Three-dimensional ultrasound observation of carotid artery plaque ulceration

Background and Purpose-Carotid artery plaque ulceration is associated with an increased risk of cerebral embolism. However, because of the rather poor diagnostic quality of conventional 2-D ultrasound and angiography compared with the evaluation of pathological specimens, little information exists on the natural course of carotid plaque ulceration. Recently, the introduction of 3-D ultrasound has made reproducible investigation of plaque morphology possible, providing a reliable plaque surface analysis. Methods-We performed 3-D ultrasound examinations of 17 carotid artery plaques with an ulcerated surface in a prospective study of 16 patients (10 men, 6 women; mean+/-SD age 68.9+/-7.1 years) over a mean observation period of 17.6+/-6.3 months. Exactly parallel B-mode ultrasound scans (slice distance 0.1 mm) were acquired with a 5-MHz linear array probe clamped in a carriage device and driven by a mechanical step motor. The recorded images were reconstructed into a volumetric data set in a Cartesian coordinate system. Results-At the end of the observation period, surface configuration had changed in 4 cases (23.5%). plaque ulceration regressed in 3 cases, whereas ulcer progression occurred in 1 case. The remaining 13 plaques (76.5%) showed an unchanged surface configuration. Conclusions-Through the use of 3-D ultrasound, it is possible to noninvasively examine the regression and progression of carotid artery plaque ulceration.