Vibration response imaging (VRI) in lung transplant recipients.

Background: In the first 6 months following lung transplantation, the most frequently occurring complications are infection, acute rejection and anastomotic dysfunction. The utility of vibration response imaging (VRI) lung images in assisting with the detection of these complications was evaluated.

Objectives: The study aimed to evaluate if VRI is a good, non-invasive method of detecting clinical problems in lung transplant (LTx) recipients during early follow-up.

Methods: Between 06/2006 and 03/2007 all LTx patients who received transplants during the preceding 6 months at the Hannover Medical School received baseline VRI at enrollment with subsequent reassessment in combination with standard follow-up at 1, 3 and 6 months thereafter. The resulting images were analysed by two blinded reviewers.

Results: Fifty-five lung transplant recipients were enrolled in the study, with 49 patients successfully completing follow-up. Device operability and patient participation occurred without significant problems. High numbers of abnormal scans were detected. According to the clinical diagnosis, 29 patients (59.2 %) were stable at all four visits. Twenty clinical problems occurred (e.g., infections, rejections, obstructions, unknown deterioration). Agreement with clinical interpretation of rejections and infections was poor. Central airway obstruction (CAO) was detected in 80% by both reviewers. Accuracy in detecting obstructions was 89%; positive predicted value and negative predicted value were 80% and 90%, respectively.

Conclusion: The VRI system is a non-invasive easy-to-use method with technical success and good image quality. The high number of abnormal scans makes interpretation following LTx difficult. VRI was unable to detect deterioration in graft function with the exception of ventilation disorders like central airway complications.