What is the method
Ultrasound is a high frequency waves.
Principle is that special device sends ultrasound waves into the body. The waves reflect from tissues that have different density. The reflected signal is recorded by special sensor.
Received signal varies depending on tissue density. Then it is converted into digital form which can be seen by the doctor on the monitor as an image of anatomical structures.
The main part of the ultrasound scanner is a special ultrasound probe comprising piezoelectric crystal. This crystal is the source and receiver of ultrasound waves. It sends waves with short intervals in the direction of the examined organ. Sound waves reflect from the organ and are returned as echo.
Echo is captured by the probe and converted into electrical impulses. Then computer transforms them into glowing points of different intensity: the stronger the echo, the brighter the point. These points form the image of the anatomical structure on the screen.
An important component of ultrasound exam is Doppler scanning. The Doppler effect is the frequency change of the sound by reflection from moving object. In biological fluids such object is the blood inside the vessels. This method is used to diagnose cardiovascular pathologies and for monitoring of the fetus.
What it is for
Ultrasound diagnostics provides important information about the state of internal organs, heart, gland, soft tissues, joints, ligaments and blood vessels.
In addition ultrasound is used to determine gestational age and fetal position, birth defects as well as to examine the brain of newborns and infants.
During the sonography the liver is well visualized. Not only gallstones can be detected but also change of tissue structure. For example it is possible to diagnose fatty liver, cirrhosis or tumors.
Kidney and spleen as well as prostate and uterus are well visualized using ultrasound.
Transvaginal ultrasound is widely used in gynecology to examine female internal genital organs.
How it goes
You will be invited to the ultrasound office and proposed to lie on the couch.
The doctor will use special gel which does not contain any drugs and is completely neutral to the body. Gel will ensure better conduction of ultrasound waves.
During the exam doctor will press to the body ultrasound probe in different positions. The images will be displayed on the monitor and printed.
During vessels investigation function of flow rate calculation will be turned on – Doppler scan. In this case study will be accompanied by a special sound which reproduces movement of blood through the vessel.
A research of the abdominal cavity is held in the morning on an empty stomach (previous meal not earlier than 6-8 hours before the test). Beans, raw vegetables, brown bread, milk should be excluded from the diet for 1-2 days. Activated charcoal is recommended if gas-formation is possible: 1 tablet 3 times a day. Others enterosorbents will also be useful. In the case of diabetes light breakfast is allowed: hot tea, dried white bread.
Performing of pelvic transabdominal exam (bladder, uterus or prostate) requires filling of the bladder. It is recommended to refrain from urinating for 3 hours before the research or drink 300-500 ml of water an hour before the procedure.
Endocavitary investigation (through the vagina for women or through the rectum for men) on the contrary should be made when the bladder is empty.
Ultrasound examination of heart, blood vessels and thyroid gland does not require special preparation.