The prognostic value of visual and automatic coronary calcium -scoring from low dose CT-[15O]-water PET.

PURPOSE: Firstly, to validate automatically and visually scored coronary artery calcium (CAC) on low dose CT (LDCT) scans with a dedicated calcium scoring CT (CSCT) scan. Secondly, to assess the added value of CAC scored from LDCT scans acquired during [15O]-water-PET myocardial perfusion imaging (MPI) on prediction of major adverse cardiac events (MACE). METHODS: 572 consecutive patients with suspected coronary artery disease, who underwent [15O]-water-PET MPI with LDCT and a dedicated CSCT scan were included. In the reference CSCT scans, manual CAC scoring was performed, while LDCT scans were scored visually and automatically using deep learning approach. Subsequently, based on CAC score results from CSCT and LDCT scans, each patient's scan was assigned to one out of five cardiovascular risk groups (0; 1-100; 101-400; 401-1000; >1000) and the agreement in risk group classification between CSCT and LDCT scans was investigated. MACE was defined as a composite of all-cause death, nonfatal myocardial infarction, coronary revascularization, and unstable angina. RESULTS: The agreement in risk group classification between reference CSCT manual scoring and visual/automatic LDCT scoring from LDCT was 0.66 (95% CI: 0.62-0.70) and 0.58 (95% CI: 0.53-0.62), respectively. Based on visual and automatic CAC scoring from LDCT scans, patients with CAC>100 and CAC>400, respectively, were at increased risk of MACE, independently of ischemic information from the [15O]-water-PET scan. CONCLUSIONS: There is a moderate agreement in risk classification between visual and automatic CAC scoring from LDCT and reference CSCT scans. Visual and automatic CAC scoring from LDCT scans improve identification of patients at higher risk of MACE.

Caloric restriction reduces proteinuria in male rats with established nephropathy.

Reducing proteinuria is a crucial approach in preventing kidney function loss. Previous preclinical studies indicated that caloric restriction (CR) imposed at a young age protects against age-related proteinuria. However, these studies have not explored CR in established renal disease. Therefore, this study aimed to investigate the impact of CR on established proteinuria. Rats, aged 12 ± 2 weeks, were administered 2.1 mg/kg of Adriamycin. Six weeks after injection, protein excretion was measured, and a [13 N]ammonia positron emission tomography (PET) scan was conducted to assess kidney perfusion. After 7 weeks rats were divided into four groups: ad libitum (AL) and CR groups fed either a 12% or a 20% protein diet. All groups were treated for 12 weeks. Blood pressure was measured and a second PET scan was acquired at the end of the study. The animals subjected to CR exhibited a 20.3% decrease in protein excretion (p = 0.003) compared to those in the AL groups. Additionally, blood pressure in the CR group was 21.2% lower (p < 0.001) than in the AL groups. While kidney function declined over time in all groups, the 20% CR group demonstrated the smallest decline. Thus CR effectively reduces urinary protein excretion and lowers blood pressure in rats with established proteinuria.

Cardiac [99mTc]Tc-hydroxydiphosphonate uptake on bone scintigraphy in patients with hereditary transthyretin amyloidosis: an early follow-up marker?

PURPOSE: There is a need for early quantitative markers of potential treatment response in patients with hereditary transthyretin (ATTRv) amyloidosis to guide therapy. This study aims to evaluate changes in cardiac tracer uptake on bone scintigraphy in ATTRv amyloidosis patients on different treatments. METHODS: In this retrospective cohort study, outcomes of 20 patients treated with the transthyretin (TTR) gene silencer patisiran were compared to 12 patients treated with a TTR-stabilizer. Changes in NYHA class, cardiac biomarkers in serum, wall thickness, and diastolic parameters on echocardiography and NYHA class during treatment were evaluated. RESULTS: Median heart/whole-body (H/WB) ratio on bone scintigraphy decreased from 4.84 [4.00 to 5.31] to 4.16 [3.66 to 4.81] (p < .001) in patients treated with patisiran for 29 [15-34] months. No changes in the other follow-up parameters were observed. In patients treated with a TTR-stabilizer for 24 [20 to 30] months, H/WB ratio increased from 4.46 [3.24 to 5.13] to 4.96 [ 3.39 to 5.80] (p = .010), and troponin T increased from 19.5 [9.3 to 34.0] ng/L to 20.0 [11.8 to 47.8] ng/L (p = .025). All other parameters did not change during treatment with a TTR-stabilizer. CONCLUSION: A change in cardiac tracer uptake on bone scintigraphy may be an early marker of treatment-specific response or disease progression in ATTRv amyloidosis patients.

