Hi I am not sure if my question went through was I was resubmitting . I have 2 questions . First is it safe to do a full T3 MRI if the spine including lumbar and the a few hours later in the same day do an abdominal pelvic CT ? Does that increase cancer risk ? Second i know they say that MRIs are safe but if they use the sane RF as cell phones then why do they say cell phones cause cancer ? Can MRIs cause cancer like the cell phones can possibly do ? If that is a possibility then could it be dangerous to do an MRI before a CT scan ? Could the heating up of the tissue prior to x rays with the CT lead to more DNA damage ? Thank you , Lisa

CT scans, MRI scans and cell phones have one thing in common. They all emit energy known as electromagnetic radiation. However, the energy range and the intensity levels used are quite different, and the ways that the energy interacts with the human body are also different. There is no reason to be concerned that the energy from MRI will affect your body in a way that enhances the effect from the CT scan, or vice versa. There is also no reason to be concerned about cell phone use, because cell phones cannot cause cancer, and neither can MRI scans. CT scanning uses x-rays, which are a type of ionizing radiation. At very high radiation dose levels of ionizing radiation, cancer risk is increased. We know this because of studies of atomic bomb survivors and nuclear workers who received very high doses. For patients receiving lower doses such as from medical x-rays like CT scans, there is no evidence of an increased cancer risk above the baseline risk that we all face by simply living on Earth, unless many such scans are performed in a compressed time period. Natural DNA repair mechanisms can counteract the effects of ionizing radiation at low doses and dose rates. Using diagnostic imaging to detect a potentially serious disease is generally considered to be a good trade-off when compared with the small (or possibly non-existent) theoretical risk of causing a cancer that would not appear until many years into the future, if at all.

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When talking about the risks of radiation in X-rays, often it is compared to background radiation. However, scans are usually aimed at a concentrated area of the body in very short amount of time, whereas I assume background radiation is spread across the whole body. Can the two be compared when we talk about risk to individual organs? Does 1 mSv aimed at one part of the body does more damage to that part than 1 mSv worth of background radiation?
How can I find your guidelines for CT radiation limits? I am 60 years old, both my parents with cancer (mom died), and the insurer recommended me to do a hip CT even though the orthopedic doctor clearly wrote MRI in the referral. I understand the insurer’s preference to save money but given my radiation concern, exacerbated by age and family history and the fact that I already had 5 XRay imaging sessions in the past 12 months (three dental and 2 chest views) – I of course prefer to go for the MRI option. I tried to find in your site any official reference (because they said that “according to the AAPM there is zero risk for me”) – but failed. Can you please advise – considering my history, age, and previous xray sessions this year – what would you consider as an exposure to avoid? Is there really a zero risk? Shouldn’t I insist on the MRI – as recommended by the doctor? Basically I see the discrepancy between the clinical doctor and the administrational doctor. And I need to know that they don’t just use your establishment name in order to “disarm” me and save some dollars… Your insights will be highly appreciated. Especially if you would have advised to insist on the MRI (all considered)