EJNMMI Physics最新文献

{"title":"Multi-site distributed training with data protections for PET-based synthetic CT.","authors":"Kasper Jørgensen, Lauren Partin, Raghavan Ashok, Vijay Shah, Anders Bertil Rodell, Martin Bazik, Bruce Spottiswoode, Flemming Littrup Andersen","doi":"10.1186/s40658-026-00868-2","DOIUrl":"https://doi.org/10.1186/s40658-026-00868-2","url":null,"abstract":"","PeriodicalId":11559,"journal":{"name":"EJNMMI Physics","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147688933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of data driven motion correction for clinical brain PET/MRI radiotracers.","authors":"Martin Bolin, Anna Falk Delgado, Emilia Palmér","doi":"10.1186/s40658-026-00863-7","DOIUrl":"10.1186/s40658-026-00863-7","url":null,"abstract":"<p><strong>Purpose: </strong>The Positron Emission Tomography (PET)/Magnetic Resonance Imaging (MRI) scanner combines two diagnostic imaging modalities, providing information on anatomy and physiology. Beneficial diagnosis areas are epilepsy ([[Formula: see text]F]Fluorodeoxyglucose (FDG)) and cancer recurrence ([[Formula: see text]C]methionine (MET)), where subject motion during PET acquisition reduces image quality, potentially compromising diagnostic accuracy. This project aimed to evaluate the impact of PET data-driven motion correction (ddMC) of these clinical PET radiotracers and to assess, for the first time, whether the automatic motion categorization reflects motion levels impacting the image quality.</p><p><strong>Methods: </strong>Eighty-nine PET scans (66 [[Formula: see text]C]MET, 23 [[Formula: see text]F]FDG) were reconstructed with ddMC and without motion correction (noMC) using the research software lmDuetto toolbox (GE Healthcare, Chicago, IL, USA), and were automatically categorized into motion groups. MRI images were segmented, and the regions of interest (ROIs) transferred to the PET space. The effect of ddMC was analyzed by relative signal differences between ddMC and noMC. Motion estimation and categorization were evaluated by normalized cross correlation (XC) over time and the proposed cumulative displacement-time histogram (cDTH).</p><p><strong>Results: </strong>Overall, ddMC increased signal values within cortical ROIs compared to noMC. In the high motion category, median relative mean signal differences were 0.61% (0.41-0.80%) for [[Formula: see text]F]FDG and 0.70% (0.61-0.79%) for [[Formula: see text]C]MET. The XC improved ([[Formula: see text]F]FDG: 0.80 to 0.97, [[Formula: see text]C]MET: 0.85 to 0.98). Low and medium motion groups had lesser impact, indicating motion correction is most relevant for high motion. The XC and cDTH identified subjects whose motion classification should be revised.</p><p><strong>Conclusion: </strong>In conclusion, the results confirm previous findings with ddMC using [[Formula: see text]F]FDG and demonstrate its suitability for lower-accumulating [[Formula: see text]C]MET. The automatic motion categorization needs re-evaluation to better reflect motion affecting PET image quality.</p>","PeriodicalId":11559,"journal":{"name":"EJNMMI Physics","volume":"13 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13083739/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147689000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parametric analysis of dynamic long axial field-of-view ¹⁸F-FDG PET/CT studies.","authors":"Charlotte L C Smith, Gerben J C Zwezerijnen, Marijke E den Hollander, Henricus N J M Greuter, Nienke R Gerards, Josée Zijlstra, C Willemien Menke-van der Houven van Oordt, Idris Bahce, Maqsood Yaqub, Ronald Boellaard","doi":"10.1186/s40658-026-00859-3","DOIUrl":"https://doi.org/10.1186/s40658-026-00859-3","url":null,"abstract":"","PeriodicalId":11559,"journal":{"name":"EJNMMI Physics","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147671447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contrast-enhanced CT for attenuation correction in ultra-high sensitivity long-axial field-of-view lymphoma PET: amplified quantification problems?","authors":"Jan-Luca Penner, August Blomgren, Alexander Weissensee, Michelle Amon, Shayan Acikgöz, Clemens Mingels, Justin Ferdinandus, Foroud Aghapour Zangeneh, Urban Novak, Thomas Pabst, Axel Rominger, Kuangyu Shi, Hasan Sari, Robert Seifert","doi":"10.1186/s40658-026-00866-4","DOIUrl":"https://doi.org/10.1186/s40658-026-00866-4","url":null,"abstract":"<p><strong>Purpose: </strong>It is unclear whether the use of contrast enhanced (CE) CT for attenuation correction (AC) of [¹⁸F]FDG PET leads to higher quantification inaccuracies when used in high-sensitivity LAFOV systems. This project aimed to assess the clinical feasibility of CE-CT for AC in LAFOV-PET for lymphoma patients.