Reference values and postural effects on pulmonary perfusion in dynamic chest radiography.

Objectives: Dynamic chest radiography (DCR) is a novel non-invasive radiographic technique that measures pulmonary perfusion. A semi-quantitative assessment of perfusion distribution has recently been proposed to enhance its clinical utility. This study aimed to establish reference values of pulmonary perfusion distribution and its alterations due to postural changes.

Methods: Forty-five healthy volunteers (24 males, 21 females) underwent DCR. Lungs were divided into six areas (upper, middle, and lower for both), and the percentage of lung perfusion was calculated for each area in the standing and supine positions.

Results: Significant differences were observed in the pulmonary perfusion measurements between the standing position (right upper: 13.9 ± 1.9%, right middle: 30.6 ± 2.3%, right lower: 12.5 ± 2.1%, left upper: 14.2 ± 2.0%, left middle: 22.0 ± 2.8%, left lower: 6.8 ± 2.1%) and supine position (right upper: 15.7 ± 1.7%, right middle: 29.6 ± 3.1%, right lower: 11.5 ± 2.3%, left upper: 17.3 ± 2.7%, left middle: 20.6 ± 3.3%, left lower: 5.3 ± 1.6%). In particular, perfusion shifted to the upper lungs when measurements were taken from the standing to the supine position (P < 0.001).

Conclusions: Reference values for pulmonary perfusion distribution on DCR in the standing and supine positions were established, demonstrating significant changes in distribution between the two.

Advances in knowledge: The established normal distribution on DCR will aid in the identification of subtle changes or abnormal perfusion shifts.