Re: Ultrasound vs. DXA

[Guest guest]

Hi Arturo:

Ask your doctor, providing him/her the reference for the study I

posted that says CUS is superior to DXA for predicting fracture. If

s/he doesn't know where to get one ask him/her who does know.

If yer doctor doesn't know who knows then yer have to start

wondering.

As a last resort, contact the 'bone health' department of a hospital

or local university medical department.

Make a careful note for future reference of the time of year the

test is done. And get a 25(OH)D test around the same time also, so

that you know your vitamin D status corresponding to the test result.

Rodney.

>

> Hi Rodney

> I finally convinced my primary care physician to order a bone

density study (DEXA) to establish a base. I haven't made the

appointment yet. I'm ignorant of what is involved and now you're

educating me. how does one find out where to get calcaneal

ultrasounds? If it's inexpensive and safer I'd rather do that than

DXA. Would my doctor have to prescribe the calcaneal even if I were

to pay for it? I have the order for the DEXA, but I haven't acted on

it. How do I find calcaneal measurements in my city?

> Cheers,

> Arturo

>

>

> Ultrasound vs. DXA

> Posted by: " Rodney " perspect1111@... perspect1111

> Fri Feb 1, 2008 8:20 am (PST)

> Hi folks:

>

> This paper suggests that calcaneal ultrasound measurement of bone

> mass is somewhat superior to DXA for the prospective prediction of

> bone fracture. And it is quick (two minutes), involves no

> radiation, and is very inexpensive (simple equipment and quick)

and

> involves much less opportunity for operator error.

>

> Why does anyone use DXA? Could it be that a quick examination

> doesn't provide as much revenue per visit? If there is another

> reason perhaps anyone who knows what it is could enlighten us?

>

> My opinion is that those who keep saying DXA is the 'gold

standard'

> have spent too much time reading the promotional literature, and

too

> little time exercising their grey cells in the matter of DXA's

> shortcomings.

>

> This happens to be very relevant to me because I am having

frequent

> calcaneal ultrasound tests as part of my bone mass experiment. I

> certainly would not want to have frequent exposure to DXA

radiation.

>

> Here is the paper:

>

> J Bone Miner Res. 2006 Mar;21(3):413-8. Epub 2005 Dec 19.

>

> " Long-term fracture prediction by DXA and QUS: a 10-year

prospective

> study. "

>

> A, Kumar V, Reid DM.

>

> Osteoporosis Research Unit, Department of Medicine and

Therapeutics,

> University of Aberdeen, Aberdeen, United Kingdom.

> a.stewart@...

>

> " This study investigated the ability of DXA and QUS to predict

> fractures long term when measured around the time of the

menopause.

> We found both DXA and QUS are able to predict both any fracture

> and " osteoporotic " fractures and that QUS can predict

independently

> of BMD. INTRODUCTION: There are now many treatments available for

> prevention of osteoporotic fracture. To be cost-effective, we need

> to target those most at risk. This study examines the ability of

DXA

> and QUS to predict fractures in an early postmenopausal population

> of women. MATERIALS AND METHODS: We prospectively measured 3883

> women who had been randomly selected from a community-based

> register. At baseline, they were measured using DXA of spine and

hip

> (Norland XR-26) and QUS of the heel ( Sonix UBA 575). Follow-

> up had a mean of 9.7 +/- 1.1 (SD) years. All incident fractures

were

> identified and validated by examination of X-ray reports, and

these

> were compared with those without fracture in a -regression

model

> to calculate hazard ratios (HRs). RESULTS: We found adjusted HRs

for

> any fracture per 1 SD reduction in spine BMD to be 1.61 (1.42-

1.83),

> whereas neck of femur BMD was 1.54 (1.34-1.75). Areas under the

> curve (AUC) for a receiver operator characteristic (ROC) analysis

> were 0.62 for spine BMD and 0.59 for neck BMD. In a subgroup where

> QUS was also measured, the HR for a 1 SD reduction in BMD was 1.69

> (1.29-2.22) for spine BMD and 1.55 (1.17-2.06) for neck BMD. The

HR

> for a 1 SD reduction in broadband ultrasound attenuation (BUA) was

> 1.53 (1.19-1.96), and 1.44 (1.12-1.86) when further adjusted for

> neck BMD. The AUCs were 0.63 for spine BMD, 0.59 for neck BMD, and

> 0.62 for BUA. When only osteoporotic fractures were examined, the

> HRs increased in all situations. BUA showed the highest HR of 2.25

> (1.51-3.34), and when further adjusted for neck BMD was 2.12 (1.38-

> 3.28). CONCLUSIONS: In conclusion, it may be possible to scan

women

> around the time of the menopause to predict future fractures. It

> seems that, for " osteoporotic " fractures, BUA may be an improved

> predictor of fractures in comparison with DXA, because the

relative

> risk is highest for BUA, and independent of BMD. "

>

> PMID: 16491289

>

> Rodney.