</p><p><strong>Methods: </strong>Lymphoma patients who underwent LAFOV-[¹⁸F]FDG-PET for restaging with low dose AC-CT and diagnostic CE-CT were included in this retrospective analysis. PET images were reconstructed using ultra-high sensitivity (UHS) mode with CE-CT and AC-CT. Lesions and reference regions (liver and mediastinal blood pool (BP)) were evaluated.</p><p><strong>Results: </strong>SUV_max of BP and the liver increased when CE-CT was used instead of AC-CT for AC (BP: median 2.41vs.2.21, p < 0.01, 8.78% intra-patient increase; liver: 3.07vs.2.87, p < 0.01, 7.86% medina intra-patient increase). Similarly, SUV_mean was higher in CE-CT reconstructions (BP: 1.96vs.1.77, p < 0.01, 10.14% median intra-patient increase; liver: 2.50vs.2.32, p < 0.01, 7.54% median intra-patient increase). SUV_max of lesions showed a similar magnitude of increase (5.97vs.5.68, p < 0.01, 5.80% median intra-lesion increase). The SUV-ratio of the lesions to reference organs decreased when CE-CT instead of AC-CT was used for AC (BP: 2.79vs.2.99, p < 0.01, median per-lesion decrease - 4.90%; liver: 1.85vs.1.97, p < 0.01, median per-lesion decrease - 2.64%).</p><p><strong>Conclusion: </strong>The use of CE-CT for AC of LAFOV-PET in UHS mode leads to higher SUV measurements. Also, lymphoma lesions show a consistent increase in uptake. The errors in the lesions seem higher than in conventional standard axial field-of-view PETs that use CE-CT for AC. Therefore, interpretation of borderline cases warrants attention to potential errors.</p>","PeriodicalId":11559,"journal":{"name":"EJNMMI Physics","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147671452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of iterative deconvolution in ¹⁷⁷Lu-SPECT imaging for lesion dosimetry.","authors":"Zachary Ells, Grigory Liubchenko, Mikhail Rumiantcev, Maximilian Scheifele, Angelica Noto, Sophie C Siegmund, Sandra Resch, Andreas Harbach, Rudolf A Werner, Matthias Brendel, Gabriel Sheikh, Mathias Zacherl, Guido Böning, Lena M Unterrainer, Sibylle I Ziegler, Astrid Delker","doi":"10.1186/s40658-026-00865-5","DOIUrl":"10.1186/s40658-026-00865-5","url":null,"abstract":"<p><strong>Aim/introduction: </strong>Quantitative ¹⁷⁷Lu-SPECT allows for patient specific dosimetry, but due to the limited spatial resolution absorbed doses (AD) can be underestimated. Implementation of the Lucy-Richardson deconvolution (LRD) algorithm for spill-over correction in PET has been investigated. Therefore, the aim of this study was to extend the potential application of LRD to ¹⁷⁷Lu-SPECT based tumor dosimetry.</p><p><strong>Materials/methods: </strong>The NEMA IEC Body Phantom (foreground-to-background ratio 8:1, 237:30 kBq/mL) was measured according to the local imaging and reconstruction protocol. The two main parameters of LRD, sigma and number of iterations, were determined in two steps. First, a matched filter resolution analysis was conducted on the ground truth activity distribution as segmented from the NEMA IEC Body Phantom data to define the sigma of a 3D Gaussian point-spread-function, which describes the system's spatial resolution. Secondly, using this sigma, a suitable number of LRD iterations was determined by comparing sphere recovery coefficients (RC) and signal-to-noise ratios. The selected parameters were then applied to the reconstructed SPECT series (24, 48, and 72 h post-injection) of 20 patients who received either [¹⁷⁷Lu]Lu-DOTA-TATE (n = 10) or [¹⁷⁷Lu]Lu-PSMA-I&T (y = 10) treatment, in order to evaluate its impact on AD estimates. Lesion AD from the original reconstruction (OR) and OR + LRD were estimated using MIM SurePlan™ MRT. The AD from OR, OR + LRD, and OR + RC (phantom-based recovery correction based on volume) were compared.</p><p><strong>Results: </strong>A sigma of 6.0 mm and four iterations resulted in an average improvement of 18.9 ± 4.7% and 17.4 ± 7.6% in the sphere recovery coefficients and the signal to noise ratio, respectively. In total, 98 lesions were evaluated ([¹⁷⁷Lu]Lu-DOTA-TATE: n = 42) ([¹⁷⁷Lu]Lu-PSMA-I&T: y = 56). For OR + LRD and OR + RC an average increase of 22 ± 12% and 57 ± 36% of tumor AD was found.