Zeitschrift fur medizinische Physik最新文献

{"title":"Association between ECAP signal artifacts and electrical components from a cochlear implant impedance model.","authors":"Julia Veloso de Oliveira, Nora M Weiss, Barbara Wollenberg, Wilhelm Wimmer","doi":"10.1016/j.zemedi.2026.10.002","DOIUrl":"https://doi.org/10.1016/j.zemedi.2026.10.002","url":null,"abstract":"<p><p>electrically evoked compound action potentials (ECAPs) are among the few objective measures of auditory nerve activity available in clinical practice and provide valuable insight into a patient's neural status. ECAP recordings are typically performed using different electrodes for stimulation and recording to avoid amplifier saturation caused by electrode polarization. However, same-electrode recording could reduce the spatial separation between the site of neural activation and the recording site, potentially providing a more localized assessment of neural activity and improving the sensitivity of ECAP-based biomarkers. Here, we introduce a method to characterize stimulation artifacts and estimate their parameters using a previously published impedance model. The artifact waveform was described by a shared double exponential function, while electrical components of an equivalent circuit were estimated from impedance measurements acquired with multiple pulse durations. Artifact recordings exhibited clear polarity-dependent behavior. Nevertheless, the amplitude of the fast exponential component showed a significant association with its impedance-based estimate (fixed-effect coefficient β=0.37 and β=0.44 for anodic-cathodic and cathodic-anodic stimulation, respectively; p<0.001). Furthermore, longitudinal changes in the fast exponential component were similar to changes in near-field impedance subcomponent, suggesting that the ECAP artifact could be partially influenced by postoperative changes at the electrode-electrolyte interface.</p>","PeriodicalId":101315,"journal":{"name":"Zeitschrift fur medizinische Physik","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149229670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review on carbon ion minibeam radiotherapy: Dosimetry, dynamic phantoms and radiobiology.","authors":"Christina Stengl, José Vedelago, Oliver Jäkel","doi":"10.1016/j.zemedi.2026.09.004","DOIUrl":"https://doi.org/10.1016/j.zemedi.2026.09.004","url":null,"abstract":"<p><p>Carbon ion minibeam radiotherapy (CIMRT) is an emerging technique that intends to combine the biological and physical advantages of carbon ions with the normal-tissue sparing potential of spatially fractionated dose delivery. The increased linear energy transfer (LET) and higher relative biological effectiveness (RBE) of carbon ions compared with photons and protons, together with the immunomodulatory effects reported for carbon ion therapy and the biological responses observed after minibeam irradiation for photons and protons, suggest the potential for enhanced tumor control while preserving normal tissue during CIMRT. Given the poor prognosis associated with tumors such as pancreatic cancer, CIMRT may offer an option to increase therapeutic efficacy for these kinds of tumors. However, the clinical translation of CIMRT remains challenging due to unresolved questions in beam physics, dosimetry, radiation biology, and treatment robustness. A comprehensive understanding of carbon-ion-specific biological effects in spatially fractionated fields is required, and accurate dosimetric methods must be developed to characterize steep peak-to-valley dose gradients in high-LET environments. Furthermore, geometric and anthropomorphic phantoms are needed for treatment validation, and the influence of organ motion on the minibeam pattern should be systematically investigated. This review summarizes the current progress in CIMRT from four key perspectives: (i) physical and biological aspects, including the particularities of carbon-ion RBE and the biological responses to minibeam irradiation; (ii) dosimetric approaches for high-LET spatially fractionated fields; (iii) development of anthropomorphic and motion-capable phantoms; and (iv) the impact of organ motion and motion mitigation strategies. By highlighting recent advances and remaining challenges, this review provides a framework for future CIMRT development. It evaluates the requirements for its long-term transition from an experimental technique toward a clinical treatment modality.