Department of Electronic Engineering, Fudan University, Shanghai, China.
Institute of Sports Biology, Shaanxi Normal University, Xi'an, China.
Ultrasound Med Biol. 2020 Jan;46(1):108-121. doi: 10.1016/j.ultrasmedbio.2019.08.025. Epub 2019 Oct 4.
This study investigated the effects of low-intensity pulsed ultrasound (LIPUS) of different spatial-average-temporal-average intensity (I) ranging from 15-150 mW/cm on the treatment of osteoporosis in ovariectomized rats. Healthy 3-mo-old female Sprague-Dawley rats were randomly divided into nine groups (n = 12 per group): sham-ovariectomy (OVX) control group, OVX control group and OVX groups treated with LIPUS at seven different intensities (I: 15, 30, 50, 75, 100, 125 and 150 mW/cm, respectively). LIPUS was applied to bilateral femurs 12 wk post-OVX for 20 min/d for 6 wk. Micro-computed tomography, biomechanical tests, serum biochemical analysis and grip strength tests were performed to evaluate the therapeutic effects of LIPUS at different intensities. Results revealed that LIPUS intensity yielded strong correlations with bone mineral density and bone microstructure (R = 0.57-0.83) and bone mechanical strength (R = 0.80-0.97), and that the intensity of 150 mW/cm, instead of the 30 mW/cm widely used in bone fracture healing, was most effective in maintaining bone mass among all the LIPUS signals between 15 and 150 mW/cm. This suggests that higher ultrasound intensity (i.e., 150 mW/cm) may be more effective than lower intensity in mitigation of osteopenia and osteoporosis.
本研究旨在探讨不同空间-平均-时间平均强度（I）范围在 15-150 mW/cm 的低强度脉冲超声（LIPUS）对去卵巢大鼠骨质疏松症治疗的影响。健康的 3 月龄雌性 Sprague-Dawley 大鼠被随机分为 9 组（每组 12 只）：假手术（OVX）对照组、OVX 对照组和 OVX 组分别用 7 种不同强度（I：15、30、50、75、100、125 和 150 mW/cm）的 LIPUS 治疗。OVX 后 12 周，LIPUS 应用于双侧股骨，每天 20 分钟，共 6 周。进行微计算机断层扫描、生物力学测试、血清生化分析和握力测试，以评估不同强度 LIPUS 的治疗效果。结果表明，LIPUS 强度与骨矿物质密度和骨微结构（R=0.57-0.83）和骨机械强度（R=0.80-0.97）具有很强的相关性，而 150 mW/cm 的强度，而不是广泛用于骨折愈合的 30 mW/cm，在维持所有 15 至 150 mW/cm 之间的 LIPUS 信号的骨量方面是最有效的。这表明，较高的超声强度（即 150 mW/cm）可能比低强度更能有效缓解骨质疏松症。
