Portable Dynamic Digital Radiography Detects Airflow Impairment Following Lung Transplantation

A novel application of portable dynamic digital radiography (DDR) has demonstrated its potential in evaluating bronchial stenosis in post-lung transplant patients, offering real-time functional insight into pulmonary mechanics at the bedside.

In a recent case published in Radiology, a 62-year-old man with a history of bilateral lung transplantation for fibrotic interstitial lung disease experienced ongoing complications due to right bronchial stenosis. Over a two-year period, he underwent several balloon dilation and stenting procedures to manage the condition.

Two weeks after his most recent intervention, portable DDR was performed in a semierect position during tidal breathing. The cine images revealed significantly reduced movement of the right hemidiaphragm—limited to just 8 mm of excursion—paired with a compensatory increase to 51 mm on the left side. This imbalance suggested compromised right lung function.

Ventilation analysis derived from pixel density changes across the 7-second cine loop further confirmed reduced ventilation on the right, pointing to impaired airflow. Subsequent bronchoscopy and CT imaging corroborated the findings, revealing persistent narrowing and irregularity at the bronchial anastomosis and bronchus intermedius.

DDR is a non-invasive imaging approach that captures sequential radiographs at a rate of 15 frames per second, generating a cine loop for dynamic analysis. The portable system used in this case enabled high-temporal resolution imaging at the patient’s bedside, facilitating evaluation without the need for transfer to a radiology suite.

While DDR has previously been explored in lung disease evaluation, this case marks the first reported use of portable DDR to assess post-transplant bronchial stenosis. The ability to visualize diaphragmatic motion and ventilation changes dynamically and conveniently suggests a promising role for this technology in managing complex pulmonary conditions, especially in critical care or post-surgical settings.