Comparison between metacarpal bone measurements by computarized radiogrammetry and total body DEXA in normal and osteoporotic women.

We evaluated the precision of metacarpal radiogrammetry by computed radiography as a technique for bone mass measurement. Measurements obtained using this method were compared with densitometric measurements of total body bone mass using dual-energy X-ray absorptiometry. Our results showed that the coefficients of variation for radiogrammetric measurements were similar in 60 women with osteoporosis and in 100 normal women: 0.7% in both groups for external diameter of the second metacarpal, 2.41% in the normal women and 2.03% in the women with osteoporosis for internal diameter, and 2.3% and 2.4%, respectively, for cortical thickness. Except for external metacarpal diameter, which did not differ between normal and osteoporotic women, all the measurements were smaller in the women with osteoporosis (p < 0.001). The correlation between metacarpal cortical thickness and total body bone mineral content was r2 = 0.462 in the women with osteoporosis, r2 = 0.476 in the controls, and r2 = 0.522 in the two groups combined (all p < 0.001). There was a significant correlation (p < 0.001) between cortical thickness and densitometric metacarpal measurements of both the diaphysis and epiphysis. These results confirm the value of radiogrammetry as a technique for quantitating bone mass under normal and pathological conditions. Additional advantages of the method are minimal radiation dose delivered, possibility for storing the image and data, and technical facility.