</p><p><strong>Conclusion: </strong>OR + LRD increased AD compared to OR, independent of administered radiopharmaceutical and lesion location. This study suggests that implementing LRD may be a promising option for image-based spill-over correction in ¹⁷⁷Lu-SPECT based dosimetry. Further studies are necessary to investigate the effect of different PVC methods, such as LRD or phantom-based correction factors, on overall uncertainty of lesion ADs.</p>","PeriodicalId":11559,"journal":{"name":"EJNMMI Physics","volume":"13 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13076692/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147671450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Continuous bed motion versus step-and-shoot acquisition in LAFOV PET/CT: insights from multi-phantom and patient studies.","authors":"P M Linder, W Lan, E Calderón, I Rausch, C la Fougère, F P Schmidt","doi":"10.1186/s40658-026-00867-3","DOIUrl":"10.1186/s40658-026-00867-3","url":null,"abstract":"<p><strong>Background: </strong>Continuous bed motion (CBM) allows flexible extension of the scan range compared to conventional step‑and‑shoot (S&S) acquisition but has not yet been evaluated in long axial field‑of‑view (LAFOV) PET/CT. This study systematically assessed the impact of CBM on image quality, noise, and quantitative performance in the Biograph Vision Quadra LAFOV PET/CT using multi‑phantom and patient scans compared to S&S.</p><p><strong>Methods: </strong>A uniform tube phantom and a NEMA IEC phantom, positioned centrally and off-centre, were scanned across bed speeds (2.8-50 mm/s), sensitivity modes and scan ranges (106 and 150 cm) to evaluate image uniformity, axial count profiles, noise and contrast recovery coefficients (CRC). Ten oncological patients receiving [¹⁸F]PSMA-1007 or [¹⁸F]FDG underwent sequential CBM (2.8 mm/s, 378 s) and S&S (300 s) scans. Image noise, net true counts, and liver and lesion SUV values were compared using paired statistics and Bland-Altman analysis, along with PSMA expression scores.</p><p><strong>Results: </strong>For comparable count statistics and image noise, CBM required a prolonged acquisition (378 s) to match the S&S (300 s) protocol, resulting in comparable image quality for phantoms and patients. CRC and image uniformity were preserved across all evaluated conditions, even at the FOV's axial edge (50.5 cm) for 8.4 mm/s (22 mm sphere: CRC 76% S&S vs. 71% CBM). In patient scans, minor differences in axial count profiles, net true counts, and SUV values (SUV_mean bias - 0.1 (liver) and - 0.8 (lesions)) did not affect clinical scores.</p><p><strong>Conclusions: </strong>The prolonged CBM protocol provides image quality and quantitative performance comparable to S&S in LAFOV PET/CT. While the reconstructed image range remains constrained by CT coverage, the patient scan comparison with 106 cm scan range, together with extended range phantom measurements, indicate that CBM can support scan range extension beyond 106 cm without compromising diagnostic accuracy.</p>","PeriodicalId":11559,"journal":{"name":"EJNMMI Physics","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13076829/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147662356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fast [¹⁷⁷Lu]Lu-PSMA SPECT/CT with dual-energy acquisition and Monte Carlo-based scatter correction.","authors":"Arda Könik, Benjamin Auer, Shir Hazut Krauthammer, Praful Ravi, Thomas S C Ng, Heather A Jacene","doi":"10.1186/s40658-026-00864-6","DOIUrl":"https://doi.org/10.1186/s40658-026-00864-6","url":null,"abstract":"","PeriodicalId":11559,"journal":{"name":"EJNMMI Physics","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147662393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of regularization factor and attenuation correction method of Q.Clear reconstruction for brain PET/MR in epileptic patients.","authors":"Xiaolong Niu, Jieqin Lv, Hao Sun, Zhifeng Chen, Xiang Liang, Zanting Ye, Youliang Wu, Xiaojing Zhang, Lijun Lu, Pengcheng Ran","doi":"10.1186/s40658-026-00860-w","DOIUrl":"https://doi.org/10.1186/s40658-026-00860-w","url":null,"abstract":"<p><strong>Purpose: </strong>To identify suitable regularization factor β and attenuation correction (AC) method for Q.Clear reconstruction in brain [¹⁸F]FDG PET/MR imaging of patients with epilepsy.</p><p><strong>Methods: </strong>We retrospectively collected 27 PET/MR brain images from patients with temporal lobe epilepsy. PET images were reconstructed using both ordered subset-expectation maximization and Q.Clear reconstruction (β from 50 to 600) with three AC methods: Atlas-based AC (Atlas-AC), Partial Head-based AC (PH-AC), and Zero Echo Time-based AC (ZTE-AC). Image quality was assessed using lesion-to-background (LBR) ratio, normalized standard deviation (NSD) ratio, SUV_max, and SUV_mean.