Interpreting an ultrasound

[han14tra]

Could someone please explain why turning the ultrasound probe 90 degrees gives you a different view?

I'm a MS2 and got to do obstetric ultrasounds today. When I was holding the probe horizontal with the marker on the patient's right, the baby looked like her feet was towards the mom's head. When I turned the probe with the marker towards the mom's head, the baby looked like it's head was on the mom's left.

I'm not making sense of this. What was the actual position of the baby?
I also don't understand the orientation of the heart with different probe positions. Could someone put all of this in simple terms please?

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[BigRedBeta]

Think back to your anatomy course when you learned about coronal vs sagital views. You have to think about three dimensional structures and what "slice" you're taking out of them.

As far as your baby today...I'm not sure how much stock I should put in your assessment of fetal positions. Did you mean that with changes in position it appeared that different parts of the fetus looked closer to the probe? I think some people automatically interpret what's at the top of the screen as "mom's head" when that's not actually the case.

 

[han14tra]

Thanks. To clarify:

If I'm holding the probe with the marker towards the patient's head and I see the baby's head on the right side of the screen and it looks like the baby is laying horizontal on the screen, how is the baby actually positioned in utero? How does the image change if I turn the probe so the marker is on the patient's right?

 

[BigRedBeta]

Thanks. To clarify:

If I'm holding the probe with the marker towards the patient's head and I see the baby's head on the right side of the screen and it looks like the baby is laying horizontal on the screen, how is the baby actually positioned in utero? How does the image change if I turn the probe so the marker is on the patient's right?

Assuming that your screen is not reversed (ie, marker on the screen is on the *your* left, which would be the patients right, vs having the marker on the screen be on your right, keeping the probe marker towards your right - I find the latter more intuitive).

Based on my preferred method, what you've described would have the baby in a breech position, head towards the mother's head, and you're getting a saggital view. If the baby's spine is towards the top of your screen (closer to the probe), then the baby is facing towards the mother's back. If the spine is towards the bottom of the screen (deeper) than the baby would be facing forward.

Turning the probe 90 degrees so that the probe is horizontal is going to give you a cross sectional view, much like a CT would. This is the part where how your screen is set up is important. The probe itself, is creating identical images regardless of whether your marker is on the your right or the patient's right. What you see on the screen however, would be dependent on your set up. They're going to be mirror images of each other on the screen - think about how it would change if you kept the probe in the exact same spot, but flipped it so the marker was now the patient's left, the baby's anatomy hasn't changed, but your image would. I use an ultrasound when I'm attempting to place a central line, and I prefer my screen marker to my right, and then I always keep my probe marker towards the patient's head, or to MY right. That way, when I'm moving the probe to my right (patients left, typically) what is under my probe marker is on the right of the screen. Again, I find that more intuitive, but others have different opinions/methods. The key is to pick one method and get comfortable with it.

 

[km11]

Imagine the probe as a giant knife/deli slicer that'll slice the patient in half. However you point it is how its gonna cut and you're staring into the goop. So depending on how you're holding the probe, the view you see on the screen might have to be rotated 90 degrees etc.

If you're holding the probe horizontally at the woman's belly button with the notch to the woman's right (your left), the picture you get should be similar to a CT slice. If you rotate it clockwise 90 degrees so that the notch is pointing to the head, yo'ure now cutting her in half from head to pubis. Just think of it like that

 

[tsdary]

Hello,

I hope I can get some insight from this post!! I was originally pre-Optometry that had applied 2x and didn't make it in.. so I then thought about Sonography school. I got in and start in a few weeks, but the more I look into this and talk to sonographers, the more I hear about the issues w/ ergonomics. I had a spinal fusion when I was 17, have regular back pain, and have a little bit of carpal tunnel. From what I hear about sonography is that the ave. career span for an ultrasound tech is now 7 years due to work related injury! (this info was given to me at the orientation!) That scared me big time. I don't want to waste the next few years of my life, and the money if I'm not going to be able to physically handle it. Any words of advice out there??? Help!! I've GOT to make my decision this week - already got the first college bill!

Thanks in advance!!!

 

[Rendar5]

Hello,

I hope I can get some insight from this post!! I was originally pre-Optometry that had applied 2x and didn't make it in.. so I then thought about Sonography school. I got in and start in a few weeks, but the more I look into this and talk to sonographers, the more I hear about the issues w/ ergonomics. I had a spinal fusion when I was 17, have regular back pain, and have a little bit of carpal tunnel. From what I hear about sonography is that the ave. career span for an ultrasound tech is now 7 years due to work related injury! (this info was given to me at the orientation!) That scared me big time. I don't want to waste the next few years of my life, and the money if I'm not going to be able to physically handle it. Any words of advice out there??? Help!! I've GOT to make my decision this week - already got the first college bill!

Thanks in advance!!!

Hey, unfortunately this is not the right board for you to seek answers in. Most posters here are medical students and this post is about learning to understand the images seen. If you want to find a board for u/s techs, I'm sure there is a forum out there for you.

 

[Mattabet]

Imagine the probe as a giant knife/deli slicer that'll slice the patient in half. However you point it is how its gonna cut and you're staring into the goop. So depending on how you're holding the probe, the view you see on the screen might have to be rotated 90 degrees etc.

^^This is how I understand it too. The probe cuts a slice in whatever orientation you hold it.