Ultrasound (or sonogram) technology allows doctors to “see” inside a patientwithout resorting to surgery. A transmitter sends high-frequency sound wavesinto the body, where they bounce off the different tissues and organs to produce a distinctive pattern of echoes. A receiver “hears” the returning echo pattern and forwards it to a special computer, which translates the data into an image on a television screen. Ultrasound is better than x rays at distinguishing subtle variations between soft, fluid-filled tissues, so it is particularly useful in providing diagnostic images of the abdomen, breast, eye, pelvis, scrotum, and thyroid. Unlike x rays, it does not damage tissues with ionizing radiation. Improvements in the technology, application, and interpretation of ultrasound continue. Its low cost, portability, versatility, safety, andspeed have made it a popular medical imaging technique. Ultrasound remains faster and less expensive than computed tomography scans (CT), its primary rival.
Why the test is done:
This is a very simple test in a lot of ways and can give your practitioners a lot of valuable information. However, it is important to note that the routine use of ultrasound is questioned, even by the American College of Obstetricians and Gynecologists in healthy, low risk pregnancies.
The most frequent reasons for its use are:
• Dating of the pregnancy
• Rule out ectopic pregnancy (tubal pregnancy)
• Check for fetal viability, particularly after bleeding or other complication
• Screening for certain genetic defects or anomalies
• Assist in certain genetic testing procedures like Amniocentesis and CVS
How the test is done:
This test can be done with an abdominal or vaginal probe depending on the stage of the pregnancy and what they are looking for. The transducer or probe sends out high frequency sound waves which are sent into the body. As they pass through they bounce off different objects and are sent back as electrical signals, which are then processed and displayed as the image on the screen. You may be asked to have a full bladder for better viewing of the baby and uterus.
For the abdominal ultrasound you will usually slip your pants down to the top of your thighs and a cold gel will be applied to aid in the visualization of the baby. The transducer is moved slowly over your abdomen and the signals are sent back to the machine which will project the images of your baby.Vaginal ultrasound is used earlier on in pregnancy. You will remove your pants and the vaginal probe will be inserted into your vagina for a better view.
When the test is done:
This test can be done at any point in pregnancy depending on the results that they wish to obtain. It is nearly impossible to see anything prior to the hCG levels of pregnancy reaching 1,500 – 2,000 mIU.
How the results are given:
Depends on the use of the test. Usually your practitioner will explain the results to you.
