Everything You Need To Know About PET CT Scan

Posted By: admin | Posted on: 10 November, 2017 07:58 am

Thessaloniki, Greece - February 17, 2016 Official opening of the first CT imaging PET-CT scanner (PET-SCAN) in northern Greece in the hospital C. Papageorgiou
PET CT Scanning Machine

(Image Credits: shutterstock.com)

 

PET CT

Positron Emission Tomography-Computed Tomography (PET CT scan) combines two imaging techniques. It provides information from a precise location, size and details of an internal organ or tissue, as well as any aberrance in its metabolic activity during a single imaging session.

The dual scanning technique enables excellent fusion of the PET and CT images. Because of the effectiveness of the dual technique, it makes it possible to diagnose diseases in their earliest stages. Also, provide a more accurate way in patient evaluation, a subsequent therapy strategy and monitoring of patients responses to treatment.

Which body parts are commonly scanned in PET CT?

  • Head (tumor or Alzheimer’s disease)
  • Neck
  • Esophagus (throat)
  • Lungs
  • Hepatocellular carcinoma (HCC), liver
  • Pancreas
  • Stomach
  • Ovarian
  • Cervical
  • Colorectal (colon)
  • Lymphoma (cancer of the immune cells called lymphocytes)

Why Do I Need A PET CT?

Why is a PET Scan Required
Why Do I Need A PET Scan

(Image Credits: shutterstock.com)

 

PET-CT scan is a non-invasive way to enable earlier and effective disease diagnosis as follows:

  • Precise location and detection of cancer: This is important for obtaining a biopsy for further testing and surgery.
  • Staging cancer: It determines the location of cancer and whether it has spread by infiltration (invasion) into other parts of the body, such as the organs or lymph nodes.
  • Monitoring the effectiveness of a treatment: To check if a therapy such as cancer is working for a particular patient.
  • Monitoring patients’ response to treatment: This allows doctors to maintain the existing treatment plan or work out alternative strategies.
  • Detection of cancer recurrence: To determine if cancer has returned after treatment.
  • Allows detection of a precise region of impairment: By superimposing PET andCT scan, a specific area of tissue abnormality as well as aberrance in metabolic can be identified. For example, a deformed tissue area with over activity or high-intensity signal called “hotspot”, is an indication of cancer. In contrast, a dim tissue area with minimal metabolic activity and a very low-intensity signal called “cold spot” is an indication of degenerative disease or stroke.
  • Enables evaluation of brain diseases such as tumors, memory loss, and seizures.
  • Enables assessment of blood flow to the heart muscle.
  • Determination of how a heart attack or myocardial infarction has affected certain areas of the heart.
  • Identification of areas of abnormalities in the heart muscle that will require repair from blood vessel blockage (angioplasty) or Coronary Artery Bypass Grafting (CABG) to treat Coronary Heart Disease (CHD).

What makes combined PET CT more important than PET or CT alone test?

It is having two tests performed in one scheduled appointment. It evaluates different characteristics exhibited by the same condition so that a more accurate conclusion can be drawn in the diagnosis of the disease.

In PET scan, a tracer containing a very little radioactive material is administered to the individual undergoing the test. The cells of the body uptake the tracer and use it to generate energy in the form of pairs of gamma rays. A detector then detects the rays that are emitted by the tracer molecule, which is constructed by 3D computer software into images. Furthermore, if an organ of the body is cancerous, it will uptake and utilize the tracer to generate more energy rapidly. The gamma emission will be greater and that location will be more conspicuous (hot spot). By contrast, in degenerative disorders, such as Parkinson’s or Alzheimer’s disease, the brain cells (neurons) are destroyed so there is very little tracer uptake thus the brain scan will look dim (cold spot).

The CT  scan on other hand, utilizes a special beam of X-rays, absorbed by different parts of  body. So it detects at various angles inside of the body by a camera which is then used to create images by 3D computer software. In certain situations, the doctor will administer contrast dye to the individual to improve the clarity of the multiple images taken. CT images reveal details of organ or tissue structure, its location and size, hence helps to determine if there is any structural abnormality in a tissue or organ.

Thus the combined PET and CT scans provide images with information at a precise location within the body.

How Do I Prepare For PT CT?

