Comparison of (18)F-fluorodeoxyglucose positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) in corticosteroid-naive patients with conduction system disease due to cardiac sarcoidosis.

PURPOSE: Cardiac sarcoidosis (CS) is a cause of conduction system disease (CSD). (18)F-Fluorodeoxyglucose-positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) are used for detection of CS. The relative diagnostic value of these has not been well studied. The aim was to compare these imaging modalities in this population. METHODS: We recruited steroid-naive patients with newly diagnosed CSD due to CS. All CS patients underwent both imaging studies within 12 weeks of each other. Patients were classified into two groups: group A with chronic mild CSD (right bundle branch block and/or axis deviation), and group B with new-onset atrioventricular block (AVB, Mobitz type II or third-degree AVB). RESULTS: Thirty patients were included. Positive findings on both imaging studies were seen in 72 % of patients (13/18) in group A and in 58 % of patients (7/12) in group B. The remainder (28 %) of the patients in group A were positive only on CMR. Of the patients in group B, 8 % were positive only on CMR and 33 % were positive only on FDG PET. Patients in group A were more likely to be positive only on CMR, and patients in group B were more likely to be positive only on FDG PET (p = 0.02). Patients in group B positive only on FDG PET underwent CMR earlier relative to their symptomatology than patients positive only on CMR (median 7.0, IQR 1.5 - 34.3, vs. 72.0, IQR 25.0 - 79.5 days; p = 0.03). CONCLUSION: The number of positive FDG PET and CMR studies was different in patients with CSD depending on their clinical presentation. This study demonstrated that CMR can adequately detect cardiac involvement associated with chronic mild CSD. In patients presenting with new-onset AVB and a negative CMR study, FDG PET may be useful for detecting cardiac involvement due to CS.

Advanced imaging of cardiac sarcoidosis.

Sarcoidosis with cardiac involvement is underdiagnosed and can put patients at risk of morbidity including conduction defects, arrhythmias and heart failure, as well as sudden cardiac death. In addition, cardiac sarcoidosis may have no clinical manifestations or non-specific presentation and diagnosis may be difficult on clinical criteria. Investigation for cardiac sarcoidosis should be considered in those with extra-cardiac sarcoidosis and cardiac findings as well as those under the age of 60 years presenting with atrioventricular block without a clear cause. Advanced imaging modalities including cardiac magnetic resonance and positron emission tomography may help in both the diagnosis and assessment of response to treatment for cardiac sarcoidosis. This ultimately may help to minimize associated adverse outcomes from this enigmatic disease.

Atrioventricular block as the initial manifestation of cardiac sarcoidosis in middle-aged adults.

INTRODUCTION: Atrioventricular block (AVB) can be caused by several conditions, including cardiac sarcoidosis (CS). The prevalence of CS causing this presentation in a North American population has not been investigated and was the purpose of this study. METHODS: We prospectively evaluated patients aged 18-60 years presenting with unexplained 2nd or 3rd degree AVB and no previous history of sarcoidosis in any organ. All patients had fluorodeoxyglucose-positron emission tomography (FDG-PET) scans for the evaluation of CS. Japanese Ministry of Health Welfare (JMHW) criteria and biopsy results were used to confirm the diagnosis of CS. Subjects with advanced imaging suggestive of CS were investigated for extracardiac involvement. Patients were followed for major adverse cardiac events. RESULTS: Thirty-two patients presenting with unexplained AVB underwent cardiac and whole body FDG-PET for the investigation of CS from February 2010 to June 2013. Mean age was 52.8 ± 6.2 years, and 20 were male. CS was diagnosed in 11/32 (34%) subjects and 11/11 were subsequently diagnosed with extra-CS. Average follow-up was 21 ± 9 months. Adverse events were observed in 3 subjects with CS but none in subjects with idiopathic AVB. All 3 patients presented with heart failure, 2 also had recurrent VT resulting in ICD shocks. CONCLUSIONS: In this prospective study of consecutive patients aged ≤60 years presenting with unexplained AVB, we found that 11/32 (34%) had previously undiagnosed CS. Among patients with CS, 3/11 had adverse clinical outcomes compared with 0/21 (P = 0.011). Our data suggest that all patients aged ≤60 years with unexplained AVB should be investigated for CS. Moreover, patients diagnosed with CS should be closely followed.

