Yongjun Chang, Presenter: Nothing to Disclose

Jangpyo Bae MS, Abstract Co-Author: Nothing to Disclose

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

Sang Min Lee MD, Abstract Co-Author: Nothing to Disclose

Joon Beom Seo MD, PhD, Abstract Co-Author: Nothing to Disclose

In patients with chronic obstructive pulmonary disease (COPD), diaphragm function may be deteriorated because of reduced muscle fibre length, resulting in the morphological change of the diaphragm. Therefore, we developed a quantitative analysis method for the diaphragm for patients with COPD in 3D volumetric CT data.

Volumetric CT data for thirty patients with COPD were obtained from a 16-multi detector row CT scanner (Siemens Sensation 16) with in 0.75mm collimation. A threshold-based lung segmentation followed by the3D ray projection for the diaphragm segmentation was performed. Based on the resultant diaphragm data, the diaphragm was modeled with a quadratic 3D surface fitting. The segmentation result was evaluated by an expert thoracic radiologist. The overall accuracy of the segmentation was 95.58 ±2.52% (mean±SD). To take into consideration shape features of the diaphragm, shape index on the apex (SIA) was obtained from principal curvatures on the apex on the fitted diaphragm surface (CA). The height (H) between the apex and the base plane determined by three points on the bottom of the diaphragm model was also evaluated. In addition, the diaphragm lengths along the x, y, and z axes (XL, YL, ZL), quadratic fitting diaphragm lengths on z axis (FZL), average curvature (C), and surface area (SA) were measured with in-house software. Quantitative morphological parameters including SIA, CA, H, XL, YL, ZL, FZL, C, and SA are 0.85±0.05, 0.01±0.00, 17.93±10.78, 129.80±11.66, 163.19±13.45, 71.27±17.52, 61.59±16.98, 0.01±0.00, and 34380.75±6680.06, respectively.

The proposed method is especially useful in quantifying diaphragm characteristics including the reduced muscle fibre length and morphological change of diaphragm. This study could further be used for evaluating etiology and progress of COPD using 3D volumetric chest CT.

We proposed an automatic method for evaluating quantitative morphological parameters of the diaphragm with quadratic 3D surface fitting from volumetric chest CT data for patients with COPD. Our method may be useful for assessing the morphological diaphragm change of COPD patients.

Chang, Y, Bae, J, Kim, N, Lee, S, Seo, J, Quantitative Morphological Parameters of Diaphragm with Quadratic 3D Surface Fitting from Volumetric Chest CT in Patients with Chronic Obstructive Pulmonary Disease .  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13027390.html