Plaque vulnerability due to inflammation has been shown to be a participating factor in the degenerative process in the arterial wall that contributes to stenosis and embolism. This is believed to have an important role to play also in the genesis of stroke or cerebrovascular diseases. In order to appropriately screen patients for treatment, there is an absolute need to directly or indirectly visualize both the normal carotid and the suspected plaque. This can be done with a variety of techniques ranging from ultrasound to computed tomography (CT) and magnetic resonance imaging (MRI). In addition to angiographic techniques, direct imaging of the plaque can be done either by ultrasound or by the so-called molecular imaging techniques, i.e. positron emission tomography (PET). These findings, together with other clinical and paraclinical parameters should finally guide the therapeutic choice.