CT and PET: What’s the Difference?

To better diagnose health conditions, doctors need to see what’s going on inside the body. Of course, they don’t have to dissect the body to achieve that. All they have to do is to take pictures of it through an imaging technology.

Computed Tomography (CT) and Positron Emission Tomography (PET) are two of the few imaging technologies available today. Although they are both tomography (meaning they use some form of penetrating wave to capture images of enclosed tissues), they have some striking differences.

CT Scan

One of the oldest imaging method, CT produces cross-sectional images of the body using x-rays. Because the machine used for this test is more common than that of PET or MRI, this test can be seen performed in hospitals and outpatient offices.

During a CT scan, an IV will be inserted in a patient’s to introduce a contrast. The patient will then be asked to lie down on a narrow table placed in the middle of the donut-shaped scanner. As the bed moves into the scanner, the x-rays the scanner produces rotate around the body. The contrast that is now inside the patient’s body helps the scanner distinguish bad tissues from good ones.

PET Scan

The process followed during a PET scan is similar to that in a CT scan in that a substance that reacts to the electromagnetic wave used for scanning is introduced to the patient’s body. There are several apparent differences though. For instance, instead of being injected into the body, the tracers are mixed with a solution that the patient will be asked to drink.

Full Recovery: What You Should Know About Knee Injuries and MRI Scans

Knee injuries are a common occurrence in the United States. In fact, ACL injuries account for over 150,000 cases in the U.S. each year. Fortunately, knee injuries are no longer the “career-ending” injuries they were in the past. This is largely thanks to improved and more accurate imaging technology in the form of MRI scans. If you experience any pain, swelling, and/or instability in your knee, it’s best to see a doctor as soon as possible. After all, quick diagnosis and treatment is vital in making sure that your knee fully recovers without complications.

What Your Doctor Can See

MRI scans are essential in diagnosing and treating knee injuries like a torn ACL or torn meniscus. With the help of the accurate images that an MRI can provide, doctors can easily see the extent of ligament damage to the affected knee. This is important because treating a partially torn ACL is different from the treatment needed to address a general knee sprain.

Special PET Scan Instructions for People with Diabetes

Positron emission tomography (PET) is a nuclear medicine imaging test conducted to provide doctors with accurate basis for diagnosing a variety of diseases. It involves the injection of a special form of glucose, called 18-F fluorodeoxyglucose (18-F FDG) or simply FDG, to aid in imaging the condition of the tissues and organs. 

Because FDG is sugar, the test results are likely to be affected if the person undergoing it has diabetes, a condition characterized by high blood sugar levels. The blood will not take up FDG efficiently since it already contains too much sugar. This, however, doesn’t mean that diabetics can no longer have a PET scan. They only need to do the following preparations to make sure that the results of the test will be reliable. 

MRI Scan and Neurological Disorders: Can Machine Really Detect Issues?

Mixed martial arts competitions have never been more popular throughout the United States and the rest of the world. In fact, to say that the combat sport gets the adrenaline pumping is an understatement. However, what spectators find exciting and entertaining can prove to riskier than what MMA fighters and their trainers may initially believe—and we aren’t just talking about getting beaten up. There is also a significant risk of neurological damage, which may lead to neurodegenerative disorders and movement dysfunction.

One of the most difficult aspects of diagnosing and treating neurodegenerative disorders is the fact that many symptoms are quite subtle, especially in the early stages. This often leads to delayed treatment. Fortunately, medical researchers may have found a way to detect neurodegenerative disorders early on with the help of MRI technology.

PET Scan: Understanding Brain Function and Diagnosing Memory Disorders

Positron emission tomography or PET uses sophisticated computer analysis to provide accurate images of the brain. Unlike MRI or CT images, a PET scan provides a detailed image of one's brain function instead of its structure. PET works by injecting radioactive variants of molecules like glucose, oxygen, neurotransmitters, and hormones in the bloodstream to be carried throughout the body. A PET scanner then detects these radioactive molecules that emit radiation, allowing for the study of its uptake and distribution in the brain. In a PET image, the patches where accumulated radiation is highest (active) is typically red and lowest (decreased activity) is usually colored blue.

PET Imaging Used for Diagnosing Memory Disorders

While MRI and CT can give detailed images of the brain's structure, PET imaging are better at detecting functional abnormalities in the brain. Specialists say that it's even possible to detect these abnormalities very early in the course of the disease and before any anatomical changes occur. The decrease or increase in glucose metabolism at a cellular level are said to be the results of disorders that start with functional abnormalities.

Using MRI in Detecting and Assessing Slowly Progressing Conditions

Because of how it progresses, facioscapulohumeral muscular dystrophy or FSHD is among several disorders that are difficult to detect using current testing methods. This is likely due to the fact that severity, age of onset, and progression of this hereditary muscular disorder vary greatly. Some might notice symptoms in their teens, but studies show muscle weakness can start at infancy. Other people, on the other hand, only have mild FSHD that they don't notice its symptoms at all and are only diagnosed after a more affected family member has been diagnosed with FSHD.

People experience various symptoms depending on how mild or strong the disease is. Symptoms range from abdominal muscle weakness, mild hearing loss and abnormalities of the retina to facial weakness, hip weakness and shoulder weakness, among a host of other symptoms.

Tracking Repeated Concussion Injuries Among NFL players with PET Scans

A wide variety of tests can be used to determine if a patient has brain injury, and PET (positron emission tomography) is one of them. PET scanning technology relies on the fact that the brain stores glucose, and by tagging the glucose inside the brain with a radioactive tracer, the PET scanner can identify the areas of the brain where glucose is underutilized.

With PET scans being a useful imaging tool for brain injuries, experts now believe that it can be an indispensable tool in monitoring the brains of NFL players and athletes in other contact sports. Recently, scientists discovered that they can use PET scans to look for brain injury and repair markers in the brains of active and retired NFL players.

According to Jennifer Coughlin, assistant professor of psychiatry and behavioral sciences at Johns Hopkins University, the scientists believe that in PET scans, they have “a useful tool to monitor the brains of NFL players and athletes in other contact sports.”