Carotid artery plaque composition : Relationship to clinical presentation and ultrasound B-mode imaging

Objective: To correlate B-mode ultrasound findings to carotid plaque histology. Design: European multicentre study (nine centres). Material and Methods: Clinical presentation and risk factors were recorded and preoperative ultrasound Duplex scanning with special emphasis on B-mode imaging studies was performed in 270 patients undergoing carotid endarterectomy. Perioperatively macroscopic plaque features were evaluated and the removed specimens were analysed histologically for fibrous tissue, calcification and 'soft tissue' (primarily haemorrhage and lipid). Results: Males had more soft tissue than females (p = 0.0006), hypertensive patients less soft tissue than normotensive (p = 0.01) and patients with recent symptoms more soft tissue than patients with earlier symptoms (p = 0.004). There was no correlation between surface description on ultrasound images compared to the surface judged intraoperatively by the surgeon. Echogenicity on B-mode images was inversely related to soft tissue (p=0.005) and calcification ions directly related to echogenicity (p < 0.0001). Heterogeneous plaques contained more calcification than homogeneous (p = 0.003), however there was no difference in content of soft tissue. Conclusion: Ultrasound B-mode characteristics are related to the histological composition of carotid artery plaques and to patient's history. These results may imply that patients with distant symptoms may be regarded and treated as asymptomatic patients whereas asymptomatic patients with echolucent plaques should be considered for carotid endarterectomy

Using consensus as a criterion for groupness: implications for the cohesion-group success relationship

The purpose of the study was to examine how the exclusion of teams failing to meet varying statistical criteria for consensus on cohesiveness influences the magnitude of the cohesion-team success relationship. The index of agreement was calculated for 78 teams (n = 1000 athletes) that had completed the Group Environment Questionnaire. Results showed that excluding teams because they fail to satisfy various criteria for consensus leads to changes in the magnitude of the cohesion-team success relationship. The magnitude of the relationship between team success and the Individual attractions to group-task manifestation of cohesion showed progressive decreases as criteria required to demonstrate consensus became more stringent. Conversely, the magnitude of the relationship between team success and the Group integration-task and Group integration-social manifestations of cohesion showed progressive increases as criteria required to demonstrate consensus became more stringent. The results are discussed in terms of their relationship to group dynamics theory and practice