I am sure you have heard about people going for an ultrasound test now and then. But are you aware of what an ultrasound is and how it came to be?
In this article, we have curated answers to the queries you may have. You will also read how ultrasound has brought about a significant change in the world and whether or not it helps detect cancer.
1. What is An Ultrasound?
An ultrasound, often referred to as ultrasonography, sonography, or a sonogram, assists medical professionals in finding cancers in parts of the body where x-rays are less effective. An ultrasound is a type of imaging test that works with high-frequency sound waves to produce images of the inside organs and tissues of the body.
Organs and tissues are reached by sound waves from a portable device known as a transducer that is moved over the external part of the body being investigated. A transducer is an ultrasound probe (ultrasound scanner) that has a microphone-like appearance, and is used for emitting sound waves to create pictures.
Ultrasound scan is used by medical professionals for various medical procedures like; visualizing a fetus during pregnancy, listening to its heartbeat, performing a breast exam, analyzing a heart, observing blood vessels, etc.
2. Types of Ultrasound Scan
There are various types of ultrasound scans. The type that you require depends on the section of your body that is being scanned.
The different types of ultrasound exams are:
2.1. External Ultrasound Scan or Abdominal Ultrasound
These types of ultrasound scan include imaging tests where the doctor or the sonographer examines the internal organs and tissues externally with ultrasound technology.
The doctor scans your abdominal area using an ultrasound probe which with the help of sound waves creates real pictures on the computer screen. These ultrasound images retrieved with the help of ultrasound machine further helps doctors determine various underlying problems of the patient.
The liver, gallbladder, spleen, pancreas, bile ducts, kidneys, and bladder are among the organs in the abdomen that can have a medical condition, which can be detected with abdominal ultrasound. The source of stomach pain, gallstones, blood clots, and other issues may also be diagnosed with the help of an abdominal ultrasound.
The test is conducted on a full bladder.
2.2. Internal Ultrasound Scans
Internal ultrasounds can be classified into four categories depending on the site they are performed. These three are as follows:
2.2.1. Endoscopic Ultrasound
An endoscopic ultrasound includes a combined process of endoscopy and an ultrasound.
This process is typically used by doctors to examine the digestive system from the inside. Alternatively, the endoscope’s tip can be an ultrasonic probe that provides the physicians with more thorough information.
The doctors use endoscopic ultrasound to examine the oesophageal wall, the bile ducts, the gallbladder, and the stomach.
During this procedure, the lymph nodes in your chest and belly can also be inspected.
2.2.2. Transvaginal Ultrasound
Transvaginal ultrasound or TVS, is used alongside abdominal imaging tests to get a better picture of the pelvic organs.
During the ultrasound, a thin transducer that resembles a tampon in terms of shape and size is inserted into a woman’s vagina, to examine the ovaries, womb, and surrounding structures.
The test is conducted on an empty bladder.
2.2.3. Transrectal Ultrasound
Transrectal ultrasound or TRUS is done to have a thorough check of your prostate gland and to recognize any problems or illness.
Typically, you must ensure that you have a bowel movement before your appointment so that your rectum is empty.
2.2.4. Endobronchial Ultrasound
Endobronchial ultrasound images are frequently used to stage lung cancer and determine if the disease has progressed to other organs, such as the lymph nodes, or not.
Additionally, it can be used to biopsy a sample of fluid or tissue from the lymph nodes or lungs in the chest.
3. What Does Ultrasound Show?
An ultrasound machine emits high-frequency sound waves that travel through your body which generate images known as sonograms. These echoes are converted by the device into real-time pictures (two-dimensional images) that display the anatomy, movement, and even blood flow through blood arteries of the organs, on an ultrasound screen.
Some soft tissue illnesses that are difficult to detect on X-rays can be captured very effectively by ultrasound. Along with some soft tissue diseases, an ultrasound also helps distinguish solid tumors and fluid-filled cysts from one another.
4. How Does an Ultrasound Work?
A transducer, which typically resembles a microphone or computer mouse, is one of the three main components of an ultrasound machine. The other two sections are the control panel and the display screen. The transducer emits sound waves and detects their echoes.
The transducer is moved over the area of the body being evaluated by the doctor or technologist. The machine’s primary computer analyzes the signals and displays the results as an image on the display screen.
The density of the tissue affects how the echoes are shaped and how intense they are. For instance, the majority of sound waves just pass through a fluid-filled cyst and only a few or weak echoes are returned, rendering the sound waves to appear black on the monitor. However, in a solid tumor, the sound waves bounce off, producing a pattern of reverberation that the computer will display as a lighter-colored image.
Therefore, an ultrasound scan helps identify whether a lump is a solid tumor, which is frequently an indication of cancer, or a fluid-filled cyst, which is typically a benign growth.
5. Can Ultrasound Detect Cancer?
An ultrasound is a specialized imaging technique that provides data that can be useful for diagnosing cancer, especially of soft tissues. It is frequently used as an initial step in the typical cancer diagnosis procedure.
Although an ultrasound alone cannot conclusively determine if a lump is cancer, it is frequently employed in cancer diagnosis procedure. This is due to the fact that solid masses and abnormal tissue produce an echo that differs from cysts filled with fluid and healthy tissue. Further testing will be required to determine the presence of cancer if ultrasound scans indicate the former.
