A Closer Look at SPECT

What Your Patients Can Expect During a SPECT Test

Imaging is done at stress and at rest. The standard procedure uses ECG data as the heart beats to guide image acquisition (also known as ECG-gated SPECT).7,8,11

1. Stress Test

Patient ECG, heart rate, and blood pressure are monitored during stress. Exercise is the preferred stress method, but if patients are unable to exercise adequately, a pharmacologic stress agent can be used.1 Pharmacologic stress simulates exercise effects by increasing blood flow to the heart.8

2. Radiotracer Injection

A small amount of radioactive tracer is injected into the patient's arm.8 Radiotracers are distributed throughout the myocardial tissue proportional to blood flow.7

3. Radionuclide Imaging

A gamma camera captures images of myocardial perfusion after stress and at rest for comparison.7,8

SPECT Considerations

Like other imaging tests, SPECT uses ionizing radiation to gather information. When choosing an appropriate test, it's important to consider whether the benefit of information from SPECT imaging results would outweigh the risk of exposing a patient to any amount of radiation.2

Also, image quality and diagnostic accuracy of SPECT may be affected by attenuation artifacts, which can be seen in obese patients or those with a large amount of breast tissue. Artifacts can be reduced with several techniques.7

  • Using Tc-99m radiotracers
  • Imaging patients in the prone position
  • Applying attenuation correction algorithms in image-processing software