How to prepare for PET CT Scan, before, during and after care
How One Should Prepare For PET CT

(Image Credits: shutterstock.com)

 

The Day your doctor ordered the PET CT

  • Remind your doctor about your health history to help you to take necessary precautions. For example, if you have diabetes, they will ask you not to take your medication on the day your test is schedule. Once the test is complete, you can take it.
  • Tell your doctor about prescription and over the counter medications you are taking.
  • Let your doctor know if you are pregnant since foetuses are more sensitive to very low levels of the radioactive
  • Tell your doctor if you are breastfeeding since the tracer can pass on to the young child through breast milk.
  • Let your doctor know about any allergies you might have so that they can decide whether you will need to take allergy medication for the tracer injection (this is very rare).
  • Tell your doctor if you are nervous about close spaces (claustrophobia) so you could be given medication to calm you down.

When you schedule an appointment for the test: the staff at the facility will tell you how to prepare for the scan on the day before the test and on the day of your test. You must get this information from the staff before the test.

The Day before the PET CT test

  • Eat low carbohydrate diet.
  • Drink lots of fluids to keep hydrated.
  • Expect to spend about 3 hours at the facility

On the Day of the PET CT

  • If you have diabetes, don’t take your insulin medication. Wait and take it after the test otherwise it will interfere with the results.
  • Plan on 3 hours stay at the facility for the whole procedure.
  • Do not eat 4-6 hours before your scan and drink only water.
  • Wear comfortable and loose, “easy-to-wear” outfit with essentially no metal decorations so as to avoid interference with the image scanning.
  • Most probably your doctor may ask you to change your cloths into the hospital gown so as to avoid scanning interference.
  • Don’t wear jewellery as they will interfere with the scan and introduce false positives in the results.
  • Due to weak radioactive nature of the traces, pregnant women and children are not allow in the rooms where the injection is given.
  • The staff will ask you to sign a consent form saying you had followed all guidelines hence indicating you have agreed to take the test.
  • The scanning room temperature will be a bit cooler than the rest of the rooms in the facility. This is intended for the best performance of the PET scanning machine.

After your scan

  • Your doctor will advice you to drink lots of fluids for the rest of the day so as to help flush the tracer.
  • The Radiologist Specialist interprets the result and finally sends the report to your doctor who requests the test.
  • Your doctor will inform you when the report arrives at the physician’s office. It usually takes 3-5 business days.

Procedure for PET CT

How the PET CT Scan machine works and what is the procedure
Procedure Of PET CT

(Image Credits: shutterstock.com)

 

  • Firstly, the doctor will introduce a very small amount of radioactive substance – tracer (an example: common drug fluorodeoxyglucose – FDG) into your blood. This is done by inserting a needle into arm vein and administering tracer with a syringe through the needle.
  • The tracer then flows with the blood while slowly accumulating in the tissues and organs. This usually takes about 1 hour.
  • The Radiologist Technologist will then ask you to empty your bladder and lie on a flat scanner bed attached to the scanner.
  • The doctor will slide you into the scanner for 20-30 minutes. So the scanner will detect signals emitted by the tracer which had built-up in your organs.
  • The Technologist will ask you to remain still on the bed during the test.
  • A 3D computer connecting the scanner records the signals. Use them to create images which therefore, a radiologist specialist reads and interprets.
  • Finally, after taking the images, the doctor will slide you out of the scanner indicating the completion of test.
  • In certain disease conditions, the tracer build-up and metabolism is either:
    • Abnormally high, (called hotspot) as in the case of cancer, because the cells in that organ location are overgrowing; or
    • Very low (cold spot), as in Alzheimer’s disease, because most of the cells have been destroyed in the organs.

These differences, compared to normal tracer uptake and metabolism make it possible to detect which part of an organ is affected by a disease.

Limitations of PET CT

  • The test takes at least 3 hours, which many people may find inconvenient.
  • Furthermore, patients might not be able to drive home immediately after the test if they took medications to calm them from the nervousness of closed space (claustrophobia).
  • The PET-CT machine cannot fit obese individuals who weigh over 450 pounds.
  • The doctor needs to adjust the tracer dosage and the scanner so as to cater for children test.

PET CT Scan Side Effects

  • PET CT is non-invasive way to enable earlier and effective disease diagnosis.
  • None of the two techniques are painful. However, the prick of a needle from the tracer injection which might cause little skin redness and swell in the area.
  • However, there is no known adverse event.
  • You may experience a cold sensation as the injected tracer travels down your veins but it soon fades away.
  • You may be allergic to the contrast dye. That is why you have to make a previous arrangement with your doctor to have allergy medication for the test.
  • Diabetic patients might have problems with balancing blood sugar level from long fasting periods. Therefore, they should seek advice from their doctor.

