Ultrasound method applied to characterize healthy femoral diaphysis of Wistar rats in vivo

Ultrasound-based Measurement of the Intra-scaphoid angle

INTRODUCTION

Ultrasound is gaining popularity for diagnosing scaphoid fractures. However, it hasn't been used to assess fracture displacement, such as humpback deformity. We propose a sonographic method to measure the intra-scaphoid angle, potentially serving as an alternative to CT scans for detecting fragment malposition after a scaphoid fracture.

METHODS

We recruited 11 healthy adult volunteers without wrist pathology and performed bilateral wrist ultrasounds, totaling 22 examinations. Each wrist was splinted at 50 ° extension and fully supinated. Two hand surgeons independently performed the ultrasounds. All images were then evaluated separately by two evaluators. The following measurements were taken: 1. Inter-poles distance (IPD): Distance between the summits of the two scaphoid poles on the palmar cortex. 2. Palmar cortical intra-scaphoid angle (PCISA): Angle between the two summits and the deepest point of the waist on the palmar cortex. Measurements were compared for inter-investigator and inter-evaluator reliability using the intraclass correlation coefficient (ICC).

RESULTS

The study included four males and seven females, with an average age of 35 years (range 21-56). The mean PCISA was 142 ° (SD 10 °) and the mean IPD was 16.3 mm (SD 2.1 mm). Differences in IPD measurements averaged 0.3 mm (range 0-5.2 mm) among investigators and 1.0 mm (range 0.1-3.8 mm) among evaluators. For PCISA, the differences averaged 4 ° (range 0-17 °) among investigators and 6 ° (range 0-15 °) among evaluators. The ICC for IPD was 0.804 (investigators) and 0.572 (evaluators); for PCISA, it was 0.704 (investigators) and 0.602 (evaluators).

CONCLUSION

This study presents a cost-effective and accessible sonographic technique to measure the intra-scaphoid angle. Further research is required to assess its effectiveness in scaphoid fractures and compare it to CT-based measurements like the H/L ratio, LISA, and DCA.

Influence of Low-Intensity Pulsed Ultrasound Parameters on the Bone Mineral Density in Rat Model: A Systematic Review

OBJECTIVE

Bone recovery typically depends on the age of organisms or the prevalence of metabolic disorders such as osteoporosis, which is a metabolic condition characterized by decreased bone strength and bone mineral density (BMD). Therefore, low-intensity pulsed ultrasound (LIPUS), a non-invasive method for osteogenic stimulation, presents promising results. However, heterogeneity in animal study designs is a typical characteristic. Hence, we conducted a systematic review to evaluate the effectiveness of LIPUS in the recovery of experimental bone defects using rat models. We examined the areal and volumetric BMD to identify LIPUS doses to be applied and evaluated the accuracy reported by previous studies.

METHODS

The Virtual Health Library regional portal, PubMed, Embase, EBSCOhost, Scopus and CAPES were reviewed for animal studies that compared fracture treatments based on LIPUS with sham or no treatments using rat models and reported BMD as an outcome. The tool provided by the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) and the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies (CAMARADES) checklist were used to assess the bias and quality of such studies.

RESULTS

Of the six studies reviewed, the most frequently used LIPUS dose had an ultrasonic frequency of 1.0 MHz, repetition rate of 0.1 kHz and pulse duration of 2000 μs. An intensity (ISATA) of 30 mW/cm2 was the most preferred for bone recovery. However, the BMD could not solely irrefutably evaluate the effectiveness of LIPUS in bone recovery as the results were discordant with each other. The discrepancies in experimental methodologies, low-quality classifications and high risk of bias in the selected studies, however, did not validate the undertaking of a meta-analysis.

CONCLUSION

On the basis of the BMD results, no sufficient evidence was found to recommend the use of LIPUS for bone recovery in rat models. Thus, this systematic review indicates that the accuracy of such reports must be improved to improve their scientific quality to facilitate a transition of LIPUS applications from pre-clinical research to clinic use.

Designing and Calculating the Nonlinear Elastic Characteristic of Longitudinal–Transverse Transducers of an Ultrasonic Medical Instrument Based on the Method of Successive Loadings

This paper presents a numerical method for studying the stress–strain state and obtaining the nonlinear elastic characteristics of longitudinal–transverse transducers. The authors propose a mathematical model that uses a direct numerical solution of the boundary value problem based on the plain curved rod equations in Matlab. The system’s stress–strain state and nonlinear elastic characteristic are obtained using the method of successive loadings based on the curved rod’s linearized equations. For most ultrasonic instruments, the operating frequency of ultrasonic vibrations is close to 20 kHz. On the other hand, the received own oscillation frequencies are close to the working range. Using the method of successive loadings in the mathematical complex Matlab, a numerical calculation of the stress–strain state of a flat, curved rod at large displacements has been carried out. The proposed model can be considered an initial approximation to the solution of the spatial problem of the longitudinal–torsional transducer.

