Physics in medicine and biology最新文献

{"title":"Evaluation of 4D cone-beam CT reconstruction methods for lung images acquired using rapid cone-beam CT acquisition: a phantom study.","authors":"Mark Gardner, Owen Dillon, Tess Reynolds, John Kipritidis, Magdalena Bazalova-Carter, Hilary Byrne, Maegan Stewart, Jeremy Booth, Paul J Keall","doi":"10.1088/1361-6560/ade6bd","DOIUrl":"10.1088/1361-6560/ade6bd","url":null,"abstract":"<p><p><i>Objective</i>. Cone-beam CT (CBCT) technological advances for linear accelerators (Linacs) have led to CBCT imaging in <20 s, which can reduce radiation therapy treatment times. However, these rapid CBCT scans only allow for 3DCBCT images. In this paper we evaluate 4DCBCT reconstruction methods for rapid acquisition 3DCBCT protocol scans using an anthropomorphic breathing phantom.<i>Approach</i>. We evaluate two previously developed motion-compensated Feldkamp-Davis-Kress (MCFDK) methods, using a prior-motion model (MCFDK-Prior) and a data-driven MCFDK method (MCFDK-DD), on CBCT images of the phantom using an Ethos linac. The deformable phantom lungs contained three synthetic tumours and a commercial phantom motion platform with a sinusoidal breathing pattern. The phantom was imaged in free-breathing with rapid (16.6 s) and standard (30.8 s) thorax 3DCBCT acquisition protocols, then reimaged while stationary at inhale and exhale, which were the ground truth reconstructions. MCFDK reconstructions were compared with conventional 3D-FDK and 4D-FDK reconstructions. Image quality was compared between all reconstructions using mean square error (MSE), structural similarity index measurement (SSIM), peak signal-to-noise (PSNR), edge response width (ERW) for the diaphragm-lung border for the right lung, tumour centroid accuracy, tumour dice similarity coefficient and sphericity.<i>Main results</i>. For all metrics the MCFDK-Prior reconstructions performed better than the 3D-FDK reconstructions. Similarly for all tumour-related metrics as well as ERW the MCFDK-DD reconstructions performed better than then 3D-FDK reconstructions, but the overall MSE, SSIM and PSNR were similar for the MCFDK-DD and 3D-FDK reconstructions. For all metrics except for tumour centroid error the MCFDK-Prior method produced better quality reconstructions than the MCFDK-DD method. 4D-FDK reconstructions produced poor quality volumes.<i>Significance</i>. We demonstrated that 4DCBCT reconstruction for rapid CBCT acquisition protocols is possible and leads to reduced motion artefacts and more accurate reconstructions when compared to 3DCBCT reconstructions. The 4DCBCT methods demonstrated in this paper will allow for fast, accurate 4DCBCT acquisition for new linacs.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144336735","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":"Limited-angle SPECT image reconstruction using deep image prior.","authors":"Kensuke Hori, Fumio Hashimoto, Kazuya Koyama, Takeyuki Hashimoto","doi":"10.1088/1361-6560/adea09","DOIUrl":"https://doi.org/10.1088/1361-6560/adea09","url":null,"abstract":"<p><p>[Objective] In single-photon emission computed tomography (SPECT) image reconstruction, limited-angle conditions lead to a loss of frequency components, which distort the reconstructed tomographic image along directions corresponding to the non-collected projection angle range. Although conventional iterative image reconstruction methods have been used to improve the reconstructed images in limited-angle conditions, the image quality is still unsuitable for clinical use. We propose a limited-angle SPECT image reconstruction method that uses an end-to-end deep image prior (DIP) framework to improve reconstructed image quality.&#xD;[Approach] The proposed limited-angle SPECT image reconstruction is an end-to-end DIP framework which incorporates a forward projection model into the loss function to optimise the neural network. By also incorporating a binary mask that indicates whether each data point in the measured projection data has been collected, the proposed method restores the non-collected projection data and reconstructs a less distorted image.&#xD;[Main results] The proposed method was evaluated using 20 numerical phantoms and clinical patient data. In numerical simulations, the proposed method outperformed existing back-projection-based methods in terms of peak signal-to-noise ratio and structural similarity index measure. We analysed the reconstructed tomographic images in the frequency domain using an object-specific modulation transfer function, in simulations and on clinical patient data, to evaluate the response of the reconstruction method to different frequencies of the object. The proposed method significantly improved the response to almost all spatial frequencies, even in the non-collected projection angle range. The results demonstrate that the proposed method reconstructs a less distorted tomographic image.&#xD;[Significance] The proposed end-to-end DIP-based reconstruction method restores lost frequency components and mitigates image distortion under limited-angle conditions by incorporating a binary mask into the loss function.