Zepa Yang MS, Presenter: Nothing to Disclose

Hyeongmin Jin, Abstract Co-Author: Nothing to Disclose

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

Accuracy of airway wall measurement has been impaired by the combined effect of partial volume and point spread blurring in CT systems. We present a novel technique which enables to determine the wall thickness of small airways by using a model-based lesion quantification technique.  

Point spread functions of a commercial CT(Sensation 16, Siemens) was acquired by using a wire phantom scanning for two different kernels(B30s and B50s). The COPDgene phantom was scanned with 120kVp, 100mAs, 1mm thickness setting and was reconstructed with the two kernels. A set of model-derived line profiles were created by taking convolution of the point spread functions with a set of numerical airway phantoms having varying thickness ranging 0.1 - 5.0mm with 0.1mm thickness interval. These model-derived line profiles were compared with the measured line profiles across the wall from the airway phantoms in COPDgene phantoms. The wall thickness of the phantom was determined as the thickness of numerical model giving minimum error between two line profiles. Measurements were made for 4 types of airway phantoms with wall thickness of 0.6, 0.9, 1.2, 1.5 mm in 40 CT slices.   

The mean measurement error of wall thickness with B30s kernel was 0.10 ±0.03mm for 0.6mm thickness, 0.06±0.04 for 0.9mm thickness, 0.07±0.01 for 1.2mm thickness, and 0.05±0.01 for 1.5mm thickness. The error with B50s was -0.04 ±0.07mm for 0.6mm thickness, -0.08±0.05 for 0.9mm thickness, -0.11±0.05 for 1.2mm thickness, and -0.07±0.06 for 1.5mm thickness.  

By applying a model-based line profile matching technique, our technique could determine the airway wall thickness accurately even for the small airways. 

Our technique may allow detection of early change of airway wall thickening in early diagnosis, patient sub-typing, and therapeutic monitoring in the management of COPD disease.

Yang, Z, Jin, H, Kim, J, Accurate Measurement of Airway Wall Thickness with a Model-based Line Profile Matching Technique in MDCT.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13024972.html