Physics in medicine and biology最新文献

{"title":"3D electroacoustic tomography image enhancement using deep learning with the SAM-Med3D encoder.","authors":"Yankun Lang, Jadon Buller, Yifei Xu, Leshan Sun, Zhuoran Jiang, Shawn Xiang, Lei Ren","doi":"10.1088/1361-6560/ae077d","DOIUrl":"10.1088/1361-6560/ae077d","url":null,"abstract":"<p><p><i>Objective.</i>To overcome the limitations of electroacoustic tomography (EAT) in clinical settings-particularly the artifacts and distortions caused by limited-angle data acquisition-and enable accurate, efficient visualization of electric field distributions for electroporation-based therapies.<i>Approach.</i>We developed a deep learning-based framework that enhances 3D EAT image reconstruction from single-view projections by leveraging the large foundation model (LFM) SAM-Med3D. The encoder was modified into a local-global feature fusion architecture that extracts multi-scale features from intermediate transformer layers, preserving fine structural details while maintaining computational efficiency. A lightweight decoder with progressive up-sampling and skip connections was employed to generate high-resolution images, addressing limitations of conventional U-Net architectures.<i>Main results.</i>We collected a dataset of 50 EAT scans-each with 120 views-for a total of 6000 views. These were acquired from water phantoms and tissue samples under varied electrode configurations and voltages, and split into training (30 scans, 3600 views), validation (10 scans, 1200 views), and testing (10 scans, 1200 views). Our model significantly outperformed baseline 3D U-Nets, achieving an RMSE of 0.0092, PSNR of 41.10, and SSIM of 0.9377. Remarkably, our method reconstructs a full-view 3D EAT image from a single view in just 2 s, demonstrating its potential for near real-time monitoring and adaptive dose verification in electroporation-based therapies.<i>Significance.</i>This is the first application of a LFM like SAM-Med3D for enhancing 3D EAT imaging. The proposed framework addresses the critical challenge of limited-angle data in EAT and demonstrates strong potential for improving precision and safety in electroporation-based therapies, thereby advancing the technique's clinical viability.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145075957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reinforcement learning with mechanistic models to optimise radiotherapy and immunotherapy combinations: a proof of concept.","authors":"Allison M Ng, Du Q Huynh, Rebecca A D'Alonzo, Synat Keam, Pejman Rowshanfarzad, Anna K Nowak, Suki Gill, Alistair M Cook, Martin A Ebert","doi":"10.1088/1361-6560/ae0863","DOIUrl":"10.1088/1361-6560/ae0863","url":null,"abstract":"<p><p><i>Objective.</i>To investigate the use of reinforcement learning (RL) algorithms to optimise complex combination cancer therapies. The RL algorithm investigated the effect of varying the radiotherapy (RT) dose in each fraction when administered in conjunction with the immune checkpoint inhibitors (ICIs) anti-PD-1 and anti-CTLA-4.<i>Approach.</i>Data were available for BALB/c mice inoculated with a syngeneic mesothelioma tumour on the flank, treated with combination RT and ICI with tumour growth subsequently measured. A deep<i>Q</i>-network (DQN) and a double DQN were trained using a mechanistic model fitted to the mesothelioma volumes to simulate the dynamics of the tumour microenvironment. Two reward functions were created for the RL algorithm to optimise: the first only considered tumour cell killing, while the second penalised treatment schedules with higher total RT dose. Comparison with experimental results was via the tumour control probability (TCP).<i>Main Results.</i>All the TCPs obtained with the RL algorithm exceeded the TCPs obtained with the same mechanistic model when only 1 or 2 fractions of RT were administered. However, the baseline schedule of 2 Gy per fraction outperformed the treatment schedules generated by RL.<i>Significance.</i>This study highlights the potential for RL to explore the vast solution space of possible treatment schedules, conceivably at the individual patient level.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145080522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alvar whole-body model: impact of muscle anisotropy on computational dosimetry.","authors":"Otto Kangasmaa, Tuukka Lehtinen, Ilkka Laakso","doi":"10.1088/1361-6560/adfe31","DOIUrl":"10.1088/1361-6560/adfe31","url":null,"abstract":"<p><p><i>Objective.