EJNMMI Research最新文献

{"title":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\">Machine learning to identify suitable boundaries for band-pass spectral analysis of dynamic [ <ns0:math><ns0:mmultiscripts><ns0:mrow /> <ns0:mrow /> <ns0:mn>11</ns0:mn></ns0:mmultiscripts> </ns0:math> C]Ro15-4513 PET scan and voxel-wise parametric map generation.","authors":"Zeyu Chang, Colm J McGinnity, Rainer Hinz, Manlin Wang, Joel Dunn, Ruoyang Liu, Mubaraq Yakubu, Paul Marsden, Alexander Hammers","doi":"10.1186/s13550-025-01251-5","DOIUrl":"10.1186/s13550-025-01251-5","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Spectral analysis is a model-free PET quantification technique that treats the time-space signal as an impulse response to a bolus injection. Band-pass spectral analysis, considering specific frequency ranges, enables calculation of separate parametric maps of receptor subtype tracer binding for suitable radiopharmaceuticals such as [ &lt;math&gt;&lt;mmultiscripts&gt;&lt;mrow&gt;&lt;/mrow&gt; &lt;mrow&gt;&lt;/mrow&gt; &lt;mn&gt;11&lt;/mn&gt;&lt;/mmultiscripts&gt; &lt;/math&gt; C]Ro15-4513 binding to GABA&lt;sub&gt;A&lt;/sub&gt; &lt;math&gt;&lt;mi&gt;α&lt;/mi&gt;&lt;/math&gt; 1/5 subunits. Frequency ranges are based on inspection of spectra, prior knowledge of receptor distribution, and blocking studies. The process currently requires the manual selection of frequency ranges based on the data. To enhance the efficiency of band-pass spectral analysis and extend its application to a broader range of tracers, we propose employing machine learning to automate the selection of spectral boundaries. Based on these boundaries, voxel-wise parametric maps can be generated. The machine learning models utilized in this study include 1D Convolutional Neural Network, Neural Network, Support Vector Machine, Logistic Regression, K-nearest neighbors, and Fine Tree.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;The best machine learning model, Fine Tree, agreed with the manual frequency boundary in 96.92% of 3185 ROIs. The absolute mean error was 3.80% for slow component volume-of-distribution ( &lt;math&gt;&lt;msub&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mrow&gt;&lt;mi&gt;slow&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/math&gt; , largely representing &lt;math&gt;&lt;mi&gt;α&lt;/mi&gt;&lt;/math&gt; 5) and 4.74% for fast component volume-of-distribution( &lt;math&gt;&lt;msub&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mrow&gt;&lt;mi&gt;fast&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/math&gt; , largely representing &lt;math&gt;&lt;mi&gt;α&lt;/mi&gt;&lt;/math&gt; 5), while the relative error was 2.83% ± 43.47% for &lt;math&gt;&lt;msub&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mrow&gt;&lt;mi&gt;slow&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/math&gt; and &lt;math&gt;&lt;mo&gt;-&lt;/mo&gt;&lt;/math&gt; 2.01% ± 78.04% for &lt;math&gt;&lt;msub&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mrow&gt;&lt;mi&gt;fast&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/math&gt; . The median test-retest intraclass correlation coefficient across six representative regions was 0.770 for &lt;math&gt;&lt;msub&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mrow&gt;&lt;mi&gt;slow&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/math&gt; , 0.670 for &lt;math&gt;&lt;msub&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mrow&gt;&lt;mi&gt;fast&lt;/mi&gt;&lt;/mrow&gt; &lt;/msub&gt; &lt;/math&gt; , and 0.502 for total component volume-of-distribution( &lt;math&gt;&lt;msub&gt;&lt;mtext&gt;V&lt;/mtext&gt; &lt;mi&gt;d&lt;/mi&gt;&lt;/msub&gt; &lt;/math&gt; ). Parametric maps applying different boundaries for different ROIs were generated.