</p>","PeriodicalId":101315,"journal":{"name":"Zeitschrift fur medizinische Physik","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Photon-Counting CT Acquisition Modes on Coronary Stenosis Assessment and Radiation Dose: A Phantom and Clinical Evaluation.","authors":"Thomas Stein, Friederike Lang, Fabian Bamberg, Christopher L Schlett, Jakob Weiss, Philipp Ruile, Jana Taron","doi":"10.1016/j.zemedi.2026.10.001","DOIUrl":"https://doi.org/10.1016/j.zemedi.2026.10.001","url":null,"abstract":"<p><strong>Introduction: </strong>Photon-counting detector computed tomography (PCD-CT) offers high spatial resolution and dose-efficient coronary CT angiography (cCTA), but protocol selection, especially optimal acquisition mode, requires balancing spacial resolution, temporal robustness and radiation exposure. This study evaluated various PCD-CT acquisition modes in terms of image quality, blooming, stenosis grading, diagnostic accuracy, and radiation dose using phantom and clinical cCTA.</p><p><strong>Methods: </strong>First-generation dual-source PCD-CT was used with four acquisition modes: high-pitch spiral with prospective ECG-gating (Flash), Sequence, Spiral, and retrospective ultra-high-resolution (UHR) spiral mode. Phantom experiments used six 3D-printed coronary artery models with stenoses ranging from 21% to 73%. In a retrospective clinical study, 41 cCTA examinations were analyzed. Qualitative and quantitative image assessments used invasive coronary angiography as reference standard for diagnostic accuracy. Patient characteristics and radiation doses were recorded.</p><p><strong>Results: </strong>UHR demonstrated the highest image quality and the lowest quantitative blooming in phantom and clinical data (clinical image quality score: UHR 4.12 ± 0.99 vs. Flash 3.00 ± 0.86; p = 0.002). Diagnostic accuracy varied across protocols for detecting ≥50% and ≥70% stenoses was high across all modes (e.g., Flash: 76.5% each; Sequence: 100% and 57.1%; UHR: 64.7% and 82.4%). Radiation dose was highest in UHR (26.44 ± 9.76 mSv) compared with Sequence (13.65 ± 8.86 mSv) and Flash (1.40 ± 0.32 mSv); all p ≤ 0.011.</p><p><strong>Conclusion: </strong>While UHR acquisition provides highest image quality in PCD-CT cCTA, lower-dose acquisition modes achieve comparable diagnostic accuracy for coronary stenosis detection. Protocol selection should therefore be individualized, and prospective controlled studies are required.</p>","PeriodicalId":101315,"journal":{"name":"Zeitschrift fur medizinische Physik","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149207981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The cobalt-60 lesson: When does a medical technology become transformative?","authors":"Michael Oertel, Uwe Haverkamp, Heinz-Peter Schlemmer, Ingo Zenger, Uwe Busch, Hans Theodor Eich, Oliver Micke","doi":"10.1016/j.zemedi.2026.09.003","DOIUrl":"https://doi.org/10.1016/j.zemedi.2026.09.003","url":null,"abstract":"","PeriodicalId":101315,"journal":{"name":"Zeitschrift fur medizinische Physik","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149129802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the detection accuracy of a fully automated AI-based lesion segmentation tool in whole-body FDG PET/CT for lymphoma.","authors":"Tshegofatso Masogo, Palak Wadhwa, Chimbabantu Kaoma, Yashna Seebarruth, Milani Qebetu, Kaluzi Banda, Pryaska Goorhoo, Khomotso Legodi, Dileep Kumar, Mike Sathekge, Keamogetswe Ramonaheng","doi":"10.1016/j.zemedi.2026.09.002","DOIUrl":"https://doi.org/10.1016/j.zemedi.2026.09.002","url":null,"abstract":"<p><strong>Background: </strong>This study evaluated an AI-based lesion segmentation tool using a hybrid 2D-3D deep learning model based on the nnUNet architecture with a ResNet18 backbone, incorporating post-processing to reduce false positives and segmentation-related quantitative errors.</p><p><strong>Methods: </strong>Whole-body FDG PET/CT scans from 72 lymphoma patients (mean age 39.2 ± 18.6 years; 33 females, 39 males; 43.1% Hodgkin lymphoma, 56.9% non-Hodgkin lymphoma) acquired on a uMI550 digital PET/CT system were retrospectively analysed. Automated AI-based segmentations were compared with manual delineations by experienced physicians. Performance was assessed using F1-score, sensitivity, and positive predictive value. Quantitative agreement for all PET metrics was evaluated using Pearson correlation, concordance correlation coefficient, intraclass correlation coefficient, regression, and Bland-Altman analysis. McNemar's test assessed detection differences. The correlations between DSC and image quality metrics were examined.