Annals of Nuclear Medicine最新文献

{"title":"Zero-TE MRI-based attenuation correction for bone components on chest [¹⁸F] FDG PET/MRI: accuracy, repeatability, and external validation of an unsupervised deep learning approach using unpaired PET/CT data.","authors":"Munenobu Nogami, Hidetoshi Matsuo, Mizuho Nishio, Feibi Zeng, Junko Inoue Inukai, Miho Tachibana, Florian Wiesinger, Sandeep Kaushik, Takako Kurimoto, Kazuhiro Kubo, Martin W Huellner, Hidehiko Okazawa, Takamichi Murakami","doi":"10.1007/s12149-026-02213-0","DOIUrl":"https://doi.org/10.1007/s12149-026-02213-0","url":null,"abstract":"<p><strong>Objective: </strong>In positron emission tomography (PET)/magnetic resonance imaging (MRI), attenuation correction (AC) for PET of the head is achieved by MRI data to generate pseudo-computed tomography (CT) images. However, for the torso, AC becomes more challenging due to the complexity of separating bone components. Additionally, generating accurate MRI-based CT using deep learning poses significant difficulties for the chest, primarily because perfectly paired MRI and CT training data are hard to obtain owing to respiratory motion and body movements. We previously demonstrated that MRI-to-CT conversion can be achieved without deformation, even using unsupervised learning for zero echo time (ZTE) MRI and CT data from different individuals. Building on this foundation, our study aims to apply this approach to AC in chest PET/MRI and assess their quantitative accuracy, reproducibility, and external validity.</p><p><strong>Methods: </strong>The datasets used included (1) training dataset (unpaired ZTE MRI and CT of PET/CT, n = 360 and 500, respectively); (2) test dataset (paired PET/MRI and PET/CT, n = 25 and 25, respectively); (3) repeatability assessment dataset (repeated PET/MRI, n = 15 × 2 scans for the same patient); and (4) external validation dataset (paired MRI component of PET/MRI and CT, n = 30 and 30, respectively, acquired at another institution). Unpaired training data were used to train the deep learning model of pseudo-CT generation from ZTE. The accuracy, repeatability, and reproducibility of the PET/MRI scans using ZTE- and deep learning-based AC (MRAC_ZTE) were evaluated based on the similarity of the histograms and the mean standardized uptake value (SUVmean) of physiological background of bone and liver.</p><p><strong>Results: </strong>The histogram correlation coefficients between MRAC_ZTE and the AC map based on the CT (CTAC) for the spine were significantly higher than those between conventional AC (MRAC_Dixon) and CTAC. Additionally, bone SUVmean obtained using MRAC_ZTE showed reduced bias relative to CTAC compared with MRAC_Dixon. This method proved to be reproducible on each patient level and robust against external validation.</p><p><strong>Conclusions: </strong>Unsupervised learning with unpaired ZTE and CT data enabled pseudo-CT generation with bone components that closely matched CT-based attenuation maps. Integration into MR-based attenuation correction resulted in stable physiological uptake measurements in chest PET/MRI, supporting the feasibility of this approach.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Myocardial flow reserve estimation from standardized uptake values of ¹³N-ammonia imaging with a silicon photomultiplier positron emission tomography/computed tomography system.","authors":"Masateru Kawakubo, Yoko Kaimoto, Atsushi Yamamoto, Masaki Watanabe, Akiko Sakai, Michinobu Nagao","doi":"10.1007/s12149-026-02219-8","DOIUrl":"https://doi.org/10.1007/s12149-026-02219-8","url":null,"abstract":"<p><strong>Objective: </strong>To assess the feasibility of estimating myocardial flow reserve (MFR) from static standardized uptake values (SUVs) derived using stress and rest ¹³N-ammonia positron emission tomography (PET) images acquired with a silicon photomultiplier-based PET/computed tomography (CT) system. The goal was to simplify MFR assessment by avoiding dynamic acquisition while maintaining diagnostic accuracy.</p><p><strong>Methods: </strong>We retrospectively included 121 consecutive patients who underwent ¹³N-ammonia PET myocardial perfusion imaging. The mean SUVs of the left and right ventricles were measured on transverse-axis slices corresponding to the largest cross-sectional area, and the stress-to-rest SUV ratio was calculated. A logarithmic transformation was applied to the MFR, and linear regression models between the log-transformed MFR and the stress-to-rest left ventricular-SUV ratio were developed using six-fold cross-validation across 121 patients. The predicted MFR values from the test folds were then combined to evaluate model performance across all patients with a comparable MFR distribution. Model performance was assessed using the root mean square error (RMSE) between the estimated and true MFR values, and the diagnostic performance for identifying MFRs < 2.0 by receiver operating characteristic (ROC) curve analysis with 95% confidence intervals.</p><p><strong>Results: </strong>The RMSE of the predicted MFR calculated using the linear regression model was 0.39. Using an optimal cut-off value of 1.79 for the predicted MFR, the model achieved an area under the ROC curve of 0.89 (95% confidence interval: 0.83-0.95), with a sensitivity of 75% and a specificity of 88%. The proposed simplified SUV-based approach exhibited clinically acceptable error for MFR estimation and could effectively identify patients with an impaired MFR.</p><p><strong>Conclusion: </strong>This method may facilitate quantitative MFR assessment in clinical settings where dynamic PET protocols or dedicated software are not available, thereby broadening access to physiological evaluation of myocardial perfusion.