Use of ultrasonography in the diagnosis of osteomalacia: Preliminary results on experimental osteomalacia in the rat

This study was performed to investigate the ability of ultrasonographic tec hnique to distinguish osteomalacia fi-om normal bone with the same mineral content. Ten rats with experimentally induced osteomalacia (group A) and 12 control rats having similar body size and weight (group B) were studied. H istomorphometric analysis confirmed the presence of osteomalacia in two rat s from group A and showed normally mineralized bone in two rats from group B. Whole body bone mineral density, measured by dual-energy x-ray absorptio metry, was similar in the two groups (86 +/- 6 mg/cm(2) in group A and 89 /- 4 mg/cm(2) in group B). The velocity of the ultrasound beam in bone was measured by densitometer at the first caudal vertebra of each rat. The velo city was measured when the first peak of the waveform reached a pre-determi ned minimum amplitude value (amplitude-dependent speed of sound) as well as at the lowest point of this curve before it reaches the predetermined mini mum amplitude (first minimum speed of sound). Although the amplitude-depend ent speed of sound was similar in the two groups (1381.9 +/- 11.8 m/s in gr oup A and 1390.9 +/- 17.8 m/s in group B), the first minimum speed of sound was clearly different (1446.1 +/- 8.9 m/s in group A and 1503.3 +/- 10.9 m /s in group B; P < 0.001). This study shows that ultrasonography could be u sed to identify alterations in bone quality, such as osteomalacia, but furt her studies need to be carried out before this method can be introduced int o clinical practice.