Contents
Duplex scanning of the renal arteries is a modernized approach for diagnosing abnormalities related to changes in the functioning of the vessels of the internal organs. It is based on two already known medical examination formats.
The first solution involves classical ultrasound diagnostics. And the second relies on the Doppler effect. With its help, it turns out to study not only the speed of blood flow, but also the current state of the arteries. Briefly, this technique is called ultrasound and can be applied not only to the kidneys, but also to a number of other internal organs that need to be diagnosed.
Features and differences
Against the background of the fact that the duplex testing format provides a more accurate and at the same time detailed information picture of the health of the renal arteries, the price of the procedure will be higher than that of a standard ultrasound. But the result will please with the ability to accurately determine whether there are malfunctions in these vessels.
The basis of the Doppler effect relies on providing data on the difference between the frequencies sent to the organs and the response echoes of the ultrasonic pulse. The waves directed to the area under study are reflected from the red blood cells and allow you to get a picture of the condition of the problematic arteries. All collected information is transmitted to a computer monitor and then decrypted by a diagnostician.
For ease of use of the technique, experts sorted it into two broad categories: visualization and spectral. The latter option is necessary to assess the current state of blood flow, which is expressed as a curved line. And the visual component gives a general idea in black and white or even color mode, depending on the characteristics of a particular device.
Color resolution is more informative, as it reduces the risk of errors almost to zero. The color mapping mode uses two colors: red and blue. The first is responsible for the indicators of blood flow directed to a highly sensitive sensor. And the blue color shows the reverse flow of blood.
Also, the specialist will definitely pay attention to the brightness of the colors, since the richer the tone, the higher the blood flow rate.
The main advantage of a vessel duplex over traditional ultrasound is the ability to comprehensively examine an organ. Ultrasound standards do not allow qualitative identification of some vascular pathologies, which can affect the effectiveness of treatment, the rate of development of the disease and the prognosis.
With a deep examination, it is possible to detect deviations at an early stage of development, which helps to almost completely negate its negative consequences for the organ. The technique allows you to find problem areas of the renal arteries, even if the patient did not have any characteristic complaints.
What does the scan diagnose and when is it shown?
The most common diagnoses that are made after passing such an examination are atherosclerotic growths and blood clots. Sometimes an aneurysm is found in patients, which indicates the expansion of the vascular walls. Congenital anomalies in the structure of blood vessels can also be detected. Thanks to an accurate image, narrowing, expansion, change in shape, or the presence of inclusions in the lumen of the arteries can be found.
Patients who are oncological records at the dispensary or who have applied for the first time can be sent to a duplex. Due to ultrasound, it will be possible to make an assumption about the nature of the neoplasm – is it benign or malignant. Additionally, scanning helps to identify:
- urolithiasis;
- deviations in the structure and condition of the renal structures;
- fetal hypoxia during pregnancy.
Despite the fact that the innovative mechanism of ultrasound is safe and quite simple to carry out, it is not prescribed for everyone and not always. First, the attending physician must make sure that the symptoms meet the generally accepted criteria. The results of other types of analyzes are also taken into account. Against the background of the above, the doctor concludes whether it is necessary to resort to a duplex study.
The most common signs that the renal artery has ceased to cope with its duties are called:
- pain in the lumbar region, which is in no way associated with muscle overload;
- pain, discomfort when emptying the bladder;
- feeling of incomplete emptying of the bladder after going to the toilet;
- deviations from the norms of indicators of the content of protein, blood and leukocytes in laboratory analyzes of urine;
- hypertension in the second or third stage of development;
- periodic exacerbations of renal diseases of any type;
- disruptions in the functioning of the endocrine system;
- suspicion of the presence of oncological neoplasms;
- pathological changes in blood vessels, or simply suspicion of them;
- pathological condition during gestation.
Due to the fact that the diagnosis is carried out on an outpatient basis, it does not cause any significant discomfort and remains safe. The examination has no contraindications, it is approved for use in pregnant women.
If duplex scanning could not find any abnormalities, and the patient’s condition is getting worse, then the patient is offered to undergo an MRI and CT scan. The reason for this is the only drawback of such an advanced technique in the form of the inability to carefully examine small vessels near the artery.
How to prepare for the procedure?
To obtain an objective assessment of the health of the arteries, you need to properly prepare the body. Precautions before undergoing an ultrasound scan are quite simple and include an appointment for the afternoon.
Two days before the reception, it is desirable to unload the diet. To do this, the following products are excluded from the menu:
- dairy;
- bakery products;
- raw vegetables and fruits;
- peas;
- beans;
- carbonated drinks;
- sweets.
This will avoid flatulence, which can make imaging difficult. For identical purposes, sometimes special drugs are additionally prescribed. Their list, as well as the dosage, is prescribed by the attending physician, based on the well-being of a particular patient.
Separately, care must be taken not to eat or drink in the morning on the day of the procedure.
The only significant contraindication for scanning the artery are open wounds of any type from trauma to burns in the area of examination. Also, the doctor will not do the test immediately after examining the digestive tract.
For ease of viewing, the patient is examined in the supine position on the side. All restrictive clothing is offered to be removed and located on a medical couch.
The procedure will last no more than half an hour. During this time, the expert will drive over the area under study with a highly sensitive sensor, previously lubricated with gel for better signal transmission.
Do not be afraid of unusual rustling sounds during the examination. They testify to the movement of blood. Uniform sound means a completely normal clinical picture. But if the sounds are energetic in nature, then this may indicate a detected pathological area.
Despite the fact that the technique is still listed as relatively new, it has long managed to establish itself on the good side. Doctors give her preference over standard ultrasound and other types of examinations due to minimal trauma.
The duplex approach is classified as a non-invasive manipulation, which provides for the absence of damage to the skin. It has no manipulation and contraindications according to age criteria.
Another positive quality is the receipt of results immediately after the completion of reading data from the monitor. A timely scan allows you to “catch” diseases at an early stage of development.
Help with decryption
Usually, the conclusion of the diagnostician is handed over to the patient himself, or sent to the attending physician, who will deal with the detailed decoding. Comparing the results with the generally accepted norms, the doctor will tell the patient whether his renal arteries are in a normal state or they need treatment.
It is believed that normal indicators are smooth and clear contours of the kidneys, and the organ itself should be about 15 centimeters in size. A difference in size between the kidneys up to two centimeters is also allowed. Separately, the mobility of the organ during breathing is calculated, but if destabilization of the renal vessels is suspected, it is more important to take into account their condition.
Abnormalities include ruptures of varying severity, thinning or thickening, and aneurysms. Arterial lumen indicators are also taken into account. If there is a narrowing there, then you will have to look for the source of the problem.
When making a diagnosis, the emphasis is on the size of the studied artery, the trunk of which should not go beyond 3,3 mm – 5,6 mm. Segmental components normally range from 1,9 mm to 2,3 mm.
The diastolic blood flow velocity is considered in detail, which, according to the parameters of the trunk, should be about 36-38 cm/sec, and the interlobar segment – 9-17 cm/sec. Slightly different requirements for systolic speed, which should be 47-99 cm / s in terms of the trunk, and 29-35 cm / s in the interlobar arteries.