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147832729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fibroblast activation protein-targeted molecular imaging in interstitial lung disease: a systematic review.","authors":"Ali Ghorbani Olya, Mehrzad Bahtouee, Esmail Jafari, Maryam Ravanipour, Ali Hamidi, Nahid Aram, Soodabeh Zendeboodi, Moloud Abbaszadeh, Majid Assadi","doi":"10.1007/s12149-026-02223-y","DOIUrl":"https://doi.org/10.1007/s12149-026-02223-y","url":null,"abstract":"<p><p>Interstitial lung diseases (ILDs) are characterized by progressive lung scarring. Fibroblast activation protein (FAP), overexpressed on activated fibroblasts, has emerged as a key molecular target for imaging active fibrosis. This systematic review synthesizes the current evidence on the role of FAP-targeted imaging in evaluating ILD. A systematic search was conducted across PubMed, Scopus, and Web of Science according to PRISMA guidelines. Twelve studies met the inclusion criteria and were included in a qualitative synthesis. FAP inhibitors (FAPI) imaging consistently demonstrated elevated tracer uptake in ILD patients, showing strong spatial correlation with fibrotic patterns on high-resolution computed tomography (HRCT), particularly reticulation. Increased FAPI uptake was significantly associated with declining lung function, including forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (DLCO). Histopathological analyses confirmed that FAPI uptake corresponds to fibroblast-rich regions, validating its specificity for active fibrogenesis. Dual-tracer imaging showed potential in differentiating fibrotic from inflammatory activity. FAP-targeted imaging is a promising non-invasive modality for visualizing and quantifying active fibrosis in ILD. It offers valuable insights into disease activity, functional impairment, and prognosis, potentially guiding personalized treatment strategies.</p>","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147832650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coronary microvascular injury detection and prediction after successful primary percutaneous coronary intervention: non-invasive assessment using single photon emission tomography myocardial perfusion imaging.","authors":"Ragab Abdulsalam Mahfouz, Mohammad Gouda Mohammad, Shady G Ouf, Azza Seddiq Ahmad Zidan, Mohamed Mesbah Taha","doi":"10.1007/s12149-026-02208-x","DOIUrl":"https://doi.org/10.1007/s12149-026-02208-x","url":null,"abstract":"","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147760448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Error analysis of cerebral blood flow and oxygen metabolism in three-dimensional ¹⁵O-gas positron emission tomography acquisition.","authors":"Keiji Shimizu, Keiichi Matsumoto, Wataru Omasa, Go Akamatsu, Yasuhiko Ikari, Masahiro Sasaki, Takeharu Ibaraki, Michio Senda, Tomohiko Yamane","doi":"10.1007/s12149-026-02217-w","DOIUrl":"https://doi.org/10.1007/s12149-026-02217-w","url":null,"abstract":"","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147760372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response to the comment on \"Kinetic and quantitative analysis of [¹⁸F]SMBT-1 PET imaging for monoamine oxidase B\".","authors":"Kotaro Hiraoka","doi":"10.1007/s12149-026-02214-z","DOIUrl":"https://doi.org/10.1007/s12149-026-02214-z","url":null,"abstract":"","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147721600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reply to the letter regarding \"Long-term efficacy and safety of peptide receptor radionuclide therapy in Japanese patients with unresectable neuroendocrine tumor: extension of the Japanese phase I and phase I/II study\".","authors":"Noritoshi Kobayashi","doi":"10.1007/s12149-026-02216-x","DOIUrl":"https://doi.org/10.1007/s12149-026-02216-x","url":null,"abstract":"","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147721583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Letter to the editor: [¹⁸F]SMBT-1 PET quantification - methodological considerations and future directions.","authors":"Qing Song, Mengxing Li","doi":"10.1007/s12149-026-02203-2","DOIUrl":"https://doi.org/10.1007/s12149-026-02203-2","url":null,"abstract":"","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147715697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi-quantitative evaluation of early phase ^99mTc-DPD scintigraphy in patients with suspected cardiac amyloidosis.","authors":"Lukas Kessler, Leon Ferber, Christoph Rischpler, Stephan Settelmeier, Tugce Telli, Zohreh Varasteh, Clemens P Spielvogel, Tim Hagenacker, Wolfgang P Fendler, Alexander Carpinteiro, Lars Michel, Ken Herrmann, Tienush Rassaf, Miriam Sraieb, David Kersting","doi":"10.1007/s12149-026-02209-w","DOIUrl":"https://doi.org/10.1007/s12149-026-02209-w","url":null,"abstract":"","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147697168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visceral technetium-99 m-labeled pyrophosphate uptake in patients with wild-type transthyretin cardiac amyloidosis.","authors":"Koji Takahashi, Shuhei Yamamoto, Daisuke Sasaki, Takaaki Iwamura, Yoshiyasu Hiratsuka, Sohei Kitazawa, Nobuhisa Yamamura, Mitsuharu Ueda, Yushi Utsunomiya, Hiroe Morioka, Shigeki Uemura, Tomoki Sakaue, Katsuji Inoue","doi":"10.1007/s12149-026-02174-4","DOIUrl":"https://doi.org/10.1007/s12149-026-02174-4","url":null,"abstract":"","PeriodicalId":8007,"journal":{"name":"Annals of Nuclear Medicine","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147697230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}