Tremor, stiffness, slowed movement and balance changes can have more than one cause. A neurological examination and medical history remain central to evaluating possible Parkinson’s disease, but imaging may provide additional information when the diagnosis or cause of symptoms is uncertain.

Understanding PET scan vs. DaTscan for Parkinson’s disease can help patients see why a physician may recommend one study instead of the other.

Both are nuclear medicine examinations that use a radiotracer, but they use different imaging technology and answer different clinical questions.

What Is a DaTscan

A DaTscan is a specialized SPECT examination that evaluates dopamine transporter activity in the brain. The patient receives a small amount of a radioactive imaging agent before a gamma camera creates images of the brain’s dopamine system.

DaTscan may be helpful when a physician needs to determine whether symptoms are associated with reduced dopamine-transporter activity. For example, it can support the distinction between a parkinsonian syndrome and essential tremor when the clinical findings are unclear.

An abnormal DaTscan does not identify Parkinson’s disease specifically. Other degenerative parkinsonian syndromes can also produce abnormal findings, so the scan must be interpreted alongside the patient’s symptoms and neurological examination.

What Is a Brain PET Scan

Positron emission tomography uses a radiotracer, a specialized camera and a computer to show activity or function in tissues. Brain PET imaging can evaluate different biological processes depending on the tracer selected and the condition being investigated.

PET is used for a broader range of neurological questions than DaTscan. Depending on the study, physicians may use brain PET to assess patterns of metabolism or particular proteins and other targets.

Its role in a patient’s evaluation depends on the suspected condition, available tracer and information the referring clinician needs.

PET Scan vs DaTscan for Parkinsons Symptoms

The most important difference is not which scan is more advanced. It is what each scan is designed to measure.

  • DaTscan uses SPECT imaging to evaluate dopamine transporter activity.
  • Brain PET uses PET imaging to evaluate tracer-specific activity or function.
  • DaTscan may support evaluation of a suspected parkinsonian syndrome when the clinical picture is uncertain.
  • PET may be considered when a different question about brain function or another neurological condition needs to be investigated; the tests are not interchangeable.

Can Either Scan Confirm Parkinsons Disease

Neither PET nor DaTscan should be viewed as a stand-alone confirmation of Parkinson’s disease. Parkinson’s is usually evaluated clinically through the history, pattern of symptoms and neurological examination. Imaging may support that evaluation, help clarify an uncertain presentation or contribute to consideration of other causes.

A normal or abnormal scan must therefore be interpreted in context. Patients should discuss the result with the neurologist or referring physician who understands the complete clinical picture.

When Might a Physician Recommend Imaging

A physician may consider DaTscan when tremor or other movement symptoms could reflect essential tremor, medication effects or a parkinsonian disorder and the examination does not provide a clear answer. Brain PET may be ordered when the physician needs tracer-specific information about brain function, metabolism or another neurological process.

Not every patient with possible Parkinson’s symptoms needs either scan. The decision should be individualized and based on whether the result is likely to add useful information or influence the next step in care.

What to Expect From Nuclear Medicine Imaging

Both examinations involve receiving a radiotracer and waiting for it to distribute before imaging begins. The timing, preparation, camera and length of the appointment differ according to the ordered study.

Tell the imaging team about medications, supplements, allergies, recent illnesses and medical conditions. Patients who are pregnant, may be pregnant or are breastfeeding should notify their physician and the imaging facility. Follow the exam-specific instructions provided by the referring clinician and imaging center rather than relying on general preparation advice.

Schedule PET and Nuclear Medicine Imaging With ADR

Advanced Diagnostic Radiology provides PET scanning and nuclear medicine services at 952 Seton Drive, Suite 210, in Cumberland, Maryland.

If your physician has recommended a PET scan, DaTscan or another nuclear medicine examination, contact ADR to confirm availability, referral requirements and preparation instructions for the specific study.

Call Advanced Diagnostic Radiology at 301-777-3522 or request an appointment online. Your referring physician can explain why the examination was ordered and how the imaging findings fit into your overall evaluation.