Tissue characterization by an analysis of the distribution of attenuation values in computed tomography scans: a preliminary report.

Attenuation values as measured by a computed tomography scanner are distributed in both magnitude and space. The distribution in magnitude can be described by the mean, standard deviation, and skewness of histograms of attenuation values. The distribution in space can be characterized by auto-correlation functions or histograms of gradients. Using these measures of scan structure, it has been shown that the spatial distribution of attenuation values can be influenced by tissue. Also, there are some indications that changes in tissue structure corresponding to disease can be detected.