超声背散射技术在松质骨骨质无损评价中极具前景。本文介绍了一种新型超声背散射骨质诊断仪 (UBBD) 及其在新生儿骨质状况评价中的应用。超声背散射骨质诊断仪具有无损、无电离辐射、便携及操作简便等优点，可以在短时间内 (5 s) 获得人体松质骨背散射信号。笔者共采集了467例新生儿 (268男/199女) 左侧跟骨处的背散射信号，所用探头中心频率为3.5 MHz。逐步调节背散射有效信号 (SOI) 的延迟 (T₁) 和长度 (T₂)，计算表观积分背散射 (AIB)、表观背散射频率斜率 (FSAB) 及零频率截距 (FIAB) 和频谱质心偏移量 (SCS) 等参数。结果表明，背散射有效信号的选取对背散射测量有直接的影响。当T₁较短时 (< 8 μs)，AIB和FIAB与新生儿胎龄有显著的正相关性(|R|_max = 0.45, P < 0.001)；而当T₁较长时 (> 10 μs)，AIB和FIAB负相关于新生儿胎龄 (|R|_max = 0.56, P < 0.001)，还可以观察到FSAB和SCS与新生儿胎龄有中度的正相关性 (|R|_max = 0.45, P < 0.001)。T₂对背散射测量的影响较小，引起相关系数的波动较小。本文通过自制的松质骨超声诊断仪证明超声背散射信号用于评价新生儿骨质状况的可行性。本文还提出了明确的背散射有效信号选取规则及新生儿骨质评价标准。

Ultrasonic backscatter technique has shown promise as a noninvasive cancellous bone assessment tool. A novel ultrasonic backscatter bone diagnostic (UBBD) instrument and an in vivo application for neonatal bone evaluation are introduced in this study. The UBBD provides several advantages, including noninvasiveness, non-ionizing radiation, portability, and simplicity. In this study, the backscatter signal could be measured within 5 s using the UBBD. Ultrasonic backscatter measurements were performed on 467 neonates (268 males and 199 females) at the left calcaneus. The backscatter signal was measured at a central frequency of 3.5 MHz. The delay (T₁) and duration (T₂) of the backscatter signal of interest (SOI) were varied, and the apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB), zero frequency intercept of apparent backscatter (FIAB), and spectral centroid shift (SCS) were calculated. The results showed that the SOI selection had a direct influence on cancellous bone evaluation. The AIB and FIAB were positively correlated with the gestational age (|R| up to 0.45, P < 0.001) when T₁ was short (< 8 µs), while negative correlations (|R| up to 0.56, P < 0.001) were commonly observed for T₁ > 10 µs. Moderate positive correlations (|R| up to 0.45, P < 0.001) were observed for FSAB and SCS with gestational age when T₁ was long (> 10 µs). The T₂ mainly introduced fluctuations in the observed correlation coefficients. The moderate correlations observed with UBBD demonstrate the feasibility of using the backscatter signal to evaluate neonatal bone status. This study also proposes an explicit standard for in vivo SOI selection and neonatal cancellous bone assessment.