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;The machine learning model developed provided accurate boundary predictions in 96.92% of regions, with minimal average bias. However, when errors occur, they can be large, owing to the sparsity of peaks. The model enables setting boundaries automatically for the vast majority of regions, followed by manual checking of the outliers. It opens the possibility of accelerating analyses e.g. of GABA&lt;sub&gt;A&lt;/sub&gt; &lt;math&gt;&lt;mi&gt;α&lt;/mi&gt;&lt;/math&gt; 1/2/3/5 subunit binding using [&lt;sup&gt;11&lt;/sup&gt;C]flumazenil and of extending band-pass spectral analysis to other r","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"85"},"PeriodicalIF":3.1,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12254443/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144607767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Altered glucose metabolism in default mode network and prefrontal circuit in patients with Kallmann syndrome.","authors":"Chunqing Zhou, Xueying Wang, Meichao Men, Xiaoping Yi, Ke Cao, Weidan Pu, Marcus Hacker, Xiang Li, Min Zhao","doi":"10.1186/s13550-025-01282-y","DOIUrl":"10.1186/s13550-025-01282-y","url":null,"abstract":"<p><strong>Background: </strong>This study delineates brain metabolic signatures underlying neuroendocrine-psychosocial interactions in Kallmann syndrome (KS), a rare genetic disorder characterized by congenital hypogonadism and anosmia. In this prospective case-control study, 30 KS patients and 30 matched healthy controls (HCs) underwent brain [¹⁸F]FDG PET scans, sex hormone assays, and standardized neuropsychological assessments. A voxel-wise group comparison analysis was conducted to identify clusters of brain metabolic patterns between KS patients and HCs. Subsequently, correlation and mediation analyses were performed to investigate the interrelationships and mediating effect among brain metabolic patterns, sex hormone levels, and psychosocial factors.</p><p><strong>Results: </strong>We identified six hypermetabolic clusters in KS patients, predominantly located in the fronto-limbic system and the default mode network (DMN) in KS patients. These clusters of hypermetabolism were significantly associated fertility anxiety scale (FAS), health information avoidance scale (HIAS) and health information overload scale (HIOS). In addition, mediation analysis indicated that bilateral basal ganglia hypermetabolism acted as a significant mediator between HIAS and FAS (β = 0.274, P = 0.031).</p><p><strong>Conclusion: </strong>Patients with KS exhibited a distinct hypermetabolism pattern in the DMN-prefrontal circuit, which functionally bridges neuroendocrine dysfunction and reproductive health anxiety.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"84"},"PeriodicalIF":3.1,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12254444/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144607768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiation dosimetry and fasting-dependent hepatobiliary clearance of the VAChT-specific PET radioligand ¹⁸F-VAT in humans.","authors":"Scott A Norris, Noah L Goldman, Mahdjoub Hamdi, Stephen M Moerlein, Richard Laforest, Morvarid Karimi, Joel S Perlmutter, Zhude Tu","doi":"10.1186/s13550-025-01273-z","DOIUrl":"10.1186/s13550-025-01273-z","url":null,"abstract":"<p><strong>Background: </strong>The vesicular acetylcholine transporter ligand (-)-(1-((2R,3R)-8-(2-[(18)F]fluoro-ethoxy)-3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)piperidin-4-yl)(4-fluorophenyl)-methanone (¹⁸F -VAT) enables positron emission tomography PET quantification of cholinergic dysfunction in neurologic and psychiatric disorders. Determining its bio-distribution and dose exposure in humans is essential for clinical implementation, particularly given hepatobiliary clearance observed in pre-clinical models. Based on pre-clinical data, eight healthy subjects (4 males, 4 females) received 385-533 MBq ¹⁸F-VAT immediately followed by three sequential whole-body PET/CT scans. PET data were collected under three different fasting conditions relative to administration of Ensure®Plus oral supplement and PET image acquisition: (1) complete fasting (n = 3), (2) oral partial fasting (n = 3), or (3) non-fasting (n = 2). We defined volumes of interest (VOIs), and generated organ time-activity curves (TACs). Organ radiation dosimetry was calculated using OLINDA/EXM v2.2 software.