BIG DIFFERENCE IN BONE DENSITY SCAN RESULTS!

[5annie7]

Hi, I had 2 bone density scans in the last 5 years via I think the QCT method, per my rheumatoligist. Both scans shows me to have SEVERE OSTEOPOROSIS.  I got to reading about how a DEXA scan was considered the gold standard for bone density scans. I got one prescribed by my family doctor prior to my next appointment with the rheumatologist (who HAD already agreed to my getting a DEXA scan for comparison). I got my DEXA scan results today, which showed LOW NORMAL DENSITY for my spine (L1-L4 lumbar vertebrae) and OSTEOPENIA in my hips..... NO out and out Osteoporosis and certainly not severe osteoporosis!!! I would LOVE any feedback/opinions on this MAJOR difference in scans.......... After feeling like I've been walking around with eggshells prone to break at a whisper, I am ready to celebrate, but did want to get some opinions about the above before getting overly joyous....! Thanks!!!

[DrNavneetMD]

Hello Dear,
DEXA bone density testing is the most accurate method available for the diagnosis of osteoporosis. It is also considered an accurate estimator of fracture risk. It will not tell whether you will or will not have a fracture, but gives relative risk of suffering a fracture, just as cholesterol and blood pressure help determine risk for heart disease. A low reading should not cause you to be anxious but may help you set healthy goals. As with other diseases and conditions, early detection is the key to prevention of further bone loss and eventual fractures. DEXA equipment is widely available making DEXA bone densitometry testing convenient for patients and doctors alike.
Quantitative computed tomography (QCT) provides a three-dimensional bone density image and thus provides separate estimations of cortical and trabecular bone densities. Based on the three-dimensional bone density image, QCT method can provides a structural stability of a bone to some extent. However, there are some limitations to use the QCT as a routine screening tool for osteoporosis because the price of the QCT equipment is very high and the radiation dose of a QCT scan is generally several hundred times larger than that of a plain x-ray imaging.

The most widely used method for measuring bone mineral density and for follow-up study of osteporosis patients is a dual energy x-ray absorptiometry (DEXA). The precision error of the DEXA in determining bone mineral density is reported to be about few percents. Furthermore, the radiation dose of a DEXA scan is very small compared with a QCT scan
DEXA scan results should be considered as  right .
Refer http://www.sagarapollo.com/dexa.htm,http://www.patentstorm.us/patents/7046834/description.html
Best

[5annie7]

Thanks SO much for your comments! They reinforce what I thought to be the case from research I found on the net. I really appreciate it!!!

[blacmik]

I read your comments regarding DEXA and QCT with interest. 1 year ago I had a QCT which gave a T score for L2-4 of 0.2 . Prior to starting hormone therapy for prostate cancer I have just had a DEXA L1-3 of -3.45 The difference appears to be much greater than normal between the two techniques.
About 50% of the web information supports DEXA and about 50% support QCT - they claim that DEXA picks up calcification caused by arthritis and sees it as bone calcium which increases the "apparent" but not the real bone density.
I am rather confused and any comments would be much appreciated.
Best Mike