Improved [18F]FDG PET/CT Diagnostic Accuracy for Infective Endocarditis Using Conventional Cardiac Gating or Combined Cardiac and Respiratory Motion Correction (CardioFreezeTM).

Infective endocarditis (IE) is a serious and diagnostically challenging condition. [18F]FDG PET/CT is valuable for evaluating suspected IE, but it is susceptible to motion-related artefacts. This study investigated the potential benefits of cardiac motion correction for [18F]FDG PET/CT. In this prospective study, patients underwent [18F]FDG PET/CT for suspected IE, combined with a conventional cardiac gating sequence, a data-driven cardiac and respiratory gating sequence (CardioFreezeTM), or both. Scans were performed in adherence to EANM guidelines and assessors were blinded to patients' clinical contexts. Final diagnosis of IE was established based on multidisciplinary consensus after a minimum of 4 months follow-up and surgical findings, whenever performed. Seven patients participated in the study, undergoing both an ungated [18F] FDG-PET/CT and a scan with either conventional cardiac gating, CardioFreezeTM, or both. Cardiac motion correction improved the interpretability of [18F]FDG PET/CT in four out of five patients with valvular IE lesions, regardless of the method of motion correction used, which was statistically significant by Wilcoxon's signed rank test: p = 0.046. In one patient the motion-corrected sequence confirmed the diagnosis of endocarditis, which had been missed on non-gated PET. The performance of the two gating sequences was comparable. In conclusion, in this exploratory study, cardiac motion correction of [18F]FDG PET/CT improved the interpretability of [18F]FDG PET/CT. This may improve the sensitivity of PET/CT for suspected IE. Further larger comparative studies are necessary to confirm the additive value of these cardiac motion correction methods.

Positron emission tomography in the diagnosis and follow-up of transthyretin amyloid cardiomyopathy patients: A systematic review.

PURPOSE: Transthyretin (ATTR) amyloidosis is a progressive protein misfolding disease with frequent cardiac involvement. This review aims to determine the value of PET in diagnosis, assessment of disease progression or treatment response and its relation to clinical outcome in follow-up of ATTR amyloid cardiomyopathy (ATTR-CM) patients. METHODS: Medline, Cochrane Library, Embase and Web of Science databases were searched, from the earliest date available until December 2022, for studies investigating the use of PET in ATTR-CM patients. Studies containing original data were included, except for case reports. Risk of bias was assessed by QUADAS-2. RESULTS: Twenty-one studies were included in this systematic review, investigating five different tracers: carbon-11 Pittsburgh compound B ([11C]PIB), fluorine-18 Florbetaben ([18F]FBB), fluorine-18 Florbetapir ([18F]FBP), fluorine-18 Flutemetamol ([18F]FMM) and fluorine-18 Sodium Fluoride (Na[18F]F). In total 211 ATTR amyloidosis patients were included. A majority of studies concluded that [11C]PIB, [18F]FBP and Na[18F]F can distinguish ATTR amyloidosis patients from controls, and that [11C]PIB and Na[18F]F, but not [18F]FBP, can distinguish ATTR-CM patients from patients with cardiac light chain amyloidosis. Evidence on the performance of [18F]FBB and [18F]FMM was contradictory. No studies on the use of PET in follow-up were found. CONCLUSION: [11C]PIB, Na[18F]F and [18F]FBP can be used to diagnose cardiac amyloidosis, although [18F]FBP may not be suitable for the distinction of different types of amyloid cardiomyopathy. No studies on PET in the follow-up of ATTR amyloidosis patients were found. Future research should focus on the use of these PET tracers in the follow-up of ATTR amyloidosis patients.

Severely increased albuminuria in patients with type 2 diabetes mellitus is associated with increased subclinical atherosclerosis in femoral arteries with Na [18F]F activity as a proxy - The DETERMINE study.

