Physica Medica-European Journal of Medical Physics最新文献

{"title":"Pre-Treatment 18F-FDG PET/CT reveals altered brain metabolic network connectivity in patients with diffuse large B-cell lymphoma: Implications for cancer-related cognitive impairment","authors":"Xiaoyan Zheng ,&nbsp;Qi Tian ,&nbsp;Runying Li ,&nbsp;Yubin Wang ,&nbsp;Weishan Zhang ,&nbsp;Xiaoyi Duan ,&nbsp;Guogang Luo ,&nbsp;Zhichao Zhang ,&nbsp;Kun Zhu","doi":"10.1016/j.ejmp.2025.105079","DOIUrl":"10.1016/j.ejmp.2025.105079","url":null,"abstract":"<div><h3>Background</h3><div>Cancer-related cognitive impairment (CRCI) is prevalent among patients with diffuse large B-cell lymphoma (DLBCL), often manifesting prior to treatment and frequently remaining unrecognized.</div></div><div><h3>Purpose</h3><div>This study aims to assess CRCI in DLBCL patients before treatment by utilizing 18F-FDG PET/CT metabolic networks to facilitate early detection and intervention.</div></div><div><h3>Methods</h3><div>We conducted a cross-sectional study involving 77 participants from our hospital’s PET-CT center, which included 15 healthy controls and 62 DLBCL patients (29 in stages I + II and 33 in stages III + IV). Using the automated anatomical atlas 3 (AAL3) template, we segmented the 18F-FDG PET brain images into 90 regions, extracted the standard uptake value (SUV) for each region, and calculated its ratio (SUVr) using the cerebellum as a reference. We analyzed connectivity within the brain’s metabolic network across the three groups.</div></div><div><h3>Results</h3><div>DLBCL patients exhibited significantly lower mean degree, closeness centrality, degree of participation in connected components (DPCC), average clustering coefficient (ACC), and clustering coefficient compared to controls (P &lt; 0.001). Patients in stages III + IV demonstrated even lower values. The average shortest path length (ASPL) was significantly higher in DLBCL patients, with stage III + IV patients showing an ASPL nearly three times that of controls and twice that of stage I + II patients. Significant differences in mean degree, closeness centrality, and clustering coefficient were observed among the groups (P &lt; 0.001).</div></div><div><h3>Conclusions</h3><div>CRCI is apparent in DLBCL patients at early stages and deteriorates with disease progression. It is crucial to integrate early detection and cognitive assessments into clinical practice for DLBCL patients.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105079"},"PeriodicalIF":2.7,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144911682","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":"Monte Carlo study of the eye lens exposure of medical staff administering Sc-47 and Cu-67 labelled radiopharmaceuticals","authors":"P. Ferrari ,&nbsp;F. Becker ,&nbsp;J. Dabin ,&nbsp;J. Eakins ,&nbsp;Z. Jovanović ,&nbsp;D. Krstić ,&nbsp;E. Michaś-Majewska ,&nbsp;K. Tymińska ,&nbsp;A. Benali ,&nbsp;R. Bouwman ,&nbsp;A. McCann ,&nbsp;K. Hürkamp ,&nbsp;F. Fioroni","doi":"10.1016/j.ejmp.2025.105077","DOIUrl":"10.1016/j.ejmp.2025.105077","url":null,"abstract":"<div><h3>Purpose</h3><div>In the last decades, new technologies and new radiopharmaceuticals for diagnosis and therapy have continuously grown, and that growth was accompanied by an increasing use in clinical practice, but, as with any other application involving radiation, the extent to which they may contribute to increasing the radiation dose to the operator must be studied. For that reason, EURADOS (European Radiation Dosimetry Group) decided to evaluate the exposure of medical staff in nuclear medicine to new possible radiopharmaceuticals labelled with Sc-47 and Cu-67.</div></div><div><h3>Methodology</h3><div>Modified ICRP voxel model were employed to determine the exposure of the eye lens and of the thyroid of operators administrating radiopharmaceuticals in a typical Peptide Receptor Radionuclide Therapy scenario. The simulations were validated comparing Monte Carlo results with TLD measurements performed in hospital with Lu-177 labelled compounds.</div></div><div><h3>Results</h3><div>Doses to the eye lens and thyroid are derived from the photon emissions (the beta contribution is three order of magnitude lower). The agreement obtained for Lu-177 provides confidence that, notwithstanding the limits of the simulations, the robustness of the followed approach can be extended also to the evaluation performed for Sc-47 and Cu-67.