By Dr Deepshikha Goel
One of the most common uses of an ultrasound is during pregnancy, to monitor the growth and development of the foetus, but there are many other uses as well. As a medical test, this is used to create images of soft tissue structures, such as the gallbladder, liver, kidneys, pancreas, bladder, and other organs and parts of the body. There are different types of ultrasound scans, i.e. external, internal, and endoscopic, depending on the part of the body that is examined.
While there are multiple diagnostic uses of ultrasound, there are several myths associated with it.
Myth 1: Ultrasounds use radiation
This is absolutely not true. Ultrasounds use harmless high-frequency sound waves that reflect to give a graphic description of the body’s internal structures. Radiations are used in X-rays and CT scans.
Myth 2: Ultrasounds are harmful if done too frequently
Ultrasounds are totally safe done whenever, however, any number of times and for any indication. In high risk situations, frequent monitoring is needed to get optimum results. As fun as it may be, you don’t need an ultrasound every week, and requesting unnecessary medical tests is not a good practice for anyone.
Myth 3: Ultrasounds are bad for the baby
Not at all. On the contrary, an ultrasound is a good window through which we can have a look at the unborn baby. A WHO systematic review of the literature and meta-analysis also states that “according to the available evidence, exposure to diagnostic ultrasonography during pregnancy appears to be safe”.
Myth 4: An ultrasound can cause miscarriage in the first three months of pregnancy
Early USG is extremely important for confirmation and location of pregnancy; to monitor early growth and heartbeat of the foetus. If a baby is not developing at the right place in the uterus, it can be a threat to the mother as well as growth of the baby. Under guidance of the physician, medicines have to be taken to ensure brain growth of the baby.
Myth 5: Transvaginal ultrasound (TVS) is risky
If done gently, it is as safe as any other simple test. And, on the plus side, being a high-resolution modality, it gives the best possible picture of the baby in real time. (Remember the beautiful, smiling 3D face of the baby seen in the images.)
Myth 6: As soon as an ultrasound procedure is over, the report is ready
All important and good things take time to be prepared. A USG report contains lot of patient specific parameters and information that need to be entered in the system to generate accurate and meaningful information. Be patient so it can be thoroughly checked before being handed over.
Myth 7: 3D/4D/5D ultrasounds are more accurate than 2D
The 3D/4D/5D ultrasounds look mesmerising but may not necessarily be adding technical information. Every type of USG gives different information. A 2D ultrasound is more accurate in amniotic fluid and growth assessment and also majority of birth defects. A 3D one provides more detail and depth imaging, giving us images that are more readily understood by the patient. These can be more accurate for catching physical defects in a foetus, like a cleft lip, misshapen limbs, or problems with the spinal cord, while 4D and 5D ultrasounds give more information about the heart. So, different types of ultrasounds serve a variety of purposes, and one isn’t necessarily more accurate than the other.
Myth 8: Normal USG gives 100 per cent guarantee of normal baby
The foetus is not a miniature adult and continues to grow structurally as well as functionally with each passing day. An abnormality best seen at three months may get obscured as the baby grows and may not just be visible at six months. So, you need multiple scans at specific periods so as not miss most of the major defects. In addition, though a USG is usually able to detect most structural lethal abnormalities, the functional well-being of a baby cannot be ascertained by ultrasounds.
Myth 9: A USG always give accurate gestational age or estimated foetal weight
The accuracy of measurement depends on many factors like the pregnancy month, BMI of the mother, any previous operation, the baby’s position, etc, so considering all these factors, it isn’t always completely accurate, but it does get close most of the time. You need multiple ultrasounds in pregnancy to ensure the baby’s wellbeing. Similar to exams conducted annually to assess a student, USG is needed at regular intervals to assess the growth and development of the baby.
Myth 10: An ultrasound is a painful procedure
It is an absolutely painless procedure. However, sometimes in case of region specific USG like transrectal or transvaginal scans, you might feel slight discomfort.
Myth 11: USG films are sufficient for re-evaluation
An ultrasound is a dynamic procedure that can be studied only while it is being done. Therefore, USG images (especially done elsewhere) are usually insufficient to comment on the findings or the lack of it.
Myth12: An ultrasound done anywhere will give the same result
It is not a branded grocery, where the items remain the same at any location. On the contrary, an ultrasound is a highly skilled procedure which is largely dependent on the doctor performing it. Therefore, the experience of the doctor and time spent makes a huge difference.
Myth 13: Every ultrasound gives complete information of the whole body
Every ultrasound is tailored according to the need of the patient and gives information only about the examined part. For a patient suffering from abdominal pain, the USG will be tailored to look for the cause of pain; for a pregnant lady, the foetal USG will monitor the baby. Similarly, if an ultrasound of the leg is done, information of only the said body part will be available.
Myth 14: They are only for pregnancies
A USG gives a better picture of what is going on inside one’s body, pregnant or not. It can be helpful to doctors in detecting a variety of conditions in other areas of the body. Some of the most common uses of ultrasounds include assessing major organs like the heart, liver, bladder, and kidneys to check possible damage to the organs.
Myth 15: One must not eat before any ultrasound
It is partially correct as you should not eat if you have an abdominal ultrasound, otherwise it is perfectly fine to eat before the procedure. This is important especially for pregnant women who should not go hungry for long hours.
Ultrasound findings, such as a stone or cyst, will remain the same in serial scans. The human body is dynamic and it keeps change while going through its functions. Similarly, diseases can increase, remain the same or decrease with time. Therefore, it is possible that your ultrasound report will show changes during different time periods. In fact, serial USGs take place mainly for the purpose of monitoring.
(The writer is Foetal Medicine Consultant, Cloudnine Group of Hospitals, Chandigarh.)