Viewing Density Information

You can view the Probe result information to know the measure of pixel intensity or density. The density is measured in Hounsfield units and the intensity is measured on the images where Hounsfield values are inapplicable.

It is simply the grayscale value of the current pixel. The Probe result is displayed on the bottom bar in the image viewer for PET images. For non-PET images, the relevant pixel value is displayed.

Standardized Uptake Value (SUV) is defined as the ratio of activity in tissue per millimeter to the activity in the injected dose per patient body weight. The unit appears for NM/PET studies.

You can set this up from the Windows preset tool drop down menu.

The drop down menu contains a default option for SUV value and options to derive values in SUV Body Weight (SUVbw), SUV Lean Body Mass (SUVlbm) and SUV Body Surface Area (SUVbsa). The default unit for PET images is SUVbw.

You can use this value in Fusion view (studies which allow a fused view of CT and PET studies) where it is very useful in identifying the level of activity in a tissue.