</p><p><strong>Results: </strong>There were no adverse events after ¹⁸F-VAT dosing. Radioactivity accumulated predominantly in the brain, hepatobiliary system, small intestine, bone, and urinary bladder. Across all fasting states, organ dosimetry revealed gallbladder as the critical organ (201.0 μSv/MBq) followed by liver (64.3 μSv/MBq), with a gender averaged effective dose of 17.5 ± 2.1 μSv/MBq (15.7 and 19.4 μSv/MBq for males and females, respectively.) Mean gallbladder time integrated activity significantly differed across non-fasting (36.6 MBq*h, 155.5 µSv/MBq), partial fasting (21.8 MBq*h, 107.6 µSv/MBq) and fasting PET acquisition (74.1 MBq*h, 270.5 µSv/MBq) (Kruskal-Wallis H 6.5, p = 0.04).</p><p><strong>Conclusions: </strong>Human bio-distribution data showed high retention of ¹⁸F-VAT in the gallbladder and liver, where rat dosimetry studies do not accurately predict a safety profile given lack of gallbladder. Human dosimetry data appear different from fasting non-human primate data, indicating that up to 249 MBq (6.7 mCi) of ¹⁸F-VAT can be administered without exceeding a maximum dose to the gallbladder of 50 mSv (5 rem) without consideration of fasting state. Oral supplementation, administered just before and especially 90 min after ¹⁸F-VAT administration, accelerates gallbladder clearance. This reduces critical organ radiation exposure, allowing an administered dose of ¹⁸F-VAT to 465 MBq (12.6 mCi) in the optimal partial fasting state without exceeding a gallbladder dose of 50 mSv (5 rem).</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"83"},"PeriodicalIF":3.1,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12234429/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144575077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tolerability of PSMA radioligand therapy in metastatic prostate cancer patients with baseline mild to moderate leukopenia.","authors":"Moritz B Bastian, Tilman Speicher, Arne Blickle, Caroline Burgard, Julius L D Bastian, Mark Bartholomä, Andrea Schaefer-Schuler, Stephan Maus, Samer Ezziddin, Florian Rosar","doi":"10.1186/s13550-025-01280-0","DOIUrl":"10.1186/s13550-025-01280-0","url":null,"abstract":"<p><strong>Background: </strong>Aim of this study was to analyze the safety of prostate-specific membrane antigen radioligand therapy (PSMA-RLT) in patients with metastatic castration-resistant prostate cancer (mCRPC) with preexisting mild to moderate leukopenia (CTCAE ≥ 1).</p><p><strong>Results: </strong>Thirty-seven mCRPC patients with preexisting leukopenia (leukocyte count < 3.8 × 10⁹/L) were included in this study. Patients received a median of 3 cycles of [¹⁷⁷Lu]Lu-PSMA-617 (range 1-9). No significant difference in leukocyte counts was observed between baseline and follow-up after each PSMA-RLT cycle: first cycle (3.0 ± 0.5 at baseline vs. 3.4 ± 1.4 at follow up [in × 10⁹/L], p = 0.0921), second cycle (3.1 ± 0.4 vs. 3.8 ± 1.7, p = 0. 0.0509), and third cycle (3.1 ± 0.4 vs. 3.2 ± 2.0, p = 0.2929), respectively. Similarly, baseline and end of treatment values, irrespective of the number of administered cycles, did not reveal a significant difference (3.0 ± 0.5 vs. 3.5 ± 1.4, p = 0.0684). After the end of therapy, irrespective of the number of administered cycles, 27% patients remained stable in terms of CTCAE scoring, 46% changed to a higher score and 27% improved to a lower score.</p><p><strong>Conclusion: </strong>Although marked preexisting leukopenia is often considered a relative contraindication for PSMA-RLT, our findings indicate that PSMA-RLT is feasible in patients with leukopenia of CTCAE grade ≥ 1. In our cohort, leukocyte counts remained stable without significant RLT-induced deterioration. Therefore, patients with leukopenia should not be categorically excluded from receiving PSMA-RLT.</p><p><strong>Trial registration: </strong>Clinicaltrials.gov identifier: NCT04833517, registered 01.01.2016.