Author: Southwest Diagnostic Center for Molecular Imaging

You’ve likely heard of MRI, CT, and PET scans, but understanding how they work and when they’re useful can help you make informed decisions about your health. Here’s a closer look at the differences between these vital imaging tools and how they can benefit you or your loved ones.

What They Have in Common

All three imaging tests allow doctors to see inside the body without surgery. They’re used to diagnose diseases, monitor treatment progress, stage cancer, and detect conditions early when intervention is most effective.

What Is CT (Computed Tomography)?

This test uses X-rays and radiation to produce 3D images inside our body. It takes cross-sectional pictures to show internal organs and their shape along with bones and blood vessels. All these images are then put back together and shown on a computer screen for the radiologist to interpret. Each image can be turned around or spun so it can be viewed from all angles.

Common Uses for CT:

• A CT scan is used for:
• Diagnosing cancer or heart disease
• Evaluating trauma or injury
• Detecting musculoskeletal disorders

What Is MRI (Magnetic Resonance Imaging)?

MRI uses strong magnets and radiowaves to produce highly detailed images of soft tissues without radiation exposure. Patients must remove any metal objects and inform the technician about implants or devices.

The test is loud and patients are given headphones or earplugs. They can take 30 to 60 minutes to complete.

Common Uses for MRI:

• Detecting tumors
• Identifying torn ligaments
• Diagnosing brain and spinal cord injuries
• Planning future surgeries

Sometimes this test requires the patient to be injected with a contrast dye so the radiologist can highlight specific areas.

What Is PET (Positron Emission Tomography)?

PET scans detect chemical changes in the body and can detect abnormalities before any structural changes occur. They are highly effective at identifying early-stage cancer.

The patient is injected with a small dose of a radioactive substance through an IV line. This is known as a radiotracer which moves through your bloodstream and any activity is recorded.

Common Uses for PET Scans:

• Early cancer detection
• Evaluating heart disease or brain disorders
• Monitoring unusual cellular activity

Key Differences of CT, MRI, and PET Scans

• CT scans offer fast, clear images ideal for emergency situations.
• MRI scans provide superior contrast resolution for soft tissue evaluation.
• PET scans detect early signs of disease at the cellular level, particularly for cancer.

Why Choose Southwest Diagnostic Center for Molecular Imaging

At Southwest Diagnostic Center for Molecular Imaging, we are proud to offer state-of-the-art CT and PET imaging services in Dallas. Our expert radiologists and compassionate staff ensure every patient receives personalized care in a comfortable environment. We use the latest technology to provide fast, accurate results, helping your healthcare team make informed decisions about your care.

If your doctor has recommended an imaging test, trust Southwest Diagnostic Center for Molecular Imaging for precise, high-quality diagnostics. Call (214) 345-8300 to learn more about the imaging services we offer.

Whenever technology can make medical testing easier and less cumbersome for patients, we applaud their efforts. We give major kudos to the latest medical advances in cancer diagnosis. We are talking about combining PET and CT and its power of hybrid imaging in cancer diagnosis. Let’s explain what this new imaging is and how it improves diagnostic accuracy.

What Are PET/CT Scans?

This is a hybrid scan that blends two imaging tests in one appointment to diagnose and find the location of cancer while improving the comfort and convenience for the patient. The PET/CT scanner provides great sensitivity in detecting any abnormalities in tissue throughout your body.

The test is non-invasive and quick, taking just around a half hour. It provides better imaging and decreases the number of appointments needed. In addition, PET/CT scans are generally covered by health insurance, including Medicare.

How PET/CT Works

PET, or positron emission tomography, is a type of nuclear medicine imaging which monitors biochemical functions of cells by analyzing how they process certain elements like glucose or sugar. Cancer cells metabolize glucose significantly more than normal tissues. As PET imaging detects increased glucose that other tests may miss.

However, PET does not exactly pinpoint the size and position of tumors necessary for treatment planning.

CT, or computed tomography, provides a detailed image of cross sectional x-rays of the body, but may miss tiny or beginning stages of cancers.

Combining the two in one machine, allows radiologists with Southwest Diagnostic Center for Molecular Imaging to conduct both scans in a single session without requiring the patient to move, helping them identify the where the tumors are and the stage to better target and treat cancers.

Every PET/CT scan is reviewed by a board-certified nuclear medical doctor and a board-certified radiologist. The result is they can make a more detailed image than either test could make by itself.

What Types of Cancer Can PET/CT Diagnose?

