6 ms·

Routinely scanning people without symptom or otherwise cause for concern is not a good idea. The human body is very messy and variable, and it's hard for anyone

Routinely scanning people without symptom or otherwise cause for concern is not a good idea. The human body is very messy and variable, and it's hard for anyone or anything to reliably spot thing that are actually worth acting on. If the doctor spots a vague blob - how can they know what it is without any symptoms? The course of action is then "come back in three months for another scan." Subjecting a population to unnecessary routine full body scans, especially with radiation, will cause harm statistically. There are also countless examples of people undergoing unnecessary operation and suffering complications, like losing a perfectly fine healthy heart and requiring transplant.

dan00 4y ago
Yes, the breast cancer screening already has quite questionable results.
landryraccoon 4y ago
Wouldn’t the skill of analyzing scans improve if they were done more frequently? It seems like you’re promoting a self fulfilling prophecy. Doctors aren’t good at reading scans, so scans will cause false positives. But doctors are capable of learning and improving their skills. They will surely rapidly learn to screen a lot of false positives, thereby saving lives.
- MauranKilom 4y ago
  You seem to assume that radiologists currently see patient scans too rarely to deliver accurate diagnosis. That seems very unfounded to me. "More frequent scans per patient" != "More scans seen per clinician". You would just end up having to hire more clinicians. (Yes, your family doctor might end up seeing more scans in this scheme, but it is implausible that they would be better at evaluating them than a trained radiologist, which is who this would almost surely be deferred to anyway.)
  - landryraccoon 4y ago
    Is the argument then that scans are intrinsically error prone, as in the noise level is so high that even a team of highly trained radiologists can’t accurately determine if cancer is present from a scan?
    - MauranKilom 4y ago
      It's not the quality of the scan (although that can certainly be a factor). It's that there is a lot of variation in human anatomy, and "these pixels are brighter than the rest" can mean any of many things. Relatedly, for many types of brain tumors, you simply don't know what exact kind of tumor it is until you actually do a biopsy (= you undergo surgery). This can be important information ("how aggressive is it?"), so in some hospitals it is common practice to send a tissue sample for identification and get back the result while the surgery is still going on.
- moonchrome 4y ago
  This is a very naive argument, it assumes the entire problem is lack of skill and that early intervention on positive diagnosis is always a good thing. Mammography is a really good candidate for random screening and it's still debated because of false positives and the impacts of misdiagnosis.
valenterry 4y ago
We need yearly scans or even monthly scans (MRI) for everyone. Privacy concerns aside, I think we would learn an awesome lot. We could then monitor changes over time and machine-learning could probably get really good at recognizing what changes are harmless and which are harmful and need a doctor to look into. It's a dream scenario, but maybe some day it will be like that. Or it will be like that and be dystopia. :)
- discardable_dan 4y ago
  MRIs would need to take a fraction of the time for this to be viable.
  - derefr 4y ago
    Or, y'know, we could have 10x more MRI machines, thus incentivizing them to be cost-optimized in ways they absolutely aren't today.
    - Broken_Hippo 4y ago
      That's not really going to help. For an MRI, you have to lay there being still, and for some you have to hold your breath, all while in a loud little tube. I have to get a couple every year, and I*m lucky not to find them too uncomfortable. Some folks, though, would have serious issues with the cage over your head when you get your brain scanned: Your brain and spinal column will take 45 minutes, as will other areas. You will need to be repositioned often, adding and removing things to get the pictures of all the areas. In other words, you'll need an entire day off to do this if it is even possible for you to lay there for so long in one event, even if you get breaks. And for some folks it is going to be hours of torture. More MRI machines won't solve the issue.
  - likeabbas 4y ago
    Not necessarily, we just need cheaper ones. I interviewed at Hyperfine last year and they seemed to have a promising product https://hyperfine.io/ https://hyperfine.io/
  - 4y ago
ssivark 4y ago
> especially with radiation, will cause harm statistically. Ultrasound is not radiation (as in photons). To the best of our understanding (from a physics/engg perspective) ultrasound imaging capped by appropriate energy/etc limits is expected to be perfectly safe. Likewise with MRI. If we want more pointed study to be sure of this, that's fair, but let's be clear & specific about it and commit to figuring it out one way or another so we don't repeat the same discussion a couple of decades down the line. (We have to think of moving the state of the art forward, instead of festering in unresolved disagreements) Further, if you're concerned about under-studied possible side-effects of radiation from occasional diagnostic testing, what do you plan to do about being blanketed by mm waves once 5G gets deployed more ubiquitously? > There are also countless examples of people undergoing unnecessary operation and suffering complications This sounds far more serious (and fixable) compared to the physics/biology interaction of diagnostic testing. Why do we continue to bury our heads in the sand collectively, instead of trying to fix this with better decision-making tools?
- DanBC 4y ago
  > Likewise with MRI MRI isn't radiation, but is sometimes used with contrast dye. People can be allergic to the dye. For one person this is a small risk. Across a population we'd be causing harm. We'd balance the risks of harm against the benefits, and so far no-one can find a benefit to routine whole body MRI scans. And if the benefit was there the MRI machine companies probably would have found it by now because it'd massively increase the numbers of machines they could sell.
  - robocat 4y ago
    MRI uses electromagnetic radiation. MRI uses a magnetic field with a radio-frequency pulse and then the protons emit a radio-frequency response - that response location is used to synthetically generate the image. MRI does not use ionising radiation. Nice overview here: https://www.nibib.nih.gov/science-education/science-topics/magnetic-resonance-imaging-mri https://www.nibib.nih.gov/science-education/science-topics/m...
    - 4y ago
voldacar 4y ago
This is just silly. You are never disadvantaged by knowing more about what's inside your body. What you don't know can easily kill you, though. Hopefully in the long term future we will have extremely cheap & frequent MRI and blood testing so you can assemble a high resolution digital history of your body. Doctors are generally not very innovative people though and they will probably resist it to the end.
- bagels 4y ago
  It's not silly. Look at how the mammogram guidelines are set. If the scans are too frequent, the harm done from false positives (unnecessary surgeries and risks from those surgeries) can become too great. The standards were relaxed to include fewer scans in the last few years because of this. Apply this to more invasive exploratory surgeries, and you see people dying from internal surgery complications for benign cysts and lumps.
  - derefr 4y ago
    That's because single datapoints are used to trigger intervention. We should be intervening based on growth trends from time-series data. Time-series data which can only be collected by... frequent scans.
    - Sebb767 4y ago
      Don't discount psychological stress. "You have something growing in your breast which might be cancer, just wait a few months and we'll scan again" is not something that gives people a good nights sleep.
      - derefr 4y ago
        So don't tell them. Like I said, a single datapoint by itself is meaningless — so you wouldn't bring it to the patient's attention. Heck, the software shouldn't flag it for the doctor's attention. (Think: metrics-based alerting thresholds in software systems.)
    - 4y ago
paulpauper 4y ago
the screening guidelines take into account those risks and it's still deemed worthwhile because cancer can grow and become lethal despite being asymptomatic. colon cancer is the mid-life killer...plenty of ppl in their 50s or even 40s get it despite no risk factors. Screening is the only option to catch it early.

