Focused ultrasound (FU) technology is extensively employed in clinical applications such as tumor ablation, Parkinson’s disease treatment, and neuropathic pain management. The safety and efficacy of FU therapy critically depend on the accurate quantification of the acoustic field, particularly the high-pressure distribution in focal region. To address the limitations of existing acoustic measurement techniques—including invasiveness, inability to measure high sound pressure, and system complexity—this study proposes a non-invasive method termed Laser Deflection Acoustic Field Quantification (LDAQ), based on the laser deflection principle. An experimental system was constructed utilizing the acousto-optic deflection effect, which incorporates precision displacement control, rotational scanning, and synchronized triggering. Through tomographic scanning, laser deflection images of the acoustic field were acquired at multiple orientations. An inversion algorithm using Radon transforms was proposed to reconstruct the refractive index gradient distributions from the variations of light intensity and spot displacement. An adaptive weighted fusion strategy was then employed to map these optical signals to the sound pressure field. To validate the LDAQ technique, an acoustic field generated by an FU transducer operating at 0.84 MHz was measured. The reconstructed results were compared with both hydrophone measurements and numerical simulations. The findings demonstrated high consistency among all three results within the focal zone. Full-field analysis yielded a root mean square error (RMSE) of 0.1102 between LDAQ and simulation, and an RMSE of 0.1422 between LDAQ and hydrophone measurements. These results confirm that LDAQ enables non-invasive and high-precision quantification of megapascal-level focused acoustic fields, offering a reliable methodology for acoustic field characterization to support FU treatment optimization and device standardization.

Core parameters of the Musculoskeletal Ultrasound Computed Tomography System (MUCTS), such as spatial resolution, slice thickness, and three-dimensional reconstruction volume error, directly determine imaging performance and clinical diagnostic accuracy. To objectively and systematically assess the imaging quality and diagnostic reliability of this device, this study took the MUCTS developed by Weishi Medical Imaging Co., Ltd., as the test object. Multidimensional performance tests were carried out using standard ultrasound phantoms and polyurethane-based tissue-mimicking musculoskeletal phantoms. Under unified imaging and reconstruction parameters, key indicators, including effective detection radius, axial resolution, lateral resolution, imaging dead zone, slice thickness, geometric position accuracy, and three-dimensional reconstruction volume error, were quantitatively measured, and compliance verification was performed against product technical specifications. The test results demonstrated that the nominal center frequency was 3 MHz with a measured frequency deviation of 3%, and the effective detection radius reached 90 mm. Within the valid imaging range, the axial resolution was 0.5 mm, lateral resolution was 1 mm, imaging dead zone was 1 mm, and slice thickness was 3.2 mm. The relative error of geometric position accuracy was 3%, the relative deviations in perimeter and area measurements were both −1%, and the relative deviation in three-dimensional reconstructed volume was −8%. All indicators satisfied product technical requirements. Qualitative comparative experiments on tissue-mimicking phantoms confirmed that the system could reproduce multiscale and multi-contrast musculoskeletal anatomical features, and the acquired images showed favorable consistency with designed phantom targets. In conclusion, this musculoskeletal ultrasound tomographic system exhibits stable imaging performance and credible quantitative measurements, and can meet clinical and research demands for tomographic imaging and three-dimensional reconstruction of human musculoskeletal tissues.