The Journal of Nuclear Medicine最新文献

{"title":"Myelin Imaging of the Spinal Cord in Animal Models and Patients with Multiple Sclerosis Using [11C]MeDAS PET: A Translational Study","authors":"Chris W.J. van der Weijden, Ahmed K.M.A. Ahmed, Anouk van der Hoorn, Junqing Zhu, Chunying Wu, Yanming Wang, Gilles N. Stormezand, Rudi A.J.O. Dierckx, Jan F. Meilof, Erik F.J. de Vries","doi":"10.2967/jnumed.123.266896","DOIUrl":"https://doi.org/10.2967/jnumed.123.266896","url":null,"abstract":"<sec><st>Visual Abstract</st><p><fig loc=\"float\"><link locator=\"jnumed.123.266896absf1\"></fig></p></sec>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142782399","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":"Quantitative Accuracy Assessment of the NeuroEXPLORER for Diverse Imaging Applications: Moving Beyond Standard Evaluations","authors":"Negar Omidvari, Ekaterina Shanina, Edwin K. Leung, Xishan Sun, Yusheng Li, Tim Mulnix, Paul Gravel, Shannan Henry, David Matuskey, Tommaso Volpi, Terry Jones, Ramsey D. Badawi, Hongdi Li, Richard E. Carson, Jinyi Qi, Simon R. Cherry","doi":"10.2967/jnumed.124.268309","DOIUrl":"https://doi.org/10.2967/jnumed.124.268309","url":null,"abstract":"<p>Quantitative molecular imaging with PET can offer insights into physiologic and pathologic processes and is widely used for studying brain disorders. The NeuroEXPLORER is a recently developed dedicated brain PET system offering high spatial resolution and high sensitivity with an extended axial length. This study evaluated the quantitative precision and accuracy of the NeuroEXPLORER with phantom and human data for a variety of imaging conditions that are relevant to dynamic neuroimaging studies. <strong>Methods:</strong> Thirty-minute scans of an image quality (IQ) phantom and a 3-dimensional Hoffman brain phantom filled with [¹⁸F]FDG were performed over 13 h, covering phantom activities of 1.3–177 MBq. Furthermore, a uniform cylindric phantom filled with 558 MBq of ¹¹C was scanned for 4 h. Quantitative accuracy was assessed using the contrast recovery coefficient (CRC), background variability, and background bias in the IQ phantom, the recovery coefficients (RCs) in the Hoffman phantom, and the bias in the uniform phantom. Results were compared at delayed time points, with different reconstruction parameters and frame lengths down to 1 s. Moreover, randomly subsampled frames of 2 imaging time points (0–2 min and 60–90 min) from a dynamic scan of a healthy volunteer with a 177-MBq injected dose of (<em>R</em>)-4-(3-fluoro-5-(fluoro-¹⁸F)phenyl)-1-((3-methylpyridin-4-yl)methyl)pyrrolidin-2-one ([¹⁸F]SynVesT-1) were used to assess quantification of brain uptake and image-derived input function extraction. <strong>Results:</strong> Negligible effects were observed on CRC and background bias with 3–177 MBq in the IQ phantom, and bias was less than 5% with 1–558 MBq in the uniform phantom. RC variations were within ±1% with 2–169 MBq in the Hoffman phantom, showcasing the system’s high spatial resolution and high sensitivity. Short-frame reconstructions of the 60- to 90-min healthy-volunteer scan showed a ±1% mean difference in quantification of brain uptake for frame lengths down to 30 s and demonstrated the feasibility of measuring image-derived input function with mean absolute differences below 10% for frame lengths down to 1 s. <strong>Conclusion:</strong> The NeuroEXPLORER, with its high detection sensitivity, maintains high precision and accuracy across a wide range of imaging conditions beyond those evaluated in standard performance tests. These results demonstrate its potential for quantitative neuroimaging applications.