Tomohito Saito MD, PhD, Presenter: Nothing to Disclose

Miho Horie MSc, Abstract Co-Author: Research Grant, Toshiba Corporation

Daisuke Nakajima, Abstract Co-Author: Nothing to Disclose

Masaaki Sato, Abstract Co-Author: Nothing to Disclose

Narinder S. Paul MD, Abstract Co-Author: Research funded, Toshiba Corporation

Shafique Keshavjee MD, Abstract Co-Author: Nothing to Disclose

The long-term success of lung transplantation is challenged by the development of chronic lung allograft dysfunction (CLAD) and its distinct subtypes: bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS). However, the current diagnostic criteria for subtyping CLAD subtypes that relies on total lung capacity (TLC) which is not always measured during routine post-transplant assessment. Our aim is to investigate the utility of 3D computed tomography (CT) lung volumetry for differentiating RAS from BOS.

Retrospective evaluation of 103 patients following bilateral lung or heart-lung transplantation; including 44 patients without CLAD and 59 patients who developed CLAD of whom 41 had BOS and 18 RAS. All patients had complete PFT and CT data. Median duration of post-transplabr follow-up was 47 months in BOS and 27 months in RAS. Median Interval of CT volumetry timepoints was 11 months in both BOS and RAS. The changes in CT lung volume over time and the diagnostic accuracy of CT lung volume (measured as % of baseline) for differentiating RAS from BOS were investigated.

The CT lung volumes varied over time; patients without CLAD experienced increase in lung volume (p= 0.001); patients with BOS had no significant post-transplant change, whereas patients with RAS showed a significant decrease at disease onset compared to baseline (p< 0.0001) . The area under the receiver operating characteristic curve of CT lung volume for differentiating RAS from BOS was 0.958 (95% confidence interval, 0.908 to 1.00, p< 0.0001) and the calculated accuracy was 0.932 at a threshold of 85%.

In patients with chronic lung allograft dysfunction, a decrease in CT lung volume to 85% of baseline differentiates lung transplant recipients who develop RAS from those who develop BOS.

Computed tomography volumetry is useful tool for subtyping chronic lung allograft dysfunction. Restrictive allograft syncrome shows significant decrease in lung volume after lung transplantation.

Saito, T, Horie, M, Nakajima, D, Sato, M, Paul, N, Keshavjee, S, Computed Tomography Volumetry for Subtyping Chronic Lung Allograft Dysfunction.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14002030.html