Examination Methods


Examination of the arteries using contrast media is known as angiography.

For this purpose, an iodine-based contrast medium is injected directly into the artery or into a vein. During venous administration, the contrast medium passes through the lungs and the left ventricle and is then pumped into the body, where the relevant area is subsequently examined (venous DSA).

In order to inject the medium directly in the artery to be examined, a small puncture point has to be made (usually in the groin).

In both methods, the X-ray image data obtained undergo computer-aided analysis.

Computed Tomography

Computed tomography is a radiographic cross-sectional examination method using computer-controlled analysis.

Several generations of devices have been developed since this technique was first introduced in 1972. The current examination time for one layer is only approx. 2-3 seconds. The total examination time for a CT of the abdominal region is normally no more than a few minutes.

The principle of the examination is based on an x-ray machine rotating around the patient. The x-ray images are then measured and a linked computer produces a cross-sectional image.

Doppler Sonography of the Vessels
(arteries and veins)

Doppler examination of blood vessels provides information about the direction of blood flow and flow rate.

The procedure involves emitting ultrasound waves, which are reflected by the moving red corpuscles, creating a frequency shift which is rendered audible and corresponds to the speed of movement.

Duplex Sonography of Vessels

Duplex sonography with colour-coded blood vessel imaging is a combination of ’normal’ sonography and the determination of flow intensity and direction in blood vessels. The Doppler examination method is principally used for this procedure.

Treadmill Ergometry

Patients with circulatory disorder of the legs suffer from reduced ability to walk.

This restriction is due to an exertion-dependent insufficient oxygen supply to the muscles, resulting in typical claudication pain. The maximum pain-free walking distance a patient can manage is an important measure of the seriousness of the circulatory disorder. For standard measurement of this walking distance, we ask our patients to walk on a treadmill under supervision until the pain threshold is reached.

The walking distance achieved is then recorded and used as a reference value in any treatment of the circulatory disorder.

Nuclear Magnetic Resonance Tomography

Nuclear magnetic resonance tomography (also known as magnetic resonance tomography) has proved to be a very valuable diagnostic technique in recent years.

This technique avoids using both x-ray radiation and contrast media. In many cases, this new examination technique is able to provide accurate information on the vascular system.

Light Reflection Rheography

This examination is performed for varicose veins and for check-ups following thromboses. The level of reflection of infrared rays in the skin is measured using a sensor that is applied to the skin.

Moving the foot causes blood to be pumped through the veins and out of the leg, which alters the filling of the veins of the skin and the reflection of infrared rays in the skin as a result.
The values measured are plotted on a curve and provide information about the function of the deep and superficial venous systems.

Phlebography of the Legs

X-ray contrast examination of the leg veins is known as phlebography. With the patient is a standing position, a contrast medium is injected into a vein in the back of the foot and the flow of the contrast medium is recorded in a series of x-ray images of the leg. Precise information about the deep veins of the leg and the superficial veins can be obtained through this procedure.
Since an iodised contrast medium is used, it is important to inform the physician of any known thyroid disorders or allergies.


Imaging sonography has developed in leaps and bounds over the past few years. The basic principle, however, has remained the same.

Ultrasound waves are generated by a piezoelectric process in the transducer and transmitted into the tissue. Either a large number of piezoelements are arranged in parallel in the transducer or a single element is pivoted to and fro (linear or sector array).

The transmitted sound waves are modified in the tissue and reflected. An image is subsequently computed based on the reflected signal received. New devices are even capable of displaying blood flows within vessels in colour.

Occlusion Pressure Measurement

Blood pressure may also be measured in the legs in the normal way.

Blood pressure values approximately 10-20 mmHg higher than in the arm are normally recorded here for healthy individuals.

Cuff pressure is measured in both feet at the point when blood flow in the artery at the back of the foot and the medial malleolar artery stops.
These pressure values are also important parameters during the course of treatment in cases of circulatory disorders.

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Academic Teaching Hospital of the RWTH Technical University, Aachen

Clinic for Vascular Surgery

Dechant-Deckers-Str. 8
52249 Eschweiler

+49 2403 - 76-1814

St.-Antonius-Hospital Eschweiler
Dechant-Deckers-Str. 8
52249 Eschweiler
tel.: 02403 76 - 0
fax: 02403 76 -1119