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142782454","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":"CD70-Targeted Immuno-PET/CT Imaging of Clear Cell Renal Cell Carcinoma: A Translational Study","authors":"Xiang Zhou, Qianyun Wu, Wei Zhai, You Zhang, Yanfei Wu, Min Cao, Cheng Wang, Yihui Guan, Jianjun Liu, Fang Xie, Weijun Wei","doi":"10.2967/jnumed.124.268509","DOIUrl":"https://doi.org/10.2967/jnumed.124.268509","url":null,"abstract":"<p>The diagnosis and surveillance of clear cell renal cell carcinoma (ccRCC) remains a clinical challenge. The high and specific expression of the cluster of differentiation 70 (CD70) in ccRCC makes it a potential diagnostic and therapeutic target. <strong>Methods:</strong> We detected and analyzed CD70 expression in various renal cell carcinomas (RCCs) and normal kidneys using immunohistochemical staining. Two novel CD70-specific single-domain antibodies, RCCB3 and RCCB6, were produced and labeled with ⁶⁸Ga to develop radiotracers. We performed immuno-PET/CT imaging with [⁶⁸Ga]Ga-NOTA-RCCB3 and [⁶⁸Ga]Ga-NOTA-RCCB6 in subcutaneous ccRCC patient–derived xenograft models. We recruited 8 RCC patients in a pilot clinical trial (ClinicalTrials.gov identifier: NCT06148220) to evaluate the diagnostic utility of [⁶⁸Ga]Ga-NOTA-RCCB3 and [⁶⁸Ga]Ga-NOTA-RCCB6 immuno-PET/CT. <strong>Results:</strong> Expression of CD70 is associated with sex, tumor differentiation, tumor thrombus, necrosis, distant metastasis, and overall survival of RCC patients. RCCB3 and RCCB6 had high affinities for recombinant human CD70. Immuno-PET/CT imaging with [⁶⁸Ga]Ga-NOTA-RCCB3 and [⁶⁸Ga]Ga-NOTA-RCCB6 rapidly visualized subcutaneous ccRCC with clarity. Tumor uptake of [⁶⁸Ga]Ga-NOTA-RCCB6 was significantly reduced after the blockade of CD70. [⁶⁸Ga]Ga-NOTA-RCCB6 PET/CT in ccRCC patients outperformed traditional ¹⁸F-FDG PET/CT in specifically identifying CD70-positive ccRCC metastases. <strong>Conclusion:</strong> CD70-targeted immuno-PET/CT imaging with [⁶⁸Ga]Ga-NOTA-RCCB6 or [⁶⁸Ga]Ga-NOTA-RCCB3 is a precise and superior method for evaluating tumor burden and suspected metastases in ccRCC patients. This advancement in imaging technology has the potential to improve the clinical decision-making process for this patient cohort significantly.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596935","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":"International Metabolic Prognostic Index Is Superior to Other Metabolic Tumor Volume–Based Prognostication Methods in a Real-Life Cohort of Diffuse Large B-Cell Lymphoma","authors":"Vibeke K.J. Vergote, Gregor Verhoef, Ann Janssens, F.J. Sherida H. Woei-a-jin, Wies Deckers, Annouschka Laenen, Thomas Tousseyn, Daan Dierickx, Christophe M. Deroose","doi":"10.2967/jnumed.124.268152","DOIUrl":"https://doi.org/10.2967/jnumed.124.268152","url":null,"abstract":"<p>Baseline metabolic tumor volume (MTV) is a promising prognostic marker in diffuse large B-cell lymphoma (DLBCL). We assessed the prognostic value of 4 novel metabolic risk scores in a real-life DLBCL cohort and compared them with the revised international prognostic index (IPI). <strong>Methods:</strong> We included a consecutive series of untreated DLBCL, not otherwise specified cases that were diagnosed in our hospital from 2008 to 2021 with available baseline [¹⁸F]FDG PET/CT. Clinical data were collected retrospectively, including the individual components of the revised IPI. MTV and other radiomic features, including lesion dissemination and tumor volume surface ratio, were calculated. Four novel metabolic risk scores including the international metabolic prognostic index (IMPI), the MTV/World Health Organization performance status, the MTV/standardized maximum distance, and clinical PET models were used to calculate the risk of progression using predefined cutoffs. Survival outcomes considered were 3-y progression free survival (PFS), 3-y time to progression (TTP), and 3-y overall survival (OS). The Harrell C-index was used to assess the discriminative performance of the risk scores. A multivariable model was built. <strong>Results:</strong> We included 355 DLBCL, not otherwise specified cases with a median MTV of 219 cm³ (range, 0–5,656 cm³). The IMPI had the highest C-index for 3-y PFS, 3-y TTP, and 3-y OS among the 4 metabolic risk scores (0.674, 0.696, and 0.677, respectively). For the 3-y TTP, the IMPI outperformed the strongest clinical risk score, the IPI, although the difference in the Harrell C-indices was small (0.696 vs. 0.693). Regarding the 3-y PFS and 3-y OS, the IPI has the highest C-index of all risk scores (0.696 and 0.693). The IMPI, the MTV/World Health Organization performance status, and the IPI score can recognize a poor risk group with a 3-y OS below 50% (43%, 32%, and 39%, respectively). In multivariable analysis, the IMPI remains an independent prognostic factor (<em>P</em> = 0.0089; hazard ratio, 1.207; 95% CI, 1.048–1.389). MTV and standardized maximum distance have the strongest prognostic values when used as a continuous variable. The tumor volume surface ratio has no significant prognostic value in our analysis. <strong>Conclusion:</strong> The IMPI has the strongest prognostic performance compared with the other 3 novel metabolic risk scores. However, in our real-world dataset, the IMPI could not replace the IPI, and further prospective trials are needed to compare their performance.