</p><p><strong>Results: </strong>A total of 711 AI and 848 manually segmented lesions were analysed. The AI model achieved an excellent DSC (89.2%), sensitivity (82.9) and PPV (96.5) which indicated balanced detection performance. Strong correlations were observed for all quantitative parameters (r > 0.95, p < 0.001; CCC > 0.94; ICC > 0.94; 95% CI: 0.93-0.99), with minimal bias on Bland-Altman analysis. DSC showed a moderate negative correlation with liver SNR (r = -0.40, p < 0.001) and weak correlations with liver SUV metrics.</p><p><strong>Conclusion: </strong>The fully automated AI-based segmentation tool demonstrated good-to-excellent lesion detection accuracy and high quantitative concordance with manual segmentation in whole-body FDG PET/CT for lymphoma patients. Continued model refinement and region-specific training are warranted to enhance detection performance.</p>","PeriodicalId":101315,"journal":{"name":"Zeitschrift fur medizinische Physik","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149070874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-time-point renal TIA estimation, sparse SPECT/CT data, and nonlinear mixed-effects modelling in [¹⁷⁷Lu]Lu-PSMA-617 therapy.","authors":"Fira Dwi Ananda, Deni Hardiansyah, Rien Ritawidya, Ambros J Beer, Ludovic Ferrer, Nicolas Varmenot, Gerhard Glatting","doi":"10.1016/j.zemedi.2026.09.001","DOIUrl":"https://doi.org/10.1016/j.zemedi.2026.09.001","url":null,"abstract":"<p><strong>Purpose: </strong>This study evaluates the feasibility of Single-Time-Point (STP) renal Time-Integrated Activity (TIA) estimation using Population-Based Model Selection (PBMS) and Nonlinear Mixed-Effects Modelling (NLMEM) with sparse time-activity data in [¹⁷⁷Lu]Lu-PSMA-617 therapy.</p><p><strong>Methods: </strong>Kidney biokinetics of [1⁷⁷Lu]Lu-PSMA-617 from 64 metastatic castration-resistant prostate cancer (mCRPC) patients were collected at TP1=(4.8±0.9h)(n=62),TP2=(24.5±1.5 h)(n=6),TP3=(94.0±6.6h)(n=16),and TP4=(128.5±12.7h)(n=47) post-injection with 1-4 data per patient. Six sum-of-exponentials functions (4-7 adjustable parameters) were fitted to all-time-point (ATP) data using NLMEM, evaluating combinations of fixed effects, inter-individual, and residual variability. The best-supported PBMS-NLMEM model was used to derive the ATP-based internal comparator TIA. Agreement between STP-derived TIAs and ATP-based internal comparator TIAs was quantified using relative deviation (RD), mean absolute percentage error (MAPE), and root-mean-square error (RMSE).</p><p><strong>Results: </strong>Based on PBMS-NLMEM analysis, function [Formula: see text] with a fixed-effect value of λ₃=7.19×10^-2/h, residual variability of 0.079, and inter-individual variabilities of A₃=0.38 and λ₃=0.52 assigned from the literature was selected as the best function for TIA estimation. STP TIA estimation with NLMEM showed better agreement than Hänscheid's method across all investigated TPs. Moreover, NLMEM-based STP estimation was technically feasible at each TP, with maximum RMSE and MAPE values of 25.2% and 16.5%, respectively. However, findings should be interpreted cautiously because patient subsets differed across TPs, particularly at TP2(n=6).</p><p><strong>Conclusion: </strong>In this retrospective sparse-data cohort, PBMS-NLMEM-based STP renal TIA estimation was technically feasible at the investigated TPs and showed agreement with an ATP-based internal comparator, with MAPE below 16.5%. Prospective validation in balanced cohorts is required before recommending a specific STP imaging window or clinical implementation.