dan00 4y ago

Yes, the breast cancer screening already has quite questionable results.

landryraccoon 4y ago

Wouldn’t the skill of analyzing scans improve if they were done more frequently? It seems like you’re promoting a self fulfilling prophecy. Doctors aren’t good at reading scans, so scans will cause false positives. But doctors are capable of learning and improving their skills. They will surely rapidly learn to screen a lot of false positives, thereby saving lives.

MauranKilom 4y ago
You seem to assume that radiologists currently see patient scans too rarely to deliver accurate diagnosis. That seems very unfounded to me. "More frequent scans per patient" != "More scans seen per clinician". You would just end up having to hire more clinicians. (Yes, your family doctor might end up seeing more scans in this scheme, but it is implausible that they would be better at evaluating them than a trained radiologist, which is who this would almost surely be deferred to anyway.)
- landryraccoon 4y ago
  Is the argument then that scans are intrinsically error prone, as in the noise level is so high that even a team of highly trained radiologists can’t accurately determine if cancer is present from a scan?
  - MauranKilom 4y ago
    It's not the quality of the scan (although that can certainly be a factor). It's that there is a lot of variation in human anatomy, and "these pixels are brighter than the rest" can mean any of many things. Relatedly, for many types of brain tumors, you simply don't know what exact kind of tumor it is until you actually do a biopsy (= you undergo surgery). This can be important information ("how aggressive is it?"), so in some hospitals it is common practice to send a tissue sample for identification and get back the result while the surgery is still going on.
moonchrome 4y ago
This is a very naive argument, it assumes the entire problem is lack of skill and that early intervention on positive diagnosis is always a good thing. Mammography is a really good candidate for random screening and it's still debated because of false positives and the impacts of misdiagnosis.

