Fundamental study for bone mass measurement in the cortical bone of the tibia with quantitative ultrasound *
Recently,various non-invasive bone mineral density (BMD) measurements have been developed, and applied to the diagnosis of osteoporosis. Quantitative ultrasound (QUS) is expected to be as a useful method evaluating BMD without radiation. In present paper, among from QUS methods, the Sound Scan 2000 of a QUS device which can measure cortical BMD in the tibia was used in a fundamental study. The subjects were total 265 (261 women and 4 men) of normal controls and osteoporotic patients. The precisions of measurments of speed of sound (SOS) in the tibia were good ; 0.60% of CV for an infra-assay, and 0.99% for an intcr-assay, respectively. Regarding difference in the SOS between the left and right sides of six subjects whom were all right-handed, SOS values in the left side showed significantly higher than those in the right side (p< 0.01). As to change in the SOS values in different positions of mcasurment, the SOS was higher by 3.5 ±0.8% in the 5 cm-distal site, and lower by 1.0 ±2.2% in the 5 cm-proximal site, compared with mid-portion of the tibia. The former is significantly higher than the latter (p<0.02). The age-distribution of SOS in women was found to decrease after the fifth decade with aging. The SOS in young women correlated slightly with height but not weight or body mass index. The correlation between the SOS and radial BMD (r =0.557, p< 0.001), consisted of mainly cortical bone, was better than the lumbar BMD (r = 0.383, p< 0.01), and the femoral BMD (r = 0.354, p<0.05). Thus, it was shown in this fundamental study that measurements of the tibial cortical SOS using QUS could evaluate cortical bone BMD, and have good precision, although it is necessary to take measurements on the same tibial side and in the same tibial side and in the same positions. (Accepted on September 10, 1999) Kawasaki Igukkaishi 25( 3 ) : 203-210, 1999