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598086","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 Characteristics of a New Generation 148-cm Axial Field-of-View uMI Panorama GS PET/CT System with Extended NEMA NU 2-2018 and EARL Standards","authors":"Haiqiong Zhang, Chao Ren, Yu Liu, Xinchun Yan, Meixi Liu, Zhixin Hao, Haiqun Xing, Li Huo","doi":"10.2967/jnumed.124.267963","DOIUrl":"https://doi.org/10.2967/jnumed.124.267963","url":null,"abstract":"<sec><st>Visual Abstract</st><p><fig loc=\"float\"><link locator=\"jnumed.124.267963absf1\"></fig></p></sec>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"127 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596933","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":"SPECT/CT in Early Response Assessment of Patients with Metastatic Castration-Resistant Prostate Cancer Receiving 177Lu-PSMA-617","authors":"Ridvan Arda Demirci, Roman Gulati, Jessica E. Hawley, Todd Yezefski, Michael C. Haffner, Heather H. Cheng, Robert B. Montgomery, Michael T. Schweizer, Evan Y. Yu, Peter S. Nelson, Delphine L. Chen, Amir Iravani","doi":"10.2967/jnumed.124.267665","DOIUrl":"https://doi.org/10.2967/jnumed.124.267665","url":null,"abstract":"<p>¹⁷⁷Lu-PSMA-617 (LuPSMA) is a newly established treatment for patients with metastatic castration-resistant prostate cancer (mCRPC), but survival outcomes vary widely, and predictors of treatment responses are needed. This study investigated the role of total tumor volumes (TTVs) and new lesions (NLs) determined by LuPSMA SPECT/CT in early cycles to predict subsequent outcomes in a real-world practice setting. <strong>Methods:</strong> Between June and December 2022, consecutive patients with mCRPC who received at least 2 administrations of LuPSMA with SPECT/CT 24 h after treatment were retrospectively reviewed. We evaluated associations between TTVs and the appearance of NLs at cycles 2 and 3 with subsequent prostate-specific antigen (PSA) progression-free survival and overall survival (OS) using multivariate Cox regression. All analyses were adjusted for changes in PSA level relative to baseline. <strong>Results:</strong> Sixty-six mCRPC patients (median age, 74 y) received a median of 4 (interquartile range, 3–5) cycles of LuPSMA. Median follow-up starting at cycle 2 was 42 wk (interquartile range, 33–48 wk), with 24 of 66 patients deceased at the time of the analysis. Changes in TTV measured at the start of cycles 2 and 3 relative to baseline correlated significantly with corresponding changes in PSA level (<em>r</em> = 0.55 and 0.56), but absolute TTVs did not correlate significantly (<em>r</em> = 0.00 and 0.18). Patients with a higher absolute TTV at the start of cycle 2 had worse PSA progression-free survival and OS (hazard ratio [HR], 1.4 [95% CI, 1.1–1.8] and 2.1 [95% CI, 1.5–2.9]), with consistent results at the start of cycle 3 (HR, 2 [95% CI, 1.4–2.9] and 2 [95% CI, 1.2–3.2]). NLs were identified in 13 of 66 and 11 of 51 patients at the start of cycles 2 and 3. NLs at the start of cycle 2 were associated with worse OS (HR, 5.8 [95% CI, 1.9–17.5]), with consistent results at the start of cycle 3 (HR, 4.9 [95% CI, 1.3–18.6]). In multivariate analysis, a higher TTV and the appearance of NLs at the start of cycles 2 and 3 were independently associated with poorer OS. <strong>Conclusion:</strong> Higher TTVs and NLs on LuPSMA SPECT/CT at the start of cycles 2 and 3 were independently associated with higher risk of death. These measures provided prognostic information independent of changes in PSA. Development of prognostic and predictive models including TTV, NLs, and PSA changes is warranted.