I went to the doctor complaining of constipation. He sent me for a CT scan which showed that I was literally full of shit. The prescription was for a large dose of MiraLax. Now I wonder if the risk of the CT scan was really justified given that plenty of people already tell me that for free and without radiation.
A. Newer CT scan machines use lower radiation doses.
B. If you're getting only one scan a year you're fine and within yearly limits of radiation dosage considered acceptable.
Remember that you'll get comparable levels of radiation even if you commute through the grand central station every day.
This paper is for lack of a better word, crap. It's becoming sensational for the conclusion it makes and I'm afraid it's now going to create more harm because of that.
> B. If you're getting only one scan a year you're fine and within yearly limits of radiation dosage considered acceptable.
But doesn't it make a difference if that "acceptable yearly limit" is spread out throughout the year as opposed to a few minutes of CT scan session?
I had a CT of my pelvis and abdomen recently and worked out it was equivalent to about 5 years worth of background radiation.
The dose required is actually quite a lot higher than typical comparisons to eg chest X-rays and the like
What about contrast? I've heard it's really hard on your thyroid.
> Remember that you'll get comparable levels of radiation even if you commute through the grand central station every day.
Gemini says this:
> A single typical CT scan delivers a dose that is roughly 1,000 to over 5,000 times higher than the dose you'd get from spending a few hours in Grand Central Terminal.
Where did you get that from?
If the hallucination machine can cite a source, check and cite that for facts, but don't cite the hallucination machine.
Weird you don't have this requirement for the OP spewing his urban myths above.
Human hallucinations are natural.
Machine hallucinations are avoidable.
Was it hallucinating here, or are the commenters hallucinating? What OP is saying is just not true. A CT scan and normal daily commute in Grand Central station are NOT comparable in terms of radiation received. Somehow this is controversial because an AI said it?
The machine appears to have hallucinated the incomparable comparison, instead of a human.
(And I'm not picking on the machine at all here. I use it all the time. At first, I used to treat it like an idiot intern that shouldn't have been hired at all: Creative and full of spirit, but untrustworthy and all ideas need to be filtered. But lately, it's more like an decent apprentice who has a hangover and isn't thinking straight today. The machine has been getting better as time presses on, but it still goes rather aloof from time to time.)
Did you actually discredit someone or have you not properly considered your units in this response?
Commute through the Grand Central station everyday is certainly not a few hours.
And people don't tend to get a CT scan very frequently so the timeline here is massive.
In your opinion how many hours spent in Grand Central station equal the radiation received from a CT scan?
Somewhere between 7 and 700 days.
CT Scan: 10-1000 mrem
Grand Central Station: 525 mrem / yr
So OP's statement is true for people who live IN the station.
It's roughly 40 min per workday over a typical year. That's a bit high but not unreasonably so.
That would amount to 10 mrem of radiation per year. I don't believe this is a realistic estimate for a CT scan though. From epa.gov [1]:
- Head CT: 2.0 mSv (200 mrem)
- Chest CT: 8.0 mSv (800 mrem)
- Abdomen CT: 10 mSv (1,000 mrem)
- Pelvis CT: 10 mSv (1,000 mrem)
So for a head CT, one would need to spend more than 13 hours per workday in the station. OP was off at least an order of magnitude.
https://www.epa.gov/radiation/frequent-questions-radiation-m...
This data is from 2006. Over 20 years, there has been substantial progress in CT radiation reduction through model-based iterative reconstruction and now ML-assisted reconstruction, aside from iterative advances in detector sensitivity and now photon-counting CT.
In clinical practice, those doses are about 2-3x what I see on the machine dose reports every day at my place of work.
In thin patients who can hold still, I've done full-cycle cardiac CT and achieved a < 1 mSv dose. We are always trying to get the dose down while still being diagnostic.
Source: Practicing radiologist.
Fair enough. That was the first number I pulled from Google, but I trust your source a good deal more.
I used the word comparable. Given they are in the same ballpark of log scale i stand vindicated in my opinion.
Also there's an apple store there. RIP all the geniuses there i suppose
Someone I know got partial constipation, lack of apetite and stomach reflux. After some month of triying to fix the reflux, they discovered it was intestine cancer when the cancer was big enough to block almost all the flow.
IIUC from a sibling reply, you already used a few laxative, so perhaps a CT scan was the next step.
I had a CT scan ordered for abdominal discomfort which had been making sleep a nightmare for years.
I started taking ag1 and Metamucil and the stomach discomfort has completely gone away over a span of weeks/months.
