Bone mass measurement of cortical bone of the tibia using quantitative ultrasound: Clinical application *
Quantitative ultrasound (QUS) is a unique method, for measurement of bone mass, which is simple in operation and without radiation. Among bone mass measurements, it can evaluate not only bone mineral density (BMD) but also bone quality. Most QUS equipments use the calcaneus as a measurement site, but the recently developed Sound Scan 2000 measures the speed of sound (SOS) in tibial cortical bone. Its fundamental performance has been reported to be good. In this study, the clinical application of Sound Scan 2000 was examined. The young adult mean (YAM, age 25-44) of SOS in tibial cortical bone was 3939 ± 84 (mean ± SD) m/sec. The SOS equivalent to YAM-2. 5SD, which is the cut-off value for osteoporosis in the diagnostic criteria proposed by WHO, was calculated as 3729m/sec. When diagnosis of osteoporosis by radial or lumbar BMD measurements was done as a gold standard, the SOS measurement showed good sensitivity and had a positive predictive rate in diagnosis of osteoporosis in the radius. Regarding change in the SOS and the % change in the SOS per two years, in 24 premenopausal cases, they were 7. 2 ± 65. 9m/sec and 0.17 ± 1. 68%, respectively. In 21 postmenopausal cases, they were -48. 9 ± 90. Om/sec and -1. 29 ± 2. 32% , respectively. Both the SOS and % changes in the SOS in postmenopausal women were significantly (both p< 0.05) lower than those in premenopausal women. This clinical study showed that SOS measurement in tibial cortical bone could be useful as a screening test of osteoporosis, especially in the radius. (Accepted on October 16, 2000) Kawasaki Igakkaishi 27(1) : 17-22, 2001
