Apparent Backscatter Research Articles

Effect of transducer position on ultrasonic backscatter measurements of cancellous bone.

Ultrasonic backscatter techniques are being developed to detect changes in bone caused by osteoporosis and other diseases. Backscatter measurements performed at peripheral skeletal sites such as the heel may place the interrogated region of bone tissue in the acoustic near field of the transducer. The purpose of this study is to investigate how measurements in the near field affect backscatter parameters used for ultrasonic bone assessment. Ultrasonic measurements were performed in a water tank using a planar 2.25 MHz transducer. Signals were acquired for five transducer-specimen distances: N/4, N/2, 3 N/4, N, and 5 N/4, where N is the near-field distance, a location that represents the transition from the near field to far field. Five backscatter parameters previously identified as potentially useful for ultrasonic bone assessment purposes were measured: apparent integrated backscatter, frequency slope of apparent backscatter (FSAB), frequency intercept of apparent backscatter, normalized mean of the backscatter difference, and backscatter amplitude decay constant. All five parameters depended on transducer-specimen distance to varying degrees with FSAB exhibiting the greatest dependence on distance. These results suggest that laboratory studies of bone should evaluate the performance of backscatter parameters using transducer-specimen distances that may be encountered clinically including distances where the ultrasonically interrogated region is in the near field of the transducer.

In Vivo Comparison of Backscatter Techniques for Ultrasonic Bone Assessment at the Femoral Neck.

Ultrasonic techniques are being developed to detect changes in cancellous bone caused by osteoporosis. The goal of this study was to test the relative in vivo performance of eight backscatter parameters developed over the last several years for ultrasonic bone assessment: apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB), frequency intercept of apparent backscatter (FIAB), normalized mean of the backscatter difference (nMBD), normalized slope of the backscatter difference (nSBD), normalized intercept of the backscatter difference (nIBD), normalized backscatter amplitude ratio (nBAR) and backscatter amplitude decay constant (BADC). Backscatter measurements were performed on the left and right femoral necks of 80 adult volunteers (age=25 ± 11 y) using an imaging system equipped with a convex array transducer. For comparison, additional ultrasonic measurements were performed at the left and right heel using a commercially available heel-bone ultrasonometer that measured the stiffness index. Six of the eight backscatter parameters (all but nSBD and nIBD) exhibited similar and highly significant (p < 0.000001) left-right correlations (0.51 ≤ R ≤ 0.68), indicating sensitivity to naturally occurring variations in bone tissue. Left-right correlations for the stiffness index measured at the heel (R=0.75) were not significantly better than those produced by AIB, FSAB and FIAB. The short-term precisions of AIB, nMBD, nBAR and BADC (7.8%-11.7%) were comparable to that of the stiffness index measured with the heel-bone ultrasonometer (7.5%).

Ultrasonic Bone Assessment: Ability of Apparent Backscatter Techniques to Detect Changes in the Microstructure of Human Cancellous Bone.

Ultrasonic backscatter techniques may offer a useful approach for detecting changes in bone caused by osteoporosis. The goal of this study was to investigate how bone mineral density (BMD) and the microstructure of human cancellous bone affect three ultrasonic backscatter parameters that have been identified as potentially useful for ultrasonic bone assessment purposes: the apparent integrated backscatter (AIB), the frequency slope of apparent backscatter (FSAB), and the frequency intercept of apparent backscatter (FIAB). Ultrasonic measurements were performed with a 3.5-MHz broadband transducer on 54 specimens of human cancellous bone prepared from the proximal femur. Microstructural parameters and BMD were measured using X-ray microcomputed tomography (micro-CT). Relationships between AIB, FSAB, FIAB, and the micro-CT parameters were investigated using univariate and multivariate statistical analysis techniques. Moderate-to-strong univariate correlations were observed between the backscatter parameters and microstructure and BMD in many cases. The partial correlation analysis indicated that the backscatter parameters are dependent on microstructure independently of BMD in some cases. Multiple stepwise linear regression analysis used to generate multivariate models found that microstructure was a significant predictor of the backscatter parameters in most cases.