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144529309","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":"Anatomical feature-prioritized loss for enhanced MR to CT translation.","authors":"Arthur Longuefosse, Baudouin Denis de Senneville, Gaël Dournes, Ilyes Benlala, Fabien Baldacci, Pascal Desbarats","doi":"10.1088/1361-6560/adea07","DOIUrl":"https://doi.org/10.1088/1361-6560/adea07","url":null,"abstract":"<p><strong>Objective: </strong>Accurate reconstruction of localized anatomical details is essential in medical image synthesis, particularly when addressing specific clinical requirements such as the identification or measurement of fine structures. Traditional methods for image translation and synthesis are generally optimized for global image reconstruction but often fall short in providing the finesse required for detailed local analysis. This study represents a step toward addressing this challenge by introducing a novel anatomical feature-prioritized (AFP) loss function into the synthesis process.&#xD;Approach. The AFP loss integrates features from pre-trained task-specific models, such as anatomical segmentation networks, into the image synthesis pipeline to enforce attention to critical structures. This loss function is evaluated across multiple architectures, including GAN-based and CNN-based models, and applied in two cross-modality contexts: (1) lung MR to CT translation with an emphasis on bronchial structure preservation, using a private thoracic dataset; and (2) pelvis MR to CT synthesis, targeting organ and muscle reconstruction, using the public SynthRAD2023 dataset. Feature embeddings from domain-specific segmentation networks are extracted to guide synthesis toward anatomically meaningful outputs. &#xD;Results. The AFP loss demonstrated consistent improvements in downstream segmentation accuracy across both domains. For lung airway reconstruction, the Dice coefficient increased from 0.534 with standard L1 loss to 0.584 using AFP loss. In pelvic imaging, bone reconstruction Dice scores improved from 0.738 using L1 loss to 0.780 with AFP loss. These results confirm that the AFP loss improves the reconstruction of anatomical structures while maintaining comparable intensity-based metrics, indicating that global image quality is not compromised. &#xD;Significance. The proposed AFP loss provides a modular and generalizable approach for embedding anatomical task-awareness into medical image synthesis. By aligning image translation objectives with clinically relevant features, it offers a pathway toward more precise and useful synthetic images for downstream tasks, supporting broader integration of image synthesis in clinical workflows.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144529306","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 in-silico evaluation of a novel beamline for precision small animal pencil beam scanning delivery at clinical proton therapy facilities.","authors":"Neeraj Kurichiyanil, Marco Pinto, Katia Parodi","doi":"10.1088/1361-6560/adea08","DOIUrl":"https://doi.org/10.1088/1361-6560/adea08","url":null,"abstract":"<p><strong>Objectives: </strong>Preclinical small animal proton beam irradiation systems are increasingly in demand. However, the absence of dedicated systems comparable in precision to those in clinical settings presents a considerable hurdle to investigations in this field. To address this need, the SIRMIO project has developed a novel compact beam transport system configured to degrade and focus clinical proton beams. The beamline, about 1 meter long, housed in an environment to minimize scatter, includes degraders, collimators, and a permanent magnet quadrupole triplet to focus protons degraded from clinical energies. It is tailored to transport focused proton beams within the energy range of 20 to 50 MeV, ideal for small animal preclinical studies. The flexibility of this beamline design allows achieving beam-spot sizes of 1 mm sigma at the isocenter for all focused energies, with the particle fluence and spot sizes being variable through dynamic adjustment of the&#xD;collimator and magnetic lattice. 3-D scanning of the target volume is possible due to lateral beam scanning integrated into this design, without the use of additional scanning dipole magnets. &#xD;Approach: The beamline was optimized using an accelerator beam optics code, followed by a Monte Carlo model to account for beam-matter interactions. Using an experimentally validated clinical proton beam phase space as input, degraded beams are transported through the Monte Carlo model. Outcomes are assessed for beam characteristics and dosimetric properties Main Results: Beams transported by our proposed beamline design are shown to result in dosimetric properties suitable for preclinical studies, while also emulating realistic clinically relevant beam delivery scenarios like pencil beam scanning. Compared to a similar-sized collimator-only beamline, this design&#xD;enhances transmission and reduces secondary dose at the target due to absence of scattering elements nearby.