</i>Computational electromagnetic dosimetry relies on accurate whole-body models to assess human exposure to electromagnetic fields. However, existing models lack anisotropic properties of tissues. This work addresses these limitations by introducing a whole-body model, Alvar, containing fully anisotropic skeletal muscles.<i>Approach.</i>The Alvar model has been constructed based on an anatomic atlas and developed specifically for computational dosimetry. Anisotropic models of skeletal muscles were created using Laplacian vector field simulations. Computational dosimetry was performed using anisotropic and isotropic versions of Alvar and six existing isotropic body models to estimate the electric fields induced due to exposure to spatially uniform magnetic and electric fields at 50 Hz.<i>Main results.</i>Modelling skeletal muscle anisotropy resulted in small variations in the 99th percentile induced electric field values (±5%) when the Alvar model was exposed to a magnetic field. When exposed to an external electric field, using anisotropic muscles systematically decreased the 99th percentile values by 13%. However, local differences in the induced electric field were larger (26%-29%) and even more significant inside muscle tissue (35%-39%).<i>Significance.</i>The results show that isotropic models are sufficient for calculating 99th percentile values when assessing whole-body exposure at power line frequencies but can lead to errors in local electric fields, especially in muscle tissue. This research contributes to the characterisation of uncertainty in low-frequency electromagnetic dosimetry, which can inform the development of human exposure limits.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144965082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linear magnetic nanoparticle structures as key feature in magnetic particle imaging.","authors":"M Schoenen, L Göpfert, B Bauer, C Emonts, T Gries, E M Buhl, S Schober, T Schmitz-Rode, I Slabu","doi":"10.1088/1361-6560/ae05e5","DOIUrl":"10.1088/1361-6560/ae05e5","url":null,"abstract":"<p><p><i>Objective</i>. Magnetic particle imaging (MPI) opens huge possibilities in image-guided therapy. Its effectiveness is strongly influenced by the quality of the magnetic nanoparticles (MNP) used as tracers. Besides MNP optimisation following different synthesis routes, MNP assembly into linear structures can significantly enhance their performance in MPI. The present study investigates the influence of linear MNP structures on MPI signal for different MNP types. With regard to theranostic applications the role of linear structures in hybrid stent imaging is explored.<i>Approach</i>. Three MNP types were used to create linear MNP structures. MNP respectively the MNP structures were immobilised in a hydrogel and positioned at various orientations relative to the coordinate system of the MPI. A multi-channel reconstruction approach was applied to assess the orientation-specific signal. The insights gained were used to reconstruct a fibre-based polymer stent with incorporated linear structures.<i>Main results</i>. Different linear structure orientations could be delineated and visualised in multi-colour images. Linear structures orientated parallel to the direction of a magnetic excitation field lead to the highest signal intensities and peak positions of MPI frequency spectra were located near multiples of the frequency of the excitation coil. Image reconstructions of the stent were very sensitive to the orientation of linear structures within the fibres.<i>Significance</i>. This study reveals that the assembly of MNP results in non-linear contributions to the MPI signal. Consequently, the MPI signal intensity is not as usual merely linearly correlated with MNP concentration increasing the complexity in image reconstruction. The findings demonstrate the necessity of accounting for MNP structure orientation in image reconstruction. They also reveal the high potential of MPI to detect different MNP types and structures. Linear structures cause either significant signal reduction or signal increase depending on the angular position of the linear structures relative to the direction of MPI magnetic fields.