</div></div><div><h3>Conclusions</h3><div>The dose to the lens of the eye is of the order of 2 µSv/GBq per patient for Lu-177 compounds and, due to the different energies and yields, about 8 µSv/GBq for both Sc-47 and Cu-67. These evaluations can be useful to optimize the radiation protection of medical staff in the nuclear medicine environment and assess the correct personnel workload in these kinds of practices.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105077"},"PeriodicalIF":2.7,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902990","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":"Protoacoustic range verification by direct comparison with beam range measurements using a tissue-equivalent polymer gel","authors":"Takeshi Miyashita ,&nbsp;Ye Chen ,&nbsp;Yasutoshi Kuriyama ,&nbsp;Masashi Tomida ,&nbsp;Hidenobu Tachibana ,&nbsp;Yoshihisa Iwashita ,&nbsp;Takayuki Nonoyama ,&nbsp;Sena Hidani ,&nbsp;Taichi Murakami ,&nbsp;Taeko Matsuura","doi":"10.1016/j.ejmp.2025.105099","DOIUrl":"10.1016/j.ejmp.2025.105099","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Protoacoustics offers a promising method for in vivo range verification in proton therapy. To experimentally assess the protoacoustic range accuracy, conventional tissue-mimicking phantoms (TMPs) often require Monte Carlo (MC) simulations to estimate the ground truth. However, limited knowledge of material properties and/or insufficient fine-tuning of dose models can introduce range errors in MC simulations. This study aims to propose a TMP capable of measuring the dose distribution concurrently with the protoacoustic measurement, thereby circumventing the need for MC simulations and their associated uncertainties.</div></div><div><h3>Methods</h3><div>Normoxic <em>N</em>-vinylpyrrolidone-based polymer gel dosimeters were employed as TMPs. Two gel dosimeters of varying sizes were irradiated with a 226.5 MeV proton beam from a clinical synchrocyclotron. Post-irradiation, magnetic resonance imaging was used to determine the beam range within the gels. Concurrently, protoacoustic ranges were measured using an optical hydrophone, employing both a time-of-arrival (TOA) method and an acoustic simulation-based approach. The ranges obtained from the gel dosimeters were then compared with those from the protoacoustic methods.</div></div><div><h3>Results</h3><div>The range differences between the gel dosimeter measurements and both protoacoustic methods were within 1 mm for both gel sizes. In contrast, the maximum deviation between the protoacoustic range and the MC simulation-derived range was 2.1 mm, potentially attributable to inaccuracies in the assumed material properties within the MC simulation.</div></div><div><h3>Conclusions</h3><div>Polymer gel dosimeters provide a direct method for validating protoacoustic beam range measurements in clinical proton beams, circumventing the reliance on MC simulations and their associated uncertainties.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105099"},"PeriodicalIF":2.7,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907514","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":"Foetal dose in novel full body cone beam computed tomography device","authors":"Siru M. Kaartinen,&nbsp;Mimmi K. Liukkonen,&nbsp;Ari-Petteri Ronkainen","doi":"10.1016/j.ejmp.2025.105082","DOIUrl":"10.1016/j.ejmp.2025.105082","url":null,"abstract":"<div><h3>Purpose</h3><div>To evaluate foetal doses at different stages of pregnancy in sinus and cervical spine imaging protocols using a novel supine cone beam computed tomography (CBCT) device.</div></div><div><h3>Method</h3><div>Foetal doses were measured at three different stages of the pregnancy in sinus and spine imaging protocols using an anthropomorphic phantom and a solid-state dosimeter.</div></div><div><h3>Results</h3><div>The foetal doses varied between 0.4 and 3.9 µGy and 2.2 and 32.6 µGy, in sinus and cervical spine examinations, respectively, being highest in the third trimester of pregnancy. A conversion factor for calculating the estimate of the foetus dose from kerma area product (KAP) varies between 0.0002–0.007 μGy/mGy cm².</div></div><div><h3>Conclusions</h3><div>Foetal doses for sinus and cervical spine examinations in a supine CBCT device are low and do not produce a concern about radiation detriment to the foetus.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105082"},"PeriodicalIF":2.