&#xD;Significance: The portable SIRMIO beamline offers a flexible, precise alternative to passive methods for adapting clinical proton beams for small animal irradiation, enhancing preclinical research with clinically relevant beam delivery and enabling experiments in conditions more closely matching clinical practice.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144529307","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":"Exploring the limits to quantitative elastography: supersonic shear imaging in stretched soft strips.","authors":"Samuel Croquette, Alexandre Delory, Daniel A Kiefer, Claire Prada, Fabrice Lemoult","doi":"10.1088/1361-6560/adea2a","DOIUrl":"https://doi.org/10.1088/1361-6560/adea2a","url":null,"abstract":"<p><p>Objective --- Shear wave elastography has enriched ultrasound medical imaging with quantitative tissue stiffness measurements. We aim to explore the limitations that persist related to viscoelasticity, guiding geometry or static deformation.&#xD;Approach --- A nearly-incompressible soft elastomer strip is chosen to mimic the mechanical behavior of an elongated tissue. A supersonic shear wave scanner measures the propagation of shear waves within the strip. It provides a wide range of shear wave velocities, from 2 to 6~m/s, depending on the frequency, the static strain as well as the orientation of the strip.&#xD;Main results --- To explain these different measurements, the guided wave effect is highlighted and analysed from the dispersion diagrams provided by the spatio-temporal Fourier transform of the raw data. The guided waves are then described using a material model that accounts for both the rheology and the hyperelastic behavior, and allows to extract the mechanical parameters of the sample.&#xD;Significance --- To overcome some limitations of current elastography, we propose a theoretical framework which allows the simultaneous characterization of the viscoelastic and hyperelastic properties of soft tissues, paving the way for robust quantitative elastography of elongated tissues.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144529308","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":"Refined signal space separation methods for on-scalp MEG systems.","authors":"Alexandria McPherson, Iman Fahmy, Eric Larson, Wanjin Yeo, Niall Holmes, Samu Taulu","doi":"10.1088/1361-6560/ade6ba","DOIUrl":"10.1088/1361-6560/ade6ba","url":null,"abstract":"<p><p><i>Objective.</i>The reliability of biomagnetic measurements is improved by data processing techniques like the signal space separation (SSS) method, which transforms multichannel signals into device-independent channels with separate components for internal biomagnetic and external interference signals based on sensor geometry. Newer on-scalp sensors, such as optically-pumped magnetometers (OPMs), have recently been deployed in magnetoencephalography (MEG) systems, bringing a need for refined SSS variants to capture the potentially improved spatial resolution provided by the on-scalp sensors. Standard single-origin SSS may fail to capture the full brain-space when the sensors are on scalp. In this paper, we propose potential solutions to this problem including novel multi-origin SSS (mSSS). With multiple optimized origins and radii used together, the basis can span the brain-space without encroaching on the sensor space. Other adaptations to SSS include vector spheroidal harmonics, which create signal space expansions using ellipsoidal geometry to model the brain-space. This adaptation is further modified to combine an interior spheroidal with exterior single-SSS.<i>Approach.</i>Focusing on two-origin mSSS, the spheroidal constructions and the single-origin SSS are investigated with simulated data from an internal current dipole source coupled with an external interference signal with geometry from the 432-channel Kernel Flux OPM system, the 306-channel MEGIN/Elekta Neuromag SQUID system, and the 192-Channel Triaxial QuSpin OPM system. Finally, each variant is used to process collected data including auditory evoked data measured at the University of Washington with the Kernel Flux OPM system, previously recorded empty-room data collected in a lightly-shielded magnetically shielded room with 192-channel third generation triaxial QuSpin Zero Field Magnetometers, and publicly available single-subject audiovisual data collected with an 86-Channel dual-axis QuSpin OPM system at the University College London.<i>Main results.</i>The mSSS method has comparable or better stability to the SSS method in all sensor geometries and reconstructs interior simulated signals while successfully suppressing exterior interference, and performs better in simulated cases with variably placed on-scalp MEG systems. Additionally, results with Kernel and QuSpin data show the mSSS basis provides a lower noise floor than other SSS variants and had the best performance with on-scalp systems, even with low-channel-count OPM systems.<i>Significance.</i>With on-scalp MEG systems becoming more widely available, the MEG community needs updated data analysis techniques. mSSS is a straightforward and robust modification to the SSS method which functions for novel on-scalp sensor systems without needing drastic modification to the underlying mathematical method.