[Relative values of carotid ultrasonic diagnosis and the Doppler test]

The rapid development of techniques for vascular imaging raises questions as to the hierarchy of exploratory non-invasive investigations of cervical vessels. However, caution is necessary when interpreting data provided by different teams because of the unequal experience in the use of these methods by the teams and the variable quality of the apparatuses used. A general rule should be to avoid dissociating imaging and Doppler. Too many teams give priority to ultrasound because of its simplicity in use and the apparent quality of data supplied. However, errors may arise from the weak reflectivity of soft plaques, particularly recent clots, from an acoustic shadow associated with some calcified plaques and from an unfavorable position of the lesion in relation to possible section planes. These problems increase when the apparatus is poorly adjusted, when resolution is insufficient or when there is a threshold to the detection of echos.