PET/CT scans are used to diagnose and monitor various types of cancer, including:

• Lung Cancer: PET/CT scans can help detect tumors in the lungs and assess if the cancer has spread to lymph nodes or other organs.
• Breast Cancer: These scans can be used to evaluate the extent of breast cancer and check for metastasis in other parts of the body.
• Colorectal Cancer: PET/CT imaging helps in staging colorectal cancer and monitoring for recurrence after treatment.
• Lymphoma: PET/CT scans are particularly effective in diagnosing and staging both Hodgkin and non-Hodgkin lymphoma.
• Melanoma: These scans can help determine the extent of melanoma and detect any spread to lymph nodes or distant organs.
• Head and Neck Cancers: PET/CT scans are used to assess tumors in the head and neck region, including oral, throat, and nasal cancers.
• Pancreatic Cancer: They can assist in evaluating pancreatic tumors and checking for metastatic disease.
• Prostate Cancer: PET/CT scans can help assess prostate cancer, especially when looking for recurrence or metastasis.
• Thyroid Cancer: These scans can be used to evaluate thyroid nodules and detect any spread of thyroid cancer.
• Sarcomas: PET/CT scans can assist in diagnosing and staging soft tissue sarcomas and bone sarcomas.

These scans provide crucial information about the location, size, and metabolic activity of tumors, aiding in accurate diagnosis and treatment planning.

Contact Southwest Diagnostic Center for Molecular Imaging at (214) 345-8300 if you would like more information on our PET/CT scans in Dallas.

Sources: The Role of PET/CT Scans in Oncology | Stanford Health Care

PET/CT Scan for Cancer | Baltimore | University of Maryland Medical Center (umms.org)

PET CT Scan for Cancer: PET vs CT vs MRI Scan (cancercenter.com)

GRH Introduces PET/CT Scans to Improve Cancer Diagnosis and Treatment – Glencoe Regional Health (grhsonline.org)

A PET/CT scan is a powerful imaging tool that incorporates two types of scans—positron emission tomography (PET) and computed tomography (CT)—to provide detailed pictures of your body. This scan is often used for cancer screening, as it helps doctors detect and monitor cancerous tissues and other abnormalities. If your doctor recommended a PET/CT scan, you’re probably wondering what to expect. This guide will walk you through the process, from how to prepare for the scan to what happens during and how long it takes.

What Happens During a PET/CT Scan?

A PET/CT scan involves two imaging techniques to create a comprehensive view of your body. The CT scan uses X-rays to produce detailed images of your body’s internal structures, while the PET scan tracks how your cells are functioning. This is done by detecting metabolic activity with a small amount of radioactive material, called a tracer.

Let’s look at the process in detail:

1. Injection of the tracer: Before the scan begins, a technician will inject the radioactive tracer into a vein, usually in your arm. This tracer helps highlight areas of high metabolic activity, which can indicate the presence of cancer cells.
2. Waiting period: After the injection, you will need to wait about 30-60 minutes for the tracer to travel through your body and accumulate in the areas being examined. During this time, you may be asked to relax in a quiet room and avoid movement.
3. The scan: Once the waiting period is over, you will lie down on a table which moves into the PET/CT scanner. The machine is shaped like a large donut, and it takes images of your body as you pass through. The scan itself is painless, and you’ll be able to communicate with the technician throughout the process.
   Imaging: The PET scan detects the tracer’s radiation to measure cellular activity, while the CT scan captures detailed structural images. Together, these images provide your doctor with valuable information about potential abnormalities in your body, such as cancerous growths.

How Long Does a PET/CT Scan Take?

The entire PET/CT scan process can take anywhere from 1.5 to 3 hours, depending on the specifics of your procedure and the area being examined. The actual scanning process typically lasts around 20 to 40 minutes, but you should allow extra time for the waiting period after the tracer injection.

How to Prepare for a PET/CT Scan

Proper preparation can help ensure accurate results from your PET/CT scan. It can also help you feel calm and relaxed, which is always important! Here are a few key things to keep in mind:

Fasting

You will likely be asked to fast for at least 4 to 6 hours before your scan. This is because certain foods, especially those high in sugar, can interfere with the results by affecting the tracer’s distribution.

Avoid strenuous activity

Intense physical activity before the scan can also affect the accuracy of the results, as it increases the metabolic activity in your muscles. It’s best to avoid exercise for 24 hours before the scan.

Wear comfortable clothing

You should wear loose, comfortable clothing with no metal (ex: zippers or underwire bras) on the day of your appointment. You may also be asked to change into a hospital gown for the procedure.

Inform your doctor

Let your radiologist know if you are pregnant, breastfeeding, or have any allergies, especially to contrast dyes or other materials that might be used during the scan.

Your PET/CT Scan: What to Expect

A PET/CT scan is a highly effective imaging tool for cancer screening and other diagnostic purposes. Understanding the process, from the injection of the tracer to the scanning itself, can help ease any concerns you may have, making the process as smooth as possible!

The scan is painless, and while it can take a few hours from start to finish, it provides your doctor with critical information to guide your diagnosis and treatment. Always follow your radiologist’s instructions for preparing for the scan.

Don’t hesitate to ask any questions about the procedure beforehand! Contact Southwest Diagnostic Center for Molecular Imaging at (214) 345-8300 today.

Sources:

https://www.baptisthealth.com/care-services/services/cancer-care/screening-and-diagnosis/molecular-imaging

https://radiology.ucsf.edu/patient-care/prepare/pet-ct

https://www.mayoclinic.org/tests-procedures/pet-scan/about/pac-20385078