>

[Guest guest]

Rodney--FYI,

I looked for additional studies beyond the one you referenced. I found some --

and they

aren't all quite as positive. It appears to me that the primary motivation for

the ultrasound

method is to reduce cost, although I agree that avoiding radiation is also a

factor.

Below are two of the other studies I looked at.

Thanks,

Todd

1: Aten Primaria. 2007 Dec 1;39(12):655-9.

[Predictive value of ultra-sound densitometry as a method of selective screening

for osteoporosis in primary care.]

Arana-Arri E, Gutiérrez Ibarluzea I, Ecenarro Mugaguren A, Asua Batarrita J.

OBJECTIVE: To determine the cut-off point of calcaneous quantitative ultrasound

densitometry (QUS) as a selection method in primary care for referral of

postmenopausal women for dual energy x-ray absorptiometry (DXA).

The estimated sensitivity of QUS was 78.9% (56.7-91.5) and

the specificity was 64.7% (55.6-72.8). The negative predictive value (NPV) was

94.9% (87.7-98.0) and the positive predictive value (PPV) was 26.8% (17.0-39.6).

CONCLUSIONS: Given its high NPV, QUS can be considered a useful

device for screening before DXA. Its low PPV means it has to be combined with

other complementary or substitutive selective screening methods, such as

predictive rules, which should be evaluated in each specific use.

PMID: 18093504 [PubMed - in process]

2: Ann N Y Acad Sci. 2007 Nov;1117:352-6. Epub 2007 Sep 13.

Quantitative ultrasound technology in evaluating bone status and osteoporosis in

patients with Cushing's syndrome.

Camozzi V, etto G, Zangari M, Lumachi F.

The aim of this study was to evaluate the ability of quantitative ultrasound

technology (QUS) in diagnosingosteoporosis in patients with CS.

Unlike DXA, QUS values did not differ significantly (P = NS) between groups.

Moreover,

in the overall population, as well as in a single group, there was no

correlation

(R < 0.5, P = NS) between QUS and DXA parameters.

In conclusion, in our study QUS was not able to differentiate osteoporotic

patients

from those with normal BMD measured by DXA, and thus QUS technology should not

be

used to discriminate between osteopenic and nonosteopenic patients with CS.

PMID: 17872385 [PubMed - in process]

[Guest guest]

Hi Todd:

Thank you for those papers. To be clear, I am not trying to take sides here. I am purely trying to get to the truth, in so far as that is possible with the information that is available.

The above said, it seems to me that, if I understand what they did, the first paper you posted started out with the ASSUMPTION that DXA is the ultimate arbiter. They then looked to see how close QUS (or CUS) was to the DXA scores. And then concluded that ANY variation from the numbers provided by DXA will mean that QUS is inferior. This is truly hilarious!

The paper I provided found, prospectively, that QUS is a better *predictor of fracture*. So on the basis of what did the authors of the study you posted feel justified in assuming that if QUS numbers differ from DXA numbers then it is QUS that is inferior? Strikes me, given the findings of the paper I posted, that they would have had more justification to have assumed that any variations between the two methods demonstrated DXA to be inferior. Right?

As regards the Cushing's syndrome example, I have no idea whether the Cushings complication would make this relevant to us.

But look, I am certainly not suggesting that this post is the final word on the matter. Let's take a look and see if we can find other studies where DXA was a better (or worse) predictor of ***fractures*** than QUS.

After all it is, surely, predicting the danger of fractures that is of interest to us.

Rodney.

PS: There are other benefits of DXA which have not been discussed here previously AFAIK. One is that it examines part of your spine vertebra by vertebra and gives a T-score for each one. You can also see the size of each vertebra. They vary in size quite a lot. One of mine is smaller than the others. Whether that is normal of not for that particular vertebra I do not know. It also found that, quite apart from my overall average T-score, one of my vertebrae (not the smaller one) has much lower ' 'density' ' than the others ................ at least according to DXA (!!) If true that is certainly interesting, and it is information that cannot be provided by calcaneal ultrasound.

