Dynamic digital radiography as a minimally invasive alternative to perfusion scintigraphy for assessing pulmonary blood flow in children: a prospective study.

Abstract

Background: In congenital diaphragmatic hernia, postoperative right-left asymmetry of pulmonary perfusion affects outcome. Although pulmonary perfusion scintigraphy (PPS) is widely used to assess pulmonary perfusion, it requires the use of radionuclides and peripheral venous access. In contrast, dynamic digital radiography (DDR) visualizes and analyzes pulmonary perfusion by extracting subtle changes in X-ray attenuation from sequential images acquired using a pulsed X-ray generator and a flat-panel detector.

Objective: This study aimed to evaluate the accuracy of DDR for assessing pulmonary perfusion in children and verify the associated radiation dose.

Materials and methods: Consecutive congenital diaphragmatic hernia survivors aged 5-7 years scheduled for routine PPS between January 2024 and June 2025 underwent DDR on the same day. The images were analyzed using a dedicated workstation. For each modality, we calculated the blood-flow ratio in the affected lung and assessed the agreement using Pearson correlation and Bland-Altman analysis. Effective doses were also compared.

Results: Thirteen children (median age, 6.07 years; 10 left-sided diaphragmatic hernia) were included in the study. DDR-derived blood-flow ratio strongly correlated with PPS (r=0.977, P<0.01), with absolute inter-method blood-flow ratio differences <5%. Neither fixed nor proportional bias was observed. The median effective dose for DDR was 0.16 mSv-significantly lower than that for PPS (2.09 mSv). The blood-flow ratio calculated using DDR correlated well with the scintigraphy results.

Conclusion: DDR could serve as a minimally invasive, low-dose alternative to PPS for the evaluation of pulmonary perfusion. Future validation in a broader pediatric population is warranted.