Electrocardiographic Pad for Efficient Cardiac MR Gating.
Academic Article
Overview
abstract
PURPOSE: To assess feasibility and reliability of electrocardiographic (ECG)-gated cardiac magnetic resonance (MR) imaging with a simplified reusable electrode design that does not touch the skin. MATERIALS AND METHODS: In this institutional review board-approved, HIPAA-compliant study, a silicon positioner held four ECG leads and detected ECG signals without requiring shaving, adhesive, or removal of the gown. The patient lies down on the device and the patient's weight ensures good lead contact against patient's gown; electrode gel that soaks through the gown provides electrical contact with the skin. It was tested at 1.5 T on 12 volunteers and 52 patients by using double inversion recovery, steady-state, fast gradient-echo time course perfusion, and delayed inversion recovery sequences. Paired Student t test was used to assess the significance of differences in durations to apply and remove ECG pad and standard leads. Image quality was assessed and rated on a four-point scale by two readers. The ECG signal quality obtained from pad and leads was rated on a five-point scale. Ventricular septal sharpness and signal-to-noise ratio were measured on images generated by ECG gating from pads and standard leads. RESULTS: Application and removal duration was 444 seconds with standard leads compared with 296 seconds with the ECG pad, and mean difference in setup time was 148 seconds (P = .005). Ventricular septal sharpness (1/slope) was 165 for ECG pad and 152 for standard leads (P = .3). Septal signal-to-noise ratio on images generated by cardiac gating with ECG pad was 38 ± 12 (standard deviation) compared with 39 ± 14 for standard leads (P = .7). The qualitative image quality score for ECG pad (3.9 ± 0.19) was comparable to ECG leads (3.8 ± 0.45; P = .47). The mean ECG signal qualitative scores were also comparable (pad vs leads, 4.9 ± 0.43 vs 4.9 ± 0.14, respectively; P = .9). Volunteers preferred the ECG pad and reported that it was comfortable and convenient. ECG pad was successful in 50 of 52 (96%) patients. Two patients, including one with large pleural effusions and another with ventricular tachycardia, were not successfully gated. CONCLUSION: This simplified approach to ECG gating is faster to set up and more convenient and comfortable for patients.
