About Nuclear Medicine & Molecular Imaging

What are molecular imaging and nuclear medicine?

Molecular imaging is a type of medical imaging that provides detailed pictures of what is happening inside the body at the molecular and cellular level. Where other diagnostic imaging procedures—such as x-rays, computed tomography (CT) and ultrasound—offer pictures of physical structure, molecular imaging allows physicians to see how the body is functioning and to measure its chemical and biological processes.

Molecular imaging includes the field of nuclear medicine, which uses very small amounts of radioactive materials (radiopharmaceuticals) to diagnose and treat disease. In nuclear medicine imaging, the radiopharmaceuticals are detected by special types of cameras that work with computers to provide very precise pictures of the area of the body being imaged. Nuclear medicine can also be used to treat certain types of cancer and  other diseases.

Molecular imaging offers unique insights into the human body that enable physicians to personalize patient care. In terms of diagnosis, molecular imaging is able to:

  • provide information that is unattainable with other imaging technologies or that would require more invasive procedures such as biopsy or surgery
  • identify disease in its earliest stages and determine the exact location of a tumor, often before symptoms occur or abnormalities can be detected with other diagnostic tests

How do they help patients?

As a tool for evaluating and managing the care of patients, molecular imaging studies help physicians:

  • determine the extent or severity of the disease, including whether it has spread elsewhere in the body
  • select the most effective therapy based on the unique biologic characteristics of the patient and the molecular properties of a tumor or other disease
  • determine a patient’s response to specific drugs
  • accurately assess the effectiveness of a treatment regimen
  • adapt treatment plans quickly in response to changes in cellular activity
  • assess disease progression
  • identify recurrence of disease and help manage ongoing care

When are they used?

Molecular imaging procedures—which are noninvasive, safe and painless—are used to diagnose and manage the treatment of cancer, heart disease, brain disorders such as Alzheimer’s and Parkinson’s disease, gastrointestinal disorders, lung disorders, bone disorders, kidney and thyroid disorders,  and more.

SNMMI offers fact sheets that explain how nuclear medicine and molecular imaging can help diagnose and/or treat a wide range of diseases.

View SNMMI Fact Sheets