Alternatives to a CT Scan

If you choose not to CT, what are the other options available? Kindly elaborate on each of the options.

Dr. Greene’s Answer:

Plain x-rays use low doses of radiation, but give limited information. Sometimes this limited information is exactly what is needed. What to do if more detail is needed?  CT scans are one possibility.

As technology advances rapidly, medical imaging possibilities are also changing quickly. Still, the most common alternatives to CT scans are ultrasounds and MRIs. Unlike CT scans, neither uses ionizing radiation. Ultrasound constructs a picture using sound waves; MRI uses magnetic fields to produce an image that often has greater clarity than a CT.

Ultrasounds are blocked by bone, so head ultrasounds are not an option once a child’s soft spot has closed. Current head MRIs are not a good option for emergency evaluation of head trauma, in part because they can take 45 minutes or more to obtain, even when everyone is available and ready. When it comes to most head trauma (once the soft spot has closed), the best imaging options remain skull x-rays (to look for bone fractures) and CT scans (to look for injuries inside the skull). The main alternative to these is careful examination and observation.

MRIs are almost always preferable to CTs for imaging the head, and usually for the spine, except during trauma or when MRIs are not practical – such as when there are metal clips in the head. MRIs provide equal or superior imaging without the ionizing radiation. MRIs are also better than CTs for most musculoskeletal problems. Unfortunately, since MRIs take so much longer, children often need to undergo sedation, with its own risks, in order to remain still long enough for an MRI.

For imaging the abdomen or pelvis, the best bet might be ultrasound, MRI or CT, depending on the situation. I prefer using ultrasound whenever it will work.

Within the chest, especially within the lungs, CT scans remain the option of choice for most situations – though even here, MRI may become the best over the next few years as the technology continues to improve.

Read More From This Series:
CT Scan Defined
CT Scan, Ultrasound or MRI?
CT Scan Safety
CT Scans and Radiation Exposure
CT Scan Risks
Higher Risks in Children
Who Should Receive a CT Scan?
X-Ray or a CT Scan?
Alternatives to a CT Scan
When Should a CT Scan be Performed?
Important Tip to Reduce Radiation
Questions to Ask before Every CT Scan
Other Radiation Exposures Measures That Radiologists Should Adhere to When Administering a CT Scan
CT Scans and Cancer
When are MRIs not Practical?
What is Ionizing Radiation?
Who are Radiologists?

Dr. Alan Greene

Dr. Greene is a practicing physician, author, national and international TEDx speaker, and global health advocate. He is a graduate of Princeton University and University of California San Francisco.

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  1. jmcneil

    I need a pet scan to give my doctor an image of cancer at base of my tongue.
    Due to phobias I cant get into the Petscan machine. We have already tried Valium to knock me out.

    What other way is there to get this image.

    Thankk you. JM

  2. Mathew

    Thanks this was helpful to me. I had cancer last year and I now need cat scans every 6 months. The problem is that those iodine injects affect me very negatively. I feel like I’m going to die when they inject me with that stuff. I refuse to have another cat scan but I know I need checked out. I’m just going to have to push for an MRI. I know it’s more expensive but I just can’t get anymore iodine injections, it’s the worst feeling in the world.

    • shani

      Im so sorry you have had to go through that matthew! I have sarcoidosis and have alot of cat scans too and i feel the same way you do …Its such a bad feeling and i burn down there for days …I have made my mind up NO MORE!!! Best of luck to you dear!!


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