Data Acquisition Analysis for Femoral Morphometric X-Ray Absorptiometry

Abstract 

Bone mineral density (BMD) is a contributing factor of hip fracture risk. Other factors, such as lifestyle, the propensity for falls, and femoral geometry may influence the risk of hip fracture. The DMS Lexxos densitometer, a dual-energy X-ray densitometer can produce either a single-energy X-ray or a BMD image. The purpose of this study was to evaluate which of these 2 images enables the best detection to make femoral morphometry measurements. Spatial resolution, contrast, and noise were evaluated separately. A contrast-detail phantom was also used for the purpose of overall visual analysis. The spatial resolution was the same in the 2 images. The contrast was better with the BMD image, but the noise was higher. Using the contrast-detail phantom, the single-energy X-ray image allowed globally a better detection of the objects, but results were in the same range with high contrast values. Hip volunteers' morphometric measurements and the Singh Index were evaluated 3 times for each image by 3 observers, and the intra-, inter-, and global reproducibility was computed. The reproducibility of the measurements seems to be better with the single-energy X-ray image but results were not statistically significantly different. These results suggest that even if the image-quality indices were different, the single-energy X-ray image and BMD image are closely useful for clinical morphometric femoral evaluation.

Key Words: DXA, femoral morphometry, image quality