• I have heard conflicting responses - which is more reliable, CT scan or PET scan? Why? I have had nothing but CT's and just want to make sure I am getting the best possible reads. Any insight would be greatly appreciated!

    Asked by maloney6729 on Monday, January 30, 2012

    I have heard conflicting responses - which is more reliable, CT scan or PET scan? Why? I have had nothing but CT's and just want to make sure I am getting the best possible reads. Any insight would be greatly appreciated!

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    12 Answers from the Community

    12 answers
    • danellsar's Avatar

      CT will show them that there is "something" in a certain place, but it won't show whether that something is cancerous. PET shows specifically clusters of cancer cells because they are faster growing. They inject a glucose solution, and under PET imaging the cancer cells "light up".

      over 4 years ago
    • Cindy's Avatar

      When I get a PET scan it is combined with a CT scan. A combined PET/CT scan enables abnormalities such as cancer found on the PET imaging to be correlated with anatomy on the CT images.

      over 4 years ago
    • TJM's Avatar

      All true, but keep in mind that Pet does not have the capability of exposing "microscopic" cancer cells. Consequently it is easy to get a false sense of security thinking that a negative PET means you are free of disease. For example, elarged lymph nodes that had cancer may shrink during treatment to a point where they are within normal size and fail to uptake the glucose material. They could still harbor microscopic cancer cells.

      over 4 years ago
    • nancyjac's Avatar

      A PET scan displays organs and tissues and measures their activity and functioning in terms of blood flow, oxygen and glucose utilization and other metabolic processes.. A hot spot on a PET scan may or may not be cancer. A CT scan displays anatomical features such as the size and shape of a tumor. It is not that one is more reliable than the other, but rather they serve totally different purposes. A PET scan is a tool to find possible cancerous masses in the body while a CT scan measures the size, shape, and density of such masses.

      over 4 years ago
    • TomLand's Avatar

      All good answers. My Doc explained to me that the two types of scan work together very well and if insurance will allow he likes to do both. An example - after my first 7 week chemo series I had a CT and PET scan run. The CT scan showed sone shrinkage in all tumors. That seemed to be pretty good news. Then he went over the PET scan. It showed the 7 tumors on my liver were all metabolizing at background liver tissue levels. When asked what said in plain English he said the tumors on the liver were all dead or dying. So the CT scan showed shrinkage but the best news came from the PET scan. Hope this helps.

      over 4 years ago
    • Fusionera's Avatar

      I have had CTs and PET before, but I primarily have MRIs due to my cancer's location My neuro-oncologist advised me that they actually prefer to do MRI Spectroscopy over PET scans because of an unusual number of false positives on PET. The Spectroscopy measures amino acid levels in the affected areas, thereby differentiating active disease from radiation necrosis or scar tissue. Hope this is helpful.

      over 4 years ago
    • GregP_WN's Avatar

      I've had lot's of ct's, lot's of pet's, mri's. I love the pet. Makes me feel better, and I know my oncologist loveis it too. Where I go, I have it done in the morning at, say 10am drs apt at 1230. He looks on a computer and pulls up the petscan. He can see instantly what's up.

      over 4 years ago
    • po18guy's Avatar

      CTs show primarily masses - which may or may not be cancerous. PETs show unusually high metabolic activity - which might be natural bodily healing or a malignancy. Combine both with other tests, and you can have an accurate picture. Biopsy is definitive.

      over 4 years ago
    • maloney6729's Avatar

      Thank you everyone for your insight...it is truly invaluable!

      over 4 years ago
    • Angelina05's Avatar

      I'm going to say a PET scan is your best option. My endo and oncologist hardly ever send me for a CT scan anymore, it's right to the PET scan. I've had 2 reoccurances, so that may be why. From what I understand, PET scan light up the "hot spots" and show the doctor exactly where the cancer cells are located. CTs are great and do work, but I think PET scans are more accurate and detailed.

      over 4 years ago
    • GregP_WN's Avatar

      PET scan is one of the greatest inventions ever put out for cancer detection and treatments. When I had my first one, it detected a spot on my colon, which is nowhere near where my primary was found. (tonsil) Without the pet, we wouldn't have even known there was anything going on in the colon too.

      over 4 years ago
    • abrub's Avatar

      Each scan shows something different. With my cancer (appendix cancer) I only have CT scans, yet people with other colo-rectal cancers have both CTs and PET scans. It depends on the type of cell. PET scans show active cells that actively take up glucose. My cancer is slow growing - the cells are "indolent" and wouldn't show on a PET scan. Ask your dr. Never hesitate to ask your oncs anything. That's what you hire them for!

      over 4 years ago

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