• Overview
• Model-Based Segmentation Engine
• Lung Volumetry
• Lung Attenuation Analysis
• Lung Texture Classification
• Dynamic Imaging
• Airway Morphometry
• Fissure Integrity Scoring
• Emphysema Treatment Targeting and Outcome Assessment
• Lung Fibrosis Scoring
• Functional Imaging in Asthma

Lung Attenuation Analysis

Lung attenuation analyses are based on quantitative measures derived from the X-ray attenuation (HU) histogram (Goldin 1998). These include mean, median, 5th centile, relative area (density mask), and standard deviation.

The distribution of the histogram reflects the tissue/air density within the parenchyma. Measures such as the 5th centile and relative area (density mask) characterize the low attenuation portion of the histogram and can quantitate the severity of emphysema lung destruction and/or expiratory airflow obstruction. Conversely, a greater proportion of high attenuation voxels reflects an increase in either blood flow or in the interstitial, cellular, or fluid content of the lung parenchyma.

MedQIA has conducted extensive validation studies of the relative area (density mask) measurement for assessment of COPD in multicenter clinical trials. These studies have included assessment of the reproducibility of the density mask measurement under repeated scanning in clinical trials and under different CT acquisition technical factors, in particular reconstruction kernel (Mao 2002, Boedeker 2004).