Francois Pontana MD, Presenter: Nothing to Disclose

Chloe Chalayer MD, Abstract Co-Author: Nothing to Disclose

Jean-Baptiste Faivre, Abstract Co-Author: Nothing to Disclose

Colm Frederick Murphy MD, Abstract Co-Author: Nothing to Disclose

Martine J. Remy-Jardin MD, PhD, Abstract Co-Author: Research grant, Siemens AG

Jacques Remy MD, Abstract Co-Author: Research Consultant, Siemens AG

To investigate the frequency of pseudo-embolic perfusion defects secondary to the underlying bronchopulmonary disease in COPD patients.

170 patients with stable COPD and no history of acute and/or chronic pulmonary vascular disease, underwent dual-energy multi-detector computed tomographic angiography of the chest with reconstruction of 2 series of images, i.e., the diagnostic (contiguous 1-mm thick) and lung perfusion (2-mm thick) scans. This volumetric acquisition after deep inspiration was systematically completed by sequential expiratory scans (1mm/10 mm). Two radiologists evaluated, by consensus, (1) the presence of pseudo-embolic perfusion defects (i.e., triangular, pleural-based and sharply marginated hypoattenuated areas) on lung perfusion scans; (2) with systematic depiction of morphological changes in the corresponding areas on inspiratory and expiratory diagnostic images.

A total of 143 pseudo-embolic perfusion defects were depicted in 47 patients (27.6%) with (a) a mean number of 3.04 defects per patient (range: 1-17); (b) a predominant distribution in the lower lobes (89/143; 62.2%); (c) observed with the concurrent presence of small airways disease alone (120/143; 83.9%), emphysematous lesions alone (11/143; 7.7%), a variable association of small airways disease and emphysema (n=9; 6.3%) or the exclusive finding of central airways abnormalities (n=3; 2.1%) in the corresponding anatomical zones of diagnostic scans. The CT features of small airways disease depicted in the areas of pseudo-embolic perfusion defects included air trapping (81/120; 67.5%), focal hypoattenuated area (67/120; 55.8%), mucoid impactions (59/120; 49.2%) and/or bronchiolectasis (8/120; 6.7%). No statistically significant difference was found in the frequency of pseudo-embolic defects between the CT phenotypes of COPD (p=0.12)

Pseudo-embolic perfusion defects were identified in 27.6% of COPD patients, mainly seen in association with CT features of small airways disease in the corresponding zones.

In COPD patients, the underlying bronchopulmonary disease may be responsible for pseudo-embolic perfusion defects, a notion to be considered when searching for acute PE in this subset of patients.

Pontana, F, Chalayer, C, Faivre, J, Murphy, C, Remy-Jardin, M, Remy, J, Pseudo-Embolic Perfusion Defects in COPD: Evaluation with Dual-Energy CT in 170 Patients.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11014556.html