I’m just seeing your comment now for some reason. This is super helpful.
Regarding your first point (pain vs suffering), that’s pretty interesting and makes sense. I would just note that the degree to which people can detach from painful experiences varies. Regarding suffering from operations and stents, I have heard the same thing about stents, and that is something we would have to factor in, I think, to a Fermi estimate of the amount of suffering that could be alleviated with early interventions for kidney stones. I wonder if someone could invent a stent that actually diffuses a bit of anesthetic around it while it is in (my understanding is the stents are typically only temporary in place).
Regarding the second point “Regarding small stones being downplayed:”. So, after writing this I looked into it a bit further because I was interested in whether an AI application assisting in early detection might be high value. The idea that radiologists miss tiny stones is only my personal guess. I have only seen 1-2 examples of this, when I was running a system I developed for stone detection and it found stones in CT colonography scans that were not mentioned in the report.. but those 1-2 examples only surfaced after running on over 6,000 scans.
Regarding how what happens with tiny stones: data on this subject is very scarce, but it seems most tiny stones resolve on their own without major symptoms (?). It’s really not very clear. I found one paper which covers this question, although it doesn’t directly study it. Looking at CT scans for CT colonography they found that 7.8% of patients (all middle aged adults) had asymptomatic stones. They then found that only 10% of patients with asymptomatic stones were later recorded as having symptoms over a variable follow-up interval that extended to a maximum of 10 years. So it seems the tiny stones don’t cause symptoms… but maybe it takes longer than 10 years before they start to manifest symptoms.. Probably having a tiny stone puts you at massively higher risk for a symptomatic stone event later in life. There’s very little data on this question or about stone growth dynamics across lifespan in general.. it’s not something that’s very easy to study. Basically, scanning people with CT just to monitor their stone size is absurd, so to study this we have to mine historical scans and then try to find follow-up scans to see if the same stones are still there, and compare their volume (which is a bit tricky to do accurately when the scan parameters change). This is an application for deep learning based automated stone segmentation algorithms, actually, to assist in doing such a study. We have a conference paper under review that actually does this although I have to say it’s technically and logistically challenging to do.
Regarding the third point, “Radiation stigma”: I agree, I think the way you are thinking about this is pretty in line with the risk-benefit calculus as far as I understand it. I should have elaborated a bit more, in my post. I was not thinking of doing a screening CT only to screen for kidney stones. I’ve been working with Prof. Pickhardt at UW. One of the things we’ve been researching is the utility of a low-dose “screening CT” in middle age. The screening CT would cover many things including stones. Prof. Pickhardt is working on assembling data to support this idea, mainly focusing on the value of scanning just the abdomen (not the chest). People currently get a coronary calcium score (“CAC”) CT scan for screening their cardiovascular risk. The abdomen also contains biomarkers (like aortic plaque) that also can gauge cardiovascular risk, plus we can look for a lot of other stuff in the abdomen, including kidney stones.
I agree the preventative approach is probably the most promising (identifying patients at-risk using genetics, blood tests, and maybe other factors, not screening CT) .. especially given how safe and cheap potassium citrate is.
Hi,
I’m just seeing your comment now for some reason. This is super helpful.
Regarding your first point (pain vs suffering), that’s pretty interesting and makes sense. I would just note that the degree to which people can detach from painful experiences varies. Regarding suffering from operations and stents, I have heard the same thing about stents, and that is something we would have to factor in, I think, to a Fermi estimate of the amount of suffering that could be alleviated with early interventions for kidney stones. I wonder if someone could invent a stent that actually diffuses a bit of anesthetic around it while it is in (my understanding is the stents are typically only temporary in place).
Regarding the second point “Regarding small stones being downplayed:”. So, after writing this I looked into it a bit further because I was interested in whether an AI application assisting in early detection might be high value. The idea that radiologists miss tiny stones is only my personal guess. I have only seen 1-2 examples of this, when I was running a system I developed for stone detection and it found stones in CT colonography scans that were not mentioned in the report.. but those 1-2 examples only surfaced after running on over 6,000 scans.
Regarding how what happens with tiny stones: data on this subject is very scarce, but it seems most tiny stones resolve on their own without major symptoms (?). It’s really not very clear. I found one paper which covers this question, although it doesn’t directly study it. Looking at CT scans for CT colonography they found that 7.8% of patients (all middle aged adults) had asymptomatic stones. They then found that only 10% of patients with asymptomatic stones were later recorded as having symptoms over a variable follow-up interval that extended to a maximum of 10 years. So it seems the tiny stones don’t cause symptoms… but maybe it takes longer than 10 years before they start to manifest symptoms.. Probably having a tiny stone puts you at massively higher risk for a symptomatic stone event later in life. There’s very little data on this question or about stone growth dynamics across lifespan in general.. it’s not something that’s very easy to study. Basically, scanning people with CT just to monitor their stone size is absurd, so to study this we have to mine historical scans and then try to find follow-up scans to see if the same stones are still there, and compare their volume (which is a bit tricky to do accurately when the scan parameters change). This is an application for deep learning based automated stone segmentation algorithms, actually, to assist in doing such a study. We have a conference paper under review that actually does this although I have to say it’s technically and logistically challenging to do.
Regarding the third point, “Radiation stigma”: I agree, I think the way you are thinking about this is pretty in line with the risk-benefit calculus as far as I understand it. I should have elaborated a bit more, in my post. I was not thinking of doing a screening CT only to screen for kidney stones. I’ve been working with Prof. Pickhardt at UW. One of the things we’ve been researching is the utility of a low-dose “screening CT” in middle age. The screening CT would cover many things including stones. Prof. Pickhardt is working on assembling data to support this idea, mainly focusing on the value of scanning just the abdomen (not the chest). People currently get a coronary calcium score (“CAC”) CT scan for screening their cardiovascular risk. The abdomen also contains biomarkers (like aortic plaque) that also can gauge cardiovascular risk, plus we can look for a lot of other stuff in the abdomen, including kidney stones.
I agree the preventative approach is probably the most promising (identifying patients at-risk using genetics, blood tests, and maybe other factors, not screening CT) .. especially given how safe and cheap potassium citrate is.