valenterry 4y ago

We need yearly scans or even monthly scans (MRI) for everyone. Privacy concerns aside, I think we would learn an awesome lot. We could then monitor changes over time and machine-learning could probably get really good at recognizing what changes are harmless and which are harmful and need a doctor to look into. It's a dream scenario, but maybe some day it will be like that. Or it will be like that and be dystopia. :)

discardable_dan 4y ago
MRIs would need to take a fraction of the time for this to be viable.
- derefr 4y ago
  Or, y'know, we could have 10x more MRI machines, thus incentivizing them to be cost-optimized in ways they absolutely aren't today.
  - Broken_Hippo 4y ago
    That's not really going to help. For an MRI, you have to lay there being still, and for some you have to hold your breath, all while in a loud little tube. I have to get a couple every year, and I*m lucky not to find them too uncomfortable. Some folks, though, would have serious issues with the cage over your head when you get your brain scanned: Your brain and spinal column will take 45 minutes, as will other areas. You will need to be repositioned often, adding and removing things to get the pictures of all the areas. In other words, you'll need an entire day off to do this if it is even possible for you to lay there for so long in one event, even if you get breaks. And for some folks it is going to be hours of torture. More MRI machines won't solve the issue.
- likeabbas 4y ago
  Not necessarily, we just need cheaper ones. I interviewed at Hyperfine last year and they seemed to have a promising product https://hyperfine.io/ https://hyperfine.io/
- 4y ago

ssivark 4y ago

> especially with radiation, will cause harm statistically. Ultrasound is not radiation (as in photons). To the best of our understanding (from a physics/engg perspective) ultrasound imaging capped by appropriate energy/etc limits is expected to be perfectly safe. Likewise with MRI. If we want more pointed study to be sure of this, that's fair, but let's be clear & specific about it and commit to figuring it out one way or another so we don't repeat the same discussion a couple of decades down the line. (We have to think of moving the state of the art forward, instead of festering in unresolved disagreements) Further, if you're concerned about under-studied possible side-effects of radiation from occasional diagnostic testing, what do you plan to do about being blanketed by mm waves once 5G gets deployed more ubiquitously? > There are also countless examples of people undergoing unnecessary operation and suffering complications This sounds far more serious (and fixable) compared to the physics/biology interaction of diagnostic testing. Why do we continue to bury our heads in the sand collectively, instead of trying to fix this with better decision-making tools?

DanBC 4y ago
> Likewise with MRI MRI isn't radiation, but is sometimes used with contrast dye. People can be allergic to the dye. For one person this is a small risk. Across a population we'd be causing harm. We'd balance the risks of harm against the benefits, and so far no-one can find a benefit to routine whole body MRI scans. And if the benefit was there the MRI machine companies probably would have found it by now because it'd massively increase the numbers of machines they could sell.
- robocat 4y ago
  MRI uses electromagnetic radiation. MRI uses a magnetic field with a radio-frequency pulse and then the protons emit a radio-frequency response - that response location is used to synthetically generate the image. MRI does not use ionising radiation. Nice overview here: https://www.nibib.nih.gov/science-education/science-topics/magnetic-resonance-imaging-mri https://www.nibib.nih.gov/science-education/science-topics/m...
  - 4y ago

voldacar 4y ago

This is just silly. You are never disadvantaged by knowing more about what's inside your body. What you don't know can easily kill you, though. Hopefully in the long term future we will have extremely cheap & frequent MRI and blood testing so you can assemble a high resolution digital history of your body. Doctors are generally not very innovative people though and they will probably resist it to the end.

bagels 4y ago
It's not silly. Look at how the mammogram guidelines are set. If the scans are too frequent, the harm done from false positives (unnecessary surgeries and risks from those surgeries) can become too great. The standards were relaxed to include fewer scans in the last few years because of this. Apply this to more invasive exploratory surgeries, and you see people dying from internal surgery complications for benign cysts and lumps.
- derefr 4y ago
  That's because single datapoints are used to trigger intervention. We should be intervening based on growth trends from time-series data. Time-series data which can only be collected by... frequent scans.
  - Sebb767 4y ago
    Don't discount psychological stress. "You have something growing in your breast which might be cancer, just wait a few months and we'll scan again" is not something that gives people a good nights sleep.
    - derefr 4y ago
      So don't tell them. Like I said, a single datapoint by itself is meaningless — so you wouldn't bring it to the patient's attention. Heck, the software shouldn't flag it for the doctor's attention. (Think: metrics-based alerting thresholds in software systems.)
  - 4y ago

paulpauper 4y ago

the screening guidelines take into account those risks and it's still deemed worthwhile because cancer can grow and become lethal despite being asymptomatic. colon cancer is the mid-life killer...plenty of ppl in their 50s or even 40s get it despite no risk factors. Screening is the only option to catch it early.