Prevalence of cardiac sarcoidosis in patients presenting with monomorphic ventricular tachycardia.

INTRODUCTION: Sarcoidosis is a granulomatous disease of unknown etiology, which involves the heart in 5-25% of cases. Although ventricular tachycardia (VT) has been reported as the first presentation of sarcoidosis, its prevalence has not previously been investigated. In this prospective study, we sought to systematically investigate the prevalence of cardiac sarcoidosis (CS) in patients presenting with monomorphic VT (MMVT) and no previous history of sarcoidosis. METHODS: Consecutive patients presenting with MMVT to a tertiary care center were screened for inclusion. Patients with idiopathic VT, VT secondary to coronary artery disease, or prior diagnosis of sarcoidosis were excluded. Included patients underwent F-18-fluorodeoxyglucose positron emission tomography (PET) scan. In subjects with PET scanning suggestive of active myocardial inflammation, histological diagnosis was confirmed through extracardiac or endomyocardial biopsy (EMB). RESULTS: A total of 182 patients presented to our institution with VT between February 2010 and September 2012 and 14 subjects met inclusion criteria. Within this group, six of 14 (42%) patients had abnormal PET scans suggesting active myocardial inflammation. Four of the six patients had tissue biopsies that were diagnostic of sarcoidosis; the remaining two patients had guided EMB indicating nonspecific myocarditis. Atrioventricular block was observed in three of four (75%) patients with CS and none in 10 of the others (P = 0.022). Three of the four patients had pulmonary sarcoidosis and one patient had isolated CS. All four patients were treated with corticosteroids. CONCLUSION: In this prospective study, four of 14 (28%) patients presenting with MMVT (without idiopathic VT, ischemic VT, or known sarcoidosis) had CS as the underlying etiology. Clinicians should consider screening for CS in patients with unexplained MMVT.

The Past, Present, and Future Role of Artificial Intelligence in Ventilation/Perfusion Scintigraphy: A Systematic Review.

Ventilation-perfusion (V/Q) lung scans constitute one of the oldest nuclear medicine procedures, remain one of the few studies performed in the acute setting, and are amongst the few performed in the emergency setting. V/Q studies have witnessed a long fluctuation in adoption rates in parallel to continuous advances in image processing and computer vision techniques. This review provides an overview on the status of artificial intelligence (AI) in V/Q scintigraphy. To clearly assess the past, current, and future role of AI in V/Q scans, we conducted a systematic Ovid MEDLINE(R) literature search from 1946 to August 5, 2022 in addition to a manual search. The literature was reviewed and summarized in terms of methodologies and results for the various applications of AI to V/Q scans. The PRISMA guidelines were followed. Thirty-one publications fulfilled our search criteria and were grouped into two distinct categories: (1) disease diagnosis/detection (N = 22, 71.0%) and (2) cross-modality image translation into V/Q images (N = 9, 29.0%). Studies on disease diagnosis and detection relied heavily on shallow artificial neural networks for acute pulmonary embolism (PE) diagnosis and were primarily published between the mid-1990s and early 2000s. Recent applications almost exclusively regard image translation tasks from CT to ventilation or perfusion images with modern algorithms, such as convolutional neural networks, and were published between 2019 and 2022. AI research in V/Q scintigraphy for acute PE diagnosis in the mid-90s to early 2000s yielded promising results but has since been largely neglected and thus have yet to benefit from today's state-of-the art machine-learning techniques, such as deep neural networks. Recently, the main application of AI for V/Q has shifted towards generating synthetic ventilation and perfusion images from CT. There is therefore considerable potential to expand and modernize the use of real V/Q studies with state-of-the-art deep learning approaches, especially for workflow optimization and PE detection at both acute and chronic stages. We discuss future challenges and potential directions to compensate for the lag in this domain and enhance the value of this traditional nuclear medicine scan.

