[Imaging of vessels supplying the brain]. / Bildgebende Darstellung hirnversorgender Gefäße.

Nowadays, several technically validated modalities are available for imaging both the extracranial and intracranial segments of arteries supplying blood to the brain. In the acute stroke setting, computed tomography (CT) angiography is of utmost importance because it provides the key diagnostic criteria indicative for the use of catheter-based recanalization techniques. Ultrasound imaging of extracranial arteries is most suitable for detecting an underlying stenosis of the internal carotid artery (ICA) in patients with stroke, transient ischemic attacks (TIA), retinal vessel occlusion and amaurosis fugax. Ultrasound imaging enables measurement of the methodologically most reliable criteria for grading stenosis of the ICA, which defines the indications for revascularization procedures in this territory. Magnetic resonance imaging (MRI) in the cross-sectional mode is of greatest value in confirming or excluding an arterial dissection even in short arterial segments, whereas MR angiography generates a more global view of the cerebral circulation. In most cases classical digital subtraction angiography (DSA) is no longer needed for diagnostic purposes only. Conversely, it is an indispensable component of any interventional approach and thus of growing importance. Ultrasound imaging is not indicated for the clarification of vertigo or syncope. In addition, there is no evidence that ultrasound screening of the ICA adds any value to the care of asymptomatic persons.

[Imaging representation of peripheral veins]. / Bildgebende Darstellung peripherer Venen.

Several techniques are available for imaging of the venous system of the legs and pelvic region. In cases of suspected deep leg vein thrombosis B­mode compression ultrasound is applied. Its accuracy is sufficient to either confirm or exclude the diagnosis with certainty. For examination of the iliac veins, however, flow information has to be added by pulsed wave (PW) Doppler or color Doppler sonography. In cases of suspected arm vein thrombosis, ultrasound is also the method of choice. The more proximal or the central parts of the venous system, i. e. brachiocephalic veins or the superior and inferior vena cava can be visualized by cross-sectional imaging procedures. Computed tomography (CT) angiography accurately shows the vessel lumen and magnetic resonance imaging (MRI) provides more details of the surrounding soft tissue. The use of classical contrast medium phlebography is nowadays restricted to interventions on proximal or central parts of the venous system. In addition, venous imaging is required in the field of chronic venous insufficiency. For both differential diagnostics and choice of treatment options, e. g. for varicose veins, the mainstay is venous ultrasound.