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145034116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bridging the resolution gap in alpha therapy dosimetry: a space for quantitative MRI?","authors":"Joshua K Marchant, Bruce R Rosen","doi":"10.1088/1361-6560/ae02dd","DOIUrl":"10.1088/1361-6560/ae02dd","url":null,"abstract":"<p><p>While external beam radiotherapy relies heavily on pre-treatment imaging for advanced treatment planning and radiation dosimetry, tools for predicting local dose delivery in systemic radiopharmaceutical therapies have generally lagged behind. Furthermore, targeted alpha particle-emitting radiopharmaceuticals, with their uniquely short range and high-energy dose deposition, require specialized dosimetry methods at the micro- and mesoscale. Magnetic resonance imaging methods may represent the missing link between standard diagnostic tumor imaging and personalized radionuclide treatment planning for patients. For example, dynamic susceptibility contrast magnetic resonance imaging reveals markedly heterogeneous tumor perfusion patterns and vascular permeability from patient to patient, suggesting variable local drug delivery, but this information is only used in rudimentary ways or not at all in treatment planning. Similarly, emerging diffusion magnetic resonance imaging (MRI) methods may provide information relevant to microscale dosimetry, such as local cell size and density. In this review, we explore advancements in MRI and computational modeling strategies that could improve our fundamental understanding of radionuclide transport in solid tumors and enable pre-treatment, patient-specific predictions of dose delivery at a biologically relevant length scale.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144993070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feasibility of prototype diamond detectors for pulsed UHDR PBS small-field proton dosimetry for proton FLASH experiments.","authors":"Jufri Setianegara, Aoxiang Wang, Nicolas Gerard, Jarrick Nys, Mark Szczepanski, Hao Gao, Yuting Lin","doi":"10.1088/1361-6560/ae023b","DOIUrl":"10.1088/1361-6560/ae023b","url":null,"abstract":"<p><p><i>Objective.</i>This study aims to investigate the responses of prototype diamond detectors under pulsed ultra-high dose rates (UHDRs) pencil-beam-scanning (PBS) protons from a compact proton synchrocyclotron (IBA Proteus®ONE) for small-field UHDR dosimetry.<i>Approach</i>. flashDiamond detectors (fDs) were cross-calibrated with their relative proton responses characterized at conventional dose rates (CONV). Then, absolute UHDR dosimetry was performed and small-field response assessed. These experiments were also conducted with Razor Diode and microdiamond detectors (mDs) for cross-reference. Cross-calibrations were performed against an ADCL-calibrated PPC05 plane-parallel ionization chamber with 59.23 cGy nC^-1calibration coefficients. fD's linearity, dose-rate, energy, and linear-energy-transfer (LET) responses were assessed under CONV protons. Pulsed UHDR PBS protons of 228 MeV were produced from a medical proton synchrocyclotron (IBA Proteus®ONE) for 1.5 × 1.5-3.0 × 3.0 cm²square fields. Nominal absolute UHDR dosimetry was performed at 3 × 3 cm²field sizes with relative responses at smaller fields benchmarked against it.<i>Main results</i>. fD had 28.6 ± 0.1 cGy nC^-1sensitivities under CONV protons and were linear in response with dose-rate independence within ±0.50%. fD were similar to mD in proton energy and LET responses. However, there is an over-response of approximately 5.49%, 6.51% and 13.7% at the 226, 150 and 70 MeV Bragg peaks respectively. Under pulsed proton UHDR irradiation (0.80% s.t.d, 32.6 ± 0.5 cGy dose-per-pulse), fD responded within ±1% as PPC05 with negligible saturation. fD agreed within ±1% with other comparable small-field detectors under small-field UHDR beams and within ±2% of RayStation treatment planning system calculations. There is negligible partial volume averaging with fDs.<i>Significance</i>. Novel fD detectors did not saturate under pulsed UHDR PBS proton irradiation. Their miniscule active crystals make them suitable for small-field dosimetry but render them relatively insensitive compared to mDs. When cross-calibrated, they are suitable for absolute small-field UHDR dosimetry or for relative exit dosimetry monitoring purposes during UHDR radiobiological experiments.