Positron emission tomography (PET) scans are powerful diagnostic tools used in modern medicine. But How Are Pet Scans Performed and what can you expect during this procedure? A PET scan is an imaging test that provides detailed pictures of the metabolic activity within your body’s tissues and organs. Unlike other imaging tests that show structure, PET scans reveal how your body is functioning at a cellular level. This is achieved through the use of a radioactive tracer, allowing doctors to detect diseases, often before they are visible on CT scans or MRIs.
To understand how are pet scans performed, it’s essential to break down the process. The procedure involves several key steps, from preparation to image acquisition and interpretation.
What to Expect Before a PET Scan
Preparation is a crucial part of how pet scans are performed. Your healthcare provider will give you specific instructions, but some general guidelines are typically followed. Firstly, inform your doctor if you have any allergies, especially to medications, or if you have any medical conditions like diabetes. It’s also important to list all medications, vitamins, and herbal supplements you are currently taking.
If there’s a possibility you might be pregnant or if you are breastfeeding, it’s vital to tell your healthcare provider. The radioactive tracer used in PET scans could expose a fetus or infant to radiation. Additionally, if you suffer from claustrophobia, inform your medical team as the PET scanner can be confining, and they can take measures to ensure your comfort.
Generally, strenuous exercise should be avoided for a couple of days leading up to your scan. You will also be asked to refrain from eating for at least four hours before the appointment. This fasting period helps ensure the tracer works effectively.
The PET Scan Procedure: A Step-by-Step Guide on How They Are Performed
Knowing how pet scans are performed can alleviate anxiety about the procedure. The process, from arrival to completion, usually takes around two hours, and typically doesn’t require an overnight hospital stay.
Getting Ready
Upon arrival, you may be asked to change into a hospital gown and empty your bladder. A healthcare professional will then explain the procedure and answer any questions you might have about how pet scans are performed.
Tracer Administration
The next key step in how pet scans are performed involves administering the radioactive tracer. This tracer is usually injected into a vein in your arm or hand. You might feel a brief cold sensation as the tracer is injected. After the injection, you will be asked to rest quietly in a reclining chair for about 30 to 60 minutes. This waiting period allows the tracer to travel through your body and be absorbed by the tissues and organs. Areas of higher metabolic activity, such as cancer cells, will accumulate more of the tracer.
Alt Text: A Positron Emission Tomography (PET) scanner machine in a medical imaging room, highlighting the doughnut-shaped opening where patients are positioned for scanning.
Scanning Process
Once the tracer has been absorbed, you will be guided to the PET-CT or PET-MRI scanner. This machine looks similar to a large doughnut standing upright. You will lie on a narrow, padded table that slides into the opening of the scanner. It’s crucial to remain very still during the scan, as any movement can blur the images and affect the clarity of the results.
The scanning process itself takes approximately 30 minutes for a PET-CT scan and around 45 minutes for a PET-MRI scan. During this time, the scanner detects the radioactive tracer in your body and records the signals. The machine may make buzzing and clicking sounds, which is perfectly normal. The test is painless, but if you experience anxiety due to enclosed spaces, inform the medical staff. They can provide medication to help you relax.
Alt Text: Combined PET-CT scan images demonstrating the enhanced diagnostic capability, showing a CT scan alone, a PET scan highlighting metabolic activity, and the merged PET-CT image pinpointing lung cancer.
After the Scan
After the scan is complete, the table will slide out of the scanner. Unless your healthcare provider advises otherwise, you can resume your normal daily activities. It’s recommended to drink plenty of fluids after the procedure. This helps to flush the radioactive tracer out of your body more quickly.
Understanding Your PET Scan Results
After how pet scans are performed and the images are acquired, a specialized doctor called a radiologist, who is trained in interpreting these scans, will analyze the images. The radiologist will prepare a report of the findings and send it to your healthcare provider. Your doctor will then discuss the results with you, explaining what the scan shows and what the next steps might be.
Often, PET scan images are reviewed in conjunction with other imaging tests like MRI or CT scans to provide a more comprehensive understanding of your condition. The combined images, PET-CT or PET-MRI, offer detailed anatomical and metabolic information, enhancing diagnostic accuracy.
Risks Associated with PET Scans
While understanding how pet scans are performed is important, it’s also natural to be concerned about potential risks. The amount of radioactive tracer used in a PET scan is very small, resulting in low radiation exposure. Therefore, the risk of negative effects from the radiation is minimal.
However, there are a few potential risks to be aware of:
- Radiation exposure to unborn babies: If you are pregnant, the tracer could expose your unborn baby to radiation.
- Radiation exposure to breastfeeding infants: Similarly, the tracer could be passed to your child through breast milk if you are breastfeeding.
- Allergic reaction: Although rare, an allergic reaction to the tracer is possible.
Discuss any concerns you have about these risks and the benefits of a PET scan with your healthcare provider.
Why Are PET Scans Performed?
PET scans are valuable tools for detecting and monitoring various conditions. They are particularly effective in:
Cancer Detection and Management
Cancer cells typically exhibit higher metabolic rates than normal cells, causing them to appear as bright spots on PET scans due to increased tracer uptake. This makes PET scans useful for:
- Detecting cancer: Identifying cancerous tumors in the body.
- Staging cancer: Determining if cancer has spread to other parts of the body.
- Monitoring treatment: Assessing whether cancer treatment, like chemotherapy or radiation therapy, is effective.
- Detecting recurrence: Identifying if cancer has returned after treatment.
PET-CT and PET-MRI scans are effective in detecting many types of solid tumors, including cancers of the brain, breast, cervix, colon, esophagus, head and neck, lung, lymphatic system, pancreas, prostate, skin, and thyroid.
Alt Text: A PET scan image of a human heart, illustrating areas of reduced blood flow, valuable for diagnosing coronary artery disease and planning interventions.
Heart Disease Diagnosis
PET scans can help assess blood flow to the heart. By revealing areas of decreased blood flow, PET scans can assist in determining the need for procedures like coronary artery bypass surgery or angioplasty to open blocked arteries.
Brain Disorder Evaluation
PET scans play a role in evaluating certain brain disorders, including tumors, Alzheimer’s disease, and seizure disorders. In the case of Alzheimer’s, PET scans can show areas of decreased metabolic activity in the brain, aiding in diagnosis and understanding disease progression.
Alt Text: Comparative PET brain scans illustrating a healthy brain versus a brain affected by Alzheimer’s disease, highlighting reduced metabolic activity in Alzheimer’s patient brain shown by color changes.
In conclusion, understanding how pet scans are performed provides clarity and can reduce anxiety associated with medical imaging procedures. PET scans are a sophisticated and essential tool in modern medicine, offering unique insights into the body’s metabolic activity, aiding in the diagnosis and management of serious conditions like cancer, heart disease, and brain disorders. By combining metabolic information with anatomical detail, PET scans empower healthcare providers to deliver more precise and effective patient care.