</p>","PeriodicalId":101315,"journal":{"name":"Zeitschrift fur medizinische Physik","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148979074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic resonance elastography of brain tumors.","authors":"Neslihan Koyuncu, Yavuz O Uca, Ingolf Sack","doi":"10.1016/j.zemedi.2026.08.001","DOIUrl":"https://doi.org/10.1016/j.zemedi.2026.08.001","url":null,"abstract":"<p><p>Magnetic resonance elastography (MRE) is a non-invasive imaging technique that can be used to quantify the mechanical properties of brain tissue. Mechanical changes in brain tissue cannot be directly assessed with conventional imaging, whereas MRE provides viscoelastic maps that reveal stiffness differences between healthy brain tissue and benign and malignant tumors. Studies in healthy individuals have demonstrated regional differences in mechanical properties between gray and white matter. Similar variability is observed in brain tumors, where mechanical properties differ with tumor type, grade, histological subtype, and microstructural composition. MRE has been applied to benign brain tumors, including meningiomas, vestibular schwannomas, and pituitary adenomas, to evaluate tumor consistency and support surgical planning. In malignant tumors like glioblastoma, stiffness differences have been linked to changes in extracellular matrix, including fibrous composition, adhesion molecules, and vascular remodeling. As suggested by preclinical research, MRE may also detect treatment-induced mechanical changes and could potentially be used to longitudinally monitor alterations in the tumor microenvironment. This review summarizes current knowledge of MRE in brain tumors, with a focus on stiffness and viscosity related parameters and their biological and structural correlates. The literature reviewed here increasingly supports reduced tissue fluidity and increased mechanical heterogeneity as biomechanical hallmarks of brain tumor aggressiveness.</p>","PeriodicalId":101315,"journal":{"name":"Zeitschrift fur medizinische Physik","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148851811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling and optimization of a multiple-ring double scattering system for proton therapy.","authors":"J P de Oliveira Lima, A Weber, G Kourkafas, A Denker, J Heufelder","doi":"10.1016/j.zemedi.2026.07.006","DOIUrl":"https://doi.org/10.1016/j.zemedi.2026.07.006","url":null,"abstract":"<p><p>This study investigates proton beam scattering systems with the aim of improving beam-shaping efficiency and increasing transmission within the radiation field for low-energy beams under intensity-limited conditions. These improvements are particularly relevant for delivering radiation fields at high dose rates for ocular proton therapy (OPT) and even at ultra-high dose rates for potential FLASH radiotherapy applications. A systematic methodology was developed to design multiple-ring double-scattering systems that maximize transmission under a field-homogeneity constraint while controlling the outgoing kinetic energy after each ring. Although generally applicable, the framework was specifically motivated by clinical and experimental requirements for proton-based ocular therapy using a 70 MeV cyclotron at the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB). A Python-based graphical user interface (GUI) was implemented to integrate a mathematical optimization model for two to four concentric rings that maximizes transmission under homogeneity constraints. The software incorporates energy degradation, range shifting, and the conversion of optimized scattering angles into physical dimensions. The mathematical optimization accurately reproduced the two-ring results reported by Takada (1994) and extended the approach to three- and four-ring configurations. The four-ring system achieved a transmission of 53±2% with a dose homogeneity of ±3%, corresponding to a dose rate of 77Gy/s at 100nA for a 30 mm field size, exceeding the threshold for FLASH conditions. Bragg-peak measurements and Monte Carlo simulations using TOPAS showed a distal penumbra below 1 mm and a water range agreement within 0.1 mm of predictions, supporting the adopted energy degradation methodology. The developed GUI provides a practical tool for designing and refining double-scattering systems, significantly improving transmission compared with single-scattering approaches. The four-ring design increased beam transmission more than tenfold compared with single scattering, making it a promising candidate for high-dose-rate irradiation in small fields.</p>","PeriodicalId":101315,"journal":{"name":"Zeitschrift fur medizinische Physik","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Swiss survey and national diagnostic reference levels for PET/CT examinations in adults.","authors":"Pascal Monnin, Silvano Gnesin, Jérôme Damet, Nicolas Stritt, Reto Linder, Siria Medici","doi":"10.1016/j.zemedi.2026.07.008","DOIUrl":"https://doi.org/10.1016/j.zemedi.2026.07.008","url":null,"abstract":"<p><strong>Purpose: </strong>Diagnostic Reference Levels (DRLs) are benchmarks for optimizing radiation doses in medical imaging. This study establishes new national DRLs (NDRLs) for PET/CT examinations in Switzerland based on a multicentre survey.