Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-14920 Wissenschaftlicher Artikel Chen, Xinyu; Werner, Rudolf A.; Javadi, Mehrbod S.; Maya, Yoshifumi; Decker, Michael; Lapa, Constantin; Herrmann, Ken; Higuchi, Takahiro Radionuclide imaging of neurohormonal system of the heart Heart failure is one of the growing causes of death especially in developed countries due to longer life expectancy. Although many pharmacological and instrumental therapeutic approaches have been introduced for prevention and treatment of heart failure, there are still limitations and challenges. Nuclear cardiology has experienced rapid growth in the last few decades, in particular the application of single photon emission computed tomography (SPECT) and positron emission tomography (PET), which allow non-invasive functional assessment of cardiac condition including neurohormonal systems involved in heart failure; its application has dramatically improved the capacity for fundamental research and clinical diagnosis. In this article, we review the current status of applying radionuclide technology in non-invasive imaging of neurohormonal system in the heart, especially focusing on the tracers that are currently available. A short discussion about disadvantages and perspectives is also included. 2015 545-558 Theranostics 5 6 urn:nbn:de:bvb:20-opus-149205 10.7150/thno.10900 Klinik und Poliklinik für Nuklearmedizin OPUS4-16708 Wissenschaftlicher Artikel Chen, Xinyu; Werner, Rudolf A.; Lapa, Constantin; Nose, Naoko; Hirano, Mitsuru; Javadi, Mehrbod S.; Robinson, Simon; Higuchi, Takahiro Subcellular storage and release mode of the novel \(^{18}\)F-labeled sympathetic nerve PET tracer LMI1195 Background: \(^{18}\)F-N-[3-bromo-4-(3-fluoro-propoxy)-benzyl]-guanidine (\(^{18}\)F-LMI1195) is a new class of PET tracer designed for sympathetic nervous imaging of the heart. The favorable image quality with high and specific neural uptake has been previously demonstrated in animals and humans, but intracellular behavior is not yet fully understood. The aim of the present study is to verify whether it is taken up in storage vesicles and released in company with vesicle turnover. Results: Both vesicle-rich (PC12) and vesicle-poor (SK-N-SH) norepinephrine-expressing cell lines were used for in vitro tracer uptake studies. After 2 h of \(^{18}\)F-LMI1195 preloading into both cell lines, effects of stimulants for storage vesicle turnover (high concentration KCl (100 mM) or reserpine treatment) were measured at 10, 20, and 30 min. \(^{131}\)I-meta-iodobenzylguanidine (\(^{131}\)I-MIBG) served as a reference. Both high concentration KCl and reserpine enhanced \(^{18}\)F-LMI1195 washout from PC12 cells, while tracer retention remained stable in the SK-N-SH cells. After 30 min of treatment, 18F-LMI1195 releasing index (percentage of tracer released from cells) from vesicle-rich PC12 cells achieved significant differences compared to cells without treatment condition. In contrast, such effect could not be observed using vesicle-poor SK-N-SH cell lines. Similar tracer kinetics after KCl or reserpine treatment were also observed using 131I-MIBG. In case of KCl exposure, Ca\(^{2+}\)-free buffer with the calcium chelator, ethylenediaminetetracetic acid (EDTA), could suppress the tracer washout from PC12 cells. This finding is consistent with the tracer release being mediated by Ca\(^{2+}\) influx resulting from membrane depolarization. Conclusions: Analogous to \(^{131}\)I-MIBG, the current in vitro tracer uptake study confirmed that \(^{131}\)F-LMI1195 is also stored in vesicles in PC12 cells and released along with vesicle turnover. Understanding the basic kinetics of \(^{18}\)FLMI1195 at a subcellular level is important for the design of clinical imaging protocols and imaging interpretation. 2018 EJNMMI Research 8 12 urn:nbn:de:bvb:20-opus-167081 10.1186/s13550-018-0365-9 Klinik und Poliklinik für Nuklearmedizin OPUS4-17218 Wissenschaftlicher Artikel Kazuhino, Koshino; Werner, Rudolf A.; Toriumi, Fuijo; Javadi, Mehrbod S.; Pomper, Martin G.; Solnes, Lilja B.; Verde, Franco; Higuchi, Takahiro; Rowe, Steven P. Generative Adversarial Networks for the Creation of Realistic Artificial Brain Magnetic Resonance Images Even as medical data sets become more publicly accessible, most are restricted to specific medical conditions. Thus, data collection for machine learning approaches remains challenging, and synthetic data augmentation, such as generative adversarial networks (GAN), may overcome this hurdle. In the present quality control study, deep convolutional GAN (DCGAN)-based human brain magnetic resonance (MR) images were validated