And yet CT scans that dose patients with radiation are still standard of care.

_kb 5 days ago | parent | next [-]

I don’t think having them stand under low flying aircraft is much safer.

A typical CT scan delivers enough radiation to give a healthy person a 1/500 chance of getting a cancer in their lifetime that they otherwise would not have gotten. The risk is higher for children.

We have people working around low-flying aircraft all the time. I’m guessing the associated job risks are better.

When you take those jobs, it’s because you want to make money, not because your life is at risk, there’s information asymmetry between you and the medical provider who is indirectly rewarded for billing for scans, and the overarching medical system prioritized CT scans over MRIs while our engineering culture failed to establish something safer and cheaper.

Would you play Russian Roulette with a revolver with 500 chambers and 1 bullet? What if by doing so a hospital would receive thousands of dollars, and would go on to be paid many more thousands of dollars if you got unlucky?

The cost-benefit trade-off is there, and the powers that be are prioritizing cancer.

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tennysont 4 days ago | parent [-]

Fascinating---I appreciate you raising awareness. This information was a big update for me, so I looked for a source and found roughly the same numbers (though my numbers were 1/1000, possibly because newer CT exams seem to be slightly safer). From [1]:

> ...93 million CT examinations performed ... projected to result in approximately 103 000 future cancers ... cancer risk was higher in children ... CT-associated cancers could eventually account for 5% of all new cancer diagnoses annually.

Although keep in mind that these numbers do need context. cancer != death. That ranges from cold comfort (in the case painful chemo treatment & years of fear) to a critical factor (based on how the USA diagnoses it, approximately 6% of men will have prostate cancer that does not require treatment).

Based only on these numbers above and my prior beliefs, I would say that that either

A) CT scans are a necessary evil that haven't been adequately replaced

B) These numbers less problematic than one might expect, due to some quirk of the data

I generally trust the USA's medical establishment on new treatment, though I've heard that they're slow to clamp down on outdated treatments.

[1] https://jamanetwork.com/journals/jamainternalmedicine/fullar... https://www.nih.gov/news-events/nih-research-matters/radiati...

	▲	odyssey7 4 days ago \| parent [-]
		I appreciate you looking into the numbers to verify. The 1/1000 odds seem better, though still important. Also, framed another way, 5% of cancer cases caused by CT scans would mean that 1 in 20 people in the cancer ward were placed there by a CT scan. Or alternatively, phasing out CT scans would prevent 1 in 20 cancer cases, with prevention being worth more than a cure for every 1 cancer patient in 20.

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iancmceachern 5 days ago | parent | prev | next [-]

Do you have any other wavelenghts of radiation that pass through flesh but not bone and metal we can use instead? If so speak up please, otherwise we need to keep using x rays because, physics.

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odyssey7 4 days ago | parent [-]

MRI.

If we had gotten our heads out of the sand on pushing CT scans as the answer, years ago we might have progressed further on other tech too.

E.g., photons: https://medicalxpress.com/news/2025-06-scientists-entire-hum...

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iancmceachern 4 days ago | parent [-]

Yeah but that's different. It's great for soft tissue (that has water which can be vibrated by the magnetic field) buy less great for things like bone. Hence why CTs are still used. Also, the magnetic field makes it so things like intraoperative imaging is very difficult.

	▲	odyssey7 2 days ago \| parent [-]
		When bone is what needs attention, you can use conventional x-rays in all but specialist cases. A single x-ray image is typically far less radiation than a whole CT scan. And yes, you can still see bone in an MRI. A related question is, how well can you see soft tissue in a CT scan? CT scans are routinely used to diagnose soft tissue problems, where they are the wrong tool for the job: an MRI would be more ideal. CT scans in these situations expose the patient to avoidable cancer risks while compromising the level of insight provided to the medical provider. Interoperative imaging is another specialist use case. The need for CT scans in specialist situations speaks to the failure to develop alternatives with lower cancer risks. Also, the need to use a CT scan in certain situations does not mean that the CT scans should be used in other situations.

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nightfly 5 days ago | parent | prev | next [-]

You get a lot more detailed information out of a CT scan

	▲	odyssey7 4 days ago \| parent [-]
		Not more detailed than an MRI. And the longer we push CT scans, the longer we delay the advancement of less invasive technologies.

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5 days ago | parent | prev | next [-]

[deleted]

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jacquesm 5 days ago | parent | prev [-]

Yes, what do those doctors know anyway... /s