Electrocardiograph‐independent, “wireless” cardiovascular cine MR imaging

A new electrocardiograph (ECG)‐independent, “wireless” gating technique for cine magnetic resonance (MR) imaging was evaluated in 23 cases of cardiovascular disease; in each case, standard ECG‐dependent image loops were available for comparison. The ECG‐independent strategy references cine MR imaging data retrospectively to inherent periodic changes in MR signal related to the cardiac cycle. With a “double‐section” method, both timing data reflecting such changes and imaging data can be acquired simultaneously. “Artificial R waves” are extracted from the timing data acquired with a projection approach. The ECG‐independent image loops were diagnostic in 91 % of cases. Their overall image quality was at least equal to that of available ECG‐dependent versions in only 39% of cases, but this proportion increased to 53% if cases with suboptimal imaging orientations for monitoring of the motion‐dependent signal changes were excluded. Orientation appeared to be the primary technical limitation associated with this ECG‐independent technique; however, poor ventricular function also significantly impaired performance. Improvement in the performance of the ECG‐independent strategy is anticipated with technical advances.