</p><p><strong>Results: </strong>Q.Clear reconstruction with β values of 50 to 600 significantly increased LBR and decreased NSD compared to OSEM. β value of 300 served as a practical operating point for the three AC methods. ZTE-AC had the largest LBR and lower NSD values, PH-AC method had the lowest NSD and relatively high LBR, while Atlas-AC showed moderate performance. Comparisons of SUV_max and SUV_mean between Q.Clear (β = 300) and OSEM across all AC methods suggest that β = 300 improves lesion contrast and reduces image noise without compromising SUV value.</p><p><strong>Conclusions: </strong>Q.Clear reconstruction can improve lesion contrast and reduce noise compared to OSEM. ZTE-AC yielded the highest lesion contrast and LBR among three AC methods, PH-AC resulted in the lowest background noise, and Atlas-AC showed balanced but suboptimal performance. These findings offer practical guidance in selecting the suitable β value and AC method for optimized brain PET/MR imaging in patients with epilepsy.</p>","PeriodicalId":11559,"journal":{"name":"EJNMMI Physics","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147644451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of the effective dose in torso ¹⁸F-fluorodeoxyglucose PET/CT: an analysis of real-world clinical data from 51,784 patient scans.","authors":"Jeongryul Ryu, Jungsu S Oh, Yong-Il Kim, Sangwon Han, Jae Seung Kim, Kyung-Hyun Do, Jin-Sook Ryu","doi":"10.1186/s40658-026-00857-5","DOIUrl":"https://doi.org/10.1186/s40658-026-00857-5","url":null,"abstract":"","PeriodicalId":11559,"journal":{"name":"EJNMMI Physics","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147644476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of dual-energy window scatter correction on technetium image quality across different energy windows in cadmium-zinc-telluride-based SPECT/CT.","authors":"Ruyi Zhang, Shen Wang, Yiming Shen, Wei Zheng, Ning Li, Peng Wang, Jian Tan, Zhaowei Meng, Qiang Jia","doi":"10.1186/s40658-026-00844-w","DOIUrl":"10.1186/s40658-026-00844-w","url":null,"abstract":"<p><strong>Background: </strong>The digital cadmium-zinc-telluride (CZT)-based SPECT system offers good energy resolution. However, the impacts of dual-energy window scatter correction on image quality under narrower primary energy windows remain to be determined. This study aimed to assess the impacts of SC (with scatter correction) and NOSC (without scatter correction) on image quality under different primary energy windows.</p><p><strong>Methods: </strong>We used a standard NEMA/IEC 2007 phantom containing six hollow spheres of various sizes to simulate the human body at four target-to-background ratios (T/B ratio, the ratio of the average radioactive activity concentration in the target region to that in the background region, 32:1, 16:1, 8:1, and 4:1, respectively), by filling with ^99mTcO₄^-. For clinical validation, we recruited 20 patients and analyzed their whole-body bone scan images. Phantom and patient images were acquired with the Discovery NM/CT 670 CZT with list mode. Image quality of phantom was measured by calculating indicators from the NEMA NU 2-2018 standard, including percent background variability and percent contrast. Image quality of patients was measured by calculating coefficient of variation (COV), contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR). Visual quality was evaluated by two experts.</p><p><strong>Results: </strong>Higher percent background variability and COV values were present when SC was applied regardless of which energy window, acquisition time, or T/B ratio used, and statistically significant differences were observed between all SC and NOSC groups for both phantoms and patients. For phantoms, percent contrast values of most SC groups were higher than those of NOSC groups. For patients, CNRs and SNRs of SC groups were higher than those of NOSC groups (all P < 0.05). Visually, SC had higher visual scores than NOSC for both phantoms and patients.</p><p><strong>Conclusions: </strong>SC significantly improves image contrast while minimizing concomitant image noise to a great extent and provides good visual image quality across different primary energy windows overall.</p>","PeriodicalId":11559,"journal":{"name":"EJNMMI Physics","volume":"13 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13062129/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147638260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}