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"105 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596934","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":"Precautions to Consider in the Analysis of Prognostic and Predictive Indices","authors":"Loïc Chartier, Aurélien Belot, Isabelle Chaillol, Mad-Hélénie Elsensohn, Cédric Portugues, Marguerite Fournier, Clémentine Joubert, Elodie Gat, Cécile Pizot, Patrick Fogarty, Tesla Murairi, Romain Ould Ammar, Jérôme Paget, Fanny Cherblanc, Romain Ricci, Laetitia Vercellino, Salim Kanoun, Anne-Ségolène Cottereau, Catherine Thieblemont, Olivier Casasnovas","doi":"10.2967/jnumed.123.267021","DOIUrl":"https://doi.org/10.2967/jnumed.123.267021","url":null,"abstract":"<p>Understanding the differences between prognostic and predictive indices is imperative for medical research advances. We have developed a new prognostic measure that will identify the strengths, limitations, and potential applications in clinical practice.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142562087","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":"Intraarterial Administration of Peptide Receptor Radionuclide Therapy in Patients with Advanced Meningioma: Initial Safety and Efficacy","authors":"Adriana Amerein, Christoph Maurer, Malte Kircher, Alexander Gäble, Anne Krebold, Andreas Rinscheid, Oliver Viering, Christian H. Pfob, Ralph A. Bundschuh, Lars Behrens, Arthur JAT Braat, Ansgar Berlis, Constantin Lapa","doi":"10.2967/jnumed.124.268217","DOIUrl":"https://doi.org/10.2967/jnumed.124.268217","url":null,"abstract":"<p>Peptide receptor radionuclide therapy (PRRT) is a treatment option for patients with advanced meningioma. Recently, intraarterial application of the radiolabeled somatostatin receptor agonists has been introduced as an alternative to standard intravenous administration. In this study, we assessed the safety and efficacy of intraarterial PRRT in patients with advanced, progressive meningioma. <strong>Methods:</strong> Patients with advanced, progressive meningioma underwent intraarterial PRRT with [¹⁷⁷Lu]Lu-HA-DOTATATE. The safety of PRRT was evaluated according to the Common Terminology Criteria for Adverse Events version 5.0. Treatment response was assessed according to the proposed Response Assessment in Neuro-Oncology criteria for meningiomas and somatostatin receptor–directed PET/CT. <strong>Results:</strong> Thirteen patients (8 women, 5 men; mean age, 65 ± 13 y) with advanced meningioma underwent 1–4 cycles (median, 4 cycles) of intraarterial PRRT with [¹⁷⁷Lu]Lu-HA-DOTATATE (mean activity per cycle, 7,428 ± 237 MBq; range, 6,000–7,700 MBq). Treatment was well tolerated with mainly grade 1–2 hematologic toxicity. Ten of 13 patients showed radiologic disease control at follow-up after therapy (1/10 complete remission, 1/10 partial remission, 8/10 stable disease), and 9 of 13 patients showed good control of clinical symptoms. <strong>Conclusion:</strong> Intraarterial PRRT in patients with advanced meningioma is feasible and safe. It may result in improved radiologic and clinical disease control compared with intravenous PRRT. Further research to validate these initial findings and to investigate long-term outcomes is highly warranted.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142489362","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":"MIRD Pamphlet No. 31: MIRDcell V4—Artificial Intelligence Tools to Formulate Optimized Radiopharmaceutical Cocktails for Therapy","authors":"Sumudu Katugampola, Jianchao Wang, Roger W. Howell","doi":"10.2967/jnumed.123.267238","DOIUrl":"https://doi.org/10.2967/jnumed.123.267238","url":null,"abstract":"<p>Radiopharmaceutical cocktails have been developed over the years to treat cancer. Cocktails of agents are attractive because 1 radiopharmaceutical is unlikely to have the desired therapeutic effect because of nonuniform uptake by the targeted cells. Therefore, multiple radiopharmaceuticals targeting different receptors on a cell is warranted. However, past implementations in vivo have not met with convincing results because of the absence of optimization strategies. Here we present artificial intelligence (AI) tools housed in a new version of our software platform, MIRDcell V4, that optimize a cocktail of radiopharmaceuticals by minimizing the total disintegrations needed to achieve