What is the difference between a CT and a PET-CT scan?


CT and PET-CT scans are very common procedures that doctors administer every day to help localize their examination and to provide the most thorough diagnosis. Both procedures contain varying, minimal risks but can provide huge benefits for patients that need a more in-depth examination and specialized treatment.

What is a CT scan?

A CT scan or a Computed Tomography scan is a medical procedure that uses x-ray radiation and fascinating computer technology to create cross-sectional images of the body’s organs and tissues. CT scans can also be called CAT or Computed Axial Tomography. CT scans take helical images of the examined part of the body which produces better 3-dimensional imaging. The better the image, the better the diagnosis your doctor can make. CT scans are particularly useful in the examination of tissues, cancer staging, and determining vascular disease.

What is a PET-CT scan?

A PET-CT scan or Positron Emission Tomography is a medical procedure similar to a CT scan but PET-CT scans are commonly used in determining the difference between healthy and diseased tissue. Using nuclear medicine these exams allow particular focus on oncological symptoms in the brain and heart as well as any vascular or tissue abnormalities.

What are the procedures like?

The biggest difference between a CT and a PET-CT scan is the machinations of the procedure. There are varying states of discomfort between both procedures, but both are relatively painless and easy to complete for any patient.

A CT machine looks like a large tire with the patient placed inside the “hole.” The patient is placed on the examination table and will be administered contrast material through the mouth or intravenously. The feet will be the first to enter into the machine and the body will be slowly moved into the chamber. The procedure lasts approximately 10-30 minutes. Patients typically report that they hear a slight whirring sound which is the machine rotating around them gathering imaging. The doctor will able to speak to you and you will be able to respond.

A PET-CT scan is similar to a CT scan in some ways but the biggest difference between the two is the instructions prior to the exam. Most doctors and facilities will request that a patient not eat at least 4 hours prior to the scan and to drink lots of water. The exam also lasts slightly longer at about 30-45 minutes. Contrast material is commonly used as well and will either be  administered through an IV or by inhalation. If the PET-CT scan is being administered because of possible heart disease, the patient will often be asked to perform a stress test. The body will be examined at rest and during exercise in efforts to determine any cardiovascular problems. You may also hear a buzzing or clicking sound during this procedure.

Which procedure is more painful?

Both procedures have a minimal amount of pain and discomfort. The most common complaint is concerning the IV injection site or a claustrophobic feeling. But the contrast material is necessary for properly determining the condition of tissues and veins as well as highlighting possible cancerous cells. Furthermore, the body moves through the machine. It only covers the area that will be examined — it does not encapsulate the entire body.

Are there any risks?

Doctors and imaging facilities have been able to minimize the risks surrounding these procedures to practically nothing. Both a CT and PET-CT scan use small amounts of radiation to image the examined area. If you are pregnant or could possibly be pregnant, you should let your doctor know. There is no medical evidence that the amount of radiation is dangerous for an unborn child. But if there is another safer method to examine, your doctor can help you understand your options. Also if you have any implanted devices, artificial body parts or features such as hearing aids or dentures, talk to your doctor about what needs to removed for the procedure.

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Medical Imaging Exams and Equipment to Help Diagnose Heart Disease

Heart disease is the leading cause of death globally. The cause is debatable between poor diets, lack of exercise or genetics, but regardless of why it is happening, people need to take the necessary steps to improving their lives. Any physician will tell a patient that the way to better cardiac health is through the tried and true methods of eating better, exercising more and taking precautions if your family has a history of heart disease.

Because of the widespread presence of heart disease around the world, doctors and scientists have been able to develop new and innovative ways to detect and combat heart disease. Medical imaging is the premier way for doctors to determine the probability of developing a heart condition and there are a few different kinds of tests to use.

MRIs are one method that doctors sometimes use to test the heart and blood flow through the coronary pathways. MRIs use strong magnetic and radio waves to create images of the internal body.

MRIs are not the only imaging exam that doctors can use when a patient is concerned about their cardiac health. Another frequently used medical imaging exam for determining the condition of the heart is through CT or CAT scans. CT scans are beneficial to examining the heart because the heart is a muscle and CT scans use X-ray and computer equipment to produce cross-sectional images of the body, including several types of tissue. In some instances, technicians administer contrast dye to view the coronary arteries in an exam called coronary CT angiography or CTA.  Other conditions to be on the look for include pericardial disease or heart disease that occurs in the pericardium or the sac that surrounds the heart. CT scans do use radiation to create the images of the body but Doctors Imaging calibrates all the machines to the lowest possible radiation setting so patients do not need to worry about further injury.

If your doctors are concerned about the possibility of a vascular problem leading to heart disease, he or she may order a carotid ultrasound. The body has two carotid arteries and if either one becomes compromised, the patient could go into cardiac arrest or stroke. If a patient is worried about their cardiac condition, ultrasounds are another completely safe and effective form of medical imaging. Ultrasounds only use sound waves and computer technology to create their images and patients and doctors can see the flow of blood throughout the body in real time, making it that much easier to determine and cause and find treatment.

All these tests are important for gauging your cardiac health. That doesn’t mean they need to be performed at once or you might miss something. Every patient and their symptoms are different and thus, every patient needs a personalized treatment plan for their illness. At Doctors Imaging in Metairie, patients may have a 15 minute consultation as well as personalized treatment plan for their injury or illness.

For more answers to your questions or for more information feel free to contact Doctors Imaging in Metairie at 504-883-3555 or by filling out our online message form.