AimsTo examine the utility of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the early diagnosis of cardiac implantable electronic device (CIED) generator pocket infection.Methods and resultsA total of 86 patients with CIEDs were evaluated with 18F-FDG PET/CT imaging: 46 with suspected generator pocket infection and 40 without any history of infection. 18F-FDG activity in the region of the generator pocket was expressed as a semi-quantitative ratio (SQR)—defined as the maximum count rate around the CIED divided by the mean count rate between normal right and left lung parenchyma. All patients underwent standard clinical management, independent of the PET/CT result. Patients with suspected generator pocket infection that required CIED extraction (n = 32) had significantly higher 18F-FDG activity compared with those that did not (n = 14), and compared with controls (n = 40) [SQR: 4.80 (3.18–7.05) vs. 1.40 (0.88–1.73) vs. 1.10 (0.98–1.40), respectively; P < 0.001]. On receiver operator characteristic analysis, SQR had a high diagnostic accuracy (area under curve = 0.98) for the early identification of patients with confirmed infection (i.e. those ultimately needing extraction)—with an optimal SQR cut-off value of >2.0 (sensitivity = 97%; specificity = 98%).ConclusionThis study highlights the potential benefits of evaluating patients with suspected CIED generator pocket infection using 18F-FDG PET/CT. In this study, 18F-FDG PET/CT had a high diagnostic accuracy in the early diagnosis of CIED generator pocket infection, even where initial clinical signs were underwhelming.

This survey paper examines selected issues related to the intersection of three broad scholarly areas: numeracy, adult education, and vulnerability. Numeracy encompasses the ways in which people cope with the mathematical, quantitative, and statistical demands of adult life, and is viewed as an important outcome of schooling and as a foundational skill for all adults. The focus on vulnerability stems from the realization that concerns of policy makers and educators alike often center on populations seen as vulnerable. The paper is organized in five sections. After a brief introduction, Section 2 examines adult numeracy, focusing on five numeracy domains (health, financial, digital, civic, and workplace numeracy), literacynumeracy linkages, functional and critical aspects of numeracy, and the centrality of numeracy practices, and notes sources of vulnerability for each of these. Section 3 sketches formal, non-formal and informal contexts in which adults learn or develop their numeracy, and examines factors that may be potential sources of vulnerability, including systemic factors and dispositional and affect factors. Section 4 reflects more broadly on the concept of vulnerability, introduces selected aspects of the papers published in this issue of ZDM Mathematics Education, and points to findings regarding adult learners who may be deemed vulnerable. The closing section summarizes conclusions and research directions regarding the intersection of the three core domains. Overall, the paper points to emerging research needs and educational challenges that are relevant to scholars, practitioners, and policy makers interested in developing the numeracy of adults as well as in the mathematics education of younger learners.

BackgroundQuantitative assessment of myocardial blood flow (MBF) from cardiovascular magnetic resonance (CMR) perfusion images appears to offer advantages over qualitative assessment. Currently however, clinical translation is lacking, at least in part due to considerable disparity in quantification methodology. The aim of this study was to evaluate the effect of common methodological differences in CMR voxel-wise measurement of MBF, using position emission tomography (PET) as external validation.MethodsEighteen subjects, including 9 with significant coronary artery disease (CAD) and 9 healthy volunteers prospectively underwent perfusion CMR. Comparison was made between MBF quantified using: 1. Calculated contrast agent concentration curves (to correct for signal saturation) versus raw signal intensity curves; 2. Mid-ventricular versus basal-ventricular short-axis arterial input function (AIF) extraction; 3. Three different deconvolution approaches; Fermi function parameterization, truncated singular value decomposition (TSVD) and first-order Tikhonov regularization with b-splines. CAD patients also prospectively underwent rubidium-82 PET (median interval 7 days).ResultsMBF was significantly higher when calculated using signal intensity compared to contrast agent concentration curves, and when the AIF was extracted from mid- compared to basal-ventricular images. MBF did not differ significantly between Fermi and Tikhonov, or between Fermi and TVSD deconvolution methods although there was a small difference between TSVD and Tikhonov (0.06 mL/min/g). Agreement between all deconvolution methods was high. MBF derived using each CMR deconvolution method showed a significant linear relationship (p < 0.001) with PET-derived MBF however each method underestimated MBF compared to PET (by 0.19 to 0.35 mL/min/g).ConclusionsVariations in more complex methodological factors such as deconvolution method have no greater effect on estimated MBF than simple factors such as AIF location and observer variability. Standardization of the quantification process will aid comparison between studies and may help CMR MBF quantification enter clinical use.

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