While your comment as a whole is thoughtful and well written, I'm surprised to hear you say, "Medical imaging is not done very often..."
Medical imaging is commonly overused, and its overuse is recognized as being one of the leading causes of certain types of cancer. For example, the original story explains...
"In a 2011 report sponsored by Susan G. Komen, the Institute of Medicine concluded that radiation from medical imaging, and hormone therapy, the use of which has substantially declined in the last decade, were the leading environmental causes of breast cancer, and advised that women reduce their exposure to unnecessary CT scans." (The substantial decline refers to hormonal therapy, not imaging.)
That is a great, powerful, article. Thank you for posting the link.
> For an individual woman in her 50s, then, annual mammograms may catch breast cancer, but they reduce the risk of dying of the disease over the next 10 years by only .07 percentage points — from .53 percent to .46 percent. Reductions for women in their 40s are even smaller, from .35 percent to .3 percent.
Many people are going to be baffled by risk presented like this. Presenting the numbers differently is helpful to let people understand the risks.
"Imagine 10,000 women like you. Of those X will die from this disease. But if we take those same 10,000 women and give them mammograms we find that Y will die from the disease".
Sometimes X will be 2 and Y will be 1 (50% decrease in risk) or X will be 100 and Y will be 2 or X will be 100 and Y will be 99.
Presenting the numbers this way allows most people to understand the risks better.
MRI is very different from CT. CT use X-rays, which is an ionizing radiation. MRI uses a very strong magnetic field, and as far as we know it doesn’t increase the cancer rates.
The final images are quite similar in appearance (semi transparent films with a black background), but the underlying process is very different.
I've lived in both the us and Canada. I noticed that mri and CT scan scans were really easy to get done in the us, but would often require a month or more of waiting in Canada for non Urgent issues. I wonder how much the overuse contributes to differences in health care costs between countries?
Medical imaging is commonly overused, and its overuse is recognized as being one of the leading causes of certain types of cancer. For example, the original story explains...
"In a 2011 report sponsored by Susan G. Komen, the Institute of Medicine concluded that radiation from medical imaging, and hormone therapy, the use of which has substantially declined in the last decade, were the leading environmental causes of breast cancer, and advised that women reduce their exposure to unnecessary CT scans." (The substantial decline refers to hormonal therapy, not imaging.)