DPD scan

For the amyloid scan used in diagnosis of Alzheimer's disease, see Positron emission tomography § Neuroimaging.

A DPD scan is a type of nuclear medicine imaging test which uses radioactive technetium-99m (^99mTc) and 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) to diagnose cardiac amyloidosis. The radiopharmaceutical is taken up only in patients with ATTR amyloidosis, making it a useful tool to differentiate from AL amyloidosis.^[1]

Amyloid deposition in aortic stenosis shown by DPD scan

DPD is a diphosphonate and can be used as an alternative to HDP or MDP in nuclear medicine bone scintigraphy.^[2]

Procedure

DPD scanning typically uses a gamma camera to obtain SPECT images, with an injection followed by an initial scan after 5 minutes, and a second scan after 3 hours.^[3]

Images are often scored using the "Perugini system" whereby:^[4][5]

• Grade 0 – no cardiac uptake and normal bone uptake
• Grade 1 – cardiac uptake which is less intense than the bone signal
• Grade 2 – cardiac uptake with intensity similar or greater than bone signal
• Grade 3 – cardiac uptake with much attenuated or absent bone signal

Availability

DPD is not currently available in the United States.^[6]

See also

• SAP scan