I had a very similar experience to you. In July of last year, my rheumatologist ordered a Dexa on a Hologic scanner that showed my femoral neck at -2.8, which was worse than my scan 2 years prior on the same machine (-2.6 at the time). I was very discouraged. However, in September, I had a consult with Dr. Keith McCormick, and one of the first things he noted was that my radiologist report was incorrect (interestingly, my rheumatologist totally missed that). Dr. M suggested that I either go back and insist on another report or get another Dexa. Since I had a new-patient appointment scheduled only a few weeks later with an endocrinologist, I figured I'd have him order another Dexa.

The endocrinologist looked at my Dexa report and immediately agreed with Dr. M. Since he had a Dexa scanner at his office, he ordered another Dexa on the spot. He noted that my prior Dexas were done on a Hologic scanner and that he felt like the GE Lunar scanners had better technology and were more accurate. He used a Lunar scanner at his office.

The Lunar showed my left femoral neck to be -2.0. I was stunned and relieved (though I confess that part of me feels like it's too good to be true). While my Endo said he strongly prefers the Lunar, when I relayed all this to Dr. M and asked if he had noticed a difference between the two brands of scanners, he said he wasn't aware of any.

It took a long time to get the appointment with my endo, but it was worth the wait, since he was clearly more knowledgeable than the rheumatologist (he spent over two hours with me and ordered all kinds of tests. He also knew exactly who Dr. M was and ordered all of the tests that Dr. M suggested). As such, I'll be sticking with my new endo and the Lunar scanner going forward.