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144336806","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":"Commissioning of a multislit collimator system for experimental pMBRT studies with uniform target dose.","authors":"Fardous Reaz, Erik Traneus, Niels Bassler","doi":"10.1088/1361-6560/ade04b","DOIUrl":"10.1088/1361-6560/ade04b","url":null,"abstract":"<p><p><i>Objective</i>. Proton minibeam radiotherapy (pMBRT) is a novel approach to widen the therapeutic window by balancing tumor control and reducing toxicity to healthy tissues. Among the various ways to generate minibeams, a multislit collimator (MSC) is a convenient approach for integration into existing beamlines. Here, we focus on optimizing the MSC to achieve uniform doses in the planning target volume (PTV), enabling direct comparisons with conventional proton therapy and highlighting pMBRT's potential clinical benefits.<i>Approach</i>. This study details the design, development, and commissioning of an MSC system for experimental pMBRT, using Geant4 simulations for collimator optimization and experimental validation with radiochromic film, a diamond detector, and a plane-parallel ionization chamber. The optimization process focused on collimator parameters such as material, thickness, center-to-center distance (CTC), and geometric throughput, tailored for a murine<i>in vivo</i>reference setup. Treatment plans were modified to ensure uniform PTV doses, compensating the effect of MSCs. Simulations emphasize on accurate collimator optimization to ensure the maximum dose contrast between peaks and valleys at the entrance while retaining uniform PTV dose.<i>Main results</i>. Although tungsten MSCs can produce sharp dose contrasts in normal tissue, our experimental findings suggest brass as the preferred material to reduce activation, particularly important for repeated high-dose irradiations. We found that a 50 mm thickness, 2 mm CTC distance, and 50% throughput were optimal for our reference treatment plan (84 to 107 MeV). With a sufficiently uniform PTV dose, we experimentally obtained a valley-to-peak dose ratio of 0.13. The dose pattern is highly sensitive to MSC alignment, although phase shifts have minimal impact.<i>Significance</i>. The non-parallel nature of pencil beam scanning underscores the importance of precise MSC alignment to preserve uniform target dose and high dose contrast at the entrance. Our optimized configurations, experimentally validated, offer a foundation for preclinical and clinical pMBRT collimator construction.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144216555","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":"Prospective quality control in chest radiography based on the reconstructed 3D human body.","authors":"Yuqi Tan, Zheng Ye, Jingyu Ye, Yuzhou Hou, Shaoqing Li, Zejun Liang, Hanyu Li, Jing Tang, Chunchao Xia, Zhenlin Li","doi":"10.1088/1361-6560/ade94c","DOIUrl":"https://doi.org/10.1088/1361-6560/ade94c","url":null,"abstract":"<p><strong>Objective: </strong>Chest radiography requires effective quality control (QC) to reduce high retake rates. However, existing QC measures are all retrospective and implemented after exposure, often necessitating retakes when image quality fails to meet standards and thereby increasing radiation exposure to patients. To address this issue, we proposed a 3D human body (3D-HB) reconstruction algorithm to realize prospective QC. Our objective was to investigate the feasibility of using the reconstructed 3D-HB for prospective QC in chest radiography and evaluate its impact on retake rates.&#xD;Approach: This prospective study included patients indicated for posteroanterior (PA) and lateral (LA) chest radiography in May 2024. A 3D-HB reconstruction algorithm integrating the SMPL-X model and the HybrIK-X algorithm was proposed to convert patients' 2D images into 3D-HBs. QC metrics regarding patient positioning and collimation were assessed using chest radiographs (reference standard) and 3D-HBs, with results compared using ICCs, linear regression, and receiver operating characteristic curves. For retake rate evaluation, a real-time 3D-HB visualization interface was developed and chest radiography was conducted in two four-week phases: the first without prospective QC and the second with prospective QC. Retake rates between the two phases were compared using chi-square tests. &#xD;Main results: 324 participants were included (mean age, 42 years±19 [SD]; 145 men; 324 PA and 294 LA examinations). The ICCs for the clavicle and midaxillary line angles were 0.80 and 0.78, respectively. Linear regression showed good relation for clavicle angles (R2: 0.655) and midaxillary line angles (R2: 0.616). In PA chest radiography, the AUCs of 3D-HBs were 0.89, 0.87, 0.91 and 0.92 for assessing scapula rotation, lateral tilt, centered positioning and central X-ray alignment respectively, with 97% accuracy in collimation assessment. In LA chest radiography, the AUCs of 3D-HBs were 0.87, 0.84, 0.87 and 0.88 for assessing arms raised, chest rotation, centered positioning and central X-ray alignment respectively, with 94% accuracy in collimation assessment. In retake rate evaluation, 3995 PA and 3295 LA chest radiographs were recorded. The implementation of prospective QC based on the 3D-HB reduced retake rates from 8.6% to 3.5% (PA) and 19.6% to 4.9% (LA) (p < .001).