Comparison of the relative performance of three ultrasonic backscatter parameters measured in vivo at the femoral neck

The global impact of osteoporosis as a major public health problem has generated interest in developing ultrasonic techniques that can be used to screen populations for this bone disease. The goal of this study was to assess the relative performance of three ultrasonic backscatter parameters: apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB) and frequency intercept of apparent backscatter (FIAB). Measurements were performed at the left and right femoral necks of 88 healthy volunteers using an ultrasonic imaging system equipped with a 3 MHz convex multi-element transducer. Backscatter signals from the femoral neck were captured for analysis. AIB was determined from the frequency averaged power in the backscatter signal compensated for the frequency dependent response of the measurement system. FSAB and FIAB were determined from the slope and intercept, respectively, of a line fitted to the compensated spectrum. Linear regression analysis was used to compare measurements performed at the left and right femur. All three parameters demonstrated similar and highly significant (p < 0.000001) correlations between left and right side measurements (R AIB = 0.62, R FSAB = 0.56, R FIAB = 0.51) indicating that they are equally sensitive to naturally occurring variations in the ultrasonic properties of the femoral neck.

Underwater 3D deblurring-gated range-intensity correlation imaging

Three-dimensional (3D) range-gated imaging has great potential in underwater target detection, navigation, and marine scientific research due to good backscatter suppression. However, in turbid water, apparent backscatter leads to bad range resolution and accuracy in 3D reconstruction. To solve this problem, a 3D deblurring-gated range-intensity correlation imaging method is proposed based on light propagation property in water. In the method, only the water attenuation coefficient and a reference image are needed to calculate the depth-noise maps (DNM) of target gate images at different ranges. By subtracting the DNMs from target gate images, new gate images with less noise can be obtained, and then 3D images with high range resolution and accuracy are reconstructed. To prove the feasibility of the proposed method, experiments have been performed in pools under different water conditions. The results show that a higher peak signal-to-noise ratio improvement is about 9 dB in new gated images.

The Ability of Ultrasonic Backscatter Parametric Imaging to Characterize Bovine Trabecular Bone.

The ultrasonic backscatter technique holds the promise of characterizing bone density and microstructure. This paper conducts ultrasonic backscatter parametric imaging based on measurements of apparent integrated backscatter (AIB), spectral centroid shift (SCS), frequency slope of apparent backscatter (FSAB), and frequency intercept of apparent backscatter (FIAB) for representing trabecular bone mass and microstructure. We scanned 33 bovine trabecular bone samples using a 7.5 MHz focused transducer in a 20 mm × 20 mm region of interest (ROI) with a step interval of 0.05 mm. Images based on the ultrasonic backscatter parameters (i.e., AIB, SCS, FSAB, and FIAB) were constructed to compare with photographic images of the specimens as well as two-dimensional (2D) μ-CT images from approximately the same depth and location of the specimen. Similar structures and trabecular alignments can be observed among these images. Statistical analyses demonstrated that the means and standard deviations of the ultrasonic backscatter parameters exhibited significant correlations with bone density (|R| = 0.45-0.78, p < 0.01) and bone microstructure (|R| = 0.44-0.87, p < 0.001). Some bovine trabecular bone microstructure parameters were independently associated with the ultrasonic backscatter parameters (ΔR2 = 4.18%-44.45%, p < 0.05) after adjustment for bone apparent density (BAD). The results show that ultrasonic backscatter parametric imaging can provide a direct view of the trabecular microstructure and can reflect information about the density and microstructure of trabecular bone.

Myocardial Fiber Mapping of Rat Hearts, Using Apparent Backscatter, with Histologic Validation

Myocardial fiber architecture is a physiologically important regulator of ejection fraction, strain and pressure development. Apparent ultrasonic backscatter has been shown to be a useful method for recreating the myocardial fiber architecture in human-sized sheep hearts because of the dependence of its amplitude on the relative orientation of a myofiber to the angle of ultrasonic insonification. Thus, the anisotropy of the backscatter signal is linked to and provides information about the fiber orientation. In this study, we sought to determine whether apparent backscatter could be used to measure myofiber orientation in rodent hearts. Fixed adult-rat hearts were imaged intact, and both a transmural cylindrical core and transmural wedge of the left ventricular free wall were imaged. Cylindrical core samples confirmed that backscatter anisotropy could be measured in rat hearts. Ultrasound and histologic analysis of transmural myocardial wedge samples confirmed that the apparent backscatter could be reproducibly mapped to fiber orientation (angle of the fiber relative to the direction of insonification). These data provided a quantitative relationship between the apparent backscatter and fiber angle that was applied to whole-heart images. Myocardial fiber architecture was successfully measured in rat hearts. Quantifying myocardial fiber architecture, using apparent backscatter, provides a number of advantages, including its scalable use from rodents to man, its rapid low-cost acquisition and minimal contraindications. The method outlined in this study provides a method for investigators to begin detailed assessments of how the myocardial fiber architecture changes in preclinical disease models, which can be immediately translated into the clinic.