BACKGROUND AND AIMS: Sodium [18F]fluoride (Na [18F]F) positron emission tomography imaging allows detailed visualization of early arterial micro-calcifications. This study aims to investigate atherosclerosis manifested by micro-calcification, macro-calcification, and aortic stiffness in patients with type 2 diabetes mellitus (T2DM) with and without albuminuria and severely decreased kidney function. METHODS: A cohort was stratified in four groups (N = 10 per group), based on KDIGO categories (G1-5 A1-3). G1-2A1 non-diabetic controls (median [IQR] estimated glomerular filtration rate (eGFR) in mL/min/1.73 m2 91 [81-104]), G1-2A1 with T2DM (eGFR 87 [84-93], and albumin-creatinin-ratio (ACR) in mg/mmol 0.35 [0.25-0.75]), G1-2A3 with T2DM (eGFR 85 [60-103], and ACR 74 [62-122], and G4A3 with T2DM (eGFR 19 [13-27] and ACR 131 [59-304]). RESULTS: Na [18F]F femoral artery grading score differed significantly in the groups with the highest Na [18F]F activity in A3 groups with T2DM (G1-2A3 with T2DM 228 [100-446] and G4A3 with T2DM 198 [113-578]) from the lowest groups of the G1-2A1 with T2DM (33 [0-93]) and in G1-2A1 non-diabetic controls (75 [0-200], p = 0.001). Aortic Na [18F]F activity and femoral artery computed tomography (CT)-assessed macro-calcification was increased in G4A3 with T2DM compared with G1-2A1 with T2DM (47.5 [33.8-73.8] vs. 17.5 [8.8-27.5] (p = 0.006) and 291 [170-511] vs. 12.2 [1.41-44.3] mg (p = 0.032), respectively). Carotid-femoral pulse wave velocity (PWV)-assessed aortic stiffness was significantly higher in both A3 groups with T2DM compared with G1-2A1 with T2DM (11.15 and 12.35 vs. 8.86 m/s, respectively (p = 0.009)). CONCLUSIONS: This study indicates that the presence of severely increased albuminuria in patients with T2DM is cross-sectionally associated with subclinical arterial disease in terms of micro-calcification and aortic stiffness. Additional decrease in kidney function was associated with advanced macro-calcifications.

Clinical Applications of Conebeam CTP Imaging in Cerebral Disease: A Systematic Review.

BACKGROUND: Perfusion imaging with multidetector CT is integral to the evaluation of patients presenting with ischemic stroke due to large-vessel occlusion. Using conebeam CT perfusion in a direct-to-angio approach could reduce workflow times and improve functional outcome. PURPOSE: Our aim was to provide an overview of conebeam CT techniques for quantifying cerebral perfusion, their clinical applications, and validation. DATA SOURCES: A systematic search was performed for articles published between January 2000 and October 2022 in which a conebeam CT imaging technique for quantifying cerebral perfusion in human subjects was compared against a reference technique. STUDY SELECTION: Eleven articles were retrieved describing 2 techniques: dual-phase (n = 6) and multiphase (n = 5) conebeam CTP. DATA ANALYSIS: Descriptions of the conebeam CT techniques and the correlations between them and the reference techniques were retrieved. DATA SYNTHESIS: Appraisal of the quality and risk of bias of the included studies revealed little concern about bias and applicability. Good correlations were reported for dual-phase conebeam CTP; however, the comprehensiveness of its parameter is unclear. Multiphase conebeam CTP demonstrated the potential for clinical implementation due to its ability to produce conventional stroke protocols. However, it did not consistently correlate with the reference techniques. LIMITATIONS: The heterogeneity within the available literature made it impossible to apply meta-analysis to the data. CONCLUSIONS: The reviewed techniques show promise for clinical use. Beyond evaluating their diagnostic accuracy, future studies should address the practical challenges associated with implementing these techniques and the potential benefits for different ischemic diseases.

Systematic assessment of coronary calcium detectability and quantification on four generations of CT reconstruction techniques: a patient and phantom study.