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12451744/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144965084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visual language model-assisted spectral CT reconstruction by diffusion and low-rank priors from limited-angle measurements.","authors":"Yizhong Wang, Ningning Liang, Junru Ren, Xinrui Zhang, Ye Shen, Ailong Cai, Zhizhong Zheng, Lei Li, Bin Yan","doi":"10.1088/1361-6560/ae0974","DOIUrl":"https://doi.org/10.1088/1361-6560/ae0974","url":null,"abstract":"<p><strong>Objective: </strong>Spectral computed tomography (CT) is a critical tool in clinical practice, offering capabilities in multi-energy spectrum imaging and material identification. The limited-angle (LA) scanning strategy has attracted attention for its advantages in fast data acquisition and reduced radiation exposure, aligning with the as low as reasonably achievable principle. However, most deep learning-based methods require separate models for each LA setting, which limits their flexibility in adapting to new conditions. In this study, we developed a novel Visual-Language model-assisted Spectral CT Reconstruction (VLSR) method to address LA artifacts and enable multi-setting adaptation within a single model.</p><p><strong>Approach: </strong>The VLSR method integrates the image-text perception ability of visual-language models and the image generation potential of diffusion models. Prompt engineering is introduced to better represent LA artifact characteristics, further improving artifact accuracy. Additionally, a collaborative sampling framework combining data consistency, low-rank regularization, and image-domain diffusion models is developed to produce high-quality and consistent spectral CT reconstructions.</p><p><strong>Main results: </strong>The performance of VLSR is superior to other comparison methods. Under the scanning angles of 90° and 60° for simulated data, the VLSR method improves peak signal noise ratio by at least 0.41 dB and 1.13 dB compared with other methods.</p><p><strong>Significance: </strong>VLSR method can reconstruct high-quality spectral CT images under diverse LA configurations, allowing faster and more flexible scans with dose reductions.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145092219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and testing of an MRI-conditional six-degree-of-freedom phantom robot.","authors":"Alexander Dunn, Mitchell Lee, Siddharth Sadanand, Mohammad Khoobani, Tanvir Hassan, M Ali Tavallaei, Dafna Sussman","doi":"10.1088/1361-6560/ae0973","DOIUrl":"https://doi.org/10.1088/1361-6560/ae0973","url":null,"abstract":"<p><strong>Objective: </strong>&#xD;Motion phantoms can help accelerate and reduce the associated costs of research focused on motion-robust imaging. Currently available phantom robots for magnetic resonance imaging (MRI) lack sufficient degrees of freedom (DOF) to replicate complex physiological motions. This work presents the design and testing of a six-DOF MRI-conditional phantom robot to simulate such motions. &#xD;Approach:&#xD;The system was fabricated predominantly with 3D printed components as well as DC stepper motors. Testing validated the actuator's functionality and conditionality with a 3T MRI system. A Faraday cage to house the motors and electronics was constructed using a conductive coating on a 3D-printed shell. &#xD;Main Results:&#xD;The Faraday cage was found to reduce the noise power produced by the motors to the baseline level measured in the MRI without the robot being present within the MRI suite. A positional accuracy measured using a modified version of ISO 9283 was found to be 0.2mm and a rotational accuracy of [-0.1°, 0.3°, -0.2°] were measured for the x, y, and z directions, respectively. Path accuracy for sample motions was found to have a positional accuracy of 0.3 mm and rotational accuracy of [0.1°, 0.1°, 0.1°].&#xD;Significance:&#xD;The created six-DOF robot enhances the development and validation of motion-robust imaging in MRI. The presented design is covered by WO patent #2023/184043, 2023/09/28.&#xD.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145092223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PWLS-SOM: alternative PWLS reconstruction for limited-view CT by strategic optimization of a deep learning model.","authors":"Changyu Chen, Li Zhang, Yuxiang Xing, Zhiqiang Chen","doi":"10.1088/1361-6560/adffe0","DOIUrl":"10.1088/1361-6560/adffe0","url":null,"abstract":"<p><p><i>Objective.