Filter:

Submit Search

#### Understanding the intensity unit

For CT and CR/DR/DX images, their pixel values are converted to pixel intensity values.

Intensity units

The following table describes the two intensity units.

Intensity unit | Meaning
Hounsfield Unit (HU) | Conveys the relative density of a pixel value compared to water. HU is the intensity unit for CT images.
Optical Density (OD) | Conveys the opacity of a pixel. OD is the intensity unit for CR/DR/DX images.

Use of the pixel intensity values

Different tissue types have unique density and opacity ranges. As a result, pixel intensity values can indicate the tissue types of a region of interest (ROI). For example, you can measure the pixel intensity value of an Elliptical ROI or a point, to examine whether there is water in the ROI. For procedures, see Adding and measuring the Elliptical Region of Interest (ROI) and Measuring the pixel intensity of a point.

Your search for returned result(s).