In computed tomography, coronary artery calcium (CAC) scores are influenced by image reconstruction. The effect of a newly introduced deep learning-based reconstruction (DLR) on CAC scoring in relation to other algorithms is unknown. The aim of this study was to evaluate the effect of four generations of image reconstruction techniques (filtered back projection (FBP), hybrid iterative reconstruction (HIR), model-based iterative reconstruction (MBIR), and DLR) on CAC detectability, quantification, and risk classification. First, CAC detectability was assessed with a dedicated static phantom containing 100 small calcifications varying in size and density. Second, CAC quantification was assessed with a dynamic coronary phantom with velocities equivalent to heart rates of 60-75 bpm. Both phantoms were scanned and reconstructed with four techniques. Last, scans of fifty patients were included and the Agatston calcium score was calculated for all four reconstruction techniques. FBP was used as a reference. In the phantom studies, all reconstruction techniques resulted in less detected small calcifications, up to 22%. No clinically relevant quantification changes occurred with different reconstruction techniques (less than 10%). In the patient study, the cardiovascular risk classification resulted, for all reconstruction techniques, in excellent agreement with the reference (κ = 0.96-0.97). However, MBIR resulted in significantly higher Agatston scores (61 (5.5-435.0) vs. 81.5 (9.25-435.0); p < 0.001) and 6% reclassification rate. In conclusion, HIR and DLR reconstructed scans resulted in similar Agatston scores with excellent agreement and low-risk reclassification rate compared with routine reconstructed scans (FBP). However, caution should be taken with low Agatston scores, as based on phantom study, detectability of small calcifications varies with the used reconstruction algorithm, especially with MBIR and DLR.

Automated cardiovascular risk categorization through AI-driven coronary calcium quantification in cardiac PET acquired attenuation correction CT.

BACKGROUND: We present an automatic method for coronary artery calcium (CAC) quantification and cardiovascular risk categorization in CT attenuation correction (CTAC) scans acquired at rest and stress during cardiac PET/CT. The method segments CAC according to visual assessment rather than the commonly used CT-number threshold. METHODS: The method decomposes an image containing CAC into a synthetic image without CAC and an image showing only CAC. Extensive evaluation was performed in a set of 98 patients, each having rest and stress CTAC scans and a dedicated calcium scoring CT (CSCT). Standard manual calcium scoring in CSCT provided the reference standard. RESULTS: The interscan reproducibility of CAC quantification computed as average absolute relative differences between CTAC and CSCT scan pairs was 75% and 85% at rest and stress using the automatic method compared to 121% and 114% using clinical calcium scoring. Agreement between automatic risk assessment in CTAC and clinical risk categorization in CSCT resulted in linearly weighted kappa of 0.65 compared to 0.40 between CTAC and CSCT using clinically used calcium scoring. CONCLUSION: The increased interscan reproducibility achieved by our method may allow routine cardiovascular risk assessment in CTAC, potentially relieving the need for dedicated CSCT.

Long axial field of view PET/CT in critically ill patients: lessons from a case report.

The introduction of new long axial field of view (LAFOV) scanners is a major milestone in positron emission tomography/computed tomography (PET/CT) imaging. With these new systems a revolutionary reduction in scan time can be achieved, concurrently lowering tracer dose. Therefore, PET/CT has come within reach for groups of patients in whom PET/CT previously was undesirable. In this case report we discuss the procedure of a continuous bed motion (CBM) total-body [18F]FDG PET/CT scan in an intensive care patient. We emphasize the clinical and technical possibilities with this new camera system, a matched clinical protocol, and the added value of a dedicated team.

Perivascular adipose tissue-derived nitric oxide compensates endothelial dysfunction in aged pre-atherosclerotic apolipoprotein E-deficient rats.

