engleski

Three dimensional ultrasound in cerebrovascular disorders

It is nowadays considered standard procedure for the neurovascular ultrasound laboratory to give the final "go" for the carotid endarterectomy procedure. Correlation analyses regarding the sensitivity and specificity of angiography versus ultrasound were done several years ago. However, the technical developments have brought us on the verge of a new era in which greater development in ultrasound may enable even safer and more accurate diagnosis. It is the three-dimensional computer based software that enables us to have "a better view" of the carotid bifurcation, the atherosclerotic plaque and its stability. It has been well established that the stability of the plaque is determined by its sonographic appearance. The future will bring vectors and mathematic analysis as more predictive methods and those showing greater likelihood for plaque instability as the cause of stroke. This new technique is still in the developmental state, giving different sonographic centers the opportunity to explore the yet unknown. Some centers use motor devices and some use freehanded techniques. Both could show advantages in certain areas of cerebrovascular exploration. The motor technique will, probably, prove itself to be of greater use in evaluation of carotid disease, while freehanded option will enable a better insight into the pathology of the circle of Willis and the vertebrobasilar system. Image acquisition is possible in several ways: B mode, color Doppler flow mode and power Doppler mode. After data acquisition substantial amount of time is spent on image postprocessing. Once computerized, the image can be sliced in all directions and virtually any number of slices is available. This allows not only three-dimensional distance and area measurement, but also precise computerized volume assessment. There are some additional features, as well, which provide more information: a reflection on the surface of the plaque is used to display its structure. Some of our pilot studies are included in this presentation as an insight of threedimensional ultrasound possibilities. We explore possible ulcerations of plaques in the carotid basin and different vertebrobasilar pathologies that include: hypoplysia and occlusion with the development of collateral flow.

three dimensional ultrasound; cerebrovascular disorder

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