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"82"},"PeriodicalIF":3.1,"publicationDate":"2025-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12229971/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144575078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Model selection for dynamic PET compartmental modelling of ¹⁸F-FDG uptake using a long axial field-of-view PET scanner with delay and motion correction.","authors":"Hamed Moradi, Rajat Vashistha, Kieran O'Brien, Amanda Hammond, Axel Rominger, Hasan Sari, Kuangyu Shi, Viktor Vegh, David Reutens","doi":"10.1186/s13550-025-01277-9","DOIUrl":"10.1186/s13550-025-01277-9","url":null,"abstract":"<p><strong>Background: </strong>In dynamic PET with tracer kinetic modeling, model complexity is an important but often under-recognised challenge affecting robust parameter estimation, particularly for noisy data. Traditional methods often neglect tissue heterogeneity and apply a single model universally. We applied a model selection approach alongside delay and motion correction, enabling the selection of models with varying complexity to better account for tissue heterogeneity.</p><p><strong>Results: </strong>The study included five subjects with breast cancer undergoing dynamic ¹⁸F-FDG PET imaging using a long axial field of view scanner. Voxel-wise kinetic model parameter estimation utilized five compartmental models, with the best model chosen using the Akaike Information Criterion. The model selection revealed diverse kinetic models within breast cancer lesions voxel-wise, with reduced parameter estimation variability attributed to the choice of simpler models. Applying delay and motion correction reduced the mean coefficient of variation in estimated kinetic parameters by 25%.</p><p><strong>Conclusions: </strong>We applied a standard model selection approach to identify the optimal compartmental model for voxel-wise parameter estimation in long field-of-view dynamic PET imaging. Our results demonstrate that accounting for tissue heterogeneity in breast lesions is critical for accurate quantification. Additionally, delay and motion correction were shown to improve image quality, enhance quantification accuracy, and support more reliable model selection.</p><p><strong>Clinical trial registration: </strong>Clinical trial number: not applicable.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"81"},"PeriodicalIF":3.1,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12227408/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144559524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"¹⁸F-FDG dose reduction using deep learning-based PET reconstruction.","authors":"Ryuji Akita, Komei Takauchi, Mana Ishibashi, Shota Kondo, Shogo Ono, Kazushi Yokomachi, Yusuke Ochi, Masao Kiguchi, Hidenori Mitani, Yuko Nakamura, Kazuo Awai","doi":"10.1186/s13550-025-01269-9","DOIUrl":"10.1186/s13550-025-01269-9","url":null,"abstract":"<p><strong>Background: </strong>A deep learning-based image reconstruction (DLR) algorithm that can reduce the statistical noise has been developed for PET/CT imaging. It may reduce the administered dose of ¹⁸F-FDG and minimize radiation exposure while maintaining diagnostic quality. This retrospective study evaluated whether the injected ¹⁸F-FDG dose could be reduced by applying DLR to PET images. To this aim, we compared the quantitative image quality metrics and the false-positive rate between DLR with a reduced ¹⁸F-FDG dose and Ordered Subsets Expectation Maximization (OSEM) with a standard dose.</p><p><strong>Results: </strong>This study included 90 oncology patients who underwent ¹⁸F-FDG PET/CT. They were divided into 3 groups (30 patients each): group A (¹⁸F-FDG dose per body weight [BW]: 2.00-2.99 MBq/kg; PET image reconstruction: DLR), group B (3.00-3.99 MBq/kg; DLR), and group C (standard dose group; 4.00-4.99 MBq/kg; OSEM). The evaluation was performed using the signal-to-noise ratio (SNR), target-to-background ratio (TBR), and false-positive rate. DLR yielded significantly higher SNRs in groups A and B than group C (p < 0.001). There was no significant difference in the TBR between groups A and C, and between groups B and C (p = 0.983 and 0.605, respectively). In group B, more than 80% of patients weighing less than 75 kg had at most one false positive result. In contrast, in group B patients weighing 75 kg or more, as well as in group A, less than 80% of patients had at most one false-positives.