Ultrasonic Backscatter Technique for Assessing and Monitoring Neonatal Cancellous Bone Status in Vivo

Metabolic bone disease (MBD) impacts the prognosis of premature infants. There is an urgent need for a portable, noninvasive, and radiation-free method for assessing neonatal bone status. The objective of this study is to evaluate the feasibility of the ultrasonic backscatter technique for assessing and monitoring cancellous bone status in neonates. Ultrasonic backscatter measurements were performed on 766 infants at birth and followed up weekly during hospitalization, utilizing transducers with central frequencies of 3.5 MHz and 5.0 MHz. Backscatter parameters, including apparent integrated backscatter (AIB), frequency intercept of apparent backscatter (FIAB), and frequency slope of apparent backscatter (FSAB) were calculated. Correlations were analyzed with both anthropometric and biochemical indices. We found that AIB ( $\vert r\vert = 0.40-0.47$ , $p ), FIAB ( $\vert r\vert = 0.36-0.45$ , $p ), and FSAB ( $\vert r\vert = 0.10-0.25$ , $p ) were significantly correlated with gestational age, weight, length, and head circumference at birth at both the 3.5 MHz and 5.0 MHz frequencies. Backscatter parameters showed regular changes at different postnatal age and correlations with anthropometric indices persisted during the first month of life. Significant differences were also found in subgroup analyses based on gestational age, birth weight, gender, multiple births, and intrauterine growth. AIB and FIAB were shown to be more effective than FSAB. This study suggests the ultrasonic backscatter technique is feasible for neonatal cancellous bone status evaluation at birth and for dynamic monitoring.

Effect of Spectral Estimation on Ultrasonic Backscatter Parameters in Measurements of Cancellous Bones

Objective: the purpose of this paper was to investigate the effect of spectral computation methods on the estimation of the four ultrasonic backscatter parameters, namely, the apparent integrated backscatter (AIB), the zero frequency intercept of apparent backscatter (FIAB), the frequency slope of apparent backscatter (FSAB), and the backscatter spectral centroid shift (SCS) from the backscattered signal of interest (SOI), and their subsequent correlations with cancellous bone parameter [bone volume/total volume (BV/TV)]. Methods: ultrasonic backscatter measurements were performed on 26 bovine cancellous bone specimens using a 1.0-MHz focused transducer. Four spectral estimation algorithms, including the classical periodogram, the autoregressive (AR) Burg algorithm, the AR covariance algorithm, and the AR modified covariance algorithm, were used to calculate the ultrasonic parameters. Influence of the signal's delay time (T1) and its length (T2) on the strength of correlation between BV/TV and backscatter parameters was also studied. Results: the results have demonstrated that the AR-based estimators provide much more reliable and stronger correlations between the BV/TV and backscatter parameters than the classical periodogram. Recommendations for choosing SOI were also suggested. Conclusion: these results indicate that the AR-based method has a promising potential to enhance the performance of evaluation and diagnosis of the cancellous bone using the ultrasonic backscatter method. Significance: the enhancement of the correlation may provide a positive impact on the ultrasonic backscatter method to diagnose and monitor the bone quantity.

Relationships of Ultrasonic Backscatter With Bone Densities and Microstructure in Bovine Cancellous Bone.