</i>While deep learning (DL) methods have exhibited promising results in mitigating streaking artifacts caused by limited-view computed tomography (CT), their generalization to practical applications remains challenging. To address this challenge, we aim to develop a novel approach that integrates DL priors with targeted-case data consistency for improved artifact suppression and robust reconstruction.<i>Approach.</i>We propose an alternative penalized weighted least squares reconstruction framework by strategic optimization of a DL model (PWLS-SOM). This framework combines data-driven DL priors with data consistency constraints in a three-stage process: (1) Group-level embedding: DL network parameters are optimized on a large-scale paired dataset to learn general artifact elimination. (2) Significance evaluation: A novel significance score quantifies the contribution of DL model parameters, guiding the subsequent strategic adaptation. (3) Individual-level consistency adaptation: PWLS-driven strategic optimization further adapts DL parameters for target-specific projection data.<i>Main results.</i>Experiments were conducted on sparse-view (90 views) circular trajectory CT data and a multi-segment linear trajectory CT scan with a mixed data missing problem. PWLS-SOM reconstruction demonstrated superior generalization across variations in patients, anatomical structures, and data distributions. It outperformed supervised DL methods in recovering contextual structures and adapting to practical CT scenarios. The method was validated with real experiments on a dead rat, showcasing its applicability to real-world CT scans.<i>Significance.</i>PWLS-SOM reconstruction advances the field of limited-view CT reconstruction by uniting DL priors with PWLS adaptation. This approach facilitates robust and personalized imaging. The introduction of the significance score provides an efficient metric to evaluate generalization and guide the strategic optimization of DL parameters, enhancing adaptability across diverse data and practical imaging conditions.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144965080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An adjustable three-layer skull phantom with realistic ultrasound transmission properties.","authors":"Jie Chen, Zhenyu Yi, Tiantian Chen, Haoyang Tong, Linming Zhou, Zijian Hong, Chengwei Tan, Jiale Qin, Feiyan Cai, Yongjun Wu, Juan Li, Yuhui Huang","doi":"10.1088/1361-6560/ae0556","DOIUrl":"10.1088/1361-6560/ae0556","url":null,"abstract":"<p><p>Transcranial ultrasound research has garnered significant attention due to its non-invasive nature, absence of ionizing radiation, and portability, making it advantageous for both imaging and therapy. A critical aspect of advancing transcranial research lies in understanding the ultrasound transmission performance of the human skull. However, inherent variations in skull shape, physical parameters, and age-related changes pose challenges for comparative studies. To address these challenges, we designed a three-layer structured skull (TSS) phantom that closely mimics the structural and ultrasound transmission properties of real skulls. The TSS substrate is composed of epoxy resin/Al₂O₃powders, with purple perilla seeds incorporated into the middle layer to replicate the porous structure found in real skulls. Both simulation and experimental results demonstrate that TSS phantom achieves acoustic transmission properties closely approximating those of human skull bone within the 1.25-1.75 MHz frequency range. Experimentally, the TSS phantom containing 27 wt% purple perilla seeds shows a sound pressure transmission coefficient ranging from 5.0% to 6.6%, closely matching the skull's transmission characteristics (4.2%-9.8%). This performance represents a significant improvement over conventional phantom materials, outperforming epoxy resin plate phantoms (42.6%-48.4%) and polyetheretherketone phantoms (64.5%-75.2%). Notably, the transmission performance of TSS can be adjusted by varying the mass fraction of purple perilla seeds, making it adaptable to diverse research needs. The TSS phantom holds significant potential as a valuable tool in transcranial research, offering a reliable and accessible alternative for comprehensive investigations into ultrasound applications in brain therapy.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145030442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}