Differences in the performance of cadmium-zinc-telluride (CZT) cameras or collimation systems that have recently been commercialized for myocardial SPECT remain unclear. In the present study, the performance of 3 of these systems was compared by a comprehensive analysis of phantom and human SPECT images. Methods: We evaluated the Discovery NM 530c and DSPECT CZT cameras, as well as the Symbia Anger camera equipped with an astigmatic (IQÁSPECT) or parallel-hole (conventional SPECT) collimator. Physical performance was compared on reconstructed SPECT images from a phantom and from comparable groups of healthy subjects. Results: Classifications were as follows, in order of performance. For count sensitivity on cardiac phantom images (countsÁs 21 ÁMBq 21 ), DSPECT had a sensitivity of 850; Discovery NM 530c, 460; IQÁSPECT, 390; and conventional SPECT, 130. This classification was similar to that of myocardial counts normalized to injected activities from human images (respective mean values, in countsÁs 21 ÁMBq 21 : 11.4 6 2.6, 5.6 6 1.4, 2.7 6 0.7, and 0.6 6 0.1). For central spatial resolution: Discovery NM 530c was 6.7 mm; DSPECT, 8.6 mm; IQÁSPECT, 15.0 mm; and conventional SPECT, 15.3 mm, also in accordance with the analysis of the sharpness of myocardial contours on human images (in cm 21 : 1.02 6 0.17, 0.92 6 0.11, 0.64 6 0.12, and 0.65 6 0.06, respectively). For contrast-to-noise ratio on the phantom: Discovery NM 530c had a ratio of 4.6; DSPECT, 4.1; IQÁSPECT, 3.9; and conventional SPECT, 3.5, similar to ratios documented on human images (5.2 6 1.0, 4.5 6 0.5, 3.9 6 0.6, and 3.4 6 0.3, respectively). Conclusion: The performance of CZT cameras is dramatically higher than that of Anger cameras, even for human SPECT images. However, CZT cameras differ in that spatial resolution and contrast-to-noise ratio are better with the Discovery NM 530c, whereas count sensitivity is markedly higher with the DSPECT.Key Words: CZT-cameras; high-speed SPECT; myocardial perfusion imaging; count sensitivity St ress myocardial SPECT has been markedly enhanced by the recent commercialization of cameras with semiconductor (cadmium-zinc-telluride [CZT]) detectors or new collimation systems. These improved systems enhance the sensitivity of count detection and thereby enable recording times or tracer doses to be reduced, a property that has highly favorable consequences on patient comfort and radiation exposure (1-4). This enhancement is based mainly on acquisitions that are heart-centric but obtained with very different technologies: first, for the IQÁSPECT system (Siemens Medical Solutions (5-8)), an Anger camera equipped with collimators convergent on the image center (astigmatic collimators); second, for the DSPECT system (Spectrum Dynamics (9-13)), mobile columns of CZT detectors with wide parallel-hole collimators; and third, for the Discovery NM 530c system (GE Healthcare (14-21)), fixed CZT detectors with multipinhole collimators.The respective performance of these new cameras and collimation systems has been analyzed, but ...

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High-level improvement of diagnostic certainty and management is provided by selective and hierarchical implementation of florbetaben PET into current standard practices for the most complex dementia cases.

Objective: To consolidate current understanding of detection sensitivity of brain 18 F-FDG PET scans in the diagnosis of autoimmune encephalitis and to de ne speci c metabolic imaging patterns for the most frequently occurring autoantibodies. Methods: A systematic and exhaustive search of data available in the literature was performed by querying the PubMed/MEDLINE and Cochrane databases for the search terms: "FDG PET" and ""encephalitis" or "brain in ammation"". Studies had to satisfy the following criteria: i. include at least one patient suspected or diagnosed with autoimmune encephalitis according to the current recommendations, ii. be an original case-report iii. speci cally present 18 F-FDG PET and/or morphologic imaging ndings. The diagnostic 18 F-FDG PET detection sensitivity in autoimmune encephalitis was determined for all cases reported in the literature and a meta-analysis, according to the PRISMA method, was performed on a subset of these, which included PET scans for at least 10 patients, and whose quality was assessed with the QUADAS-2 tool. Results: The search strategy identi ed 1113 articles. The detection sensitivity of 18 F-FDG PET was 90%, based on 176 publications and 720 patients and 80% [75%-84%] by meta-analysis based on 21 publications and 444 patients. We also report speci c brain 18 F-FDG PET imaging patterns for the main encephalitis autoantibody subtypes. Conclusion and Relevance: Brain 18 F-FDG PET has a high detection sensitivity and should be included in future diagnostic autoimmune encephalitis recommendations. Speci c metabolic 18 F-FDG PET patterns corresponding to the main autoimmune encephalitis autoantibody subtypes further enhance the value of this diagnostic.

Data suggest that static and dynamic F-FET PET parameters may allow determining non-invasively the IDH mutation status. However, IDH mutated and 1p/19q co-deleted oligodendrogliomas cannot be differentiated from glioblastomas and astrocytomas byF-FET PET.

Both F-FET PET and PWI discriminate LGG from HGG with similar diagnostic performance. Regional abnormalities in the tumor area are usually not congruent indicating that tumor grading byF-FET PET and PWI is based on different pathophysiological phenomena.

This study showed paradoxically higher F-FDOPA uptake in diffuse grade II and III gliomas with IDH mutation. Despite evident interest in the management of gliomas, and especially in relation to posttherapy evaluation, our findings raise the question of the prognostic value ofF-FDOPA uptake on PET uptake in this group of patients. This may be related to differences in amino acid integration, metabolism, or cell differentiation.

F-FDOPA PET SUV-derived indices are routinely available information that enables accurate discrimination of low-grade and high-grade gliomas. The best-correlated indices were SUVmean T/N and SUVmean T/S with thresholds of 1.33 and 1.