The Canadian Study of Arterial Inflammation in Patients with Diabetes and Recent Vascular Events, Evaluation of Colchicine Effectiveness (CADENCE): protocol for a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Inflammation is a key mediator in the development and progression of the atherosclerotic disease process as well as its resultant complications, like myocardial infarction (MI), stroke and cardiovascular (CV) death, and is emerging as a novel treatment target. Trials involving anti-inflammatory medications have demonstrated outcome benefit in patients with known CV disease. In this regard, colchicine appears to hold great promise. However, there are potential drawbacks to colchicine use, as some studies have identified an increased risk of infection, and a non-significant trend for increased all-cause mortality. Thus, a more thorough understanding of the underlying mechanism of action of colchicine is needed to enable a better patient selection for this novel CV therapy. OBJECTIVE: The primary objective of the Canadian Study of Arterial Inflammation in Patients with Diabetes and Recent Vascular Events, Evaluation of Colchicine Effectiveness (CADENCE) trial is to assess the effect of colchicine on vascular inflammation in the carotid arteries and ascending aorta measured with 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in patients with type 2 diabetes mellitus (T2DM) or pre-diabetes who have experienced a recent vascular event (acute coronary syndrome (ACS)/MI, transient ischaemic attack (TIA) or stroke). Secondary objectives include determining colchicine's effect on inflammatory biomarkers (high-sensitivity C reactive protein (hs-CRP) and interleukin-6 (IL-6)). Additionally, we will assess if baseline inflammation imaging or biomarkers are associated with a treatment response to colchicine determined by imaging. Exploratory objectives will look at: (1) the difference in the inflammatory response to colchicine in patients with coronary events compared with patients with cerebral events; (2) the difference in the inflammatory response to colchicine in different vascular beds; (3) the relationship of FDG-PET imaging markers with serum biomarkers and (4) assessment of quality-of-life changes. METHODS AND DESIGN: CADENCE is a multicentre, prospective, randomised, double-blinded, placebo-controlled study to determine the effect of colchicine on arterial inflammation as assessed with imaging and circulatory biomarkers, specifically carotid arteries and aortic FDG uptake as well as hs-CRP and IL-6 among others. Patients with T2DM or pre-diabetes who have recently experienced a CV event (within 30-120 days after an ACS (ie, ST-elevation MI (STEMI) or non-STEMI)) or TIA/stroke with documented large vessel atherosclerotic disease will be randomised to treatment with either colchicine 0.6 mg oral daily or placebo. Participants will undergo baseline clinical evaluation including EQ5D assessment, blood work for inflammatory markers and FDG PET/CT scan of the ascending aorta and left and right carotid arteries. Patients will undergo treatment for 6 months and have repeat clinical evaluation including EQ5D assessment, blood work for inflammatory markers and FDG PET/CT scan at the conclusion of the study. The primary outcome will be the change in the maximum target to background ratio (TBRmax) in the ascending aorta (or carotid arteries) from baseline to follow-up on FDG PET/CT imaging. DISCUSSION: Colchicine is an exciting potential new therapy for CV risk reduction. However, its use is associated with side effects and greater understanding of its underlying mechanism of action is needed. Importantly, the current study will determine whether its anti-inflammatory action is an indirect systemic effect, or a more local plaque action that decreases inflammation. The results will also help identify patients who will benefit most from such therapy. TRIAL REGISTRATION NUMBER: NCT04181996.

Arrhythmias in cardiac sarcoidosis: diagnosis and treatment.