Due to the fact that sound waves cannot pass through bone or air, such as those found in the lungs, its application is likewise restricted in specific areas of the body. In such scenarios other imaging tests like CT or MRI scans prove to be more detailed than ultrasound scan.
6. Procedures of Ultrasound Scan
To discuss the procedure we will divide ultrasound into its various types.
6.1. External Ultrasound
For external scan, your medical professional will ask you not to consume anything 6 hours prior to the test and ask you to drink plenty of water and have a comfortably full bladder.
After changing into a hospital gown, you will be asked to lie down beside the ultrasound machine. The sonographer will then spread a clear gel over the area to be scanned.
The process usually takes about 30-45 mins.
Once the scanning is done, you are free to do whatever.
6.2. Transvaginal Ultrasound
For this scan, no special preparation is required. You can eat, drink and take your medications as usual.
However, before the scan, your sonographer will instruct you to empty your bladder.
One the procedure starts; you lay on your bottom at the end of a brief scanning couch by the doctor or sonographer. You can lie on your side with your knees drawn up to your chest or there may be supports for your feet so you can bend your knees and spread your legs.
A tiny probe resembling a tampon in terms of size and shape will be inserted into your vagina by the doctor. The probe is coated with lubricating gel on it and is protected by a sheath that resembles a condom.
To obtain the necessary images, the sonographer will carefully rotate the probe and may occasionally press on your abdomen to move some of your organs so that they may be clearly seen on the screen.
The test shouldn’t hurt, although it might be unpleasant and feel a little chilly due to the gel.
6.3. Transrectal Ultrasound
Transrectal ultrasound is done to get a clearer picture of your prostate gland.
Written directions on how to get ready for the scan will be provided. To ensure that your rectum is empty before you arrive for your appointment, it is customary for you to ensure that you have had a bowel movement prior. You might require an enema to get your bowels emptied.
A liquid is inserted into your back channel during an enema. You could also take a liquid medication, laxative the day before. After taking the medication, you must spend a few hours near a restroom.
You will be given further instructions and medicine to take if your biopsy is being done concurrently.
For the scan, usually, the physician or sonographer will instruct you to lie on your left side with your legs drawn up to your chest or you can also be instructed to lie on your back with your legs spread and in stirrups.
Into your back canal is inserted a tiny, thin ultrasound probe which is around the thickness of a thumb. The probe has some lubricating gel on it and is protected by a sheath that resembles a condom.
Although the test is unpleasant where you may experience machine vibrations coming from the probe and could feel chilly from the gel, it shouldn’t hurt.
6.4. Endobronchial Ultrasound
During this treatment, a bronchoscope which is a small, flexible scope attached to an ultrasound scanner, is put into the patient’s mouth, guided by means of the trachea.
This enables the doctor to take photos of the lungs and their surroundings and to find tumors or cancers that are hard to reach.
6.5. Endoscopic Ultrasound
In this case, an endoscope and an ultrasonography are combined.
Endoscopic ultrasound is typically used by doctors to thoroughly examine the digestive system from the inside. This method is used to examine the esophageal wall, pancreas, gallbladder, bile ducts, lymph nodes duodenum, etc.
6.6. Doppler Ultrasound
Doppler ultrasound monitors blood flow across major arteries, veins, blood vessels, organs, and tissues.
This test is utilized to demonstrate restricted or stopped blood flow brought on by conditions such as a blood clot, plaque, or inflammation.
6.7. Duplex Ultrasound
Duplex ultrasonography creates images of blood arteries and surrounding organs by combining two different types of ultrasound waves
The Doppler sounds are plotted by the computer, showing the velocity and the direction blood flow via the arteries.
6.8. Color Doppler
Different colors appear on blood arteries in a Color Doppler pattern to indicate the blood’s flow rate and direction. The images are simpler to understand because of multiple vibrant colors.
7. Benefits of Ultrasound Scans
Although an ultrasonography might not be beneficial in detecting cancer, it is however beneficial in the following ways:
- The patients won’t be exposed to any kind of radiation during the process.
- No preparation is required for the scan.
- Usually an outpatient procedure is used to complete the task.
- Compared to other tests, ultrasound is typically far less expensive.
- Excluding some rare cases, this process involves negligible pain.
8. Risk Factors
When carried out by a professional ultrasound technologist who has the necessary training, ultrasonography is regarded a very safe procedure with normally zero side effects.
Nevertheless, just because the test didn’t detect any possible tumor doesn’t mean that you are cancer free. It is advised that you get more tests done and finally come to a conclusion.
Since ultrasound cannot detect which tumor is cancerous, your doctor won’t be able to determine which cancer is aggressive and which should be treated first.
To conclude, although ultrasound can effectively capture some soft tissue illness, solid tumors and fluid filled cysts, the images produced are not as detailed when compared to a CT scan or MRI. While it can detect tumors which can possibly be the root cause of cancers such as breast cancer, ovarian cancer, colon cancer, etc, ultrasound cannot however detect if the tumor is cancerous.
It is thus advised to all the cancer patients that for early detection and accurate diagnosis and for a proper cancer treatment, you go through a detailed series of tests like genetic testing, biopsy, blood testing, etc.
It is also important to remember that ultrasounds have a lot of restrictions. Apart from it not being able to detect cancerous tumor, performing an ultrasonography on an obese patient might not deliver a fruitful result. Furthermore, rather than relying just on the image, the accuracy of ultrasonography is dependent on the skills of the professional using the transducer.
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