How does the Radiologist distinguish between Healthy and diseased organ from the PET-CT scans?

Below are some PET CT Results:

CT and PET CT of early detection of Lung cancer
CT alone and PET CT fusion of Lung Nodules for Early Cancer Screening

Image 1 shows early screening for lung cancer in an individual who is at risk. Firstly, Image 1A displays a CT scan which revealed a suspicious pleural nodule, a very small tissue lump in the lungs.

Finally, to confirm the finding, a PET image taken from the same location was observed which clearly reveals the nodule (1B).

Cross Section, CT Scan, PET scan and PET CT scan of patient suffering from colon cancer
Identification of Colon Cancer which had spread to the liver by PET CT

Image 2A shows a cross section of a patient who originally developed colon cancer (red circle), as revealed by PET scan. This was removed by surgery.

Image 2B, however, is a CT scan which reveal an area of suspicious tissue change (indicated by two arrows), an indication that the colon cancer had spread to the liver before it was remove. However, this was confirmed by the hot spot area of a PET scan in 2C. Finally, after superimposing the CT and PET scan images; The precise location where the cancer had invaded the liver thus becomes clearer (2D).

Before and After treatment image of CT, PET and PET CT scan of cross section of a throat indicating cancer
Throat Cancer-Treatment And Monitoring

The images in 3A are CT, PET and PET CT respectively of cross sections of a throat, showing a precise location of an abnormal tissue (CT), which also happen to be a hot spot (area of high intensity tracer uptake and metabolic activity) of a PET scan, an indication of cancer. By superimposing both CT and PET images, you see structural details of the location of the hot spot.

Finally, a comparative set of images in 3B shows how chemotherapy treatment has gradually eliminated most of the cancer cells, leaving a residual spot, suggesting that the patient is responding very well to the current treatment methods.

PET CT cost:

This scan cost when done at a hospital when admitted there will cost around Rs. 25,000/. In labs outside hospitals the price can be substantially lower i.e. even as low as Rs. 9,000/-.

Check out www.chuzdr.com

The Table below highlights on the cheapest, average and highest PET procedure costs in USA; it varies with the type of insurance, part of the body the scan was performed, and also the state or city one lives in. Finally, it’s a matter of searching and being wise about how you want to spend your money.

 

The Table below highlights on costs of PET CT’s with/without health in insurance different locations in the USA

 

Insurance Type Scan Type Cost Location Source
 No Insurance Whole

body

$10,300 National

Maximum

http://arizonaoncology.com/locations-physicians/locations/detail-pet-center/
 No Insurance Whole

body

$7,000 National

Average

http://www.choosingwisely.org/patient-resources/pet-scans-after-cancer-treatment/
 No Insurance Brain $4,200 National

Average

http://arizonaoncology.com/locations-physicians/locations/detail-pet-center/
 No Insurance Chest $7,400 National

Average

http://arizonaoncology.com/locations-physicians/locations/detail-pet-center/
No Insurance Whole

Body

$4,900 New

Hampshire

Dartmouth-Hitchcock Medical Center

http://www.dartmouth-hitchcock.org/

 No Insurance Heart $6,800 New

Hampshire

Dartmouth-Hitchcock Medical Center

http://www.dartmouth-hitchcock.org/

 No Insurance Brain $6,700 New

Hampshire

Dartmouth-Hitchcock Medical Center

http://www.dartmouth-hitchcock.org/

Medicare

Insurance

Whole

Body

$1,500 New

Hampshire

Dartmouth-Hitchcock Medical Center

http://www.dartmouth-hitchcock.org/

No Insurance,

Cash Pricing

Whole

Body

$1,391 Raleigh, NC Healthcare Bluebook

https://healthcarebluebook.com

No Insurance,

Cash Pricing

Whole

Body

$1,637 Los Angeles, CA Healthcare Bluebook

https://healthcarebluebook.com

No Insurance,

Cash Pricing

Whole

Body

$1,672 New York,

NY

Healthcare Bluebook

https://healthcarebluebook.com

Other Useful Links:

Positron Emission Tomography (PET  Scan)

PET  CT Scan Cost

References:

Alzheimer’s early signs revealed by brain scans, memory tests

Lung Cancer PET Scan

Whole Body PET Scan Cost And Procedure Information

PET and The Heart

Metabolic Imaging: How PET Scans Are Changing Oncology

 

We have worked with partners to put together special packages for PET CT scans to give you quality and affordable service in your nearby clinic and hospitals

Also, for quality and affordable medical services provided by the best doctors near you, visit ChooseDoctor