Ultrasound Modes – A Review

Diagnostic medical sonography was introduced to the medical world in the late 1950s and since then it has been appropriated for nearly every branch of medicine. There are several good reasons for that, as well. It’s safe, noninvasive, versatile, accurate, and inexpensive compared to other diagnostic options. In fact, it is used more than any other type of diagnostic tool in the medical field. Most people are familiar with the images of new parents looking at their unborn child for the first time through the use of an ultrasound. But many don’t realize that there are numerous different ultrasound modes, each with benefits and drawbacks and each used for different things.

A-Mode – This is ultrasound at its simplest. The transducer simply maps out a single line as the sound passes through the body. The echoes are plotted in a depth chart on the monitor’s screen.
B-Mode – This mode uses a bank of transducers to create a 2D image on the screen by scanning an entire plane within the body instead of a single line.
C- Mode – C-Mode uses both A and B modes, starting by using A-Mode to create a specific region which is then scanned with B-Mode ultrasound to create an image of that region.
M-Mode – The M stands for motion, which is just what this ultrasound mode does. It utilizes 2D scanning technology but the pulses of sound are released rapidly. This allows the ultrasound technician to capture what amounts to video data of the area in question.
Doppler Mode – Using the Doppler Effect in its scans, this mode of ultrasound is most commonly used to chart blood flow within the body. There are numerous specific types of Doppler mode ultrasound including color, continuous, duplex, and pulse wave.
Pulse Inversion – This mode is frequently used to view gasses within the body and emits two opposite pulses which are then subtracted from each other.
Harmonic Mode – This mode uses harmonic overtones to create better depth penetration.
3D – This mode utilizes multiple 2D scans and then combines them digitally, building a 3D representation of the image. It can create striking views of organs and unborn babies.

Some of these modes are primarily utilized by certain branches of medicine, such using Doppler mode in vascular sonography applications. Others may be used by multiple branches. At any rate, there’s no denying the usefulness of diagnostic medical sonography. It has come a long way in fifty years, but is still undeniably vital to modern medicine.