PURPOSE OF REVIEW: Sarcoidosis is a granulomatous disease of unclear cause and variable presentation. Cardiac involvement can result in life-threatening conditions including heart block, ventricular tachycardia, sudden cardiac death, and heart failure. There is no consensus on the diagnosis and management of cardiac sarcoidosis and a practical update is needed to provide clinicians with guidance. RECENT FINDINGS: Three recent studies have described cardiac manifestations as the first presentation of sarcoidosis. In one study, cardiac sarcoidosis was found to be the underlying cause in 19% of adults aged less than 55 years presenting with new onset unexplained atrioventricular block. Also, there are increasing reports of patients with isolated cardiac sarcoidosis (i.e., without sarcoid in other organs). Finally, advances in imaging have enhanced our ability to detect myocardial involvement and perhaps follow response to treatment. SUMMARY: Cardiac sarcoidosis should be considered in patients aged less than 55 years presenting with unexplained atrioventricular block and in patients with idiopathic cardiomyopathy and sustained ventricular tachycardia. Much remains to be learned about the condition, including the role of steroids and devices in treatment, and the place of advanced imaging in following the response to treatment. Collaborative multicenter studies are required to answer these important clinical questions.

Prognostic importance of coincidental coronary artery calcification on FDG-PET/CT oncology studies.

Coronary artery calcification (CAC) on body CT imaging is considered a coincidental finding in cancer patients. In order to determine the significance of CAC in cancer patients we evaluated the prognostic utility of CAC detected on oncology FDG-PET/CT studies. A retrospective study was performed of consecutive FDG-PET/CT studies from January to March 2011. CAC was identified on the CT portion of FDG/PET-CT studies. Chart review documented statin use, the Framingham risk score (FRS) (includes age, diabetes, hypertension, dyslipidemia and smoking), the primary malignancy and metastases. The primary end point was a composite of death and cardiovascular (CV) events (non-fatal myocardial infarction (MI), PCI or coronary artery bypass surgery (CABG)). 266 patients had a median follow up of 41 months (95% CI 31-56 months). CAC was noted in 140 patients. Based on CAC, potentially 84 patients would have had a change in statin prescribing (p < 0.01). CAC was associated with the primary end point on univariable and multivariable analysis (OR 2.6 (95% CI 1.42-4.77) (p < 0.01). On univariable Kaplan-Meier survival analysis, CAC was associated with decreased survival only in the absence of metastases (p < 0.01). Cox proportional hazard modelling demonstrated CAC was associated with mortality and cardiac events in patients without metastases, whereas FRS was not (For CAC: HR 1.69 (95% CI 1.22-2.35), p = 0.002). CAC is commonly detected with oncology FDG-PET/CT. In cancer patients CAC was associated with an increased risk of clinical events. CAC reduced survival free time in patients without metastases. CAC might therefore be considered more than a coincidentaloma in patients without metastases.

Intensity modulated radiotherapy of non-small-cell lung cancer incorporating SPECT ventilation imaging.

PURPOSE: The authors performed this retrospective study to investigate the impact of using ventilation scans obtained from single photon emission computed tomography (SPECT) in selecting beam directions in intensity modulated radiation therapy (IMRT) planning in lung cancer radiotherapy to spare dosimetrically well ventilated lung. METHODS: For ten consecutive stage III non-small-cell lung cancer patients, the authors obtained both ventilation/perfusion SPECT scans and four-dimensional CT scans for treatment planning purposes. Each ventilation scan was registered with the corresponding planning CT and ventilation volumes corresponding to either > or = 50% (vv50) or > or = 70% (vv70) of the maximum SPECT count were automatically segmented. For each patient, three IMRT plans were generated: One using nine equally spaced beams optimized according to nonfunctional lung based mean lung dose and lung v20; a second using nine equally spaced beams optimized to avoid vv50 and vv70; and a third plan using only three beams with gantry angles chosen based on minimum mean ventilated lung dose calculated for each conformal beam at every 10 degrees gantry angle avoiding vv50 and vv70. Resultant dose volume histogram indices were calculated for each plan and were compared with respect to calculated SPECT-based ventilation parameters in order to quantify the potential utility of ventilation SPECT in this setting. RESULTS: Two patient groups were identified based on (i) the overlap volume between PTV and vv50 and (ii) the average angular mean ventilated lung dose (AAMvLD). The first parameter quantifies the proximity of the PTV to well ventilated lung and the second parameter quantifies the degree of ventilation that surrounds the PTV. For group 1 patients, < or = 5% of the vv50 overlapped with the PTV. For group 2 patients, > 5% of the vv50 overlapped the PTV. Group 1 was further classified into subgroups 1A and 1B: For subgroup 1A, AAMvLD is >18 Gy, implying that the functional lung surrounds the PTV; for subgroup 1B, AAMvLD is <18 Gy, implying that the well ventilated lung does not completely surround PTV. For subgroup 1A, the plans generated using ventilated lung avoidance reduced dose to vv50 and vv70, with below tolerance dose to normal lung and acceptable coverage of the PTV. For subgroup 1B, the dose to the total lung and well ventilated lung are reduced with the beam direction optimization for the three-beam plan. For group 2, there was no significant dosimetric advantage of using SPECT-based ventilation information in IMRT plan optimization. CONCLUSIONS: In conclusion, it is feasible to use SPECT ventilation scans to optimize IMRT beam direction and, subsequently, to reduce dose to ventilated lung when overlap of the PTV and the ventilated lung is minimal and that the PTV is not surrounded by the ventilated lung. The potential benefit of ventilation SPECT scanning can be determined by preplanning assessment of overlap volumes and the AAMvLD.