BACKGROUND AND AIMS: Atherosclerosis is a major contributor to global mortality and is accompanied by vascular inflammation and endothelial dysfunction. Perivascular adipose tissue (PVAT) is an established regulator of vascular function with emerging implications in atherosclerosis. We investigated the modulation of aortic relaxation by PVAT in aged rats with apolipoprotein E deficiency (ApoE-/-) fed a high-fat diet as a model of early atherosclerosis. METHODS AND RESULTS: ApoE-/- rats (N = 7) and wild-type Sprague-Dawley controls (ApoE+/+, N = 8) received high-fat diet for 51 weeks. Hyperlipidemia was confirmed in ApoE-/- rats by elevated plasma cholesterol (p < 0.001) and triglyceride (p = 0.025) levels. Early atherosclerosis was supported by increased intima/media thickness ratio (p < 0.01) and ED1-positive macrophage influx in ApoE-/- aortic intima (p < 0.001). Inflammation in ApoE-/- PVAT was characteristic by an increased [18F]FDG uptake (p < 0.01), ED1-positive macrophage influx (p = 0.0003), mRNA expression levels of CD68 (p < 0.001) and IL-1ß (p < 0.01), and upregulated iNOS protein (p = 0.011). The mRNAs of MCP-1, IL-6 and adiponectin remained unchanged in PVAT. Aortic PVAT volume measured with micro-PET/CT was increased in ApoE-/- rats (p < 0.01). Maximal endothelium-dependent relaxation (EDR) to acetylcholine in ApoE-/- aortic rings without PVAT was severely impaired (p = 0.012) compared with controls, while ApoE-/- aortic rings with PVAT showed higher EDR than controls. All EDR responses were blocked by L-NMMA and the expression of eNOS mRNA was increased in ApoE-/- PVAT (p = 0.035). CONCLUSION: Using a rat ApoE-/- model of early atherosclerosis, we capture a novel mechanism by which inflammatory PVAT compensates severe endothelial dysfunction by contributing NO upon cholinergic stimulation.

[18F]FDG and [18F]NaF as PET markers of systemic atherosclerosis progression: A longitudinal descriptive imaging study in patients with type 2 diabetes mellitus.

BACKGROUND: While [18F]-fluordeoxyglucose ([18F]FDG) uptake is associated with arterial inflammation, [18F]-sodium fluoride ([18F]NaF) is a marker for arterial micro-calcification. We aimed to investigate the prospective correlation between both PET markers over time and whether they are prospectively ([18F]FDG) and retrospectively ([18F]NaF) related to progression of systemic arterial disease in a longitudinal study in patients with type 2 diabetes mellitus (T2DM). METHODS: Baseline [18F]FDG PET/Low Dose (LD) Computed Tomography (CT) scans of ten patients with early T2DM without cardiovascular history (70% men, median age 63 years) were compared with five-year follow-up [18F]NaF/LDCT scans. Systemic activity was expressed as mean target-to-background ratio (meanTBR) by dividing the maximal standardized uptake value (SUVmax) of ten arteries by SUVmean of the caval vein. CT-assessed macro-calcifications were scored visually and expressed as calcified plaque (CP) score. Arterial stiffness was assessed with carotid-femoral pulse wave velocity (PWV). Five-year changes were expressed absolutely with delta (Δ) and relatively with %change. RESULTS: Baseline meanTBR[18F]FDG was strongly correlated with five-year follow-up meanTBR[18F]NaF (r = 0.709, P = .022). meanTBR[18F]NaF correlated positively with ΔCPscore, CPscore at baseline, and follow-up (r = 0.845, P = .002 and r = 0.855, P = .002, respectively), but not with %change in CPscore and PWV. CONCLUSION: This proof-of-concept study demonstrated that systemic arterial inflammation is an important pathogenetic factor in systemic arterial micro-calcification development.

Targeted optical fluorescence imaging: a meta-narrative review and future perspectives.

PURPOSE: The aim of this review is to give an overview of the current status of targeted optical fluorescence imaging in the field of oncology, cardiovascular, infectious and inflammatory diseases to further promote clinical translation. METHODS: A meta-narrative approach was taken to systematically describe the relevant literature. Consecutively, each field was assigned a developmental stage regarding the clinical implementation of optical fluorescence imaging. RESULTS: Optical fluorescence imaging is leaning towards clinical implementation in gastrointestinal and head and neck cancers, closely followed by pulmonary, neuro, breast and gynaecological oncology. In cardiovascular and infectious disease, optical imaging is in a less advanced/proof of concept stage. CONCLUSION: Targeted optical fluorescence imaging is rapidly evolving and expanding into the clinic, especially in the field of oncology. However, the imaging modality still has to overcome some major challenges before it can be part of the standard of care in the clinic, such as the provision of pivotal trial data. Intensive multidisciplinary (pre-)clinical joined forces are essential to overcome the delivery of such compelling phase III registration trial data and subsequent regulatory approval and reimbursement hurdles to advance clinical implementation of targeted optical fluorescence imaging as part of standard practice.