a given surviving fraction (SF) of tumor cells. <strong>Methods:</strong> AI tools are developed within MIRDcell V4 using an optimizer based on the sequential least-squares programming algorithm. The algorithm determines the molar activities for each drug in the cocktail that minimize the total disintegrations required to achieve a specified SF. Tools are provided for populations of cells that do not cross-irradiate (e.g., circulating or disseminated tumor cells) and for multicellular clusters (e.g., micrometastases). The tools were tested using model data, flow cytometry data for suspensions of single cells labeled with fluorochrome-labeled antibodies, and 3-dimensional spatiotemporal kinetics in spheroids for fluorochrome-loaded liposomes. <strong>Results:</strong> Experimental binding distributions of 4 ²¹¹At-antibodies were considered for treating suspensions of MDA-MB-231 human breast cancer cells. A 2-drug combination reduced the number of ²¹¹At decays required by a factor of 1.6 relative to the best single antibody. In another study, 2 radiopharmaceuticals radiolabeled with ^195mPt were each distributed lognormally in a hypothetical multicellular cluster. Here, the 2-drug combination required 1.7-fold fewer decays than did either drug alone. Finally, 2 ²²⁵Ac-labeled drugs that provide different radial distributions within a spheroid require about one half of the disintegrations required by the best single agent. <strong>Conclusion:</strong> The MIRDcell AI tools determine optimized drug combinations and corresponding molar activities needed to achieve a given SF. This approach could be used to analyze a sample of cells obtained from cell culture, animal, or patient to predict the best combination of drugs for maximum therapeutic effect with the least total disintegrations.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"97 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142489816","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 PET Data Acquired During Nonsteady Conditions: What If Brain Conditions Change During the Scan?","authors":"Evan D. Morris, Gaelle M. Emvalomenos, Jocelyn Hoye, Steven R. Meikle","doi":"10.2967/jnumed.124.267494","DOIUrl":"https://doi.org/10.2967/jnumed.124.267494","url":null,"abstract":"<p>Researchers use dynamic PET imaging with target-selective tracer molecules to probe molecular processes. Kinetic models have been developed to describe these processes. The models are typically fitted to the measured PET data with the assumption that the brain is in a steady-state condition for the duration of the scan. The end results are quantitative parameters that characterize the molecular processes. The most common kinetic modeling endpoints are estimates of volume of distribution or the binding potential of a tracer. If the steady state is violated during the scanning period, the standard kinetic models may not apply. To address this issue, time-variant kinetic models have been developed for the characterization of dynamic PET data acquired while significant changes (e.g., short-lived neurotransmitter changes) are occurring in brain processes. These models are intended to extract a transient signal from data. This work in the PET field dates back at least to the 1990s. As interest has grown in imaging nonsteady events, development and refinement of time-variant models has accelerated. These new models, which we classify as belonging to the first, second, or third generation according to their innovation, have used the latest progress in mathematics, image processing, artificial intelligence, and statistics to improve the sensitivity and performance of the earliest practical time-variant models to detect and describe nonsteady phenomena. This review provides a detailed overview of the history of time-variant models in PET. It puts key advancements in the field into historical and scientific context. The sum total of the methods is an ongoing attempt to better understand the nature and implications of neurotransmitter fluctuations and other brief neurochemical phenomena.</p>","PeriodicalId":22820,"journal":{"name":"The Journal of Nuclear Medicine","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142489817","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}