</p><p><strong>Methods: </strong>Administered activities for PET examinations and dose indicators for localization / attenuation correction (AC) CT scans were collected in Swiss nuclear medicine (NM) institutes between April and September 2025.</p><p><strong>Results: </strong>Data from 45 PET devices in 35 NM institutes were analysed (100% response). New NDRLs were defined as administered activitiesfor nine PET examinations: general oncology with [¹⁸F]FDG (3.1 MBq/kg; 220 MBq), prostate cancer imaging with [¹⁸F]F-PSMA (3.1 MBq/kg; 260 MBq), neuroendocrine tumour imaging with [⁶⁸Ga]Ga-DOTA (2.1 MBq/kg; 160 MBq), brain tumour imaging with [¹⁸F]FET (3.0 MBq/kg; 200 MBq), inflammation/infection with [¹⁸F]FDG (3.3 MBq/kg; 230 MBq), neurological examinations with [¹⁸F]FDG (2.9 MBq/kg; 200 MBq) and [¹⁸F]flutemetamol (2.8 MBq/kg; 185 MBq), parathyroid imaging with [¹⁸F]fluorocholine (2.8 MBq/kg; 200 MBq), and myocardial perfusion with [⁸²Rb]rubidium chloride (8.6 MBq/kg; 630 MBq/injection). Updated volume computed tomography dose index (CTDI_vol) and dose-length product (DLP) for four AC CT were defined for vertex to mid-thighs (3.8 mGy/410 mGy·cm), vertex to feet (3.8 mGy/680 mGy·cm), brain (6.1 mGy/150 mGy·cm) and cardiac scans (1.3 mGy/40 mGy·cm). CTDI_vol for AC CT varied considerably among NM institutes (1.0 - 7.5 mGy for vertex to mid-thighs), indicating potential for protocol optimization and standardization. The established NDRLs tended to be lower than international reference levels, and the corresponding dosimetric indices were generally low.</p><p><strong>Conclusion: </strong>The survey provides an overview of administered activities and CT doses in adult PET/CT examinations in Switzerland and establishes new NDRLs to guide protocol optimization.</p>","PeriodicalId":101315,"journal":{"name":"Zeitschrift fur medizinische Physik","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148687419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance evaluation of the Biograph Trinion EP2 PET/CT system according to NEMA NU2-2018.","authors":"Ivo Rausch, Fabian Schmidt, Martha Hoffmann, Philipp Peloschek","doi":"10.1016/j.zemedi.2026.07.009","DOIUrl":"https://doi.org/10.1016/j.zemedi.2026.07.009","url":null,"abstract":"<p><strong>Aim: </strong>This study evaluates the performance of the Siemens Biograph Trinion EP2 whole-body PET/CT system according to the NEMA NU2-2018 standard.</p><p><strong>Methods: </strong>Following the NEMA NU2-2018 standard, spatial resolution was measured using a ²²Na point source in air, sensitivity was calculated from consecutive measurements of a ¹⁸F containing line source surrounded by aluminum tubes, count rate performance, accuracy of corrections assessment and TOF resolution was based on measurements of an ¹⁸F line-source inside scatter phantom. PET-CT co-registration accuracy was assessed by radioactive and radiation dense point sources, image quality was evaluated using a NEMA IQ phantom. Measurements were done using implemented NEMA NU2-2018 acquisition protocols on a Siemens Biograph Trinion EP2 PET/CT system.</p><p><strong>Results: </strong>The Trinion EP2 showed a spatial resolution between 4.0 and 4.4 mm FWHM at the center of the FOV. Sensitivity was measured with 13.8 kBq/MBq and the peak noise equivalent count rage of 143 kcps measured at 14.8 kBq/mL with a corresponding scatter fraction of 37.5%. The maximum average error was 1.6% between 1 kBq/mL and 14.8 kBq/mL and a TOF resolution of 241 ps was measured at a clinical activity concentration. Contrast recoveries between 47.2% and 81.6% were measured in the image quality phantom when using standard reconstructions.</p><p><strong>Conclusion: </strong>The Biograph Trinion EP2 PET/CT system shows a good overall performance providing a decent image quality comparable to state-of-the-art PET/CT systems with standard axial FOV between 20 and 30 cm.</p>","PeriodicalId":101315,"journal":{"name":"Zeitschrift fur medizinische Physik","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148703300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}