An ultrasound scan is done to visualize the internal structures inside the body. It makes use of high frequency sound waves to create ultrasound images of the structures in the body. Ultrasound imaging or sonography is considered to be a non-invasive procedure and does not involve ionizing radiation which is usual in X-rays. An ultrasound scan is not only useful in assessing the structure of organs and different internal structures but can also show the movement of organs in real time.
Why is ultrasound imaging done?
Ultrasound imaging is usually done as a diagnostic test for medical conditions. It is also used to view the fetus in the womb of a pregnant woman. Different areas of the body can undergo an ultrasound scan including the thyroid, breast, testicle, and abdomen. There are also special types of ultrasound like the transvaginal ultrasound and the Doppler ultrasound which is commonly used to assess the heart, veins, and arteries. Although ultrasound imaging usually produces a thin, flat image of the structures of the body, advances in technology has now made it possible to view ultrasound images in 3D and 4D.
Preparing for an Ultrasound
Preparation for an ultrasound scan varies depending on the area to be examined. One of the most common body areas examined through an ultrasound scan is the abdomen. Depending on the internal structure to be examined, the patient needs to have a full or empty bladder for better visualization. Fluid can serve a medium to increase visibility of a structure but it can also obstruct the view of some internal structures. Sometimes, it may also be necessary to avoid intake of foods and drinks if the area to be examined is in the abdomen.
Full Bladder vs. Empty Bladder
Having a full or empty bladder can make a difference with your ultrasound results. Knowing which ultrasound scans need a full or empty bladder can help ensure more accurate results.
A transvaginal ultrasound is used to view the reproductive organs of a woman like the cervix, uterus, and ovaries. It is a kind of pelvic ultrasound wherein the ultrasound probe or transducer is inserted into the vagina. A transvaginal ultrasound may be done to diagnose ectopic pregnancy, cysts, and fibroid tumors. It may also be done to evaluate infertility, pelvic pain, and menstrual problems. Transvaginal ultrasound can also be done during pregnancy to view the placenta, monitor fetal growth in the early stage of pregnancy, and evaluate threatened abortion.
It is important to have an empty bladder during a transvaginal ultrasound scan not only to reduce discomfort on the part of the patient but also to limit distortion of the uterus which is common when the bladder is full.
KUB ultrasound is a lower abdominal ultrasound that is done to assess the urinary tract. The kidneys, urinary bladder, and ureters are scanned in females while the seminal vesicles and prostate gland are usually also included in males. A KUB ultrasound can help determine changes in the size of the kidneys, signs of kidney damage, structural abnormalities, and presence of obstruction like kidney stones, tumors, and cysts.
A 4- to 6-hour fast may be necessary prior to a KUB ultrasound. The patient is also usually instructed to drink a liter of water 1 hour before the procedure. KUB ultrasound requires a full bladder so that the urinary bladder can be properly evaluated especially since the bladder volume is measured during the scan.
Pregnancy ultrasound provides ultrasound images of the embryo or fetus inside the uterus. It is done to monitor the growth of a fetus inside the uterus and provides information such as the baby’s age, position, sex, and heart rate. A pregnancy ultrasound can also help determine any abnormalities and developmental problems in the baby. Ultrasound scans during pregnancy also provides information on the placenta and amniotic fluid. 3D ultrasound scans are usually done during the later stages of pregnancy.
In the early stages of pregnancy, usually before the 20th to 24th week, it is necessary to have a full bladder for a pregnancy ultrasound to provide better visualization of the pelvic organs. During the later stages of pregnancy, having a full bladder is no longer necessary since the fetus moves out from the pelvis and the amniotic fluid also serves as a medium for better visualization.
Ultrasound scans help in the diagnosis of different medical conditions. Ensuring that you follow the right procedure when preparing for an ultrasound scan can help lead to more accurate results and diagnosis.