The age and gender-dependent changes in pulmonary arterial flow distribution: A cardiac magnetic resonance flow study

To investigate whether the pulmonary artery blood flow distribution in the normal population changes depending on age and gender using the Cardiac Magnetic Resonance Phase Contrast Imaging method.

A total of 62 healthy volunteers aged 20-60 years were included in the study between September 2020 and November 2021. Participants were first divided into two groups according to their age (group 120-40 years old, group 2: 40-60 years old). Then, each group was divided into two according to gender (groups 1A, 1B and groups 2A, 2B). After routine MR sequences of mediastinum and heart (True Fast Imaging with Steady State Free Precession, short axis for heart (SA), 4-chamber, 2-chamber and 3-chamber CINE sequence). Phase Contrast imaging was performed to Main Pulmonary Artery (MPA), right PA and left PA. On the phase contrast (PC) images obtained, flow velocity, forward flow, backward flow and net forward flow volume and gradient were calculated for each artery. With these data, the distribution ratio for both pulmonary arteries was calculated. Measurements were made simultaneously by two radiologists.

In phase contrast sequence evaluation; No statistically significant correlation was found between RPA/LPA distribution ratio and Group 1 (p > 0.05). A moderate and positive correlation was found statistically between RPA/LPA distribution ratio and Group 2 (r:0.42, p:0.04). No statistically significant correlation was found between the RPA/LPA distribution ratio and the gender variable (p:0.59).

The distribution ratio of pulmonary blood flow to both lungs in healthy volunteers can be measured using PC-CMR without the need for invasive procedures. Knowing the normal distribution ratios according to age in the population can be used for the early diagnosis of pathological conditions.