18F-FDG PET/CT in Infective Endocarditis: Indications and Approaches for Standardization.

PURPOSE OF REVIEW: Additional imaging modalities, such as FDG-PET/CT, have been included into the workup for patients with suspected infective endocarditis, according to major international guidelines published in 2015. The purpose of this review is to give an overview of FDG-PET/CT indications and standardized approaches in the setting of suspected infective endocarditis. RECENT FINDINGS: There are two main indications for performing FDG-PET/CT in patients with suspected infective endocarditis: (i) detecting intracardiac infections and (ii) detection of (clinically silent) disseminated infectious disease. The diagnostic performance of FDG-PET/CT for intracardiac lesions depends on the presence of native valves, prosthetic valves, or implanted cardiac devices, with a sensitivity that is poor for native valve endocarditis and cardiac device-related lead infections, but much better for prosthetic valve endocarditis and cardiac device-related pocket infections. Specificity is high for all these indications. The detection of disseminated disease may also help establish the diagnosis and/or impact patient management. Based on current evidence, FDG-PET/CT should be considered for detection of disseminated disease in suspected endocarditis. Absence of intracardiac lesions on FDG-PET/CT cannot rule out native valve endocarditis, but positive findings strongly support the diagnosis. For prosthetic valve endocarditis, standard use of FDG-PET/CT is recommended because of its high sensitivity and specificity. For implanted cardiac devices, FDG-PET/CT is also recommended, but should be evaluated with careful attention to clinical context, because its sensitivity is high for pocket infections, but low for lead infections. In patients with prosthetic valves with or without additional aortic prosthesis, combination with CTA should be considered. Optimal timing of FDG-PET/CT is important, both during clinical workup and technically (i.e., post tracer injection). In addition, procedural standardization is key and encompasses patient preparation, scan acquisition, reconstruction, subsequent analysis, and clinical interpretation. The recommendations discussed here will hopefully contribute to improved standardization and enhanced performance of FDG-PET/CT in the clinical management of patients with suspected infective endocarditis.

Diagnostic value of [18F]FDG-PET/CT for treatment monitoring in large vessel vasculitis: a systematic review and meta-analysis.

PURPOSE: Monitoring disease activity in patients with large vessel vasculitis (LVV) can be challenging. [18F]FDG-PET/CT is increasingly used to evaluate treatment response in LVV. In this systematic review and meta-analysis, we aimed to summarize the current evidence on the value of [18F]FDG-PET/CT for treatment monitoring in LVV. METHODS: PubMed/MEDLINE and the Cochrane library database were searched from inception through October 21, 2020. Studies containing patients with LVV (i.e. giant cell arteritis, Takayasu arteritis and isolated aortitis) that received treatment and underwent [18F]FDG-PET/CT were included. Screening, full-text review and data extraction were performed by 2 investigators. The risk of bias was examined with the QUADAS-2 tool. Meta-analysis of proportions and diagnostic test accuracy was performed by a random-effects model and bivariate model, respectively. RESULTS: Twenty-one studies were included in the systematic review, of which 8 studies were eligible for meta-analysis. Arterial [18F]FDG uptake decreased upon clinical remission in longitudinal studies. High heterogeneity (I2 statistic 94%) precluded meta-analysis of the proportion of patients in which the scan normalized during clinical remission. Meta-analysis of cross-sectional studies indicated that [18F]FDG-PET/CT may detect relapsing/refractory disease with a sensitivity of 77% (95%CI 57-90%) and specificity of 71% (95%CI 47-87%). Substantial heterogeneity was observed among the cross-sectional studies. Both variation in clinical aspects and imaging procedures contributed to the heterogeneity. CONCLUSION: Treatment of LVV leads to reduction of arterial [18F]FDG uptake during clinical remission. [18F]FDG-PET/CT has moderate diagnostic accuracy for detecting active LVV. [18F]FDG-PET/CT may aid treatment monitoring in LVV, but its findings should be interpreted in the context of the clinical suspicion of disease activity. This study underlines the relevance of published procedural recommendations for the use of [18F]FDG-PET/CT in LVV.

The value of 18F-FDG PET/CT for the diagnosis of device-related infections in patients with a left ventricular assist device: a systematic review and meta-analysis.

