I am not a dexa operator, i am a phd student, developing a software tool to Quantify Dynamic PET images at the Hip. I am trying to replicate the ROI's that are use in dexa on to the PET images and that's why i need to understand how are those ROI's drawn on the Dexa hip images. I have been trying to read a lot of books but not really helpful. The best info i got up till now is following...
The default hip analysis includes a midline that must be placed correctly for the other sites to be identified correctly. The preferred position for the rectangular femoral neck box differs for the different manufacturers. For GE Lunar, the femoral neck box is located by the analysis program at the narrowest and lowest density section of the neck; typically this will be about half way between the femoral head and the trochanter. For Hologic the box is on the distal part of the femoral neck. This induces a large difference among these 2 measurements, because of a gradient of BMD all along the femoral neck (the proximal being the highest, the distal being the lowest). Thus careful checking of the femoral neck box is mandatory.
but in order to produce the ROI's correctly i need more information.
Thax for any help