This study was designed to investigate the associations among ultrasonic backscatter, bone densities, and microstructure in bovine cancellous bone. Ultrasonic backscatter measurements were performed on 33 bovine cancellous bone specimens with a 2.25-MHz transducer. Ultrasonic apparent backscatter parameters ("apparent" means not compensating for ultrasonic attenuation and diffraction) were calculated with optimal signals of interest. The results showed that ultrasonic backscatter was significantly related to bone densities and microstructure ( R2 = 0.17 -0.88 and ). After adjusting the correlations by bone mineral density (BMD), the bone apparent density (BAD) and some trabecular structural features still contributed significantly to the adjusted correlations, with moderate additional variance explained ( ∆R2 = 9.7 % at best). Multiple linear regressions revealed that both BAD and trabecular structure contributed significantly and independently to the prediction of ultrasound backscatter (adjusted R2 = 0.75 -0.89 and ), explaining an additional 14% of the variance at most, compared with that of BMD measurements alone. The results proved that ultrasonic backscatter was primarily determined by BAD, not BMD, but the combination of bone structure and densities could achieve encouragingly better performances (89% of the variance explained at best) in predicting backscatter properties. This study demonstrated that ultrasonic apparent backscatter might provide additional density and structural features unrelated to current BMD measurement. Therefore, we suggest that ultrasonic backscatter measurement could play a more important role in cancellous bone evaluation.

Monitoring bone changes due to calcium, magnesium, and phosphorus loss in rat femurs using Quantitative Ultrasound

Bone mineral density is an important parameter for the diagnosis of bone diseases, as well as for predicting fractures and treatment monitoring. Thus, the aim of the present study was to evaluate the potential of Quantitative Ultrasound (QUS) to monitor bone changes after calcium, phosphorus, and magnesium loss in rat femurs in vitro during a demineralization process. Four quantitative ultrasound parameters were estimated from bone surface echoes in eight femur diaphysis of rats. The echo signals were acquired during a decalcification process by Ethylenediaminetetraacetic Acid (EDTA). The results were compared to Quantitative Computed Tomography (QCT) and inductively coupled plasma optical emission spectrometry measurements for validation. Integrated Reflection Coefficient (IRC) reflection parameters and Frequency Slope of Reflection Transfer Function (FSRTF) during demineralization tended to decrease, while the backscattering parameter Apparent Integrated Backscatter (AIB) increased and Frequency Slope of Apparent Backscatter (FSAB) showed an oscillatory behavior with no defined trend. Results indicate a clear relation between demineralization and the corresponding decrease in the reflection parameters and increase in the scattering parameters. The trend analysis of the fall curve of the chemical elements showed a better relationship between IRC and QCT. It was possible to monitor bone changes after ions losses, through the QUS. Thus, it is an indication that the proposed protocol has potential to characterize bone tissue in animal models, providing consistent results towards standardization of bone characterization studies by QUS endorsing its use in humans.

Ultrasonic backscatter measurements at the calcaneus: An in vivo study

Osteoporosis is a systemic skeleton disease that has already been a major public health issue. As a traditional clinical method, dual-energy X-ray absorptiometry (DXA) measures the bone mineral density (BMD) to evaluate the bone status. However, the X-ray based method has the disadvantages of ionizing radiation and high cost. Quantitative ultrasound has played a role in the bone diagnostics with the advantages of non-ionizing radiation, portability, low cost and ease of use. This paper presents an in vivo approach of measuring the calcaneus using ultrasonic backscatter method, a total of 523 subjects were involved. The ultrasonic backscattered signals were acquired using a custom designed ultrasonic backscatter bone diagnostic (UBBD) instrument with a 5.0 MHz transducer. The time slope of apparent backscatter (TSAB) parameter was calculated and compared with the BMD measured from DXA. The TSAB and BMD showed a negative correlation (R = −0.65 ∼ −0.52, p < 0.05). Discrimination analysis was performed using receiver operating characteristic (ROC) curves to discriminate people who have been diagnosed with osteoporosis from people without osteoporosis using DXA. The area under the curve (AUC) for ultrasound backscatter parameter TSAB was 0.8 with p < 0.05. By means of the ROC analysis, the optimum thresholds of TSAB were determined to be −0.81 dB/µs. The sensitivity and specificity of TSAB for the optimum threshold were 77% and 74%, respectively. The Youden index and accuracy was 51% and 75% for the TSAB at 5.0 MHz, respectively. These results indicate that ultrasonic backscatter is promising in the in vivo bone characterization.

Characterization of a polymer, open-cell rigid foam that simulates the ultrasonic properties of cancellous bone.

