Test-retest reliability of functional transcranial Doppler ultrasonography

The present study evaluates the reproducibility of lateralised blood how ve locity (BFV) changes measured with transcranial Doppler (TCD) ultrasonograp hy during various cognitive paradigms. A total of 20 right-handed volunteer s were confronted twice with 13 verbal and visuospatial tasks, with a time interval of 23 to 71 days. No statistically significant differences were fo und between the lateralisation indices (left BFV change minus right BFV cha nge) on the first and second examinations. Lateralisation indices of eight tasks showed a significant test-retest reliability (r = 0.61 to 0.83), The reproducibility of cognitively induced lateralised BFV changes appears to b e task-dependent. The possible influence from technical, physiological, and psychological factors is discussed, We conclude that functional neuroimagi ng studies based on blood flow data should preferably select cognitive para digms that demonstrated sufficient test-retest reliability. (C) 2001 World Federation for Ultrasound in Medicine & Biology.