Early detection of vascular inflammation would allow deployment of targeted strategies for the prevention or treatment of multiple disease states. Because vascular inflammation is not detectable with commonly used imaging modalities, we hypothesized that phenotypic changes in perivascular adipose tissue (PVAT) induced by vascular inflammation could be quantified using a new computerized tomography (CT) angiography methodology. We show that inflamed human vessels release cytokines that prevent lipid accumulation in PVAT-derived preadipocytes in vitro, ex vivo, and in vivo. We developed a three-dimensional PVAT analysis method and studied CT images of human adipose tissue explants from 453 patients undergoing cardiac surgery, relating the ex vivo images with in vivo CT scan information on the biology of the explants. We developed an imaging metric, the CT fat attenuation index (FAI), that describes adipocyte lipid content and size. The FAI has excellent sensitivity and specificity for detecting tissue inflammation as assessed by tissue uptake of 18F-fluorodeoxyglucose in positron emission tomography. In a validation cohort of 273 subjects, the FAI gradient around human coronary arteries identified early subclinical coronary artery disease in vivo, as well as detected dynamic changes of PVAT in response to variations of vascular inflammation, and inflamed, vulnerable atherosclerotic plaques during acute coronary syndromes. Our study revealed that human vessels exert paracrine effects on the surrounding PVAT, affecting local intracellular lipid accumulation in preadipocytes, which can be monitored using a CT imaging approach. This methodology can be implemented in clinical practice to noninvasively detect plaque instability in the human coronary vasculature.

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IntroductionCancer survival in England lags behind most European countries, due partly to lower rates of early stage diagnosis. We report the protocol for the evaluation of a multidisciplinary diagnostic centre-based pathway for the investigation of ‘low-risk but not no-risk’ cancer symptoms called the Suspected CANcer (SCAN) pathway. SCAN is a new standard of care being implemented in Oxfordshire; one of a number of pathways implemented during the second wave of the Accelerate, Coordinate, Evaluate (ACE) programme, an initiative which aims to improve England’s cancer survival rates through establishing effective routes to early diagnosis.Methods and analysisTo evaluate SCAN, we are collating a prospective database of patients referred onto the pathway by their general practitioner (GP). Patients aged over 40 years, with non-specific symptoms such as weight loss or fatigue, who do not meet urgent cancer referral criteria or for whom symptom causation remains unclear after investigation via other existing pathways, can be referred to SCAN. SCAN provides rapid CT scanning, laboratory testing and clinic review within 2 weeks. We will follow all patients in the primary and secondary care record for at least 2 years. The data will be used to understand the diagnostic yield of the SCAN pathway in the short term (28 days) and the long term (2 years). Routinely collected primary and secondary care data from patients not referred to SCAN but with similar symptoms will also be used to evaluate SCAN. We will map the routes to diagnosis for patients referred to SCAN to assess cost-effectiveness. Acceptability will be evaluated using patient and GP surveys.Ethics and disseminationThe Oxford Joint Research Office Study Classification Group has judged this to be a service evaluation and so outside of research governance. The results of this project will be disseminated by peer-reviewed publication and presentation at conferences.

Despite the heterogeneity of the included studies, preliminary evidence supports the safe and effective use of the various embolic materials currently used for the management of varicoceles. At 1 year, glue appears to be the most effective in preventing recurrence with coils being the second most effective. The addition of sclerosants to the coil embolization did not appear to have an impact on recurrence rates. Further research is required to elucidate the cost-effectiveness of these approaches. Advances in knowledge: Varicocele embolization appears to be a safe and effective technique regardless of the embolic agent. Addition of a sclerosant agent to coil embolization does not appear to improve outcomes.