Nuclear Medicine Exams

Nuclear medicine exams are diagnostic exams that produce images of the body by using a special camera that detects energy emitting from the radioactive substance, called a radiotracer. Nuclear scans help doctors diagnose many conditions, including cancers, injuries, and infections. They can also show how organs like your heart and lungs are working.

There are new and innovative nuclear medicine treatments that target and pinpoint molecular levels within the body that are revolutionizing our understanding of and approach to a range of diseases and conditions.

Nuclear Medicine Therapy

Nuclear medicine therapy is used to treat certain medical issues.

  • Radioactive iodine therapy treats hyperthyroidism (overactive thyroid gland) and thyroid cancer.

  • Radioactive antibodies treat certain forms of lymphoma.

  • Radioactive phosphorus treats some blood disorders.

  • Radioactive materials treat painful tumor metastases to the bones.

Scheduling Your Nuclear Medicine Exam

Nuclear medicine appointments are scheduled M-F from 7:00am to 3:00pm and Saturdays from 7:30am to 11:00am (no PET exams on Saturdays). Nuclear medicine exams are by appointment only and are typically scheduled by your referring physician. If you need to reschedule your nuclear medicine exam, please call Radiology Scheduling at 314-362-7111 or 877-992-7111, M-F from 7:00am to 5:30pm.

Before Your Nuclear Medicine Exam

  • Please arrive at least 15 minutes prior to your appointment to allow for registration time.

  • Please bring a photo ID (driver’s license or state ID), insurance card(s), and a completed Medication Record with you to your appointment.

  • Take your medication as you normally do, unless your referring physician has told you otherwise.

  • Be prepared to discuss your completed Medication Record, allergies, past medical history, and any previous surgeries.

  • Women should always inform their physician and the nuclear medicine technologist if there is any possibility that they are pregnant.

  • Wear comfortable, loose-fitting clothing to your exam. In some cases, you will be given a hospital gown to wear during the procedure.

  • Jewelry and other metallic accessories can interfere with the procedure and should be left at home or removed before the exam. You will be given a place to store your items before the procedure.

  • Nuclear scans involve a special camera that detects energy emitting from the radioactive substance, called a radiotracer. Before the test, patients receive the radiotracer by injection, by swallowing, or inhaling a gas. Although radiotracers are radioactive, the dosage is small.

  • If the radiotracer is injected into your arm, you might feel a cold sensation moving up your arm. If the radiotracer is swallowed, it has little or no taste. If inhaled, you should feel no differently than when breathing normally.

  • It can take anywhere from several seconds to several days for the radiotracer to travel through your body and accumulate in the organ or area being studied. As a result, imaging might be done immediately, a few hours later, or even several days after you've received the radioactive material.

  • With some procedures, a catheter might be placed in your bladder, which might cause temporary discomfort.

During Your Nuclear Medicine Exam

  • A technologist will help you onto the screening table and make you comfortable. Once the exam begins, you will be asked to remain still until the exam is over. The technologist will leave and go to another room, but will remain in contact with you through an intercom. You will also be given a call button to talk to the technologist at any time.

  • Most nuclear medicine exams are performed using a gamma camera, a specialized camera encased in metal that is capable of detecting radiation and taking pictures from different angles. It can be suspended over the examination table or it might be beneath the table. Often, gamma cameras are dual-headed with one camera above and one camera beneath the table. The camera could also be located within a large, doughnut-shaped scanner similar in appearance to a computed tomography (CT) or MRI scanner.

  • A positron emission tomography (PET) scanner is a large machine with a round, doughnut shaped hole in the middle, similar to a CT or MRI unit. Within this machine are multiple rings of detectors that record the emission of energy from the radiotracer in your body.

  • A probe is a small hand-held device resembling a microphone that detects and measures the amount of the radiotracer in a small area of your body.

  • There is no specialized equipment used during radioactive iodine therapy, but the technologist administering the treatment might cover your clothing and use lead containers as a shield from the radioactive material you will receive.

  • A nuclear medicine exam generally takes 45 minutes to 2 hours, depending on the exam. For bone scans or cardiac exams, please allow 3 hours. For a more exact length of time, please call the Nuclear Medicine department at 314-454-8945.

Questions About Your Nuclear Medicine Exam

Please call the Nuclear Medicine department at 314-454-8945 with any questions about your nuclear medicine exam.


All radiology exams are read by a physician known as a Radiologist. The radiologists at Barnes-Jewish Hospital are all specialized experts in their field. The radiologist will send the results of your exam to your referring physician’s office within 24 hours. If needed, the radiologists are available to discuss your results with your referring physician. Your physician’s office will then in turn discuss the results with you.

About Your Bill

You will receive two bills for your exam:

  • The hospital bill includes the cost to cover equipment, supplies, and technical personnel. For questions, call Hospital Billing at 314-362-0710.

  • The radiologist’s bill covers the professional interpretation of your exam. For questions, call Mallinckrodt Institute (Washington University) Patient Accounts at 314-273-0500.

Patient Forms

To save time please download, print, fill out, and bring to your appointment.

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