Materials that simulate the ultrasonic properties of tissues are used widely for clinical and research purposes. However, relatively few materials are known to simulate the ultrasonic properties of cancellous bone. The goal of the present study was to investigate the suitability of using a polymer, open-cell rigid foam (OCRF) produced by Sawbones®. Measurements were performed on OCRF specimens with four different densities. Ultrasonic speed of sound and normalized broadband ultrasonic attenuation were measured with a 0.5 MHz transducer. Three backscatter parameters were measured with a 5 MHz transducer: apparent integrated backscatter, frequency slope of apparent backscatter, and normalized mean of the backscatter difference. X-ray micro-computed tomography was used to measure the microstructural characteristics of the OCRF specimens. The trabecular thickness and relative bone volume of the OCRF specimens were similar to those of human cancellous bone, but the trabecular separation was greater. In most cases, the ultrasonic properties of the OCRF specimens were similar to values reported in the literature for cancellous bone, including dependence on density. In addition, the OCRF specimens exhibited an ultrasonic anisotropy similar to that reported for cancellous bone.

Variability in Ultrasound Backscatter Induced by Trabecular Microstructure Deterioration in Cancellous Bone

To determine the relationship between the ultrasonic backscatter parameters and trabecular microstructural variations in cancellous bone, three erosion procedures were performed to simulate various changes in the cancellous bone microstructure. The finite difference time domain (FDTD) method was used to simulate the backscatter signal in cancellous bone. Ultrasonic backscatter properties were derived as functions of the porosity when the ultrasound incident directions were perpendicular and parallel to the major trabeculae direction (MTD), respectively. The variability in the apparent backscatter coefficient (ABC) and apparent integrated backscatter (AIB) due to the trabecular microstructure was revealed. Significant negative correlations between the backscatter parameters (ABC and AIB) and the porosity of the cancellous bone were observed. The simulations showed that the ABC and AIB were influenced by the direction of the trabecular microstructural variations. The linear regressions between the ultrasonic backscatter parameters (ABC and AIB) and the porosity showed significantly different slopes for three erosion procedures when they are ultrasonically perpendicular (for ABC, −1.22 dB, −0.98 dB, and −0.46 dB; for AIB, −0.74 dB, −0.69 dB, and −0.25 dB) and parallel (for ABC, −1.87 dB, −0.69 dB, and −0.51 dB; for AIB, −0.9 dB, −0.5 dB, and −0.34 dB) to the MTD. This paper investigated the relationship between ultrasonic backscatter and cancellous bone microstructure deterioration and indicated that the ultrasonic backscatter could be affected by cancellous bone microstructure deterioration direction.

Associations between ultrasonic backscatter, bone density, and microstructure in cancellous bone characterization

Ultrasonic backscatter is related to the microstructure of cancellous bone. However, whether backscatter measurement can provide additional information independently of BMD remains speculative. In this study, we analyzed the independent contribution of cancellous bone densities and microstructure to apparent backscatter signals in vitro. The results showed that ultrasonic backscatter and the statistics of backscatter envelope were significantly correlated with bone densities and microstructure. After adjustment for BMD, some trabecular structures still contributed significantly to the adjusted correlations, with moderate additional variance explained. Multiple linear regressions revealed that both bone density and structure contributed significantly to the prediction of ultrasonic backscatter (adjusted R2 = 0.75–0.93, p&amp;lt;0.05), explaining an additional 14.0% of the variance at most, compared with that of BMD measurements alone. We also demonstrated that the Nakagami model had great potential in trabecular microstructure characterization. The results proved that ultrasonic backscatter was primarily determined by bone apparent density, but bone densities plus microstructure structure could achieve encouragingly better predictive performance than BMD alone. This study implied that ultrasonic apparent backscatter might provide additional density and structural features unrelated to current BMD measurement. Thus, we suggest that ultrasonic backscatter measurement could play a more important role in cancellous bone evaluation.

Effects of cirrus heterogeneity on lidar CALIOP/CALIPSO data

The goal of this work is to evaluate the effects of cirrus heterogeneity on characteristics that are directly measured by the CALIOP/CALIPSO lidar, i.e. attenuated backscatter coefficient and depolarization ratio. This assessment was done using the 3D Monte Carlo simulator of Polarized Lidar signals (3DMcPOLID) together with the high-resolution 3D cloud fields-generator 3DCLOUD_V2. The evaluation is based on random sampling and on comparison between mean profiles of 3D clouds and of plane-parallel equivalent 1D clouds.Mean profiles of the apparent attenuated backscatter as well as of the integrated apparent backscatter are statistically equal when a cirrus cloud field is probed with the 325 m resolution. To the contrary, the difference between profiles is statistically significant in the case of the 1 km resolution. Profiles of the volume depolarization ratio are statistically different for both cases of the horizontal resolution. The total bias of CALIOP/CALIPSO lidar data is mainly due to the plane parallel bias and multiple scattering, i.e., horizontal photon transport.

