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463 points bookofjoe | 3 comments | | HN request time: 0s | source
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supernova87a ◴[] No.45131847[source]
Hey, I heard about how utility pole inspecting helicopters are able to tell the good/rotten state of wooden telephone poles by the reverb pattern of sound waves coming off the poles from the rotors -- it seems to me the whole field of non-invasive sensing (and using existing/ambient emission sources) is getting pretty impressive.
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odyssey7 ◴[] No.45133389[source]
And yet CT scans that dose patients with radiation are still standard of care.
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iancmceachern ◴[] No.45135207[source]
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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1. odyssey7 ◴[] No.45138917[source]
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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2. iancmceachern ◴[] No.45140838[source]
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.
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3. odyssey7 ◴[] No.45160797[source]
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.