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 OPUS4-16818 Wissenschaftlicher Artikel Werner, Rudolf A.; Marcus, Charles; Sheikhbahaei, Sara; Solnes, Lilja B.; Leal, Jeffrey P.; Du, Yong; Rowe, Steven P.; Higuchi, Takahiro; Buck, Andreas K.; Lapa, Constantin; Javadi, Mehrbod S. Visual and Semiquantitative Accuracy in Clinical Baseline 123I-Ioflupane SPECT/CT Imaging PURPOSE: We aimed to (a) elucidate the concordance of visual assessment of an initial I-ioflupane scan by a human interpreter with comparison to results using a fully automatic semiquantitative method and (b) to assess the accuracy compared to follow-up (f/u) diagnosis established by movement disorder specialists. METHODS: An initial I-ioflupane scan was performed in 382 patients with clinically uncertain Parkinsonian syndrome. An experienced reader performed a visual evaluation of all scans independently. The findings of the visual read were compared with semiquantitative evaluation. In addition, available f/u clinical diagnosis (serving as a reference standard) was compared with results of the human read and the software. RESULTS: When comparing the semiquantitative method with the visual assessment, discordance could be found in 25 (6.5%) of 382 of the cases for the experienced reader (ĸ = 0.868). The human observer indicated region of interest misalignment as the main reason for discordance. With neurology f/u serving as reference, the results of the reader revealed a slightly higher accuracy rate (87.7%, ĸ = 0.75) compared to semiquantification (86.2%, ĸ = 0.719, P < 0.001, respectively). No significant difference in the diagnostic performance of the visual read versus software-based assessment was found. CONCLUSIONS: In comparison with a fully automatic semiquantitative method in I-ioflupane interpretation, human assessment obtained an almost perfect agreement rate. However, compared to clinical established diagnosis serving as a reference, visual read seemed to be slightly more accurate as a solely software-based quantitative assessment. 2018 Clinical Nuclear Medicine 44 1 urn:nbn:de:bvb:20-opus-168181 Klinik und Poliklinik für Nuklearmedizin OPUS4-16221 Konferenzveröffentlichung Werner, Rudolf A.; Marcus, Charles; Sheikhbahaei, Sara; Higuchi, Takahiro; Solnes, Lilja B.; Rowe, Steven P.; Buck, Andreas K.; Lapa, Constantin; Javadi, Mehrbod S. The Impact of Ageing on Dopamine Transporter Imaging No abstract available. 2018 Journal of Nuclear Medicine 59 Supplement No 1 1646 urn:nbn:de:bvb:20-opus-162213 Klinik und Poliklinik für Nuklearmedizin 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 OPUS4-23036 Wissenschaftlicher Artikel Hoffmann, Jan V.; Janssen, Jan P.; Kanno, Takayuki; Shibutani, Takayuki; Onoguchi, Masahisa; Lapa, Constantin; Grunz, Jan-Peter; Buck, Andreas K.; Higuchi, Takahiro Performance evaluation of fifth-generation ultra-high-resolution SPECT system with two stationary detectors and multi-pinhole imaging Background Small-animal single-photon emission computed tomography (SPECT) systems with multi-pinhole collimation and large stationary detectors have advantages compared to systems with moving small detectors. These systems benefit from less labour-intensive maintenance and quality control as fewer prone parts are moving, higher accuracy for focused scans and maintaining high resolution with increased sensitivity due to focused pinholes on the field of view. This study aims to investigate the performance of a novel ultra-high-resolution scanner with two-detector configuration (U-SPECT5-E) and to compare its image quality to a conventional micro-SPECT system with three stationary detectors (U-SPECT\(^+\)). Methods The new U-SPECT5-E with two stationary detectors was used for acquiring data with \(^{99m}\)Tc-filled point source, hot-rod and uniformity phantoms to analyse sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR). Three dedicated multi-pinhole mouse collimators with 75 pinholes each and 0.25-, 0.60- and 1.00-mm pinholes for extra ultra-high resolution (XUHR-M), general-purpose (GP-M) and ultra-high sensitivity (UHS-M) imaging were examined. For