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Detection of atherosclerotic inflammation by 68 Ga-DOTATATE PET compared to [18 F]FDG PET imaging. See related article, https://doi.org/10.1007/s12350-022-03084-4 Since SP 18 sp F-FDG vascular uptake has been demonstrated to reflect macrophages infiltration within atherosclerotic plaques,[1] and because vulnerable plaques are rich in macrophages, a huge effort has been made to assess non-invasive monitoring of vascular inflammation using SP 18 sp F-FDG PET imaging. As activated macrophages also express SSTR2, PET with SP 64 sp Cu- or SP 68 sp Ga-DOTATATE showed specific targeting of somatostatin-2 receptor that colocalized with CD68 SP + sp macrophages. [Extracted from the article]

Background: The aim of this study was to investigate the feasibility of assessing absolute myocardial 99mTc-HMDP uptake in patients with suspected cardiac ATTR using SUV with a whole-body CZT SPECT-CT camera (DNM670CZT). Methods: Fifteen patients with suspected cardiac ATTR (Perugini ≥ 2) underwent a conventional 99mTc-HMDP planar imaging and a thoracic SPECT/CT using a DNM 670CZT. A control group consisted of 15 patients with negative scintigraphy (Perugini < 2). SUVmax (mg·L−1) and percentage of injected dose (%ID) were calculated in a cardiac volume of interest (VOI) encompassing the left ventricle. VOIs were also placed in the lung, the right pectoris major, and the sternum. A heart-to-lung SUVmax ratio (HLR) was calculated. Results: All ATTR patients demonstrated an increased cardiac HMDP SUVmax (12.2 ± 3.7 mg·L−1) vs controls (3.5 ± 1.2, P <.0001). Percentage of ID, pectoral uptake and HLR were significantly higher in the ATTR group (1.1 ± 0.3 vs 0.15 ± 0.8, P <.0001; 1.5 ± 0.3 vs 0.9 ± 0.3, P <.0001; 9.7 ± 3 vs 4.3 ± 2.2, P <.0001). Bone uptake was not statistically different between the two groups. Conclusion: This study demonstrated the feasibility of quantitative 99mTc-HMDP SUVmax measurement using a whole-body SPECT/CT CZT camera in patients with suspected cardiac ATTR. [ABSTRACT FROM AUTHOR]

Background: We compared quantification of MBF and myocardial flow reserve (MFR) with a 99mTc-sestamibi CZT-SPECT to 15O-water PET.Methods: SPECT MBF for thirty patients in the WATERDAY study was re-analyzed by QPET software with motion correction and optimal placement of the arterial input function. 15O-water PET MBF was re-quantified using dedicated software. Inter-operator variability was assessed using repeatability coefficients (RPC).Results: Significant correlations were observed between global (r = 0.91, P < 0.001) and regional MBF (r = 0.86, P < 0.001) with SPECT compared to PET. Global MBF (rest 0.95 vs 1.05 ml/min/g, P = 0.07; stress 2.62 vs 2.68 mL/min/g, P = 0.17) and MFR (2.65 vs 2.75, P = 0.86) were similar between SPECT and PET. Rest (0.81 vs 0.98 mL/min/g, P = 0.03) and stress MBF (1.98 vs 2.61 mL/min/g, P = 0.01) in right coronary artery (RCA) were lower with SPECT compared to PET. However, MFR in the RCA territory was similar (2.54 vs 2.77, P = 0.21). The SPECT-PET RPC for global MBFs and MFR were 0.95 mL/min/g and 0.94, with inter-observer RPC of 0.59 mL/min/g and 0.74, respectively.Conclusions: MBF and MFR derived from CZT-SPECT with motion correction and optimal placement of the arterial input function showed good agreement with 15O-water PET, as well as low inter-operator variability. [ABSTRACT FROM AUTHOR]

Background: We studied the impact of simultaneous dual-isotope acquisition on 123I/99mTc mismatch assessment using two CZT cameras (DNM 530c, GE Healthcare and DSPECT, Biosensors International).Methods: We used an anthropomorphic torso phantom (respectively filled with a solution of 123I alone, 99mTc alone, and a mixture of 123I and 99mTc) and its cardiac insert with two defects mimicking two matched and mismatched defects. Mismatch extent and reconstructed image contrast were evaluated.Results: The acquisition mode (single vs dual) significantly impacted (i) 99mTc (but not 123I) reconstructed segmental activities using both camera (P < .001), and (ii) image contrast (using 123I and DNM 530c, P < .0001; and using both 123I and 99mTc with DSPECT, P < .0001). However, the defect and mismatch size were not impacted by the type of acquisition. With both DNM 530c and DSPECT, Lin's concordance correlation coefficient and Bland-Altman analysis demonstrated an almost perfect concordance and agreement between single- and simultaneous dual-isotope segmental activity (123I and 99mTc).Conclusions: This study found no impact of the acquisition mode (single vs dual) or the type of camera (DSPECT vs DNM 530c) on 123I and 99mTc defect size and mismatch, providing a new step toward simultaneous dual-isotope acquisition for combined innervation and perfusion assessment. [ABSTRACT FROM AUTHOR]