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902725","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":"Radiation exposure risk for various personnel in the catheterization laboratory: A systematic review and meta-analysis","authors":"Brúnó B Balázs ,&nbsp;David Laczkó ,&nbsp;Dorottya Gergő ,&nbsp;Bence Szabó ,&nbsp;Gábor Duray ,&nbsp;Zsolt Molnár ,&nbsp;Dénes B Horváthy ,&nbsp;Judit Papp ,&nbsp;Péter Hegyi ,&nbsp;Béla Merkely ,&nbsp;István F Édes","doi":"10.1016/j.ejmp.2025.105096","DOIUrl":"10.1016/j.ejmp.2025.105096","url":null,"abstract":"<div><h3>Purpose</h3><div>Radiation exposure is a well-recognized occupational hazard for catheterization lab personnel. However, the extent of exposure disparities among different staff roles remains unclear. Existing research primarily focuses on primary operators, leaving a gap in understanding radiation risks for ancillary staff. This study aims to evaluate how staff positioning and shielding affect radiation exposure, focusing on disparities between primary operators and ancillary staff during fluoroscopy-guided cardiovascular procedures.</div></div><div><h3>Method</h3><div>After a systematic search across five databases on November 20, 2023, we included studies reporting radiation data for coronary angiographies, structural heart interventions, electrophysiological procedures, or endovascular aorta interventions, with at least one ancillary staff member in prespecified positions. Radiation exposures were compared relative to the primary operator using the Ratio of Means (ROM) during <em>meta</em>-analysis. Risk of Bias was assessed using RoB-2 or ROBINS-E. The review protocol was registered as CRD42023484491.</div></div><div><h3>Results</h3><div>Our <em>meta</em>-analysis, based on 8116 measurements from 3091 procedures across 23 studies, suggests that personnel at the patient’s head without shielding may experience higher radiation exposure than primary operators (ROM 1.77, 95% CI: 0.75–4.18), although this difference didn’t reach statistical significance. Shielded workers at the head or in secondary/assistant positions received significantly lower radiation than primary operators (ROM 0.26, 95% CI: 0.12–0.57; ROM 0.33, 95% CI: 0.25–0.43).</div></div><div><h3>Conclusions</h3><div>Our results suggest a potential disparity in radiation exposure among catheterization laboratory personnel, with unshielded workers at the patient’s head tending to receive the highest levels of exposure.</div><div>Dedicated shielding solutions and attention to all personnel are imperative.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105096"},"PeriodicalIF":2.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902727","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":"Development of a GEANT4-Based Monte Carlo algorithm for polarized nuclear imaging simulations integrated into GATE","authors":"Rasool Safari ,&nbsp;Yasaman Aboulghasemi ,&nbsp;Reza Faghihi ,&nbsp;Mohammadreza Parishan ,&nbsp;Zahra Rakeb","doi":"10.1016/j.ejmp.2025.105081","DOIUrl":"10.1016/j.ejmp.2025.105081","url":null,"abstract":"<div><h3>Background</h3><div>Polarized Nuclear Imaging (PNI) is a novel gamma imaging approach that encodes spatial information by using polarized radioactive nuclei and manipulating them with magnetic fields, gradients, and RF pulses. The resulting anisotropic photon emission yields direct k-space encoding, removing the need for collimators.</div></div><div><h3>Purpose</h3><div>The work will focus on developing the first, high-performance Monte Carlo-based algorithm for PNI, fully integrated into the GATE framework. Using Monte Carlo simulations, there is an expectation of a strong push in research concerning PNI and a better understanding and use of this new imaging technique.</div></div><div><h3>Methods</h3><div>An algorithm based on Geant4 was implemented and coupled with GATE in the form of a new type of source. This extension allows users to define a PNI source, configure its parameters, and use GATE’s basic functionalities to perform simulation studies in PNI. The source of GATE-based PNI generates photons in directions according to the PNI-encoded method, which maps spatial information into the spin orientations of polarized radioactive nuclei.</div></div><div><h3>Results</h3><div>The tool exhibited extremely small average relative errors (∼0.0000018 %) when replicating theoretical angular distributions of gamma emissions from oriented nuclei, and a 3.57 % difference from theory in extracting k-space data using the detector-based PNI method. A complex PNI source also yielded results consistent with experimental data.</div></div><div><h3>Conclusions</h3><div>This GATE-based PNI simulation toolkit offers an efficient, user-friendly, and accurate method for investigating PNI, paving the way for advanced research and system optimization.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105081"},"PeriodicalIF":2.