A comparison of ultrasonography and cerebral angiography for the evaluation of extracranial carotid stenosis

To investigate the usefulness of extracranial carotid ultrasonography for atherosclerotic plaque, we performed carotid ultrasonography and cerebral angiography (CAG) and classified the severity of the stenosis into 6 scores. We filmed 2-4 images (anterior, lateral, right anterior oblique and left anterior oblique views) for each vessel on CAG. There were 104 cases (169 vessels) with suspected or definite cerebrovascular disease. Both scores agreed in 67.5% of cases. In cases with over 50% stenosis on CAG, the scores agreed in 19 of 20 cases. But in cases with 50% or less stenosis on CAG, the scores agreed in only 95 of 149 cases. In most cases where scores were different, scores for ultrasonography were higher than those for angiography. The inconsistency of scores was attributed to eccentric plaque of early carotid atherosclerosis, uniform thickening of the intima-media complex and remodeling of the vessels. We filmed 4 images for 39 vessels to elevate CAG sensitivity for carotid stenosis. The results based on 4 images did not differ significantly from those based on 2 images. Carotid remodeling, or vessel enlargement in relation to the plaque area, was seen in 2 cases. Ultrasonography, which provided real-time information about both lumen and vessel wall characteristics, was necessary to make the diagnosis of carotid remodeling.