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Aims Dynamic myocardial computed tomography (CT) perfusion (DM-CTP) can, in combination with coronary CT angiography (CCTA), provide anatomical and functional evaluation of coronary artery disease (CAD). However, normal values of myocardial blood flow (MBF) are needed to identify impaired myocardial blood supply in patients with suspected CAD. We aimed to establish normal values for MBF measured using DM-CTP, to assess the effects of age and sex, and to assess regional distribution of MBF. Methods and results A total of 82 healthy individuals (46 women) aged 45–78 years with normal coronary arteries by CCTA underwent either rest and adenosine stress DM-CTP (n = 30) or adenosine-induced stress DM-CTP only (n = 52). Global and segmental MBF were assessed. Global MBF at rest and during stress were 0.93 ± 0.42 and 3.58 ± 1.14 mL/min/g, respectively. MBF was not different between the sexes (P = 0.88 at rest and P = 0.61 during stress), and no correlation was observed between MBF and age (P = 0.08 at rest and P = 0.82 during stress). Among the 16 myocardial segments, significant intersegmental differences were found (P < 0.01), which was not related to age, sex, or coronary dominance. Conclusion MBF assessed by DM-CTP in healthy individuals with normal coronary arteries displays significant intersegmental heterogeneity which does not seem to be affected by age, sex, or coronary dominance. Normal values of MBF may be helpful in the clinical evaluation of suspected myocardial ischaemia using DM-CTP. [ABSTRACT FROM AUTHOR]

Aims The role of atherosclerosis in the pathogenesis of aortic enlargement is uncertain. We aimed to evaluate the relationship between the diameters of the ascending, descending and abdominal aorta, and coronary artery calcification. Methods and results Individuals in the Copenhagen General Population Study underwent thoracic and abdominal computed tomography. Maximal aortic diameters were measured in each aortic segment and coronary artery calcium scores (CACS) were calculated. Participants were stratified into five predefined groups according to CACSs and compared to aortic dimensions. The relation between aortic diameter and CACS was adjusted for risk factors for aortic dilatation in a multivariable model. A total of 2678 eligible individuals were included. In all segments of the aorta, aortic diameter was associated to CACSs, with mean increases in aortic diameters ranging from 0.7 to 3.5 mm in individuals with calcified coronary arteries compared to non-calcified subjects (P -value < 0.001). After correction for risk factors, individuals with CACS above 400 had larger ascending, descending and abdominal aortic diameter than the non-calcified reference group (P -value < 0.01). Conclusion Enlarged thoracic and abdominal aortic vascular segments are associated with co-existing coronary artery calcification in the general population. [ABSTRACT FROM AUTHOR]

Aims Quantitative computed tomography (QCT) allows assessment of morphological features of coronary atherosclerosis. We aimed to test the hypothesis that clinical patient presentation is associated with distinct morphological features of coronary atherosclerosis. Methods and results A total of 1652 participants, representing a spectrum of clinical risk profiles [787 asymptomatic individuals from the general population, 468 patients with acute chest pain without acute coronary syndrome (ACS), and 397 patients with acute chest pain and ACS], underwent multidetector computed tomography. Of these, 274 asymptomatic individuals, 254 patients with acute chest pain without ACS, and 327 patients with acute chest pain and ACS underwent QCT to assess coronary plaque volumes and proportions of dense calcium (DC), fibrous, fibro fatty (FF), and necrotic core (NC) tissue. Furthermore, the presence of vulnerable plaques, defined by plaque volume and tissue composition, was examined. Coronary plaque volume increased significantly with worsening clinical risk profile [geometric mean (95% confidence interval): 148 (129–166) mm3, 257 (224–295) mm3, and 407 (363–457) mm3, respectively, P  <   0.001]. Plaque composition differed significantly across cohorts, P  <   0.0001. The proportion of DC decreased, whereas FF and NC increased with worsening clinical risk profile (mean proportions DC: 33%, 23%, 23%; FF: 50%, 61%, 57%; and NC: 17%, 17%, 20%, respectively). Significant differences in plaque composition persisted after multivariable adjustment for age, gender, body surface area, hypertension, statin use at baseline, diabetes, smoking, family history of ischaemic heart disease, total plaque volume, and tube voltage, P  <   0.01. Conclusion Coronary atherosclerotic plaque volume and composition are strongly associated to clinical presentation. [ABSTRACT FROM AUTHOR]