Posted October 1, 2022 by Anusha ‐ 5 min read
Ultrasound is a noninvasive imaging test that shows structures inside your body using high-intensity sound waves. Healthcare providers use ultrasound exams for several purposes, including during pregnancy, for diagnosing conditions and for image guidance during certain procedures.
What is an Ultrasound?
Ultrasound (also called sonography or ultrasonography) is a noninvasive imaging test.
An ultrasound picture is called a sonogram.
Ultrasound uses high-frequency sound waves to create real-time pictures or video of internal organs or other soft tissues, such as blood vessels.
Ultrasound enables healthcare providers to see details of soft tissues inside your body without making any incisions (cuts).
And unlike X-rays, ultrasound doesn’t use radiation.
How does an Ultrasound work?
During an ultrasound, a healthcare provider passes a device called a transducer or probe over an area of your body or inside a body opening.
The provider applies a thin layer of gel to your skin so that the ultrasound waves are transmitted from the transducer through the gel and into your body.
The probe converts electrical current into high-frequency sound waves and sends the waves into your body’s tissue. You can’t hear the sound waves.
Sound waves bounce off structures inside your body and back to the probe, which converts the waves into electrical signals.
A computer then converts the pattern of electrical signals into real-time images or videos, which are displayed on a computer screen nearby.
What are the different kinds of Ultrasounds?
There are three main categories of ultrasound imaging, including:
Pregnancy ultrasound (prenatal ultrasound).
Ultrasound guidance for procedures.
Healthcare providers often use ultrasound (often called prenatal or obstetric ultrasound) to monitor you and your baby during pregnancy.
Providers use prenatal ultrasound to:
Confirm that you’re pregnant.
Check to see if you’re pregnant with more than one baby.
Estimate how long you’ve been pregnant and the gestational age of your unborn baby.
Check the fetal growth and position of your unborn baby.
See the movement and heart rate of your unborn baby.
Check for congenital conditions (birth defects) in your unborn baby’s brain, spinal cord, heart or other parts of their body.
Check the amount of amniotic fluid.
Examples of diagnostic ultrasounds include
An ultrasound probe moves across the skin of your midsection (belly) area. Abdominal ultrasound can diagnose many causes of abdominal pain.
Kidney (renal) ultrasound
Providers use kidney ultrasound to assess the size, location and shape of your kidneys and related structures, such as your ureters and bladder. Ultrasound can detect cysts, tumors, obstructions or infections within or around your kidneys.
A breast ultrasound is a noninvasive test to identify breast lumps and cysts. Your provider may recommend an ultrasound after an abnormal mammogram.
This is a special ultrasound technique that assesses the movement of materials, like blood, in your body. It allows your provider to see and evaluate blood flow through arteries and veins in your body. Doppler ultrasound is often used as part of a diagnostic ultrasound study or as part of a vascular ultrasound.
A pelvic ultrasound looks at the organs in your pelvic area between your lower abdomen (belly) and legs. Some of the pelvic organs include your bladder, prostate, rectum, ovaries, uterus and vagina.
Your provider inserts a probe into your vaginal canal. It shows reproductive tissues such as your uterus or ovaries. A transvaginal ultrasound is sometimes called a pelvic ultrasound because it evaluates structures inside your pelvis (hip bones).
Providers use ultrasound to assess your thyroid, a butterfly-shaped endocrine gland in your neck. Providers can measure the size of your thyroid and see if there are nodules or lesions within the gland.
Your provider inserts an ultrasound probe transducer into your rectum. It evaluates your rectum or other nearby tissues, such as the prostate in people assigned male at birth.
Ultrasound guidance for procedures
Providers sometimes use ultrasound to perform certain procedures precisely. A common use of ultrasound is to guide needle placement to sample fluid or tissue from:
Cysts or fluid collections.
Organs (liver, kidney or prostate).
Transplant organs (liver, kidney or pancreas).
Procedure of Ultrasound
Preparation for an ultrasound varies depending on what body part you’ll have scanned. Your provider may ask you to remove certain pieces of clothes or change into a hospital gown.
Ultrasounds that involve applying the transducer (probe) over your skin (not in your body), follow these general steps:
You’ll lie on your side or back on a comfortable table.
The ultrasound technician will apply a small amount of water-soluble gel on your skin over the area to be examined. This gel doesn’t harm your skin or stain your clothes.
The technician will move a handheld transducer or probe over the gel to get images inside your body.
The technician may ask you to be very still or to hold your breath for a few seconds to create clearer pictures.
Once the technician has gotten enough images, they’ll wipe off any remaining gel on your skin and you’ll be done.
What conditions can be detected by ultrasound?
Ultrasound can help providers diagnose a wide range of medical issues, including:
Abnormal growths, such as tumors or cancer.
Ectopic pregnancy (when a fertilized egg implants outside of your uterus).
Kidney or bladder stones.
Cholecystitis (gallbladder inflammation).
Varicocele (enlarged veins in the testicles).