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PET-CT Imaging
What is a PET-CT Scan?
Combining Function and Structure for Superior Diagnosis
PET-CT is a cutting-edge imaging technique that combines Positron Emission Tomography (PET) and Computed Tomography (CT) into one powerful scanner. By merging PET and CT images, this technology delivers a unique blend of functional and structural information. It is invaluable for detecting cancer, determining the extent of disease spread, guiding treatment decisions, and monitoring therapy effectiveness. PET-CT scans are also used to study brain and heart disorders with high precision.
How PET-CT Works
Understanding the Technology Behind PET-CT Imaging
A PET scanner creates images based on your body’s metabolism using a radioactive tracer called FDG (F18-fluorodeoxyglucose), which mimics glucose. Since cancer cells consume glucose at a higher rate, areas of abnormal activity are highlighted on the PET scan. The CT scanner uses x-rays to produce detailed images of your organs, bones, and tissues. When these scans are combined, the result is a comprehensive image that provides detailed insights into both structure and function, enhancing diagnostic accuracy.
Preparing for Your PET-CT Scan
Essential Steps to Ensure Accurate and Effective Results
To ensure high-quality imaging, follow these preparation guidelines:
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Fasting: Do not eat for at least 6-8 hours before your scan (overnight fasting is preferred). The day before, stick to a low-carbohydrate, high-protein diet to optimize image quality.
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Medication and Medical History: Prepare a list of your current medications, past treatments (such as chemotherapy, radiation, or surgery), and any previous imaging studies. Bring these details and any relevant reports with you on exam day.
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Hydration: Drink 3-4 glasses of water before your appointment. Avoid wearing body jewelry and notify staff if you have a history of reactions to contrast agents, asthma, or claustrophobia.
Special Instructions for Diabetic Patients:
If you are diabetic, maintain your usual small, regular meals to keep glucose levels stable. Take your diabetes medications or insulin as instructed and schedule your scan at least 4 hours after your last insulin dose. Diabetic patients are often scheduled in the afternoon to accommodate their morning medication routine.
The PET-CT Procedure: What to Expect
A Step-by-Step Guide to Your PET-CT Experience
The PET-CT scan process takes approximately 2-3 hours:
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Initial Preparation: A small blood sugar sample will be taken, and an intravenous (IV) line will be inserted for the radioactive tracer (FDG). You may feel slight discomfort from the IV, but the injection itself is painless and has no side effects. You'll also drink an oral contrast agent to enhance imaging clarity.
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Waiting Period: After the injection, you'll rest quietly for 45-60 minutes to allow the tracer to distribute throughout your body.
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The Scan: You will lie flat on a table that moves slowly through the PET-CT scanner, which resembles a large doughnut. The scan takes 30-40 minutes, and it’s important to stay still during this time. If you feel anxious in small spaces, a light sedative may be administered. The warm, flushed feeling from the contrast injection is normal.
Safety Notes: If you experience an allergic reaction to the injected substances, it can be managed with antihistamines or steroids. Rarely, patients with pre-existing kidney conditions may experience further complications. No anesthesia is needed for the scan.
Post-Scan Instructions
Once the scan is complete, you can return to your regular diet and medications. Drink plenty of water to help clear any remaining radioactivity from your body. If you received a sedative, ensure someone is available to drive you home.
Results: Your PET-CT images will be reviewed and correlated by a board-certified Nuclear Medicine Physician and a board-certified Radiologist. Your physician will receive the results within 1-2 days.