Pulmonary emphysema extension can be reliably evaluated by histogram of density based on HRCT pixel density distribution. To date, there are no data on ILD and HRCT pixel density distribution. We evaluated the diagnostic role of the HRCT pixel density distribution to differentiate ILD patients from patients with pulmonary emphysema.
We studied 6 patients (3 M, age range: 43 to 83 yrs) with ILD and 6 patients (5 M, age range: 60 to 72 yrs) with pulmonary emphysema. Spirometry, lung volumes, diffusing capacity and blood gases were measured in all patients. The histogram of density provided a frequency distribution of voxels with specific attenuation numbers (in Hounsfield units) in the lung. We analyzed the voxel distribution vs hounsfield units plots in all patients.
We found that the 1/slope of pixel density values vs hounsfield units value were significantly steeper in patients with emphysema than those with ILD patients (−844 ± 91 vs −622 ± 91, p< 0.05).
Our results showed that the histogram of density based on HRCT pixel density distribution in ILD patients was significantly different from that of pulmonary emphysema patients.
HRCT pixel density distribution may be clinically useful to assess ILD patients.
A. Castagnaro, None.