Ultrasound Based Measurement of ‘Carotid Stenosis >70%’: An Audit of UK Practice

ObjectivesTo determine velocity thresholds for diagnosing ‘carotid stenosis >70%’ and whether Vascular Studies Units in the United Kingdom used ECST or NASCET measurement methods.DesignQuestionnaire to 102 members of the Society of Vascular Technology of Great Britain and Ireland.ResultsOne quarter (26%) of respondents reported that their unit used the NASCET measurement method, 31% used the ECST method, while 43% did not know. When all velocity criteria were pooled and compared, an almost equal proportion of ECST, NASCET and ‘do not know’ respondents used a peak systolic velocity threshold of >230 cm/s as being diagnostic of a ‘stenosis >70%’. Interestingly, this velocity is now the threshold proposed by a North American consensus group for diagnosing a NASCET stenosis of >70%.ConclusionsThis audit suggests that there is considerable confusion about what constitutes an ultrasound based diagnosis of ‘stenosis >70% in the United Kingdom.