Learners get confused sometimes about which direction the probe is facing. Let’s look at how to know if you have it right or not.

Having the probe marker pointed in the right direction is always important, but particularly so when using ultrasound for procedural guidance / needle placement. This is entry level stuff, but sometimes we need to go over the entry level stuff.

When I look at the screen, I want what is on the right side of the image to correspond to my right. One quick way to check if we have the transducer backwards is to “roll it on.” Touch one side of the probe to the patient and look at the screen to confirm that the side of the transducer making contact is the same side the the image appears on the screen. The examples below show what it looks like when it is in the correct orientation vs the incorrect orientation.

Probe in the correct orientation

Notice that as we look at the probe, the right side touches down first then rolls on to the gel model. Then notice that the image appears on the screen from right to left, then is repeated moving in the opposite direction. This is the way it should look. In this orientation, my right is screen right. If I were to move my needle to the right on the gel, it would move to the right on the screen. All is well.

Probe in the incorrect orientation

In this clip, note that (as in the first example) the right side of the probe touches down first and rolls on from right to left. On the screen, however, the image appears from left to right. This tells us that the probe is backwards. If we tried to do a procedure in this orientation, we would have to move the needle to our right to get it to move left on the screen. Clearly, this is no good, and we need to turn the probe around.

That’s it. Quick and easy.

Scan Happy, my friends.