in diagnosing pathologies of the urinary system play an important role so-called indirect methods.Since renal Doppler can give an idea of the nephrons, which explore the «in vivo» (in vivo) at the moment is not possible.
The method Doppler method
This study has two more full name.It renal ultrasound with Doppler, and Doppler ultrasound - Doppler ultrasound.This gives a less complete description of the essence of the method.It is an improvement on ultrasound.
usual method of ultrasound is based on the reading of the reflected sound waves, the frequency of which exceeds 20 thousand hertz.The denser the tissue, the more intense is the reflection of waves.The reflected waves are captured by a special sensor.And the information coming from it is displayed on the screen.Here she sees a specialist of ultrasound diagnosis, and it also makes a conclusion.
This is important! Doppler ultrasound uses the reflection of waves from moving objects.As a result, the apparatus generates a liquid movement schedule.W
This is important! construction schedule computer contains information on the basic parameters of blood flow.This velocity, linearity of movement, and the flux density.
The data are used for two main conclusions:
- patency of the renal vessels.Namely - the renal vein and renal artery.
- blood flow in the nephron.
latter figure is arbitrary, as it gives approximate results.It is based on data from studies major vascular kidney.Only they are accessible to direct investigation.The fact that only about 95% of blood flowing through the kidney nephrons tested.The rest of the blood goes through arteriovenous anastomoses.
patency of the renal vessels is determined by direct ultrasound scan.The doctor on the machine's monitor can be good enough to see the condition of the vessel.Namely, the diameter and wall condition.If there is any narrowing (stenosis, atheroma) is fixed directly on the monitor.
notion bloodstream illustrates a graph obtained by using the above-described Doppler effect.Moreover, the picture of the vessel and are arranged parallel to the schedule.Their full line in the coordinate system gives a complete picture of what is happening in the vessel.
But as the blood flow in the kidney of it can be judged by analyzing the movement of blood through the arteries and vein.Exceeding the arterial and venous blood flow velocity is likely to say in favor of the fact that more than 5% of the blood is on the anastomosis.Slowing of blood flow can be interitirovat in the opposite direction, but with a certain conventionality.Often there is a situation that the blood can not go on the anastomoses in consequence of their defeat.
Training and methodology of the study
Doppler blood vessels of the kidneys requires the same preparation as simple ultrasound of the urinary system:
- for 2-3 days before the examination is recommended to avoid foods that cause flatulence in the intestine.It's all raw vegetables and fruits, confectionery, brown bread, beans, legumes, carbonated drinks.The use of sorbents (activated carbon, semitikon) is recommended only when indicated.That is, for people suffering from bowel disease and other digestive organs with a penchant for gassing.
- For 5-6 hours of abstinence from food.Water consumed in moderation.This is especially true of those who can be held an additional study of the bladder.Therefore, research should ideally be carried out in the morning.
study conducted mostly lying on his side.This minimizes the distance between the sensor and the kidney.Immediately before the procedure on the sensor (or skin) applied a special gel.This is necessary for a better transmission of ultrasonic waves in the gel times facilitates their passage through the skin layers.
Advantages of ultrasound study using Doppler technology are obvious.The method does not bear any radial load.Research is conducted in real time and the results are comparable with it.With this method, you can very well examine the condition of the soft tissues, which are X-rays are not visible at all.Finally, Doppler ultrasound is fairly inexpensive method so widely available and requires no costly consumables.
However, in certain pathologies and simple ultrasound Doppler ultrasound is not informative.It is primarily concerned with the vessel wall calcification.In this case, ultrasonic waves are just not penetrate further through the wall.The method is not recommended for detection of abnormalities of small vessels.
Indications for research
Appointment Doppler shown in the following cases:
- Suspected poor circulation by renal vessels.Most often, this situation occurs when:
- ascending thrombophlebitis of the inferior vena cava.
- impaction tumor vessels.
- nephroptosis last stage.
- anomalies vessels.
- study blood flow in hypertension.In this case, kidney Doppler is to eliminate renal causes of high blood pressure.
- monitoring the effectiveness of treatment of the above pathologies.