FLT-PET for the assessment of systemic sarcoidosis including cardiac and CNS involvement: a prospective study with comparison to FDG-PET.

BACKGROUND: 2-deoxy-2-[18F]fluoro-D-glucose's (FDG) biodistribution limits the evaluation of cardiac sarcoidosis (CS) and neurosarcoidosis (NS). While protocols for cardiac suppression exist, they can be inconvenient for patients and lead to incomplete cardiac suppression in many cases. Furthermore, FDG PET is limited in the detection of neurosarcoidosis due to an inability to suppress high level of physiological uptake within the brain. 3'-deoxy-3'-[18F]fluorothymidine (FLT) has been shown to accumulate in sarcoidosis lesions and this tracer lacks significant physiological myocardial and brain uptake, suggesting that this tracer may be useful for the assessment of sarcoidosis, including CS and NS, without the need for patient preparation. This prospective pilot study examined the performance of FLT vs FDG PET for systemic sarcoidosis, including cardiac and neural involvement. MATERIALS AND METHODS: Fourteen subjects with sarcoidosis were prospectively recruited and imaged with FDG- and FLT-PET. Two blinded, experienced readers independently reviewed the FLT-PET and FDG-PET images. Lesion distribution was compared between FLT and FDG. Agreement between FLT- and FDG-PET was determined using Cohen's kappa and the intra-class correlation coefficient. Inter-observer variability of FLT and FDG-PET was assessed. RESULTS: Twelve subjects had CS as per Heart Rhythm Society criteria and 1 had NS. FLT-PET was positive in 12 (86%), and FDG-PET in 11 (79%), with cardiac uptake present in 6 (50%) and 7 (58%) of subjects with CS, respectively. The subject with NS demonstrated uptake on both FLT and FDG-PET, with more lesions on FLT. There were no significant differences in the anatomical distribution of lesions between FLT and FDG. SUVs were significantly (p < 0.001) higher for FDG than FLT (5.8 ± 3.0 vs 2.3 ± 1.1, respectively), but not (p = 0.90) after adjusting for blood pool activity (2.8 ± 1.4 vs 2.8 ± 1.1, respectively). Agreement between FLT- and FDG-PET was good to excellent for the diagnosis of sarcoidosis, lung involvement, CS, and NS (κ = 0.76, 0.69, 0.86, and 1.0, respectively). Inter-observer agreement for FLT was excellent for diagnosing sarcoidosis, CS and NS (κ = 0.81, 0.85, and 1.0, respectively) and comparable to that of FDG. CONCLUSIONS: FLT-PET may be useful for the assessment of systemic sarcoidosis, as well as cardiac and neural involvement.

