Pulmonary 4D-flow MRI imaging in landrace pigs under rest and stress

TL;DR

This study uses 4D-flow MRI to measure blood flow in pigs' pulmonary vessels at rest and under stress, showing significant increases in flow and velocity.

Contribution

The study provides reference values for pulmonary vessel hemodynamics in pigs under stress using 4D-flow MRI.

Findings

Mean flow increased significantly in pulmonary vessels under stress compared to rest.

Velocity measurements showed good-to-excellent reproducibility at rest but poor reproducibility under stress in some vessels.

4D-flow MRI can detect physiological changes in pulmonary vessels during stress induced by dobutamine.

Abstract

4D-flow MRI is a promising technique for assessing vessel hemodynamics. However, its utilization is currently limited by the lack of reference values, particularly for pulmonary vessels. In this work, we have analysed flow and velocity in the pulmonary trunk (PT), left and right pulmonary arteries (LPA and RPA, respectively) in Landrace pigs at both rest and stress through the software MEVISFlow. Nine healthy Landrace pigs were acutely instrumented closed-chest and transported to the CMR facility for evaluation. After rest measurements, dobutamine was administered to achieve a 25% increase in heart rate compared to rest. 4D-flow MRI images have been analysed through MEVISFlow by two independent observers. Inter- and intra-observer reproducibility was quantified using intraclass correlation coefficient. A significant difference between rest and stress regarding flow and velocity in all the pulmonary vessels was observed. Mean flow increased 55% in PT, 75% in LPA and 40% in RPA. Mean peak velocity increased 55% in PT, 75% in LPA and 66% in RPA. A good-to-excellent reproducibility was observed in rest and stress for flow measurements in all three arteries. An excellent reproducibility for velocity was found in PT at rest and stress, a good one for LPA and RPA at rest, while poor reproducibility was found at stress. The current study showed that pulmonary flow and velocity assessed through 4D-flow MRI follow the physiological alterations during cardiac cycle and after stress induced by dobutamine. A clinical translation to assess pulmonary diseases with 4D-flow MRI under stress conditions needs investigation.

The online version contains supplementary material available at 10.1007/s10554-024-03132-9.

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