by blinded radiologists. In total, 96 T1-weighted brain images from 30 healthy individuals and 33 patients with cerebrovascular accident were included. A training data set was generated from the T1-weighted images and DCGAN was applied to generate additional artificial brain images. The likelihood that images were DCGAN-created versus acquired was evaluated by 5 radiologists (2 neuroradiologists [NRs], vs 3 non-neuroradiologists [NNRs]) in a binary fashion to identify real vs created images. Images were selected randomly from the data set (variation of created images, 40%-60%). None of the investigated images was rated as unknown. Of the created images, the NRs rated 45% and 71% as real magnetic resonance imaging images (NNRs, 24%, 40%, and 44%). In contradistinction, 44% and 70% of the real images were rated as generated images by NRs (NNRs, 10%, 17%, and 27%). The accuracy for the NRs was 0.55 and 0.30 (NNRs, 0.83, 0.72, and 0.64). DCGAN-created brain MR images are similar enough to acquired MR images so as to be indistinguishable in some cases. Such an artificial intelligence algorithm may contribute to synthetic data augmentation for "data-hungry" technologies, such as supervised machine learning approaches, in various clinical applications. 2018 159–163 Tomography 4 4 urn:nbn:de:bvb:20-opus-172185 10.18383/j.tom.2018.00042 Klinik und Poliklinik für Nuklearmedizin OPUS4-16332 unpublished Nose, Naoko; Werner, Rudolf A.; Ueda, Yuichiro; Günther, Katharina; Lapa, Constantin; Javadi, Mehrbod S.; Fukushima, Kazuhito; Edenhofer, Frank; Higuchi, Takahiro Metabolic substrate shift in human induced pluripotent stem cells during cardiac differentiation: Functional assessment using in vitro radionuclide uptake assay Background: Recent developments in cellular reprogramming technology enable the production of virtually unlimited numbers of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Although hiPSC-CM share various characteristic hallmarks with endogenous cardiomyocytes, it remains a question as to what extent metabolic characteristics are equivalent to mature mammalian cardiomyocytes. Here we set out to functionally characterize the metabolic status of hiPSC-CM in vitro by employing a radionuclide tracer uptake assay. Material and Methods: Cardiac differentiation of hiPSC was induced using a combination of well-orchestrated extrinsic stimuli such as WNT activation (by CHIR99021) and BMP signalling followed by WNT inhibition and lactate based cardiomyocyte enrichment. For characterization of metabolic substrates, dual tracer uptake studies were performed with \(^{18}\)F-2-fluoro-2-deoxy-D-glucose (\(^{18}\)F-FDG) and \(^{125}\)I-β-methyl-iodophenyl-pentadecanoic acid (\(^{125}\)I-BMIPP) as transport markers of glucose and fatty acids, respectively. Results: After cardiac differentiation of hiPSC, in vitro tracer uptake assays confirmed metabolic substrate shift from glucose to fatty acids that was comparable to those observed in native isolated human cardiomyocytes. Immunostaining further confirmed expression of fatty acid transport and binding proteins on hiPSC-CM. Conclusions: During in vitro cardiac maturation, we observed a metabolic shift to fatty acids, which are known as a main energy source of mammalian hearts, suggesting hi-PSC-CM as a potential functional phenotype to investigate alteration of cardiac metabolism in cardiac diseases. Results also highlight the use of available clinical nuclear medicine tracers as functional assays in stem cell research for improved generation of autologous differentiated cells for numerous biomedical applications. 2018 International Journal of Cardiology urn:nbn:de:bvb:20-opus-163320 10.1016/j.ijcard.2018.06.089 Klinik und Poliklinik für Nuklearmedizin OPUS4-17069 Wissenschaftlicher Artikel Nose, Naoko; Werner, Rudolf A.; Ueda, Yuichiro; Günther, Katharina; Lapa, Constantin; Javadi, Mehrbod S.; Fukushima, Kazuhito; Edenhofer, Frank; Higuchi, Takahiro Metabolic substrate shift in human induced pluripotent stem cells during cardiac differentiation: Functional assessment using in vitro radionuclide uptake assay BACKGROUND: Recent developments in cellular reprogramming technology enable the production of virtually unlimited numbers of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Although hiPSC-CM share various characteristic hallmarks with endogenous cardiomyocytes, it remains a question as to what extent metabolic characteristics are equivalent to mature mammalian cardiomyocytes. Here we set out to functionally characterize the metabolic status of hiPSC-CM in vitro by employing a radionuclide tracer uptake assay. MATERIAL AND METHODS: