Masahiro Kobayashi MD, Presenter: Nothing to Disclose

Nobuyuki Shiraga MD, Abstract Co-Author: Nothing to Disclose

keiko matsumoto, Abstract Co-Author: Nothing to Disclose

Keishi Sugino, Abstract Co-Author: Nothing to Disclose

Kenichi Suzuki, Abstract Co-Author: Nothing to Disclose

Sakae Honma MD, PhD, Abstract Co-Author: Nothing to Disclose

Ehiichi Kohda MD, Abstract Co-Author: Nothing to Disclose

To assess and evaluate the feasibility of combined dual-energy CT lung ventilation/perfusion imaging in patients with chronic obstructive pulmonary disease (COPD), comparing with low attenuation area (LAA) and clinical severity of COPD.

Institutional review board approval and written informed consent were obtained. Twenty eight patients with chronic obstructive pulmonary disease (COPD, mean age:71.8 years, range 56-87 years) underwent xenon ventilation CT and pulmonary CTA using dual-energy CT. Xenon ventilation images and lung perfused blood volume (PBV) images were obtained by three-material decomposition algorithm. Ventilation, perfusion and morphological information were visually interpreted. Mean xenon enhancement values, mean lung PBV values and %LAA were also calculated and correlated each other. 

In most of all low  xenon distributed areas, iodine perfusion also decreased. However, in 37 regions of 16/28 patients, areas of low xenon distribution without decrease of iodine perfusion were noted, which indicate ventilation/perfusion (V/Q) mismatch. Comparing with LAA images, in those V/Q mismatch areas, LAA were not found and thus thought to be air way dominant type COPD. There were negative significant correlations between mean xenon enhancement values and %LAA, between mean lung PBV values and %LAA (r=-0.45, p<0.05, r=-0.42, p<0.05, respectively). In contrast, there were no significant correlations between mean xenon enhancement values and lung PBV values, also between lung PBV values and clinical severity using GOLD stage.

Dual-energy lung ventilation/perfusion imaging using xenon ventilation CT and lung PBV is feasible and provide lung morphological and functional information.This method can visualize V/Q mismatch in patients with COPD with much higher spatial resolusion than nuclear imaging. Evaluation of V/Q mismatch may predict prognosis of COPD because lung blood perfusion is known to decrease earlier than pulmonary emphysema (LAA) change. Thus, additional studies and long term observations are required for evaluation of those areas. With its higher resolusion of space and time, dual-energy lung ventilation/perfusion imaging has the potential to be the new assessment tool for COPD patients.

Combined dual energy xenon ventilation CT and lung PBV visualize V/Q mismatch in patients with COPD, which has the potential to be new assessment tool for COPD.

Kobayashi, M, Shiraga, N, matsumoto, k, Sugino, K, Suzuki, K, Honma, S, Kohda, E, CT Evaluation of V/Q Mismatch in Patients with COPD using Dual-energy Xenon Ventilation CT and Lung Perfused Blood (PBV) Image .  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014264.html