</p><p><strong>Conclusions: </strong>Our findings suggest that the injected ¹⁸F-FDG dose can be reduced to 3.0 MBq/kg in patients weighing less than 75 kg by applying DLR. Compared to the recommended dose in the European Association of Nuclear Medicine (EANM) guidelines for 90 s per bed position (4.7 MBq/kg), this represents a dose reduction of 36%. Further optimization of DLR algorithms is required to maintain comparable diagnostic accuracy in patients weighing 75 kg or more.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"78"},"PeriodicalIF":3.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12214151/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144539588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pulmonary uptake value (PUV): a new quantification method for lung PET/CT imaging.","authors":"Pierre-Yves Le Roux, Romain Le Pennec, Vincent Bourbonne, Frédérique Blanc-Béguin, Mathieu Pavoine, Kevin Kerleguer, Maëlle Mauguen, Olivier Pradier, Pierre-Yves Salaun, François Lucia, David Bourhis","doi":"10.1186/s13550-025-01274-y","DOIUrl":"10.1186/s13550-025-01274-y","url":null,"abstract":"<p><strong>Background: </strong>A current limitation to the use of lung PET/CT is the absence of a tool that reliably and reproducibly quantifies the intensity of tracer uptake. We aim to develop a quantitative approach for lung perfusion PET/CT imaging. Sixty patients who underwent [68Ga]Ga-MAA PET/CT scans before (M0) and 3 months (M3) after completion of radiotherapy were analyzed. The anatomical lung volume (ALV) was delineated on the CT scan. CT and PET images were co-registered, and the ALV was transferred onto the PET images. The measured activity concentration (kBq/L) in each voxel was converted in three metrics: SUV based on normalizing the measured activity to the patient's weight (kg) and the injected dose (kBq); SUVp by normalizing to the ALV (L) and the injected dose (kBq); pulmonary uptake value (PUV) by normalizing to the ALV (L) and the total activity measured in the ALV (kBq). The mean SUV, SUVp and PUV values within the ALV were measured.</p><p><strong>Results: </strong>The mean (SD) SUV in the ALV was 9.90 (5.24) with an inconsistently wide range of values from 0.11 to 22.52. The correlation coefficient between the patient's weight and the ALV was 0.14. The mean (SD) SUVp in the ALV was 0.54 (0.09). The mean (SD) percentage of [68Ga]Ga-MAA lung retention was 58.2% (7.7%), with significant variability both between patients and within repeated scans of the same patient. The mean PUV in the ALV used for normalization was equal to 1. Quantitative methods were tested in challenging scenarios for quantification, including patients exhibiting decorrelation between ALV and patient's weight and patients with different percentage of [68Ga]Ga-MAA lung retention between M0 and M3. In contrast to the SUV and SUVp metrics, the PUV method showed coherent results compared to visual analysis.</p><p><strong>Conclusion: </strong>The patient's weight and the injected activity are not suitable parameters for normalization in lung perfusion quantification. We proposed a quantitative metric for lung perfusion PET/CT imaging, based on normalizing the measured activity to the ALV computed from a co-registered CT scan and to the total activity measured in the ALV.</p><p><strong>Trial registration: </strong>NCT04942275. Registered 19 June 2021.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"79"},"PeriodicalIF":3.