Younghoon Cho, Presenter: Nothing to Disclose

Joon Beom Seo MD, PhD, Abstract Co-Author: Speaker, Siemens AG

Namkug Kim PhD, Abstract Co-Author: Nothing to Disclose

Hyun Joo Lee, Abstract Co-Author: Nothing to Disclose

Hye Jeon Hwang MD, Abstract Co-Author: Nothing to Disclose

Eun Young Kim, Abstract Co-Author: Nothing to Disclose

Sang Young Oh MD, Abstract Co-Author: Nothing to Disclose

To compare new integral-based half-band method (IBHB) and conventional full-width half maximum method (FWHM) in measuring peripheral airway dimensions at thin-section CT (TSCT) of chronic obstructive pulmonary disease (COPD).

In brief, IBHD determines the band showing peak mean HU value of airway wall and the integral of CT values within the band is used to determine the thickness of airway wall. For comparison, volumetric TSCT images of 50 COPD patients (stage I, 8; II, 17; III, 17; IV, 8) were used. At CT images, mid-position of 4th to 6th generations of the right apical bronchus (B1) was selected, and airway parameters (wall area percent(WA%), mean lumen radius(LR), mean wall thickness(WT)) were measured simultaneously with IBHD and FWHM. Matched results from two methods were compared. They were also were correlated with FEV1, FEV1/FVC and GOLD stage. Linear regression analysis was performed using airway dimensions and emphysema index (EI), which is the fraction of voxels with CT value lower than -950HU.

Results of WA%, LR, and WT from both methods were all significantly different (all p<0.05, paired t-test). IBHD method measured WA% and WT significantly smaller, while measuring LR larger. The airway parameter showing the best correlations with clinical parameters was WA% measured with IBHD at 5th generation, which is the sub-sub-segmental level (FEV1, r=-0.73; FEV1/FVC, r=-0.62; GOLD, r=0.74, all p<0.01). WA% measured with FWHM at the same location, showed only weaker correlation with GOLD (r=0.31, p<0.05) and no significant correlation with FEV1 and FEV1/FVC. Average WA% in each patient with IBHD showed better correlation with clinical parameters than that with FWHM (FEV, r=-0.52 vs. -0.29; FEV1/FVC, r=-0.41 vs. r=-0.21; GOLD, 0.53 vs. 0.34, respectively). Linear regression analysis revealed 5th generation WA% measured by IBHD to be an independent variable in addition to EI for all clinical parameters (FEV1, r2=0.63; FEV1/FVC, r2=0.61, GOLD, r2=0.70).

The new IBHB measured peripheral airway dimension differently than FWHM and showed better correlations with clinical parameters in COPD.

The new IBHB may be better than conventional FWHM in measuring airway dimension at CT of airway diseases.

Cho, Y, Seo, J, Kim, N, Lee, H, Hwang, H, Kim, E, Oh, S, New Integral-based Half-band Method in Assessing Peripheral Airway Dimension at Thin Section CT Images in Chronic Obstructive Pulmonary Disease Patients: Comparison with Conventional Full Width Half Maximum Method.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11011196.html