------------------------------------------------

>> Rodney--FYI,> > I looked for additional studies beyond the one you referenced. I found some -- and they > aren't all quite as positive. It appears to me that the primary motivation for the ultrasound > method is to reduce cost, although I agree that avoiding radiation is also a factor. > Below are two of the other studies I looked at.> > Thanks,> Todd> > 1: Aten Primaria. 2007 Dec 1;39(12):655-9.> > [Predictive value of ultra-sound densitometry as a method of selective screening > for osteoporosis in primary care.]> > Arana-Arri E, Gutiérrez Ibarluzea I, Ecenarro Mugaguren A, Asua Batarrita J.> > OBJECTIVE: To determine the cut-off point of calcaneous quantitative ultrasound> densitometry (QUS) as a selection method in primary care for referral of> postmenopausal women for dual energy x-ray absorptiometry (DXA). > > The estimated sensitivity of QUS was 78.9% (56.7-91.5) and> the specificity was 64.7% (55.6-72.8). The negative predictive value (NPV) was> 94.9% (87.7-98.0) and the positive predictive value (PPV) was 26.8% (17.0-39.6). > > CONCLUSIONS: Given its high NPV, QUS can be considered a useful> device for screening before DXA. Its low PPV means it has to be combined with> other complementary or substitutive selective screening methods, such as> predictive rules, which should be evaluated in each specific use.> > PMID: 18093504 [PubMed - in process]> > > 2: Ann N Y Acad Sci. 2007 Nov;1117:352-6. Epub 2007 Sep 13.> > Quantitative ultrasound technology in evaluating bone status and osteoporosis in > patients with Cushing's syndrome.> > Camozzi V, etto G, Zangari M, Lumachi F.> > The aim of this study was to evaluate the ability of quantitative ultrasound > technology (QUS) in diagnosingosteoporosis in patients with CS.> > Unlike DXA, QUS values did not differ significantly (P = NS) between groups. Moreover,> in the overall population, as well as in a single group, there was no correlation> (R < 0.5, P = NS) between QUS and DXA parameters.> > In conclusion, in our study QUS was not able to differentiate osteoporotic patients > from those with normal BMD measured by DXA, and thus QUS technology should not be > used to discriminate between osteopenic and nonosteopenic patients with CS.> > PMID: 17872385 [PubMed - in process]>

[Guest guest]

In my experience, ultrasound is a useful indicator, but nowhere near

as accurate as a DEXA. I was told by an ultrasound operator that the

readings will fluctuate, much like blood pressure readings do. For a

while I had been getting a heel ultrasound every month, to hopefully

monitor the progress of my osteoporosis treatment, but I gave it up

because of the quirky readings.

One time I got a right heel reading of T=-1.5, which seemed

impossibly improved. I asked the technician to immediately scan it

again a few minutes later, and the reading was T=-1.9 (still too

good). The scan a month later was T=-2.3. And I was asking them to

scan both heels; some times the heels would have very similar

readings, and other times there would be a difference greater than 1

SD between my left and right heel.

So I quit having any more heel ultrasounds, and I just stick with the DEXA.

--Bruce

>

> Hi Rodney

> I finally convinced my primary care physician to order a bone

density study (DEXA) to establish a base. I haven't made the

appointment yet. I'm ignorant of what is involved and now you're

educating me. how does one find out where to get calcaneal

ultrasounds? If it's inexpensive and safer I'd rather do that than

DXA. Would my doctor have to prescribe the calcaneal even if I were

to pay for it? I have the order for the DEXA, but I haven't acted on

it. How do I find calcaneal measurements in my city?

> Cheers,

> Arturo

[Guest guest]

Hi Bruce:

As I will report in a couple of months after I have had my next DXA

in mid-March, my calcaneal ultrasound T-scores have been remarkably

consistent so far (seven tests), with all the fluctuations

apparently exactly what I might have expected them to be. I am

particularly impressed with the dramatic change in trend (hopefully

it is actually happening!) since I started the D2 + squats + Ca.

Bruce will be especially pleased to hear that I have more recently

added natto to the 'treatment'!

So Bruce, jftr, my experience - so far - is different from yours.

Not sure why.

Rodney.

> >

> > Hi Rodney

> > I finally convinced my primary care physician to order a bone

> density study (DEXA) to establish a base. I haven't made the

> appointment yet. I'm ignorant of what is involved and now you're

> educating me. how does one find out where to get calcaneal

> ultrasounds? If it's inexpensive and safer I'd rather do that than

> DXA. Would my doctor have to prescribe the calcaneal even if I were

> to pay for it? I have the order for the DEXA, but I haven't acted

on

> it. How do I find calcaneal measurements in my city?

> > Cheers,

> > Arturo

>