Atrial Arrhythmias in Clinically Manifest Cardiac Sarcoidosis: Incidence, Burden, Predictors, and Outcomes.

Background Recent data have suggested a substantial incidence of atrial arrhythmias (AAs) in cardiac sarcoidosis (CS). Our study aims were to first assess how often AAs are the presenting feature of previously undiagnosed CS. Second, we used prospective follow-up data from implanted devices to investigate AA incidence, burden, predictors, and response to immunosuppression. Methods and Results This project is a substudy of the CHASM-CS (Cardiac Sarcoidosis Multicenter Prospective Cohort Study; NCT01477359). Inclusion criteria were presentation with clinically manifest cardiac sarcoidosis, treatment-naive status, and implanted with a device that reported accurate AA burden. Data were collected at each device interrogation visit for all patients and all potential episodes of AA were adjudicated. For each intervisit period, the total AA burden was obtained. A total of 33 patients met the inclusion criteria (aged 56.1±7.7 years, 45.5% women). Only 1 patient had important AAs as a part of the initial CS presentation. During a median follow-up of 49.1 months, 11 of 33 patients (33.3%) had device-detected AAs, and only 2 (6.1%) had a clinically significant AA burden. Both patients had reduced burden after CS was successfully treated and there was no residual fluorodeoxyglucose uptake on positron emission tomography scan. Conclusions First, we found that AAs are a rare presenting feature of clinically manifest cardiac sarcoidosis. Second, AAs occurred in a minority of patients at follow-up; the burden was very low in most patients. Only 2 patients had clinically significant AA burden, and both had a reduction after CS was treated. Registration URL: https://www.clini​caltr​ials.gov; unique identifier NCT01477359.

Safe Use of Radium-223 Dichloride (223RaCl2) Across a Wide Range of Clinical Scenarios, Incorporating a 10-year Single-Institution Radiation Safety Experience.

Radium 223Ra dichloride (223RaCl2) is an effective therapeutic radiopharmaceutical presently approved for the treatment of prostate cancer metastatic to bone. It is unique by virtue of being the first alpha-emitting radiopharmaceutical to achieve approval for use in the clinic, reaching this status both in the United States and Europe in 2013. In over ten years of research and approved clinical usage, the authors have encountered very few radiation-safety incidents of concern with 223RaCl2; in this review, they relate their first-hand experience with this radiopharmaceutical and share some lessons learned, including situations of bleeding, surgery and patient demise. The authors first provide a basic review of the relevant physical properties of 223Ra and aspects of its radiobiology, followed by a discussion of the biodistribution of 223RaCl2, the radiopharmaceutical presently approved for clinical use. As would be expected from a primarily alpha emitter, external exposures to staff and family members from patients administered 223Ra are typically low in comparison with exposure from patients who have undergone other nuclear medicine procedures. There still remains potential for health care workers and family members to receive a significant internal exposure, through the ingestion of even minute amounts of activity, so proper handling practices are paramount.

How common is isolated cardiac sarcoidosis? Extra-cardiac and cardiac findings on clinical examination and whole-body 18F-fluorodeoxyglucose positron emission tomography.

BACKGROUND: Sarcoidosis is a systemic inflammatory disease which can involve nearly any organ. Clinically manifest cardiac involvement occurs in perhaps 5% of patients with sarcoidosis. The reported prevalence of isolated cardiac sarcoidosis (CS) varies widely with reported rates of 27-54%. The explanation for this variability is likely multi-factorial but perhaps mostly related to the diagnostic method(s) for assessing extra-cardiac involvement. The primary aim of this study was to assess the rate of isolated CS in a homogeneous, prospectively recruited cohort of patients with clinically manifest CS, using whole body FDG PET-CT imaging as a gold standard. A secondary aim was to describe the extent and distribution of extra-cardiac sarcoidosis at the time of first presentation of clinically manifest CS. METHODS: Patients were prospectively recruited at the time of first presentation with cardiac symptoms. All patients underwent whole-body and cardiac 18F-FDG PET-CT. All patients were examined for presence of skin sarcoidosis and were assessed by an ophthalmologist. RESULTS: 31 patients were included (mean age 56±8years, 17 female, 100% Caucasian). Patients had limited extra-cardiac involvement (mean of 2.2 organs) however using the most precise definition, only 1/31 (3.2%) patients had isolated CS. There were marked differences in right ventricular (RV) and atrial involvement between patients presenting with CS as first presentation compared to patients presenting initially with extra-cardiac disease. CONCLUSIONS: Most patients had limited extra-cardiac involvement at the time of presentation of manifest CS however, isolated CS, using the proposed gold standard, was only observed in one patient.