Cardiac differentiation of hiPSC was induced using a combination of well-orchestrated extrinsic stimuli such as WNT activation (by CHIR99021) and BMP signalling followed by WNT inhibition and lactate based cardiomyocyte enrichment. For characterization of metabolic substrates, dual tracer uptake studies were performed with \(^{18}\)F‑2‑fluoro‑2‑deoxy‑d‑glucose (\(^{18}\)F-FDG) and \(^{125}\)I‑β‑methyl‑iodophenyl‑pentadecanoic acid (\(^{125}\)I-BMIPP) as transport markers of glucose and fatty acids, respectively. RESULTS: After cardiac differentiation of hiPSCs, in vitro tracer uptake assays confirmed metabolic substrate shift from glucose to fatty acids that was comparable to those observed in native isolated human cardiomyocytes. Immunostaining further confirmed expression of fatty acid transport and binding proteins on hiPSC-CM. CONCLUSIONS: During in vitro cardiac maturation, we observed a metabolic shift to fatty acids, which are known as a main energy source of mammalian hearts, suggesting hi-PSC-CM as a potential functional phenotype to investigate alteration of cardiac metabolism in cardiac diseases. Results also highlight the use of available clinical nuclear medicine tracers as functional assays in stem cell research for improved generation of autologous differentiated cells for numerous biomedical applications. 2018 229-234 International Journal of Cardiology 269 urn:nbn:de:bvb:20-opus-170699 Klinik und Poliklinik für Nuklearmedizin OPUS4-16110 unpublished Werner, Rudolf A.; Andree, Christian; Javadi, Mehrbod S.; Lapa, Constantin; Buck, Andreas K.; Higuchi, Takahiro; Pomper, Martin G.; Gorin, Michael A.; Rowe, Steven P.; Pienta, Kenneth J. A Voice From the Past: Re-Discovering the Virchow Node with PSMA-targeted \(^{18}\)F-DCFPyL PET Imaging No abstract available. 2018 Urology - The Gold Journal urn:nbn:de:bvb:20-opus-161103 10.1016/j.urology.2018.03.030 Klinik und Poliklinik für Nuklearmedizin OPUS4-16463 Wissenschaftlicher Artikel Werner, Rudolf A.; Andree, Christian; Javadi, Mehrbod S.; Lapa, Constantin; Buck, Andreas K.; Higuchi, Takahiro; Pomper, Martin G.; Gorin, Michael A.; Rowe, Steven P.; Pienta, Kenneth J. A Voice From the Past: Re-Discovering the Virchow Node with PSMA-targeted \(^{18}\)F-DCFPyL PET Imaging No abstract available. 2018 18-21 Urology - The Gold Journal 117 urn:nbn:de:bvb:20-opus-164632 10.1016/j.urology.2018.03.030 Klinik und Poliklinik für Nuklearmedizin OPUS4-17462 unpublished Werner, Rudolf A.; Bundschuh, Ralph A.; Bundschuh, Lena; Fanti, Stefano; Javadi, Mehrbod S.; Higuchi, Takahiro; Weich, A.; Pienta, Kenneth J.; Buck, Andreas K.; Pomper, Martin G.; Gorin, Michael A.; Herrmann, Ken; Lapa, Constantin; Rowe, Steven P. Novel Structured Reporting Systems for Theranostic Radiotracers Standardized reporting is more and more routinely implemented in clinical practice and such structured reports have a major impact on a large variety of medical fields, e.g. laboratory medicine, pathology, and, recently, radiology. Notably, the field of nuclear medicine is constantly evolving, as novel radiotracers for numerous clinical applications are developed. Thus, framework systems for standardized reporting in this field may a) increase clinical acceptance of new radiotracers, b) allow for inter- and intra-center comparisons for quality assurance, and c) may be used in (global) multi-center studies to ensure comparable results and enable efficient data abstraction. In the last two years, several standardized framework systems for positron emission tomography (PET) radiotracers with potential theranostic applications have been proposed. These include systems for prostate-specific membrane antigen (PSMA)-targeted PET agents for the diagnosis and treatment of prostate cancer (PCa) and somatostatin receptor (SSTR)-targeted PET agents for the diagnosis and treatment of neuroendocrine neoplasias. In the present review, those standardized framework systems for PSMA- and SSTR-targeted PET will be briefly introduced followed by an overview of their advantages and limitations. In addition, potential applications will be defined, approaches to validate such concepts will be proposed, and future perspectives will be discussed. 