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12214062/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144539590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cardiometabolic disorders affect myocardial [¹⁸F]fluorodeoxyglucose uptake- impact on diagnostic PET/CT imaging.","authors":"Suvi Hartikainen, Ville Vepsäläinen, Tuomo Tompuri, Tiina M Laitinen, Marja Hedman, Tomi Laitinen","doi":"10.1186/s13550-025-01278-8","DOIUrl":"10.1186/s13550-025-01278-8","url":null,"abstract":"<p><strong>Background: </strong>Corresponding to impaired insulin response in skeletal muscle, insulin resistance may occur in the myocardium, suggesting a link between cardiometabolic disorders and cardiac glucose metabolism. We aimed to investigate whether cardiometabolic disorders predict myocardial [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) uptake suppression in cardiac positron emission tomography / computed tomography (PET/CT) following a ketogenic diet and fasting.</p><p><strong>Results: </strong>The study included 100 patients undergoing [¹⁸F]FDG-PET/CT following a ketogenic diet of 1-2 days and a 12 h fast. Blood glucose, insulin, β-hydroxybutyrate (BHB), cholesterol, triglycerides and free fatty acid (FFA) levels were measured before [¹⁸F]FDG injection and later off-diet following overnight fast. The homeostatic model assessment-insulin resistance (HOMA-IR) value was calculated. Non-contrast computed tomography was used to assess the presence of fatty liver and visceral and subcutaneous fat areas. Suppression of myocardial [¹⁸F]FDG uptake was considered adequate if myocardial uptake was equal to or lower than the blood pool background. Compared to inadequate suppression, adequate suppression was associated with higher levels of BHB (median 0.26 mmol/l for inadequate and 0.43 mmol/l for adequate suppression, p = 0.004), FFA (0.58 mmol/l and 0.76 mmol/l respectively, p < 0.001), triglycerides (0.87 mmol/l and 1.12 mmol/l respectively, p = 0.028), and lower liver-spleen attenuation ratios (1.17 and 1.04 respectively, p = 0.013). Low HDL cholesterol, high triglycerides and off-diet HOMA-IR, as well as visceral adiposity, fatty liver and hypertension, predicted adequate suppression in men. Elevated BHB and FFA were significant predictors of adequate suppression in women.</p><p><strong>Conclusions: </strong>Cardiometabolic disorders are associated with lower myocardial [¹⁸F]FDG uptake. Insulin resistance and several other cardiometabolic risk factors are associated with attenuated uptake, especially in men. In women, factors reflecting metabolic response to a ketogenic diet and fasting have a more pronounced effect on myocardial [¹⁸F]FDG uptake.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"80"},"PeriodicalIF":3.1,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12214106/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144539589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Head to head comparison of two PET/CT imaging agents, [¹⁸F]D3FSP ([¹⁸F]P16-129) and [¹⁸F]AV45, in patients with alzheimer's disease.","authors":"David Alexoff, Dean F Wong, Hiroto Kuwabara, Robert F Dannals, Karl Ploessl, Hank F Kung","doi":"10.1186/s13550-025-01276-w","DOIUrl":"10.1186/s13550-025-01276-w","url":null,"abstract":"<p><strong>Background: </strong>A new β-amyloid (Aβ) targeting radiotracer, [¹⁸F]D3FSP ([¹⁸F]P16-129), for diagnosis of Alzheimer's disease (AD) is reported. This radiotracer is a deuterated N-methyl derivative of Amyvid (AV-45, florbetapir f18) which was FDA-approved in 2013. Deuteration may alter a tracer's PK such that imaging performance is improved. A head-to-head comparison between these two imaging agents was conducted in AD patients. A separate biodistribution study was conducted on six healthy subjects, and radiation dosimetry estimation was obtained.</p><p><strong>Results: </strong>Eight patients, clinically diagnosed with Alzheimer's disease, had an average age of 61.1 ± 10.0 years, and an average MMSE score of 21 ± 4. Each patient underwent paired 90-minute dynamic PET/CT scans separately within a few weeks (323 ± 31 MBq of [¹⁸F]D3FSP or [¹⁸F]AV45; florbetapir f18). SUVR (50-70 min) and Distribution Volume Ratio (DVR) of 43 brain regions were evaluated. The average SUVR across cortical gray matter was 1.65 ± 0.21 for [¹⁸F]AV45 and 1.65 ± 0.23 for [¹⁸F]D3FSP, while global DVRs were 1.36 ± 0.14 and 1.37 ± 0.13 for [¹⁸F]AV45 and [¹⁸F]D3FSP respectively. Strong correlations (R² = 0.8-0.9) were observed between tracers for both SUVR and DVR, with slopes of ~ 0.9 (SUVR) and ~ 1 (DVR). No image artifacts or confounds influenced the visual interpretation of [¹⁸F]D3FSP compared to [¹⁸F]AV45.