The resulting dramatic improvement in sleep cascades to just about everything in my life and different recurring health problems keep disappearing now.
It’s crazy how many problems can be caused by apparently just not getting enough fiber.
Never ended up getting the CT scan, which probably would’ve been expensive and involve some small degree of risk.
pro-tip: start your days with an unripe banana, at least slightly greenish. If it's sweet it's too ripe for medicinal value.
Beats any processed supplement or other OTC drugs IME.
But did those words really get through to you like an energetic photon? I think, it's quite ionic how frequently the last strand has to break before we realize, we should have been radicalized by people, not high voltage discharge events.
Why would you go to the doctor for that instead of first trying one of the many known solutions?
* a tablespoon of epsom salt * a tablespoon of mineral oil * several OTC products
I did try a boatload of OTC products, and eventually went to a generalist and then a specialist when it became severe and chronic. The OTC products recommend that on their labels. I now manage it with careful diet and a daily dose of polyethylene glycol.
Yeah, a plain old abdominal x-ray might've sufficed to diagnose that.
Or the pre-x-ray technique of abdominal palpation.
The same scan found a large goiter which led to surgical removal of a malignant thyroid tumor. So I have mixed feelings.
If its any consolation, having diagnosed a malignant papilary or follicular thyroid tumor (surprizingly) is correlated with equal or slightly increased lifespan compared to the population that did not have this tumor—maybe it is because of having more frequent or better access to healthcare, which is harder to control in such epidemiological studies. It is one of the few positive known relationships with cancer.
Yup, this is something that shows up¹ for melanoma, thyroid, and prostate cancers: those who are diagnosed when the cancers are in situ (haven't left the tissue of origin) have better 5-year survival chances compared to people of the same age, race, and sex. Likely because, if people are diligent enough about their healthcare to report early warning signs and get the recommended screenings, those people also have much healthier lifestyles. If there were a way to control for lifestyle, I'd imagine the "benefit" would disappear or become a small but clear negative.
1: You won't find relative net survival above 100% in the CDC's statistics. That's because they calculate survival rates using daily differences in death hazards derived from life tables of people with cancer and those without. Add up the differences across all days, do some exponential math, and voila: relative net survival rates. But, if the relative risk for a day is negative (i.e. those without cancer have a higher risk of death), then they set the relative risk to 0 instead for that day. Which is ridiculous, IMO. It's forcing a distribution of actual events to match an idealized model.
Only after the procedure my ENT told me that if she were to pick a cancer to get it would be this one, and that the experts are trying to rename it from cancer to neoplasm because of its relative benignity. But I hadn't heard that it could actually be a positive. That underlines the mixed blessing of screening tests.
It also underlines the second-order risks of unneeded diagnostic screenings, even those that don’t include ionising radiation and its ilk, as the surgery you may otherwise have not had is itself not free from risk. Of course the case generalises out from there as well to not only this specific cancer.
why a CT and not a X-ray? did they need to see the gestating turds in 3D?
not a doctor, but a CT could show mechanical obstruction or twisted intestines in a way X-ray would not.
I imagine the doctor already assumed the shit was there, but wanted to understand why.
I further imagine prescribing a megadose of laxative might be harmful if someone cant expel the shit.
I really wonder if there's value in straightening the tract in post. Sometimes something at 45 degrees doesn't really view well in the slices.
CT isnt constrained to 90 degree slices and can be viewed at any arbitrary angle, or in 3D without further processing.
This video [1] is a presentation on bowel CT with great images. For those interested in X-ray, compare the X-rays at 14 minutes with the CT at 10.
Also worth noting, that X-ray is being recommended as a quick diagnostic before moving to CT
I knew the math wasn't limited to 90 degree slices. I've had a few CT scans, and twice when I got my copy the DICOMs were a bunch of 90 degree TIFF slices. It wouldn't surprise me if the radiologist had the raw beam data and could slice it however they chose.
the Tiff slices is just post process storage. A good DICOM reader can view those tiffs in any direction.
After all, if you have the tiffs, you already know the grayscale for every pixel in the XYZ space. You just need to grab the right pixels from each slice
Interesting stuff! Could you suggest a DICOM reader that does so?
I had assumed slicing the raw beam data would give you much better output resolution whenever there were differences between transaxial and z resolution, since at some angle and offset you end up sampling across the largest gaps in the XYZ pixels. But maybe that's not a real issue? Is this how it's done in practice?
Same. The CT is to rule out diverticulitis and in my case, since the pain was located in my lower right abdomen, appendicitis.
I was just full of shit, as usual. Now I eat salads and drink more water when I am at elevation.