BME Frontiers / 2020 / Article / Fig 3

Research Article

Functional Photoacoustic and Ultrasonic Assessment of Osteoporosis: A Clinical Feasibility Study

Figure 3

The normalized power spectrum density (PSD) of the RF PA signals from the calcaneus bones in the osteoporosis group () vs. the control group (). The shadows show the standard deviations. (a) The PSD curves of the PA signals from the osteoporosis group and the control group before compensating the ultrasound attenuation. (b, c) The PSD curves of the PA signals from the osteoporosis group and the control group after compensating the ultrasound attenuation. In (b), the linear fitting over the frequency range of 0.1-1 MHz led to quantified spectral parameter slopes of 0.11 dB/MHz and 0.20 dB/MHz for the osteoporosis group and the control group, respectively. In (c), the integrated areas under the two curves over the frequency range of 0.1-1 MHz led to quantified spectral parameter weighted frequencies of 72.78 dB·MHz and 138.62 dB·MHz for the osteoporosis group and the control group, respectively.
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