Sang Joon Park, Presenter: Nothing to Disclose

Chang Hyun Lee MD, PhD, Abstract Co-Author: Editorial Consultant, Siemens AG, Korea

Jong Hyo Kim PhD, Abstract Co-Author: Nothing to Disclose

Jin Mo Goo MD, PhD, Abstract Co-Author: Research Consultant, Infinitt Healthcare Co., Ltd

Eun-Ah Park MD, Abstract Co-Author: Nothing to Disclose

Hyun Ju Lee MD, Abstract Co-Author: Nothing to Disclose

Chang Min Park, Abstract Co-Author: Nothing to Disclose

To investigate the changes of distal airflow obstruction and airways after methacholine test and salbutamol treatment on xenon-enhanced chest CTs in patients with asthma

A total of 21 non-smokers(age, 21–65 years: mean age 46.7 years, M:F=8:13) with positive methacholine tests underwent xenon-enhanced chest CTs and PFTs. Three stage CT scans(basal, after methacholine test and after salbutamol treatment) were performed consecutively for airway analysis and for xenon gas distribution. For automatic quantitative analysis of xenon gas distribution, total xenon ventilation index(TXVI, 0-50HU/total lung volume(TLV)×100) was automatically calculated using in-house software. Airway analysis(inner area, IA; wall thickness, WT; and wall/area fraction, WAF) was performed using VIDA pulmo2 software in 7 locations(trachea, RB1, RB4, RB10, LB1, LB4, and LB10). The Friedman test and Spearman’s correlation coefficient were used for statistical analysis.

TXVI significantly decreased after the methacholine test and increased after salbutamol treatment(basal, 88.8±6.3; methacholine, 82.0±11.8; salbutamol, 85.0±12.1; P<.05). Among airway parameters, airway IA significantly increased after salbutamol treatment in all airways(P<.01). Airway IA significantly decreased after the methacholine test in LB1(12.53mm2±3.62, 11.42mm2±4.32, P<.01), but not in other airways(P>.05). Airway WT was not significantly changed after the methacholine test and salbutamol treatment (P>.05). For RB1, RB10, and LB10, WAF significantly decreased after salbutamol treatment(66.1%±5.1, 64.3%±3.5; 66.5%±3.3, 64.1%±3.6; 65.1%±3.6, 61.8%±3.4, P<.05) but did not increase after the methacholine test (66.69%±3.92, 66.12%±5.19; 66.23%±3.8, 66.5%±3.3; 64.2%±4.6, 65.1%±3.6, P>.05). In other airways, WAF was not significantly changed(P>.05). IA of the trachea was well correlated with basal TXVI(r=-0.48, P<.05), TLV(r=0.84, P<.0001), percent predicted FEV1(r=0.59, P=.02), and FVC(r=0.64, P=.01), but not with FEV1/FVC(r=0.01, P=.96).

Dynamic changes of distal airflow obstruction can be seen on xenon-enhanced chest CT. Airway IA is the most reliable parameter after bronchodilator treatment and IA of trachea is well correlated with TXVI, TLV, percent predicted FEV1 and FVC.

Xenon-enhanced chest CT can show the dynamic changes of distal airflow obstruction and airway changes in the assessment of patients with asthma.

Park, S, Lee, C, Kim, J, Goo, J, Park, E, Lee, H, Park, C, Changes of Distal Airflow Obstruction and Airways after Methacholine Test and Salbutamol Treatment on Xenon-enhanced Chest CTs in Patients with Asthma.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9007635.html