Perfusion weighted imaging is a term used to denote a variety of MRI techniques able to give insights into the perfusion of tissues by blood.

There are three techniques in wide use to derive one or more perfusion values:

Techniques

• Dynamic susceptibility contrast (DSC) MR perfusion.
• Dynamic contrast enhanced (DCE) MR perfusion.
• Arterial spin labelling (ASL) MR perfusion.

Derived values

• Time to peak (TTP)
• Tean transit time (MTT)
• Cerebral blood volume (CBV)
• Cerebral blood flow (CBF)
• Negative enhancement integral (NEI)
• k-trans

The main role of perfusion imaging is in evaluation of ischaemic conditions (e.g. acute cerebral infarction to determine ischaemic penumbra, moya-moya disease to identify vascular reserve), neoplasms (e.g. identify highest grade component of diffuse astrocytomas, help distinguish glioblastomas from cerebral metastases) and neurodegenerative diseases.