</p><p><strong>Conclusions: </strong>Results showed no difference between [¹⁸F]D3FSP and [¹⁸F]AV45 and no benefit of deuteration at the N-methyl site. Even so, [¹⁸F]D3FSP may be a useful alternative for PET/CT imaging of Aβ deposits in the brain as its binding characteristics were very similar to its non-deuterated analog, the FDA-approved drug [¹⁸F]AV45.</p><p><strong>Trial registration: </strong>Clinicaltrials.org, NCT03902548. Registered 01/07/2018.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"77"},"PeriodicalIF":3.1,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12183142/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144368696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of test-retest reproducibility by [¹⁸F]Bavarostat for PET imaging of HDAC6.","authors":"Mika Naganawa, Ming-Qiang Zheng, Jean-Dominique Gallezot, Robin Bonomi, Jiwei Gu, Hong Gao, Swanee Jacutin-Porte, Nabeel B Nabulsi, Michel Koole, Koen Van Laere, David Matuskey, Yiyun Huang, Richard E Carson","doi":"10.1186/s13550-025-01268-w","DOIUrl":"10.1186/s13550-025-01268-w","url":null,"abstract":"<p><strong>Background: </strong>Histone deacetylase 6 (HDAC6) is an enzyme pivotal for gene regulation, influencing cellular pathways through protein deacetylation. HDAC6 is a potential therapeutic target in diseases such as cancer and neurodegenerative disorders. Koole et al. investigated brain binding of [¹⁸F]Bavarostat, an HDAC6 inhibitor, in healthy participants, revealing an absolute test-retest variability (aTRV) of 7.7% (n = 4) for the distribution volume (V_T) with a 1-day interscan interval. This study aims to evaluate test-retest reproducibility with a more extended interscan interval.</p><p><strong>Results: </strong>Six participants (3 M/3F) underwent a test-retest scan, each lasting for 120 min using a 4-ring Biograph mCT PET/CT scanner. Arterial blood sampling and metabolite analysis were performed to derive the input function. The two scans were 28 ± 12 days apart (14-43 days, n = 6). Regional time-activity curves (TACs) were generated for 15 regions of interest (ROIs). Kinetic analysis of the 120-min TACs was performed using one-tissue and two-tissue compartment models (1TC, 2TC) and multilinear analysis-1 (MA1) to quantify V_T values and compute absolute test-retest variability (aTRV). The effects of scan duration (60 to 120 min) and MA1 t* setting on aTRV and bias were investigated. Careful analysis of the plasma HPLC data was needed since metabolites eluted close in time to the parent. The MA1 model (t* = 40 min) adequately described regional TACs and produced stable kinetic parameters with good agreement to 2TC (MA1 V_T=0.98 × 2TC V_T + 0.48, bias: -0.1%) while 1TC underestimated V_T by 5.1%. Regional V_T values exhibited a relatively uniform pattern, highest in the amygdala and lowest in the centrum semiovale. Individual aTRV values ranged from 2 to 9%. Scan durations between 100 and 120 min provided the most consistent results, with minimal bias and acceptable aTRV across all tested t* values. Although a 90-minute scan with t*=10 or 20-minute balanced scan time and aTRV, optimal parameters varied by brain region. Smaller regions (e.g., amygdala) required longer scans to achieve reliable V_T quantification.</p><p><strong>Conclusions: </strong>The test-retest variability of [¹⁸F]Bavarostat V_T values demonstrated favorable results for a one-month scan interval, comparable to the reported values.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"76"},"PeriodicalIF":3.1,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12182542/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144340024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}