Ultrasonography, or medical sonography, is a diagnostic medical imaging technique used to visualize many internal organs, their size, structure and any pathological lesions with real time tomographic images. It is also used to visualize a fetus during routine and emergency prenatal care. Ultrasound scans are performed by medical health care professionals called sonographers. Obstetric sonography is commonly used during pregnancy. Ultrasound is one of the most widely used diagnostic tools in modern medicine. The technology is relatively inexpensive and portable, especially when compared with modalities such as magnetic resonance imaging (MRI) and computed tomography (CT).
As currently applied in the medical environment, ultrasound poses no known risks to the patient. Sonography is generally described as a safe test because it does not use ionizing radiation, which imposes hazards, such as cancer production. A typical fetal scan, including evaluation for fetal malformations, typically takes 10-30 minutes. Obstetric ultrasound can be used to identify many conditions that would be harmful to the mother and the baby. For this reason, many health care professionals consider that the risk of leaving these conditions undiagnosed is much greater than the very small risk, if any, associated with undergoing the scan.
Obstetric ultrasound is primarily used to:
- Date the pregnancy (gestational age)
- Confirm fetal viability
- Determine location of fetus, intrauterine vs. ectopic
- Check the location of the placenta in relation to the cervix
- Check for the number of fetuses (multiple pregnancy)
- Check for major physical abnormalities
- Assess fetal growth (for evidence of intrauterine growth restriction [IUGR])
- Check for fetal movement and heartbeat
- Determine the sex of the baby
Sonohysterography is a technique developed to better image the uterine cavity. It uses an infusion of sterile saline through a soft plastic catheter placed in the cervix in conjunction with transvaginal ultrasound. The saline infusion distends the uterine cavity and provides an excellent contrast to the lining, giving improved visualization of uterine and endometrial pathology.
A nuchal scan is a sonographic prenatal screening scan (ultrasound) to help identify higher risks of Down syndrome in developing babies. The scan is carried out at 11-14 weeks pregnancy and assesses the amount of fluid behind the neck of the fetus - also known as the nuchal translucency. Babies at risk of Down syndrome tend to have a higher amount of fluid around the neck. The scan may also help confirm both the accuracy of the pregnancy dates and the fetal viability. Its high definition imaging may also detect other less common chromosomal abnormalities.
Frequently Asked Questions
- Where will my ultrasound be performed?
Most insurers will allow you to have your ultrasound performed in our office.
- How many people can be in the room during my ultrasound?
You are welcome to bring along one or two family members or friends. Any children must be chaperoned by an adult other than the person having the ultrasound. Please remember that the technician needs to focus on you and your study.
- Do I need to have a full bladder for a nuchal translucency?
Your bladder needs to be quite full in order to perform this procedure. Transvaginal ultrasound is typically not successful for this type of test.
- Are copies of my ultrasound images available at anytime?
Yes, images are stored on the hard drive of our GE Voluson. Each month we copy these files to disk storage. Knowing the exact month of your scan will help use find your images.
- What is a Sonohystogram?
A very thin catheter/plastic tube is passed though the cervix to allow us to fill the uterus with fluid/ saline while the sonographer obtains images. With the fluid in place we are able to evaluate the lining of the urterus (endometrium) in much more detail than with a standard ultrasound. The entire procedure usually takes less than 15 minutes and may cause a little bit of cramping.
- Can I eat before my ultrasound?