When your doctor needs to diagnose an unknown illness or injury they often start by taking a look at what’s happening under your skin. Rather than opening you up surgically, though, they’ll start with medical imaging techniques.
These techniques, like x-rays, CT scans, and MRIs, all provide a glimpse into different parts of your body. When they need to take a look at soft tissues in real-time, doctors often rely on a particular type of imaging called sonography.
What is diagnostic sonography, and what kind of information can it help your doctor learn about you? To find out more, keep reading through our guide to medical sonography basics.
What Is Sonography?
Sonography is a type of imaging that uses ultrasonic sound waves to create a picture called a sonogram. These sound waves measure between 2-18 megahertz, a frequency hundreds of times higher than the human ear can hear. In general, the higher the frequency, the clearer the image produced will be.
To send these ultrasonic waves through your body, a sonographer will use a wand-like handheld device called a transducer. They’ll apply a specialized gel to your skin and move the transducer back and forth on top of it. Some specialized transducers can also be inserted into body cavities or blood vessels.
As the sound travels through your body, it passes through areas of fluid and soft tissue. It bounces off of denser areas and sends data back to the device.
A computer interprets this pattern of “echoes”. It then compiles them into a picture that medical professionals can understand.
A sonogram isn’t a full-color picture like a photograph. Instead, it’s made of varying shades of gray that reflect the density of the tissue in that area.
Types of Sonography
The main factor that changes between different types of sonography is the speed of the sound waves. High-frequency ultrasounds can create clear, easy-to-understand pictures. Even so, they can only pass through a few inches of tissue.
To get a look at what’s happening deeper within, doctors have to use a low-frequency ultrasound that produces a grainier image. Your ultrasound technician may use a combination of frequencies to get the full picture.
Traditional sonograms create 2D images of 3D spaces. Thanks to modern computing, though, it’s possible to create a 3D or 4D ultrasound as well. These are most often used in pregnancy to get a better look at the baby’s development.
What Conditions Can Diagnostic Sonography Identify?
The type of image an ultrasound produces isn’t useful for diagnosing every type of medical condition. They aren’t helpful when looking at broken bones, for example, because bone tissue is too dense for the sound waves to pass through. Even so, sonograms are incredibly helpful when your doctor needs a preliminary look at the health of your internal organs.
Normal and Abnormal Pregnancies
When most people think of diagnostic sonography, their minds jump to pregnant mothers getting a checkup at the OBGYN’s office. Pregnancy sonography is the type most often referred to as an ultrasound, but in reality, all sonography uses ultrasonic waves.
Pregnancy ultrasounds let doctors identify whether a baby is healthy and developing normally. They can check for physical abnormalities like cleft palate, limb deformities, and heart defects. This helps both the parents and their medical team plan for the level of support the baby will need once it’s born.
It also provides reassurance when a baby is developing as expected, and as such, it’s a normal part of prenatal care.
Diagnostic Cardiac Sonography
A special type of sonography called Doppler ultrasound is a common part of cardiac diagnostics. It helps physicians understand the speed of your blood flow, your blood pressure, and even find areas of obstruction. It’s also the basis for echocardiograms (EKGs).
Cardiologists can also use ultrasounds to examine the heart’s structure for damage. The sound waves will pass easily through the heart’s fluid-filled chambers. They’ll bounce off of muscle, valves, and other surrounding tissue to make an image.
Kidneys, Bladder, and Gallbladder
Your bladder, kidneys, and gallbladder are all prone to gathering mineral deposits known as calculi. Most often called kidney stones, bladder stones, or gallstones, these mineral deposits can be excruciatingly painful. Because the calculi are so dense compared to the surrounding tissue, they show up very clearly on a sonogram.
Some calculi will pass on their own given enough time (and adequate hydration). If they’re severe enough, they may need to be surgically removed.
There is a third option: breaking them into smaller pieces with ultrasonic waves. That’s right, the same type of sound that takes a picture of the calculi can disrupt them and make them easier to pass.
Known as Lithotripsy, this procedure sends concentrated ultrasonic shock waves toward the stones. The shock waves break them without damaging the surrounding soft tissue.
Other Abdominal Organs
Along with the three mentioned above, ultrasounds are also helpful for looking at your other internal organs. Abdominal ultrasounds are inexpensive, fast, and non-invasive. As such, they’re often the first type of imaging a physician will use to diagnose non-specific abdominal pain.
Doctors can use ultrasounds to look at your liver, pancreas, spleen, stomach, and intestinal tract. Any tumors will appear as spots on the ultrasound due to their higher density. A sonogram can also identify the presence of blood vessel abnormalities like an abdominal aortic aneurysm.
Medical Sonography Is a Valuable Diagnostic Tool
Diagnostic sonography is a powerful tool in a doctor’s arsenal. Indeed, it can’t identify every type of illness or injury. Even so, it can give medical professionals a clear visualization of what’s going on inside your body’s soft tissues.
If you think you could benefit from sonographic imaging, talk to your doctor about your options today.
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