High-resolution computed tomographic findings associated with histologically diagnosed acute lung rejection in heart-lung transplant recipients.

A group of 32 lung (single lung, [n = 14] and double lung [n = 1]) or heart-lung (n = 17) transplant recipients were studied with serial high-resolution computed tomography (HRCT) scans and transbronchial biopsies from the time of surgery. These investigations were carried out routinely every 2 weeks for the first 2 months, every 2 months for a year, every 4 months in the second year, and on any clinical suspicion of acute lung rejection or infection. A total of 190 transbronchial biopsy specimens and concurrent HRCT scans were obtained. Forty (21%) of the biopsy specimens, showed histologic evidence of lung rejection, 111 (58%) were normal, and 39 (21%) were not conclusive. The more frequent HRCT pattern encountered during an acute rejection episode was the presence of patchy "ground-glass" density areas (65%). This finding was sparsely observed during minimal and mild acute rejection episodes. Using histologic diagnosis as a standard for acute rejection, ground-glass opacities on HRCT had a sensitivity of 65% in detecting lung rejection. Although ground-glass opacities were also intermittently observed during cytomegalovirus pneumonia (14%), this finding had a specificity of 85% for detecting occurrence of an acute lung complication. The detection of ground-glass opacities on lung HRCT after lung transplantation, more particularly after the first month after surgery, can aid the decision of when and where to undertake transbronchial lung biopsy.