Proton Density(PD) Fat Saturated
MRI image appearance
The easiest way to identify proton density (PD) fat-saturated images is to look for adipose tissues in the body (e.g. subcutaneous fat and fat in bone marrow). Areas containing adipose tissues appear as dark on PD fat-saturated images. All other characteristics of the PD fat-saturated images remain the same as the PD image.
Tissues and their PD fat saturated images appearance
Bone marrow: – dark
Fat – dark
Fluids – bright
White matter – darker than bright gray
Gray matter – bright gray
Moving blood- dark
Bone – dark
Air – dark
Pathologies with adipose tissue content will appear as dark areas in PD fat-saturated images (e.g. lipoma). Due to the added fat suppression, pathological processes are usually bright on PD fat-saturated images.