&#xD;Significance: The reconstructed 3D-HB is a feasible tool for prospective QC in chest radiography, providing real-time feedback on patient positioning and collimation before exposure. Prospective QC based on the reconstructed 3D-HB has the potential to reshape the future of radiography QC by significantly reducing retake rates and improving clinical standardization.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512311","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":"Photon-counting micro-CT scanner for deep learning-enabled small animal perfusion imaging.","authors":"Alex Jeffrey Allphin, Rohan Nadkarni, Darin P Clark, Cristian T Badea","doi":"10.1088/1361-6560/ade94b","DOIUrl":"https://doi.org/10.1088/1361-6560/ade94b","url":null,"abstract":"<p><strong>Objective: </strong>In this work, we introduce a benchtop, turn-table photon-counting (PC) micro-CT scanner and highlight its application for dynamic small animal perfusion imaging.&#xD;Approach: Built on recently published hardware, the system now features a CdTe-based photon-counting detector (PCD). We validated its static spectral PC micro-CT imaging using conventional phantoms and assessed dynamic performance with a custom flow-configurable dual-compartment perfusion phantom. The phantom was scanned under varied flow conditions during injections of a low molecular weight iodinated contrast agent. In vivo mouse studies with identical injection settings demonstrated potential applications. A pretrained denoising CNN processed large multi-energy, temporal datasets (20 timepoints × 4 energies × 3 spatial dimensions), reconstructed via weighted filtered back projection. A separate CNN, trained on simulated data, performed gamma variate-based 2D perfusion mapping, evaluated qualitatively in phantom and in vivo tests.&#xD;Main Results: Full five-dimensional reconstructions were denoised using a CNN in ~3% of the time of iterative reconstruction, reducing noise in water at the highest energy threshold from 1206 HU to 86 HU. Decomposed iodine maps, which improved contrast to noise ratio from 16.4 (in the lowest energy CT images) to 29.4 (in the iodine maps), were used for perfusion analysis. The perfusion CNN outperformed pixelwise gamma variate fitting by ~33%, with a test set error of 0.04 vs. 0.06 in blood flow index (BFI) maps, and quantified linear BFI changes in the phantom with a coefficient of determination of 0.98.&#xD;Significance: This work underscores the PC micro-CT scanner's utility for high-throughput small animal perfusion imaging, leveraging spectral PC micro-CT and iodine decomposition. It provides a versatile platform for preclinical vascular research and advanced, time-resolved studies of disease models and therapeutic interventions.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512310","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":"IPEM topical report: results of a 2024 UK survey of artificial intelligence in medical physics and clinical engineering.","authors":"Paul James Doolan, Sofia Michopoulou, Richard Meades","doi":"10.1088/1361-6560/ade92b","DOIUrl":"https://doi.org/10.1088/1361-6560/ade92b","url":null,"abstract":"<p><p>Medical Physics and Clinical Engineering (MPCE) professionals have a critical role in the safe and effective deployment of AI in healthcare, however their attitudes and opinions towards AI are not well understood. A 2024 survey was launched by the Institute of Physics and Engineering in Medicine to UK MPCE professionals to gather information on the current usage of AI, whether it is believed their role will change, if there is any fear about job replacement, the training being conducted, levels of preparedness, concerns about AI introduction, and barriers to AI deployment. &#xD;&#xD;A total of 409 responses were received. It was found that AI is widely used (59% of respondents), with wide disparities between disciplines (radiotherapy 76% compared to clinical engineering 37%). Job losses are predicted by 40% of staff, with junior NHS staff more concerned. Nearly 80% of respondents are investing in their own learning, but only 23% know where to look for training resources. Only 10% of the cohort had some prior AI education. Without prior education on AI, only 13% of respondents feel prepared for AI introduction; but this increases by a factor of three with education. Lack of training and knowledge is the major concern and barrier to AI adoption, while lack of a clear AI governance framework was also frequently cited.&#xD;&#xD;This survey provides a snapshot of the current status and attitudes of the UK MPCE workforce towards AI and should be used in guiding future efforts in training and education, addressing discipline disparities and overcoming deployment barriers.&#xD;&#xD.</p>","PeriodicalId":20185,"journal":{"name":"Physics in medicine and biology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512338","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}