of two-chamber slices; second, an additional single breath-hold CS 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.

Results: 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 than with Cine (Cine: 556.7 ± 145.4 (SD) s (95% CI: 496.7-616.7 s); CS: 23.9 ± 7.9 (SD) s (95% CI: 20.6-27.1 s); < 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, but this was figure was zero using CS ( < 0.0001). The European CMR registry artifact score was lower with CS (median: 1 (range: 0-5)) than with Cine (median: 3 (range: 0-3); < 0.0001). Subjective image quality was higher in CS than in Cine (median: 3 (range: 1-3) versus 2 (range: 1-4), respectively; < 0.0001). In line, edge sharpness was higher on CS cine than on Cine images (0.054 ± 0.016 pixel (95% CI: 0.050-0.057 pixel) versus 0.042 ± 0.022 pixel (95% CI: 0.037-0.047 pixel), respectively; = 0.0001).

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