[18F]-Fluorodeoxyglucose PET/CT imaging as a marker of carotid plaque inflammation: Comparison to immunohistology and relationship to acuity of events.

BACKGROUND: [18F]-fluorodeoxyglucose (18FDG) uptake imaged with positron emission tomography (PET) and computed tomography (CT) may serve as a biomarker of plaque inflammation. This study evaluated the relationship between carotid plaque 18FDG uptake and a) intraplaque expression of macrophage and macrophage-like cellular CD68 immunohistology; b) intraplaque inflammatory burden using leukocyte-sensitive CD45 immunohistology; c) symptomatic patient presentation; d) time from last cerebrovascular event. METHODS: 54 patients scheduled for carotid endarterectomy underwent 18FDG PET/CT imaging. Maximum 18FDG uptake (SUVmax) and tissue-to-blood ratio (TBRmax) was measured for carotid plaques. Quantitative immunohistological analysis of macrophage-like cell expression (CD68) and leukocyte content (CD45) was performed. RESULTS: 18FDG uptake was related to CD68 macrophage expression (TBRmax: r = 0.51, p < 0.001), and total-plaque leukocyte CD45 expression (TBRmax: r = 0.632, p = 0.009, p < 0.001). 18FDG TBRmax uptake in carotid plaque associated with patient symptoms was greater than asymptomatic plaque (3.58 ±â€¯1.01 vs. 3.13 ±â€¯1.10, p = 0.008). 18FDG uptake differed between an acuity threshold of <90 days and >90 days (SUVmax:3.15 ±â€¯0.87 vs. 2.52 ±â€¯0.45, p = 0.015). CONCLUSIONS: In this CAIN cohort, 18FDG uptake imaged with PET/CT serves a surrogate marker of intraplaque inflammatory macrophage, macrophage-like cell and leukocyte burden. 18FDG uptake is greater in plaque associated with patient symptoms and those with recent cerebrovascular events. Future studies are needed to relate 18FDG uptake and disease progression.

Inter- and Intraobserver Agreement of 18F-FDG PET/CT Image Interpretation in Patients Referred for Assessment of Cardiac Sarcoidosis.

Recent studies have reported the usefulness of 18F-FDG PET in aiding with the diagnosis and management of patients with cardiac sarcoidosis (CS). However, image interpretation of 18F-FDG PET for CS is sometimes challenging. We sought to investigate the inter- and intraobserver agreement and explore factors that led to important discrepancies between readers. Methods: We studied consecutive patients with no significant coronary artery disease who were referred for assessment of CS. Two experienced readers masked to clinical information, imaging reports, independently reviewed 18F-FDG PET/CT images. 18F-FDG PET/CT images were interpreted according to a predefined standard operating procedure, with cardiac 18F-FDG uptake patterns categorized into 5 patterns: none, focal, focal on diffuse, diffuse, and isolated lateral wall or basal uptake. Overall image assessment was classified as either consistent with active CS or not. Results: One hundred scans were included from 71 patients. Of these, 46 underwent 18F-FDG PET/CT with a no-restriction diet (no-restriction group), and 54 underwent 18F-FDG PET/CT with a low-carbohydrate, high-fat and protein-permitted diet (low-carb group). There was agreement of the interpretation category in 74 of 100 scans. The κ-value of agreement among all 5 categories was 0.64, indicating moderate agreement. For overall clinical interpretation, there was agreement in 93 of 100 scans (κ = 0.85). When scans were divided into the preparation groups, there was a trend toward higher agreement in the low-carb group versus the no-restriction group (80% vs. 67%, P = 0.08). Regarding the overall clinical interpretation, there was also a trend toward greater agreement in the low-carb group versus the no-restriction group (96% vs. 89%, P = 0.08). Conclusion: The interobserver agreement of cardiac 18F-FDG uptake image patterns was moderate. However, agreement was better regarding overall interpretation of CS. Detailed prescan dietary preparation seemed to improve interobserver agreement.