Metrology applied to ultrasound characterization of trabecular bones using the AIB parameter

Apparent Integrated Backscattering (AIB) presents correlation between Apparent Backscatter Transfer Function and the transducer bandwidth. Replicas of trabecular bones (cubes of 20 mm side length) created by 3D printing technique were characterized using AIB with a 2.25 MHz center frequency transducer. A mechanical scanning system was used to acquire multiple backscatter signals. An uncertainty model in measurement was proposed based on the Guide to the Expression of Uncertainty in Measurement. Initial AIB results are not metrologically reliable, presenting high measurement uncertainties (sample: 5_0.2032/AIB: -15.1 dB ± 13.9 dB). It is noteworthy that the uncertainty model proposed contributes as unprecedented way for metrological assessment of trabecular bone characterization using AIB.

Ultrasonic backscatter from cancellous bone: the apparent backscatter transfer function.

Ultrasonic backscatter techniques are being developed to detect changes in cancellous bone caused by osteoporosis. Many techniques are based on measurements of the apparent backscatter transfer function (ABTF), which represents the backscattered power from bone corrected for the frequency response of the measurement system. The ABTF is determined from a portion of the backscatter signal selected by an analysis gate of width τw delayed by an amount τd from the start of the signal. The goal of this study was to characterize the ABTF for a wide range of gate delays (1 μs ≤ τd ≤ 6 μs) and gate widths (1 μs ≤ τw ≤ 6 μs). Measurements were performed on 29 specimens of human cancellous bone in the frequency range 1.5 to 6.0 MHz using a broadband 5-MHz transducer. The ABTF was found to be an approximately linear function of frequency for most choices of τd and τw. Changes in τd and τw caused the frequency-averaged ABTF [quantified by apparent integrated backscatter (AIB)] and the frequency dependence of the ABTF [quantified by frequency slope of apparent backscatter (FSAB)] to change by as much as 24.6 dB and 6.7 dB/MHz, respectively. τd strongly influenced the measured values of AIB and FSAB and the correlation of AIB with bone density (-0.95 ≤ R ≤ +0.68). The correlation of FSAB with bone density was influenced less strongly by τd (-0.97 ≤ R ≤ -0.87). τw had a weaker influence than τd on the measured values of AIB and FSAB and the correlation of these parameters with bone density.

Effect of intervening tissues on ultrasonic backscatter measurements of bone: An in vitro study.

Ultrasonic backscatter techniques are being developed to diagnose osteoporosis. Tissues that lie between the transducer and the ultrasonically interrogated region of bone may produce errors in backscatter measurements. The goal of this study is to investigate the effects of intervening tissues on ultrasonic backscatter measurements of bone. Measurements were performed on 24 cube shaped specimens of human cancellous bone using a 5 MHz transducer. Measurements were repeated after adding a 1 mm thick plate of cortical bone to simulate the bone cortex and a 3 cm thick phantom to simulate soft tissue at the hip. Signals were analyzed to determine three apparent backscatter parameters (apparent integrated backscatter, frequency slope of apparent backscatter, and frequency intercept of apparent backscatter) and three backscatter difference parameters [normalized mean backscatter difference (nMBD), normalized slope of the backscatter difference, and normalized intercept of the backscatter difference]. The apparent backscatter parameters were impacted significantly by the presence of intervening tissues. In contrast, the backscatter difference parameters were not affected by intervening tissues. However, only one backscatter difference parameter, nMBD, demonstrated a strong correlation with bone mineral density. Thus, among the six parameters tested, nMBD may be the best choice for in vivo backscatter measurements of bone when intervening tissues are present.

An Ultrasonic Backscatter Instrument for Cancellous Bone Evaluation in Neonates

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 10 µs. Moderate positive correlations (|R| up to 0.45, P 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.