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What they never told me about dexascans

Posted by joegor @joegor, Jun 2 4:52pm

I had my first scan 4 years ago at the same facility where I was starting treatment for prostate cancer. My numbers were -2.4 and -2.5. Two years later a rheumatologist I was seeing for another issue ordered another scan. Not knowing any different I had it done at the facility closest to me. Although my T-scores were down slightly my BMD numbers were improved. When I asked the doctor about the seeming contradiction he shrugged and said you really can't compare tests done on different machines. Nice time to tell me.

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gently | @gently | 2 days ago
In reply to @babybear77 "Do dexascans allow for difference in bone size. I have very small bones and diagnosed with..." + (show)
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Do dexascans allow for difference in bone size. I have very small bones and diagnosed with osteoporosis of the hip. I wonder how accurate these tests are.

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@babybear77,
Areal bone mineral density (BMD) does not account for the third dimension of depth. For two bones of the same volumetric BMD but of different sizes, the smaller bone will have a lower areal BMD on dual-energy X-ray absorptiometry (DXA).
If you think of it as measuring sugar in a glass of water, measuring from the the entire circle of the rim (areal measurement) a glass half full will be much sweeter that a glass that is full. As in your small bones having a greater density of mineral even with the same amount of mineral. Dexa doesn't allow for the dimension of depth.

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lightlifts | @lightlifts | 1 day ago
In reply to @anatomary "Yes, maddening but I think I learned (read so much it is getting hard to attribute..." + (show)
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Yes, maddening but I think I learned (read so much it is getting hard to attribute from where!) that despite there being variation between DEXA readings on different machines there is not wild variation. Otherwise, all the readings would really be useless!

So if you have severe osteoporosis you will still fall in the osteoporosis, or severe osteoporosis, range ....seems there may be a slight concern for recommended treatment (or none) for those persons with low-level osteoporosis, or osteopenia. These people might be over-treated by pharma. But I doubt those of us who have severe op would be over-treated; if we accept treatment regardless of variations in the DEXA scores across machines even if we only have moderate op, we could become low op or hit the osteopenia range.

Key is when you relocate to try to find a provider/location that has the same DEXA machine used in your past...then you will have a clearer picture whether you improved, or backslide, due to the brands specific calibrations.

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@anatomary I was told even the same brand of machine is different because they are all individually calibrated. Doesn't make a lot of sense to me it would be that way... My PCP who's an internist told me that.

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anatomary | @anatomary | 1 day ago

Thanks for letting me know! That makes it even more difficult if we move...

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naoshapiro1 | @naoshapiro1 | 10 hours ago

I must take the dexascan on same machine every two years, but was able to get the tribecular bone scan done after with new prescription given by my doctor and they just went to my machine and programmed it to give me the scan score. I have very porous bones and osteoporosis and very bad scores so on exercise routine, tai chi and eating more calcium powder with meals, low oxalate diet so won't make stones and just had reclast infusion in April, had ten years with fosomax and actonel decades ago Always exercised but had chemo and radiation 7 years ago and began higher dosage of omepraxole two years ago, that's why I lost bone, had esophajectomy in June 2019. Doing the best i can.

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petitefitsmartfemale | @petitefitsmartfemale | 4 hours ago
In reply to @kfhoz "@willowmena Unfortunately the reality of today's medicine is that doctors have too much stuff to know..." + (show)
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@willowmena Unfortunately the reality of today's medicine is that doctors have too much stuff to know or cover in the 15 minutes that insurance companies allow them.

I had much better luck with 2 PCP doctors who specialize in treating 65 & older patients only. Both of those doctors were good with putting me on HRT more than 20 years past menopause. The first doctor printed out about 15 pages behind paywalls about HRT including risks, and said that he would prescribe HRT if I felt OK with the risks after reading. Unfortunately he left the practice shortly after, but the replacement doctor did not hesitate at all. She was a big proponent of HRT for osteoporosis and was distressed that the doctor of one of her family members was not up on HRT for OP.

We tend to think of doctors who work with "geriatric" patients as dealing with people who much sicker than whatever we are. But OP is usually a disease of aging. These doctors can focus more about diseases of aging because they can concentrate on older patients and do not need to stay as up on other things that younger people experience like going through menopause or reproductive issues.

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@kfhoz , I am 64. I wonder if my gynecologist will allow me to go on HRT. I have not have hormones since I went into Menopause around age 50 or 51 since I was on the pill for genecology nonstop bleeding. I am BRCA1 positive so my gynecologist most likely will not allow it. I am trying to get my bones better through eating more protein, supplements, vitamins and strength training but maybe HRT will help me also but I don't want cancer.

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petitefitsmartfemale | @petitefitsmartfemale | 4 hours ago
In reply to @maine "So we are being diagnosed by machines unable to produce consistent results?! What happens when the..." + (show)
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So we are being diagnosed by machines unable to produce consistent results?! What happens when the one facility you have been using updates to a new machine? Suddenly your results go haywire? Somebody in manufacturing needs to go back to the drawing board!!!!

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@maine , I agree!

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petitefitsmartfemale | @petitefitsmartfemale | 4 hours ago

Thank you for sharing. I am very petite and now 4'9" tall so I wonder how accurate the machines are for me.

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