Dopamine transporter (DaT) scan
Dopamine transporter scans (DaT scans) are imaging scans that use tiny amounts of radioactive substances to determine how much dopamine a person has in their brain. A SPECT scan is used by doctors to determine the amount and location of radioactive drugs in the brain. DaT scanning is safe because the FDA has approved its use for Parkinson’s diagnosis. DaT scans do not diagnose Parkinson’s alone, but they help confirm the diagnosis. Positive results of DaT scanning can confirm Parkinson’s. A negative DaT result does not necessarily mean a person doesn’t have Parkinson’s.
Other neurological disorders can also cause dopamine loss in the brain, making it difficult to diagnose Parkinson’s. Positive DaT scans cannot differentiate Parkinson’s from other forms of parkinsonism, such as progressive supranuclear paralysis (PSP) or multiple system atrophy(MSA), which also have lower levels of brain dopamine. A positive DaT result can distinguish Parkinson’s from essential tremor because the latter does not have a dopamine deficiency.