CNR analysis, four different activity ranges representing low- and high-count settings were investigated for all three collimators. The experiments for the performance assessment were repeated with the same GP-M collimator in the three-detector U-SPECT\(^+\) for comparison. Results Peak sensitivity was 237 cps/MBq (XUHR-M), 847 cps/MBq (GP-M), 2054 cps/MBq (UHS-M) for U-SPECT5-E and 1710 cps/MBq (GP-M) for U-SPECT\(^+\). In the visually analysed sections of the reconstructed mini Derenzo phantoms, rods as small as 0.35 mm (XUHR-M), 0.50 mm (GP-M) for the two-detector as well as the three-detector SPECT and 0.75 mm (UHS-M) were resolved. Uniformity for maximum resolution recorded 40.7% (XUHR-M), 29.1% (GP-M, U-SPECT5-E), 16.3% (GP-M, U-SPECT\(^+\)) and 23.0% (UHS-M), respectively. UHS-M reached highest CNR values for low-count images; for rods smaller than 0.45 mm, acceptable CNR was only achieved by XUHR-M. GP-M was superior for imaging rods sized from 0.60 to 1.50 mm for intermediate activity concentrations. U-SPECT5-E and U-SPECT+ both provided comparable CNR. Conclusions While uniformity and sensitivity are negatively affected by the absence of a third detector, the investigated U-SPECT5-E system with two stationary detectors delivers excellent spatial resolution and CNR comparable to the performance of an established three-detector-setup. 2020 EJNMMI Physics 7 urn:nbn:de:bvb:20-opus-230361 10.1186/s40658-020-00335-6 Klinik und Poliklinik für Nuklearmedizin OPUS4-16913 Wissenschaftlicher Artikel Werner, Rudolf A.; Chen, Xinyu; Rowe, Steven P.; Lapa, Constantin; Javadi, Mehrbod S.; Higuchi, Takahiro Moving into the Next Era of PET Myocardial Perfusion Imaging - Introduction of Novel \(^{18}\)F-labeled Tracers The heart failure (HF) epidemic continues to rise with coronary artery disease (CAD) as one of its main causes. Novel concepts for risk stratification to guide the referring cardiologist towards revascularization procedures are of significant value. Myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) agents has demonstrated high accuracy for the detection of clinically relevant stenoses. With positron emission tomography (PET) becoming more widely available, mainly due to its diagnostic performance in oncology, perfusion imaging with that modality is more practical than in the past and overcomes existing limitations of SPECT MPI. Advantages of PET include more reliable quantification of absolute myocardial blood flow, the routine use of computed tomography for attenuation correction, a higher spatiotemporal resolution and a higher count sensitivity. Current PET radiotracers such as rubidium-82 (half-life, 76 sec), oxygen-15 water (2 min) or nitrogen-13 ammonia (10 min) are labeled with radionuclides with very short half-lives, necessitating that stress imaging is performed under pharmacological vasodilator stress instead of exercise testing. However, with the introduction of novel 18F-labeled MPI PET radiotracers (half-life, 110 min), the intrinsic advantages of PET can be combined with exercise testing. Additional advantages of those radiotracers include, but are not limited to: potentially improved cost-effectiveness due to the use of pre-existing delivery systems and superior imaging qualities, mainly due to the shortest positron range among available PET MPI probes. In the present review, widely used PET MPI radiotracers will be reviewed and potential novel 18F-labeled perfusion radiotracers will be discussed. 2018 The International Journal of Cardiovascular Imaging urn:nbn:de:bvb:20-opus-169134 10.1007/s10554-018-1469-z Klinik und Poliklinik für Nuklearmedizin OPUS4-16220 Konferenzveröffentlichung Werner, Rudolf A.; Marcus, Charles; Sheikhbahaei, Sara; Higuchi, Takahiro; Solnes, Lilja B.; Rowe, Steven P.; Buck, Andreas K.; Lapa, Constantin; Javadi, Mehrbod S. Diagnostic Accuracy of Visual Assessment of an Initial DaT-Scan in Comparison to a Fully Automatic Semiquantitative Method No abstract available. 2018 Journal of Nuclear Medicine 59 Supplement No. 1 626 urn:nbn:de:bvb:20-opus-162208 Klinik und Poliklinik für Nuklearmedizin