EXPLORING CORTICAL BONE DENSITY THROUGH THE ULTRASOUND INTEGRATED REFLECTION COEFFICIENT

Objective:

This work evaluates the relationship between ultrasonic reflection and bone density from fourteen cylindrical bovine cortical bone samples (3.0-cm thick).

Methods:

Twenty US reflection signals per sample were acquired along the bone surface (2.0-mm step). The Integrated Reflection Coefficient (IRC) from each signal was compared to Quantitative Computed Tomography (QCT).

Results:

Seven IRC and QCT curves presented Pearson's Correlation R-values above 0.5. For weak correlation curves, QCT and IRC showed similar trends in several segments.

Conclusion:

IRC was sensitive to bone density variation. Level of Evidence: Experimental Study, Investigating a Diagnostic Test.

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.

The role of ultrasonography in the diagnosis of occult scaphoid fractures

Background: Ultrasonography is widely utilized by emergency physicians and radiologists to diagnose various orthopaedic diseases, including fractures. We aim to derive a definitive estimate of the diagnostic accuracy of ultrasonography in clinically suspected scaphoid fractures. Methods: We undertook a systematic review and meta-analysis of included diagnostic cohort studies that discussed the use of ultrasonography in the diagnosis of occult scaphoid fractures. We searched the National Institute for Health and Care Excellence database using the Healthcare Databases Advanced Search tool. In addition, we utilized the PubMed database to search the Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Cumulative Index of Nursing and Allied Health and Allied and Complimentary Medicine databases. Studies were included if they discuss the role of ultrasound imaging in the diagnosis of scaphoid fractures based on cortical interruption, radio-carpal effusion and scapho-trapezium-trapezoid effusion. Quality assessment was performed using the methodological index for non-randomized studies scoring system. Results: 6 non-randomized control studies met the inclusion criteria. Collectively, these included 236 patients with a mean age ranging from 18 to 41.2 years. The quality of these articles ranged between moderate and high based on the methodological index for non-randomized studies score. The mean sensitivity was 88.95% (standard deviation 10.03) and mean specificity was 89.50% (standard deviation 12.21). Conclusion: The current literature reveals high sensitivity and specificity in the use of ultrasonography in scaphoid fracture diagnosis. However, multiple factors including technical differences in ultrasound machines and probes, small sample sizes and variability of subsequent confirmatory tests have created a challenge in determining the ultimate reliability of ultrasonography in the diagnosis of occult scaphoid fractures. Considering these factors and limitations, large-sample and high-quality clinical trials are needed to adequately assess its reliability for this purpose. One stop clinics, in the authors' opinion, would be an ideal setting for its introduction as well as for future trials.

Background: Ultrasonography is widely utilized by emergency physicians and radiologists to diagnose various orthopaedic diseases, including fractures. We aim to derive a definitive estimate of the diagnostic accuracy of ultrasonography in clinically suspected scaphoid fractures. Methods: We undertook a systematic review and meta-analysis of included diagnostic cohort studies that discussed the use of ultrasonography in the diagnosis of occult scaphoid fractures. We searched the National Institute for Health and Care Excellence database using the Healthcare Databases Advanced Search tool. In addition, we utilized the PubMed database to search the Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Cumulative Index of Nursing and Allied Health and Allied and Complimentary Medicine databases. Studies were included if they discuss the role of ultrasound imaging in the diagnosis of scaphoid fractures based on cortical interruption, radio-carpal effusion and scapho-trapezium-trapezoid effusion. Quality assessment was performed using the methodological index for non-randomized studies scoring system. Results: 6 non-randomized control studies met the inclusion criteria. Collectively, these included 236 patients with a mean age ranging from 18 to 41.2 years. The quality of these articles ranged between moderate and high based on the methodological index for non-randomized studies score. The mean sensitivity was 88.95% (standard deviation 10.03) and mean specificity was 89.50% (standard deviation 12.21). Conclusion: The current literature reveals high sensitivity and specificity in the use of ultrasonography in scaphoid fracture diagnosis. However, multiple factors including technical differences in ultrasound machines and probes, small sample sizes and variability of subsequent confirmatory tests have created a challenge in determining the ultimate reliability of ultrasonography in the diagnosis of occult scaphoid fractures. Considering these factors and limitations, large-sample and high-quality clinical trials are needed to adequately assess its reliability for this purpose. One stop clinics, in the authors’ opinion, would be an ideal setting for its introduction as well as for future trials.