Three-Dimensional Ultrasound Observation of Carotid Artery Plaque Ulceration

Abstract

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.