BACKGROUND: Left ventricular assist devices (LVADs) are increasingly used for the treatment of advanced heart failure. LVADs improve quality of life and decrease mortality, but the driveline carries substantial risk for major infections. These device-related LVAD and driveline infections are difficult to diagnose with conventional imaging. We reviewed and analysed the current literature on the additive value of 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) imaging for the diagnosis of LVAD-related infections." MATERIALS/METHODS: We performed a systematic literature review using several databases from their inception until the 31st of December, 2019. Studies investigating the diagnostic performance of FDG-PET/CT in patients with suspected LVAD infection were retrieved. After a bias risk assessment using QUADAS-2, a study-aggregate meta-analysis was performed on a per examination-based analysis. RESULTS: A total of 10 studies were included in the systematic review, eight of which were also eligible for study-aggregate meta-analysis. For the meta-analysis, a total of 256 FDG-PET/CT scans, examining pump/pocket and/or driveline infection, were acquired in 230 patients. Pooled sensitivity of FDG-PET/CT was 0.95 (95% confidence interval (CI) 0.89-0.97) and pooled specificity was 0.91 (95% CI 0.54-0.99) for the diagnosis of device-related infection. For pump/pocket infection, sensitivity and specificity of FDG-PET/CT were 0.97 (95%CI 0.69-1.00) and 0.93 (95%CI 0.64-0.99), respectively. For driveline infection, sensitivity and specificity were 0.96 (95%CI 0.88-0.99) and 0.99 (95%CI 0.13-1.00) respectively. Significant heterogeneity existed across studies for specificity, mostly caused by differences in scan procedures. Predefined criteria for suspicion of LVAD and/or driveline infection were lacking in all included studies. CONCLUSIONS: FDG-PET/CT is a valuable tool for assessment of device-related infection in LVAD patients, with high sensitivity and high, albeit variable, specificity. Standardization of FDG-PET/CT procedures and criteria for suspected device-related LVAD infections are needed for consistent reporting of FDG-PET/CT scans.

Diagnostic value of [18F]FDG-PET/CT in polymyalgia rheumatica: a systematic review and meta-analysis.

PURPOSE: Polymyalgia rheumatica (PMR) can be difficult to diagnose. Whole-body [18F]FDG-PET/CT allows for a comprehensive evaluation of all relevant articular and extra-articular structures affected by PMR. We aimed to summarize current evidence on the diagnostic value of [18F]FDG-PET/CT for a diagnosis of PMR. METHODS: PubMed/MEDLINE and the Cochrane Library database were searched from inception through May 31, 2020. Studies containing patients with PMR who underwent [18F]FDG-PET/CT were included. Screening and full-text review were performed by 3 investigators and data extraction by 2 investigators. Risk of bias was examined with the QUADAS-2 tool. Diagnostic test meta-analysis was performed with a bivariate model. RESULTS: Twenty studies were included in the systematic review, of which 9 studies (n = 636 patients) were eligible for meta-analysis. [18F]FDG positivity at the following sites was associated with a diagnosis of PMR: interspinous bursae (positive likelihood ratio (LR+) 4.00; 95% CI 1.84-8.71), hips (LR+ 2.91; 95% CI 2.09-4.05), ischial tuberosities (LR+ 2.86; 95% CI 1.91-4.28), shoulders (LR+ 2.57; 95% CI 1.24-5.32) and sternoclavicular joints (LR+ 2.31; 95% CI 1.33-4.02). Negative likelihood ratios (LR-) for these sites, as well as the greater trochanters, were all less than 0.50. Composite [18F]FDG-PET/CT scores, as reported in 3 studies, provided a pooled LR+ of 3.91 (95% CI 2.42-6.32) and LR- of 0.19 (95% CI 0.10-0.36). Moderate to high heterogeneity was observed across the studies, mainly due to differences in patient selection, scanning procedures and/or interpretation criteria. CONCLUSION: Significant [18F]FDG uptake at a combination of anatomic sites is informative for a diagnosis of PMR. [18F]FDG-PET/CT might be an important diagnostic tool in patients with suspected PMR. This study also highlights the need for adherence to published procedural recommendations and standardized interpretation criteria for the use of [18F]FDG-PET/CT in PMR.