The medical ultrasound is the method by which different anatomical structures can be visualized using ultrasounds. The principle of ultrasound is similar to sonar and consists of ultrasound emission by a special probe. These ultrasounds are reflected by the anatomical structures encountered and then received and transformed into a black-and-white scale on the monitor.
Ultrasounds are mechanical vibrations with frequencies of over 20,000 Hz, imperceptible to human hearing, which are harmless to the anatomical structures they encounter.
Basically, it’s an acoustic map that draws organs or tissues in different planes, depending on the position of the transducer, so it’s also called the optical stethoscope.
Medical Ultrasound Benefits
Ultrasound is a safe imaging method with no adverse effects on examined structures, easily accessible, at no cost, and can view any anatomical structures with limitations in the lung, bone, and brain, from which only certain parts can be viewed. Of the brain, it can only view at young ages, when the sutures between the bones forming the cranial box (the fontanels) are not closed completely.
As a method in which there are no adverse effects, it does not use radiation, it is not invasive and in most cases it does not require special training, such as sedation, ultrasound can be repeated as many times as needed, and in any group of patients, and especially in pregnant women and children.
At present, the medical ultrasound is the main screening method in medicine because of the benefits it offers:
- the rapidity of getting a positive diagnosis or exclusion
- the noxiousness
- the possibility of repeating, virtually unlimited as the number of examinations and time
- the obtaining of multiple plans and different examination images of the same organ
- low cost and low maintenance
Types of Medical Ultrasound Probes and Applications
From the need to study the anatomical structures as best as possible, different types of probes appeared, some for the assessment of the deeper structures, others for the superficial ones, while others for the anatomical cavities such as the vagina, rectum, or esophagus.
With the help of ultrasound exploration, various changes in organ structure, such as various tumor formations or organ pains, may be detected in metabolic disorders such as dyslipidemias, diabetes, or inflammatory diseases.
In addition to structural changes, ultrasound can also detect changes in the functioning of organs by visualizing them in real time, being very useful in the study of digestive tract, heart, muscle activity, etc.
Apart from visualizing the anatomical structures and their functionality, a series of applications have also emerged that allow the detection of blood flow and its study, known as the Doppler method.
This method is useful in studying the vascularization of organs and tumor formations as well as the quality of blood vessels and their damage in systemic diseases such as hypercholesterolemia, diabetes, etc.
Besides Doppler vascularization, there is the contrast-based ultrasound.
This consists of the intravenous injection of a substance that is made up of small particles of gas in an elastic coating and allows for a very good characterization of the vascularization of different structures, helping to differentiate between different types of malignant or benign tumor formations in the assessment of inflammation or blood vessels.
The advantage of this method is the ease of performance and the minimal or absent adverse effects of the contrast substance.
Another application of ultrasound is elastography, the method by which you can study the density of a tissue. For devices that are equipped with this feature, the method can be used in any type of ultrasound and is very useful for differentiating benign and malignant tumor formations and assessing the degree of fibrosis.
Examination indications are multiple, and at present there are virtually few or no branches of medicine that do not benefit in some way from medical ultrasound examination. This is mainly due to the technological developments of the equipment (both hardware – probes –, and software), which allows for special examinations:
- new Doppler examinations (HD, B Flow, Ultra-fast)
- volumetric examinations – 3D, 4D
- echography with contrast substance
How Long does a Medical Ultrasound Takes? Is There a Need for Special Training?
In order to get the best image, due to the optimum propagation of ultrasounds, some types of ultrasounds require preparation before performance.
For example, for abdominal ultrasound, where it is advisable not to have too much air in the digestive tract, a 4-hour rest period is recommended as well as one hour’s fluid consumption to visualize the bladder and neighboring structures.
In the case of ultrasounds that measure the flow of blood from the abdominal area by the Doppler method, such as chronic hepatitis or cirrhosis, a 6-hour rest period is required.
Urological examination involves a fluid consumption that varies depending on bladder capacity and rhythm of the urine, generally about 300ml.
The transrectal test requires a restrictive diet on the day of performance and a small enema or Fortran administration.
There are special conditions when parents and pediatrician are required to examine the baby after pharmacologically induced pre-sleep.
Other types of ultrasounds, such as those that use probes to visualize superficial structures, do not require any special training.
For gynecological examinations (breast, uterus, ovary), the examination period is based on existing pathology or symptoms, either in the first or last decade of the cycle, and requires an ingestion of 200-300 ml of fluids with 30 minutes before the examination.
The time allocated to each type of ultrasound varies depending on the organ which is under examination, the investigator, and the patient, all in terms of constitution and in terms of changes found. In general, the set time is 30 minutes for an examination.
When to do the Medical Ultrasounds Examination During Pregnancy?
The ultrasounds are done in the three trimesters of pregnancy. However, there are cases where the pregnancy poses a risk to the fetus and the doctor may recommend you to make more ultrasounds.
The first ultrasound is performed in the first trimester of pregnancy, between the 11th week and the 14th
During this ultrasound, the doctor checks if the embryo is implanted in the uterus. At the same time, using the ultrasound, the age of pregnancy is also evaluated.
Another ultrasound is done during the second trimester of pregnancy, between the 18th week and the 23rd week.
It is considered to be one of the most important and thorough ultrasounds during pregnancy. During this investigation, it is assessed whether the fetal organs have developed in the core.
The third exam is performed between the 28th week and the 33rd week.
In this ultrasound, it is checked whether the fetus has grown sufficiently and if the placenta has developed properly.
In some cases, the doctor may recommend an ultrasound at the time of birth to assess the position of the fetus and the umbilical cord.