1348462 - The Impact of Audiovisual Breathing Guidance on Respiratory-Triggered Cardiac Cine Imaging

In young or ill patients who have difficulty holding their breath, a free breathing respiratory-triggered (FBRT) cine bSSFP technique may be used [1,2]. However, the FBRT cine bSSFP technique has been shown to have inferior image quality and a longer scan time than breath-held (BH) cine bSSFP acquisitions [1]. To address this, we developed a breathing guidance (BG) program that provides audiovisual feedback and instructions to the patient during image acquisition to guide them toward a regular breathing pattern. BG uses input from the respiratory bellows to provide personalized spoken instructions and graphics on MR-compatible goggles to specify the timing of inspiration and expiration, tailored to imaging protocol. This study evaluates the effect of a BG program on FBRT cine bSSFP image quality, scan time, and ventricular measurements.

Methods:

In this single-center prospective study using a 1.5T Philips Achieva scanner, a ventricular short-axis stack of cine bSSFP images was acquired using 3 techniques in each subject: 1) FBRT, 2) FBRT with a BG program (FBRT+BG), and 3) BH. The three acquisitions were evaluated for image quality metrics (endocardial edge definition, motion artifact, and blood-to-myocardial contrast) scored on a Likert scale [1], scan time, and ventricular volumes and mass. Differences between groups were assessed using ANOVA with repeated measures or the Friedman test, and post hoc analysis was performed using Wilcoxon signed-rank tests with a Bonferroni correction.

Results:

Thirty-two subjects (19 females; median age 21 years, IQR 18-32) completed the study protocol and 24 of the subjects had congenital heart disease (the remaining subjects were referred to assess for valvar regurgitant fraction, for iron overload, or for signs of cardiomyopathy/myocarditis). Results are shown in Table 1. For scan time, the fastest was FBRT+BG followed by BH then FBRT. Endocardial edge definition was best for BH followed by FBRT+BG then FBRT (example demonstrated in Figure 1). Blood-to-myocardial contrast was equivalent between the FBRT+BG and BH, and both were higher than FBRT. Right ventricular (RV) end-diastolic and end-systolic volumes were smaller (6-7%) with FBRT+BG than BH, but not different between BH and FBRT. Among all acquisitions, there was no significant difference in RV ejection fraction, left ventricular (LV) end-diastolic volume, LV end-systolic volume, LV ejection fraction, and LV mass.

Conclusion:

The addition of a BG program to FBRT cine bSSFP acquisitions decreased the scan time and improved image quality. Thus, for patients who have difficulty holding their breath, FBRT cine bSSFP imaging with a BG program is recommended.