Ultrasonography: what it is, what it is for, how it is done and types

Ultrasonography, also known as ultrasound and ultrasound, is a diagnostic imaging test that serves to view any organ or tissue in the body in real time. When the exam is performed with Doppler, the doctor is able to observe the blood flow in that region.

Ultrasonography is a simple, fast procedure and has no restrictions, and can be done whenever the doctor deems it necessary, without having to wait between one ultrasound and another. However, it is important to check if there is any recommendation to perform the test, such as filling the bladder or taking medications to eliminate excess gas, as this can make it difficult to visualize the organs.

How Ultrasound is done

What is it for

Ultrasonography is an image exam that can be indicated by the doctor in order to identify changes in the organs. Therefore, this exam can be recommended for:

• Investigate abdominal pain, in the flaccuses or in the back; Diagnose pregnancy or evaluate the development of the fetus; Diagnose diseases of the uterus, tubes, ovaries; Visualize the structures of muscles, joints, tendons; To visualize any other structure of the human body.

Ultrasonography should be performed in a laboratory, clinic or hospital, always under medical advice, to assist in the diagnosis or treatment of various situations. In addition, before taking the exam, it is necessary to find out about the preparation for the exams, as in some types of ultrasound it may be necessary to drink a lot of water, fast, or take medication to eliminate the gases, for example.

How it is done

Ultrasonography should be done with the patient lying on a stretcher and then a thin layer of gel should be placed on the skin and the transducer placed on top of this gel, sliding the device across the skin. This device will generate images that can be seen on a computer and must be analyzed by the doctor.

After finishing the exam the doctor removes the gel with a paper towel and the person can go home. The test does not cause pain or discomfort, it is easily accessible and is generally not an expensive test, being covered by several health plans, although it can also be performed by SUS.

Main types of ultrasound

1. Morphological ultrasound

This is a special type of ultrasound that must be performed during pregnancy, between 20 and 24 weeks of gestation, to check if the baby is developing correctly or if he has any malformation, such as Down's Syndrome, myelomeningocele, anencephaly, hydrocephalus or congenital heart disease.

The exam time varies between 20 and 40 minutes and this exam is recommended for all pregnant women.

How it is done: the doctor will put a gel on the pregnant belly and pass a device throughout the uterine region. The equipment will generate images that can be seen on the computer. Check out more details of the morphological ultrasound.

2. 3D and 4D ultrasound

This is a type of exam that allows a better visualization of the structure to be studied, giving a more real aspect. The 4D ultrasound, besides allowing a great observation of the baby still inside the mother's belly, can capture their movements in real time.

They are particularly suitable for viewing the fetus and can be taken from the 3rd month of pregnancy, but better images are obtained from the 6th month of pregnancy.

3. Ultrasound of the breast

In ultrasound of the breast, the doctor can observe the appearance of a lump that can be felt on palpation of the breast. This helps to identify whether it may be a benign, suspected lump or breast cancer, and is also useful for assessing breast ducts, and investigating the causes of breast pain, for example.

How it is done: The woman should lie down without clothes and a bra while the doctor passes the equipment in every suspicious area. It is normal to take longer when there are cysts or nodules that need to be investigated. This test is not a substitute for mammography, but it can be ordered by the doctor if the woman has large, firm breasts, which makes it difficult to perform the mammogram. Learn more details about breast ultrasound.

4. Ultrasound of the thyroid

On ultrasound of the thyroid, the doctor observes the size of this gland, its shape and if it has any nodules. This test can also be performed to guide a biopsy so that a small sample of the tissue is removed, in case of suspected cancer, for example.

How it is done: The person must lie on their backs, and then a gel is placed on the neck. The doctor will slide the device and see the person's thyroid on the computer screen. It is normal during the exam for the doctor to ask if it is the first time he has had the exam or if there has been any change in previous exams, in order to compare the results. Check for symptoms that may indicate thyroid cancer.

5. Pelvic ultrasound

This exam is indicated to visualize structures such as uterus, ovaries and blood vessels in this region, and may be necessary to diagnose endometriosis, for example. It can be performed by placing the transducer on the upper part of the belly or inside the vagina, in the latter case it is called transvaginal ultrasound. Learn details of transvaginal ultrasound.

6. Abdominal ultrasound

Abdominal ultrasound is used to investigate pain in the abdomen, if there are liquids in this region, or to evaluate organs such as the liver, kidneys, presence of masses and in case of trauma or blows, in the belly region. In addition to being useful in case of evaluation of kidneys and urinary tract, for example.

How it is done: The doctor will indicate if it is necessary to do some type of preparation before, but in the case of evaluation of the kidneys, urinary tract and the bladder itself, before the exam, a 6-hour fast is recommended, and the exam needs to be performed with a full bladder. Therefore, children aged 3 to 10 years should drink 2 to 4 glasses of water, adolescents and adults should drink 5 to 10 glasses of water up to 1 hour before the exam, without being able to pee before the exam.