Acute or chronic transplant rejection - high resolution CT of the chest inlung transplant recipients.

Purpose: Aim of the study was to evaluate the postoperative changes in pati ents with single (SLTX) or double lung transplantation (DLTX) with HRCT and to correlate those findings with the clinical diagnosis. Material and meth ods: 29 patients with SLTX (n = 14) or DLTX (n = 15) were observed for more than 6 years after transplantation by HRCT (n = 82). CT examinations were performed in inspiration and expiration (n = 70) with a slice thickness of 1 mm and a feed of 10 mm. The image material was evaluated by 2 experienced radiologists in consensus. Criteria for acute rejection at HRCT were: grou nd glass opacities and focal air trapping in expiration. Criteria for chron ic transplant rejection were: bronchial dilatation, bronchial wall thickeni ng and thickening of interlobar septae. The clinical evaluation consisted o f laboratory tests, lung function tests, and bronchoscopy including bronchi al lavage in special cases. Results: 20/29 patients are still alive (mean 2 1 months). 5/9 patients died because of chronic transplantant rejection, 1 patient suffered from a non-Hodgkin's lymphoma localised at the right hilus . Severe threatening pneumonia occurred in 13 cases. 10/29 patients showed symptoms of acute rejection. Expiratory HRCT found a focal air trapping in all cases and extended ground glass opacities in 11/14 cases. Also a bronch ial dilatation was observed in more than 50% (9/14). 12/29 patients suffere d from chronic transplant rejection. HRCT showed bronchial dilatation in 26 /27 investigations and severe ground glass opacities in 21/27 investigation s. Thickening of the interlobal septa as well as centrilobular opacities we re found in more than 50% of the examinations. Conclusion: High resolution CT of the chest in patients after lung transplantation is able to show nume rous pathological alterations. Without clinical information a confident dif ferentiation in acute or chronic transplant rejection or pneumonia can be d ifficult or impossible.