2019 Journal of Nuclear Medicine urn:nbn:de:bvb:20-opus-174629 10.2967/jnumed.118.223537 Klinik und Poliklinik für Nuklearmedizin OPUS4-16699 Wissenschaftlicher Artikel Werner, Rudolf A.; Bundschuh, Ralph A.; Bundschuh, Lena; Javadi, Mehrbod S.; Higuchi, Takahiro; Weich, Alexander; Sheikhbahaei, Sara; Pienta, Kenneth J.; Buck, Andreas K.; Pomper, Martin G.; Gorin, Michael A.; Lapa, Constantin; Rowe, Steven P. MI-RADS: Molecular Imaging Reporting and Data Systems - A Generalizable Framework for Targeted Radiotracers with Theranostic Implications Both prostate-specific membrane antigen (PSMA)- and somatostatin receptor (SSTR)-targeted positron emission tomography (PET) imaging agents for staging and restaging of prostate carcinoma or neuroendocrine tumors, respectively, are seeing rapidly expanding use. In addition to diagnostic applications, both classes of radiotracers can be used to triage patients for theranostic endoradiotherapy. While interpreting PSMA- or SSTR-targeted PET/computed tomography (CT) scans, the reader has to be aware of certain pitfalls. Adding to the complexity of the interpretation of those imaging agents, both normal biodistribution, and also false-positive and -negative findings differ between PSMA- and SSTR-targeted PET radiotracers. Herein summarized under the umbrella term molecular imaging reporting and data systems (MI-RADS), two novel RADS classifications for PSMA- and SSTR-targeted PET imaging are described (PSMA- and SSTR-RADS). Both framework systems may contribute to increase the level of a reader's confidence and to navigate the imaging interpreter through indeterminate lesions, so that appropriate workup for equivocal findings can be pursued. Notably, PSMA- and SSTR-RADS are structured in a reciprocal fashion, i.e. if the reader is familiar with one system, the other system can readily be applied as well. In the present review we will discuss the most common pitfalls on PSMA- and SSTR-targeted PET/CT, briefly introduce PSMA- and SSTR-RADS, and define a future role of the umbrella framework MI-RADS compared to other harmonization systems. 2018 Annals of Nuclear Medicine urn:nbn:de:bvb:20-opus-166995 10.1007/s12149-018-1291-7 Klinik und Poliklinik für Nuklearmedizin OPUS4-16778 unpublished Werner, Rudolf A.; Bundschuh, Ralph A.; Bundschuh, Lena; Javadi, Mehrbod S.; Leal, Jeffrey P.; Higuchi, Takahiro; Pienta, Kenneth J.; Buck, Andreas K.; Pomper, Martin G.; Gorin, Michael A.; Lapa, Constantin; Rowe, Steven P. Interobserver Agreement for the Standardized Reporting System PSMA-RADS 1.0 on \(^{18}\)F-DCFPyL PET/CT Imaging Objectives: Recently, the standardized reporting and data system for prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) imaging studies, termed PSMA-RADS version 1.0, was introduced. We aimed to determine the interobserver agreement for applying PSMA-RADS to imaging interpretation of 18F-DCFPyL PET examinations in a prospective setting mimicking the typical clinical work-flow at a prostate cancer referral center. Methods: Four readers (two experienced readers (ER, > 3 years of PSMA-targeted PET interpretation experience) and two inexperienced readers (IR, < 1 year of experience)), who had all read the initial publication on PSMA-RADS 1.0, assessed 50 18F-DCFPyL PET/computed tomography (CT) studies independently. Per scan, a maximum of 5 target lesions were selected by the observers and a PSMA-RADS score for every target lesion was recorded. No specific pre-existing conditions were placed on the selection of the target lesions, although PSMA-RADS 1.0 suggests that readers focus on the most highly avid or largest lesions. An overall scan impression based on PSMA-RADS was indicated and interobserver agreement rates on a target lesion-based, on an organ-based, and on an overall PSMA-RADS score-based level were computed. Results: The number of target lesions identified by each observer were as follows: ER 1, 123; ER 2, 134; IR 1, 123; and IR 2, 120. Among those selected target lesions, 125 were chosen by at least two individual observers (all four readers selected the same target lesion in 58/125 (46.4%) instances, three readers in 40/125 (32%) and two observers in 27/125 (21.6%) instances). The interobserver agreement for PSMA-RADS scoring among identical target lesions was good (intraclass correlation coefficient (ICC) for four, three and two identical target lesions, ≥0.60, respectively). For lymph nodes, an excellent interobserver agreement was derived (ICC=0.79). The interobserver agreement for an overall scan impression based on PSMA-RADS was also excellent (ICC=0.84), with a significant difference for ER (ICC=0.97) vs. IR (ICC=0.74, P=0.005). Conclusions: PSMA-RADS demonstrates a high concordance rate in this study, even among readers with different levels of experience. This suggests that PSMA-RADS can be effectively used for communication with clinicians and can be implemented in the collection of data for large prospective trials. 2018 Journal of Nuclear Medicine urn:nbn:de:bvb:20-opus-167788 10.2967/jnumed.118.217588 Klinik und Poliklinik für Nuklearmedizin