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902728","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":"In silico evaluation of the potential of very high energy electrons delivered in both conventional and FLASH regimes for the SBRT treatment of pancreatic cancer: A report of three case studies","authors":"A. De Gregorio ,&nbsp;A. Muscato ,&nbsp;A. Burattini ,&nbsp;D. Carlotti ,&nbsp;M. Fiore ,&nbsp;G. Franciosini ,&nbsp;T. Insero ,&nbsp;M. Marafini ,&nbsp;V. Marè ,&nbsp;V. Patera ,&nbsp;F. Quattrini ,&nbsp;S. Ramella ,&nbsp;A. Schiavi ,&nbsp;M. Toppi ,&nbsp;G. Traini ,&nbsp;A. Trigilio ,&nbsp;A. Sarti","doi":"10.1016/j.ejmp.2025.105076","DOIUrl":"10.1016/j.ejmp.2025.105076","url":null,"abstract":"<div><h3>Background and purpose:</h3><div>As the incidence and mortality rates of pancreatic cancer continue to rise, the search for effective treatments is becoming increasingly urgent. Among the therapeutic approaches, highly hypofractionated stereotactic treatments are being explored. This paper explores the potential of Very High Energy Electrons (VHEE) in the range of 80-130 MeV, in light of recent advances in compact accelerator technology and its compatibility with ultra-high dose rate (UHDR) delivery.</div></div><div><h3>Materials and methods:</h3><div>Using dose-volume histograms and dose maps, we compared VHEE treatment plans simulated and optimized assuming both conventional and UHDR delivery scenarios against state-of-the-art volumetric modulated arc therapy (VMAT) treatment plans that were used to treat three patients. Dose maps have been obtained assuming an IMRT-like geometry. The implemented VHEE beam model assumes a C-band compact accelerating technology. Results show that electrons below 130 MeV have a clear potential for the effective treatment of pancreatic cancer, even if delivered in conventional conditions. UHDR delivery has been explored evaluating the gain that the FLASH effect could provide in terms of dose escalation to the PTV while constraining the maximum allowed biological dose to the duodenum.</div></div><div><h3>Conclusion:</h3><div>The obtained results demonstrate the suitability of VHEE for pancreatic cancer treatment with optimized plans that are clinically acceptable even without considering the additional sparing from the FLASH effect. Their suitability for being delivered at FLASH rates makes them an excellent candidate for the future of external beam radiotherapy.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105076"},"PeriodicalIF":2.7,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902726","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":"Evaluation of the dosimetric accuracy of HyperSight CBCT for CBCT-only adaptive radiotherapy workflow","authors":"Francesca Dusi,&nbsp;Fabio Busato,&nbsp;Alessandro Testolin,&nbsp;Davide Fiorentin,&nbsp;Francesca Tessari,&nbsp;Mattia Nicoletto,&nbsp;Marco Fusella","doi":"10.1016/j.ejmp.2025.105091","DOIUrl":"10.1016/j.ejmp.2025.105091","url":null,"abstract":"<div><h3>Background/introduction</h3><div>This study evaluates the dosimetric performance of HyperSight CBCT (HS-CBCT) images for CBCT-only adaptive radiotherapy workflows.</div></div><div><h3>Methods</h3><div>We evaluated Hounsfield unit (HU) accuracy and dose calculation performance using both Feldkamp-Davis-Kress (FDK) and Acuros reconstructions in phantom and clinical datasets (brain, breast, pelvis). HU deviations were reported relative to planning CT. Longitudinal HU stability was assessed over 20 CBCT sessions in a prostate cohort. Gamma passing rates (2 %/2mm) were used for dosimetric evaluation.</div></div><div><h3>Results</h3><div>Acuros-reconstructed CBCT images demonstrated HU agreement within 28 HU of the planning CT, compared to deviations up to 284 HU for FDK (the relative coefficient of variation −CV- of the difference from the pCT reference value were 2 % and 20 % for Acuros and FDK respectively). Dose recalculations on Acuros images resulted in higher gamma passing rates, particularly in pelvic cases (97.8 % vs 96.6 % with FDK, p &lt; 0.05). HU stability analysis over 20 CBCT sessions in prostate patients confirmed reproducibility, with standard deviations of 5.0 HU for bone and 4.2 HU for bladder.</div></div><div><h3>Conclusion</h3><div>This study provides the first comprehensive, multi-site and longitudinal clinical validation of HyperSight CBCT with Acuros reconstruction for ART workflows. Our results demonstrate high HU fidelity and robust dose calculation performance, supporting the clinical feasibility of CBCT-only workflows across different anatomical regions and throughout the course of treatment.