Diagnosis

Doppler sonography

definition

Doppler sonography is a special type of examination that is mainly used to assess the blood flow through the blood vessels. For example, vascular constrictions, bulges or occlusions can be identified and their severity assessed. Since it is a special type of ultrasound examination, the method is also known as Doppler ultrasound. In addition to vascular medicine, Doppler sonography plays a major role in diagnostics in the specialist fields of neurology (clarification of fainting attacks or a stroke) and in gynecology in pregnant women to assess the development of the growing child. Doppler ultrasound can be performed without any preparation and is completely harmless. In most cases, the examination is carried out in combination with a conventional ultrasound for imaging carried out at the same time, which is then also called Duplex sonography referred to as.

When is Doppler sonography used?

Doppler sonography is used to diagnose various clinical pictures and symptoms that may be related to damage to the blood vessels. In neurology (neurology) in particular, the examination is an important diagnostic method for researching the causes of various symptoms. For example, strokes, temporary loss of vision in one eye, and sudden fainting can be caused by narrowing of one or both of the carotid arteries. Doppler sonography can be used to assess whether the carotid arteries are narrowed and how much blood is flowing through them. Even with ringing in the ears, unclear headaches and dizziness, a Doppler sub-ultrasound examination may be appropriate in some cases. Other indications for the method of examination sometimes arise in pregnant women. On the one hand, the mother's blood vessels can be assessed, for example in pregnancy high blood pressure. On the other hand, an assessment of the heart function of the growing child in the womb is possible. In this way, childhood heart defects can be discovered early if necessary. The advantage is that, in contrast to an X-ray examination, for example, the child is not exposed to any dangers such as radiation with Doppler ultrasound.

Doppler of the legs

Doppler sonography is particularly often used to examine the blood vessels in the legs. A basic distinction can be made between an examination of the arteries and an examination of the veins. A possibly existing venous weakness can be detected or excluded by the Doppler sonography. A deep vein thrombosis (blockage of the vessel by a blood clot) can also be better detected or excluded with the help of the Doppler method than with conventional ultrasound alone. When examining the arteries, the question of possible calcification of the vessels, which is responsible for peripheral arterial occlusive disease or intermittent claudication, is investigated. This disease, which occurs particularly in smokers, leads to leg pain when walking and a reduction in the walking distance to be covered.

Doppler of the carotid artery

The examination of the carotid artery using Doppler sonography is performed if a narrowing of the vessel is suspected. A narrowed carotid artery can lead to various symptoms or sequelae. The most serious is usually a stroke, so that after such a Doppler sonography of the neck vessels is one of the necessary examinations. A temporary loss of vision in one eye or abnormal sensations in an arm or leg can also be caused by narrowed neck vessels. However, complaints such as dizziness, memory loss, ringing in the ears can justify an examination of the carotid arteries using Doppler sonography, and this diagnostic method can possibly help to identify the cause. Likewise, after an operation on the carotid artery, check-ups should be carried out using Doppler ultrasound.

Doppler in pregnancy

During pregnancy, Doppler sonography is an established method of measuring the speed of blood flow in the blood vessels in the umbilical cord. This examination can usually be carried out after the 20th week of pregnancy. Doppler sonography can also be used to measure the blood flow between the child and the placenta (placenta) represent. This can be used to estimate how well the child's organs are supplied with blood.However, Doppler sonography is not part of the routine measures of prenatal care; it is only appropriate in certain cases. The examination is carried out, for example, in high-risk pregnancies. Such is the case in pregnant women with high blood pressure, smokers, women over 45 years of age and multiple pregnancies. Even if the regular ultrasound examination reveals abnormalities (for example, if the child is noticeably small at the time of development), a Doppler sonography can be useful. The examination is harmless to the health of both the child and the mother.

Prepare for the examination

No special preparation is necessary for performing a Doppler sonographic examination. The ultrasonic waves used in no way affect the body's functions, so that no special measures have to be carried out in advance. It is sufficient for the patient to position himself on the examination table according to the instructions of the examining doctor. It may be necessary to take off clothing beforehand, as the examination can only be carried out by placing the transducer directly on the skin.

How is the examination performed?

The process of a Doppler sonography does not differ significantly from that of a normal ultrasound examination. The examination is usually carried out lying down. Depending on the area being examined, items of clothing may have to be removed. The examiner applies a gel to the area of the body that is to be scanned. The transducer is then lightly pressed onto the examination area. The doctor usually has to wander the transducer a little to get the blood vessel into focus. Using the images or sounds generated by the ultrasound device, the examiner can assess the blood flow. As a rule, part of the examination is also recorded and printed out as an image or curve. After completing the examination, the patient is given cloths to remove the gel. Afterwards there is no impairment for the patient.

How is the Doppler evaluated?

The Doppler sonography is evaluated during the examination. With this method, a real-time display takes place and the examiner sees directly, for example, the current flow rate of the examined vessel and can assess whether this is normal or abnormally reduced. In addition, the devices used enable direct documentation of the findings, for example in the form of images that are printed or digitally saved or flow curves that enable the blood flow in the examined vessels to be recorded. If necessary, the examination is followed by a more detailed evaluation by the doctor and an assessment of whether there is a change that requires therapy or when a further check-up is recommended. Usually a report on the test results is also created. The examiner can provide information on this.

What are the risks?

Doppler sonography is a form of examination without any risks or possible side effects. It is also painless and does not require any special preparation. In contrast to X-rays, for example, the ultrasonic waves used cannot cause any damage to the human body.

How long does the examination take?

How long a Doppler sonography examination lasts cannot be answered in general, as it depends on various factors. First of all, it is crucial which region of the body is examined and what the medical question is. There are also individual patient factors. The blood vessels are not always easy to find and visualize, so it is more difficult for some patients and therefore takes longer before the examiner is able to visualize them properly. In addition, a very experienced doctor will be able to carry out the examination more quickly, while a less experienced doctor will need a little more time before the examination can be successfully completed. Typically, Doppler sonography takes no more than 20 minutes.

What does the examination cost?

Doppler sonography can only be performed by a doctor who has the necessary technical equipment. If there is an indication for a Doppler sonographic examination due to a possible vascular disease or change, the family doctor can issue a referral to an appropriately equipped specialist. In such a case, the costs for the examination are covered by the health insurance. Sometimes there is also the option of having a Doppler sonography performed at your own request. The costs for such an individual health service (IGEL service) differ greatly depending on the indication and doctor and can be in the range of several hundred euros.