Positron Emission Tomography and Single-Photon Emission Computed Tomography Imaging in the Diagnosis of Cardiac Implantable Electronic Device Infection: A Systematic Review and Meta-Analysis.

BACKGROUND: The use of cardiac implantable electronic devices (CIED) is increasing, and their associated infections result in significant morbidity and mortality. The introduction of better cardiac imaging techniques could be useful for diagnosing this condition and guiding therapy. Our objective was to systematically assess the diagnostic accuracy of Fluor-18-fluorodeoxyglucose positron emission tomography and computed tomography, labeled leukocyte scintigraphy (LS), and Gallium-67 citrate scintigraphy for the diagnosis of CIED infection. METHODS AND RESULTS: A systematic review of the literature and meta-analysis on the use of all 3 modalities in CIED infection were conducted. Pooled sensitivity, specificity, and summary receiver operating characteristic curves of each imaging modalities were determined. The literature search identified 2493 articles. A total of 13 articles (11 studies for 18F-FDG PET-CT and 2 for LS), met the inclusion criteria. No studies for 67Ga citrate scintigraphy met the inclusion criteria. The pooled sensitivity of 18F-FDG PET-CT for the diagnosis of CIED infection was 87% (95% CI, 82%-91%) and pooled specificity was 94% (95% CI, 88%-98%). The summary receiver operating characteristic curve analysis demonstrated good overall accuracy, with an area under the curve of 0.935. There were insufficient data to do a meta-analysis for LS, but both studies reported sensitivity above 90% and specificity of 100%. CONCLUSIONS: Both 18F-FDG PET-CT and LS yield high sensitivity, specificity, and accuracy, and thus seem to be useful for the diagnosis of CIED infection, based on robust data for 18F-FDG PET-CT but limited data for LS. When available,18F-FDG PET-CT may be preferred.

Reducing Inappropriate Antibiotic Prescribing for Adults With Acute Bronchitis in an Urgent Care Setting: A Quality Improvement Initiative.

Acute bronchitis is a predominantly viral illness and, according to clinical practice guidelines, should not be treated with antibiotics. Despite clear guidelines, acute bronchitis continues to be the most common acute respiratory illness for which antibiotics are incorrectly prescribed. Although the national benchmark for antibiotic prescribing for adults with acute bronchitis is 0%, a preliminary record review before implementing the intervention at the project setting showed that 96% (N = 30) of adults with acute bronchitis in this setting were prescribed an antibiotic. This quality improvement project utilized a single-group, pre-post design. The setting for this project was a large urgent care network with numerous locations in central North Carolina. The purpose was to determine whether nurse practitioners and physician assistants, after participating in a multifaceted provider education session, would reduce inappropriate antibiotic prescribing for healthy adults with acute uncomplicated bronchitis. Twenty providers attended 1 of 4 training sessions offered in October and November 2015. The face-to-face interactive training sessions focused on factors associated with inappropriate antibiotic prescribing, current clinical practice guidelines, and patient communication skills. Retrospective medical record review of 217 pretraining and 335 posttraining encounters for acute bronchitis by 19 eligible participating providers demonstrated a 61.9% reduction in immediate antibiotic prescribing from 91.7% to 29.8%. Delayed prescribing, which accounted for a small percentage of the total prescriptions given, had a small but significant increase of 9.3% after training. Overall, this multifaceted, interactive provider training resulted in significant reductions in inappropriate prescriptions.