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105091"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144891836","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":"Development of a context-aware integrated training module based on large language models for continuous education in radiation protection","authors":"Anna Romanyukha,&nbsp;Mahta Mazloumi,&nbsp;Thomas De Waelheyns,&nbsp;Nidhi Mishra,&nbsp;Jurgen Jacobs,&nbsp;Niki Fitousi","doi":"10.1016/j.ejmp.2025.105090","DOIUrl":"10.1016/j.ejmp.2025.105090","url":null,"abstract":"<div><h3>Purpose</h3><div>Reliability of LLM-based AI chatbots can be enhanced by using domain-specific models with a controlled knowledge base, especially relevant in the context of education and training of healthcare professionals and researchers. The aim was to produce an LLM data model with the goal of continuous education in radiation protection, that allows users to access reliable scientific information by querying it on specific topics, eliminating the need for manually perusing educational materials.</div></div><div><h3>Method</h3><div>A domain-specific LLM data model was developed and trained using custom knowledge from several domains, tested applying various test scenarios, and fine-tuned to ensure optimal selections of hyperparameters including top k, chunk size, temperature, max tokens etc.</div></div><div><h3>Results</h3><div>The final model produced reliable and accurate answers to a variety of users and queries based on controlled educational materials. Embedding model and similarity cutoff had the greatest impact on model performance.</div></div><div><h3>Conclusion</h3><div>The developed model was trained and validated on radiation protection training material, allowing users to access information on topics including radiobiology and radiation protection in a quick and reliable manner.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105090"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890192","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":"Phantom-based assessment of focused ultrasound thermal effects with conventional magnetic resonance imaging","authors":"Anastasia Antoniou ,&nbsp;Nikolas Evripidou ,&nbsp;Antria Filippou ,&nbsp;Leonidas Georgiou ,&nbsp;Antreas Chrysanthou ,&nbsp;Antonis Christofi ,&nbsp;Yiannis Roussakis ,&nbsp;Cleanthis Ioannides ,&nbsp;Yuhan Lyu ,&nbsp;Jufeng Zhao ,&nbsp;Liyang Yu ,&nbsp;Wenjun Li ,&nbsp;Christakis Damianou","doi":"10.1016/j.ejmp.2025.105078","DOIUrl":"10.1016/j.ejmp.2025.105078","url":null,"abstract":"<div><h3>Background and objective</h3><div>This study presents key findings from Magnetic Resonance Imaging (MRI)-guided Focused Ultrasound (FUS) sonication experiments in a specialized gel phantom, aimed at demonstrating the effectiveness of using conventional T1-Weighted (T1-W) and T2-Weighted (T2-W) Turbo Spin Echo (TSE) sequences to assess FUS thermal effects and related system performance.</div></div><div><h3>Methods</h3><div>Three custom-manufactured, single-element spherically focused ultrasonic transducers were utilized in this study. The temporal regression of lesions induced by high-power FUS in the phantom model was investigated within a 3T MRI scanner for both employed sequences. Thermal effects within the phantom were characterized through visual assessment and quantitative measurements of lesion size and contrast-to-noise ratio (CNR) on TSE images, under different focal intensities, exposure durations, and focal depths, complemented by MR thermometry data.</div></div><div><h3>Results</h3><div>The phantom exhibited hyperintense lesions with excellent contrast on T2-W TSE imaging, chosen for its superior contrast and faster lesion resolution. Lesion size increased with intensity and exposure time, though trends varied by transducer. Cigar-shaped or non-uniform elongated lesions developed, reflecting sharp or poor transducer focusing, with signal intensity decreasing as focal depth increased. A strong correlation between lesion CNR and accumulated thermal dose was observed, emphasizing that changes in imaging contrast can consistently reflect thermal effects.</div></div><div><h3>Conclusion</h3><div>The proposed phantom-based MRI approach shows promise as a tool for routine assessment of FUS ablation system performance by monitoring lesion dynamics using conventional T2-W TSE imaging, thereby streamlining the quality assurance workflow.</div></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":"137 ","pages":"Article 105078"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890193","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}