# Free-breathing cardiovascular magnetic resonance flow quantification can be an alternative to standard breath-holding approach

## TL;DR

This study shows that free-breathing CMR can accurately measure blood flow in heart valves, offering a better alternative for patients who struggle to hold their breath.

## Contribution

The study demonstrates that free-breathing CMR is a viable alternative to breath-holding for flow quantification in valvular heart disease.

## Key findings

- Free-breathing and breath-holding CMR showed good agreement in aortic forward flow measurements.
- Tricuspid inflow volume measurements had a mean difference of -3 ± 6 ml between free-breathing and breath-holding methods.
- Free-breathing CMR is a feasible option for patients with breathing difficulties.

## Abstract

Cardiovascular magnetic resonance (CMR) evaluation of valvular heart disease is an important diagnostic tool when echocardiography is inconclusive. Phase contrast flow quantification is usually performed during breath hold (BH), which can be challenging in patients suffering from dyspnea and heart failure. The purpose of the present study is to compare a free-breathing (FB) with the conventional BH approach for flow quantification in the aortic, pulmonary and tricuspid valves in 20 healthy subjects (HS) and 25 patients with tricuspid regurgitation (TR). Aortic (AoFF) and pulmonary forward flow volume (PuFF), and tricuspid inflow volume (TrIF) were evaluated. Mean, standard deviation (SD) and limits of agreement (LoA) were calculated. There were good agreements between phase contrast flow volumes obtained by FB and BH approach. Mean difference ± SD / LoA for AoFF during BH versus FB were 1 ± 6 / -10 to 13 ml. The corresponding for PuFF were 1 ± 6 / -11 to 13 ml, and for TrIF − 3 ± 6 / -15 to 9 ml, respectively. Thus, free-breathing CMR flow acquisition can be an important alternative in the assessment of stroke volume, valvular regurgitant volume and be useful in all patients with difficulties to hold their breath.