Last weekend, the team from UC Davis radiology traveled to UC Irvine to teach an introductory ultrasound course. The tradition has been to teach a couple of courses there every year, and I joined the group for the first time. We had a great group of enthusiastic vets eager to get their hands on the transducer. Some had never tried scanning before, and others had ultrasound machines in their practices and were looking to develop their skills. Regardless, everyone found something to work on and made huge strides by Sunday afternoon.
We had six experienced ultrasonographers teaching with lectures and one-on-one, so there were lots of tips being offered. Here are 5 ways to improve your technique and skills in veterinary abdominal ultrasound.
The organs are laterally located
With the dog in dorsal recumbency, most of the ograns we are looking for are located around the periphery of the abdomen. The kidneys, adrenals, spleen, and right lobe of the pancreas are all more lateral than you would think.
Vary your pressure
If there is a deep structure that you need to see like the liver, a certain amount of transducer pressure will help to get you closer to it, and move other organs out of the way. But when you move on to the spleen, you need to lighten the pressure to just touching the skin, since it’s located just a centimeter or two from the transducer. Collapsible organs like the caudal vena cava and urinary bladder will have an altered shape from too much transducer pressure. You’ll get the best image of each organ, and the animal will tolerate your examination better with this technique.
Adjust one thing at a time
There are three basic motions you can scan with; sweeping (moving the transducer across the skin), fanning (keep the footprint in the same place and look from side to side) and rotation. As a novice ultrasonographer, it’s best to adjust one of these things at a time to maintain orientation. For example, you would sweep to find the kidney. Once you see it, stop, and slowly rotate the transducer so that the kidney looks as large as possible to get a true sagittal image. Then stop again, and start fanning side to side to see the parenchyma. Separating these motions will stop you from losing the structure you’re interested in, or seeing it in an odd orientation.
Keep one hand on the buttons
One hand is doing the scanning, but the other should be constantly changing depth, gain, and focal zone. Adjust the depth so that the organ of interest fills the screen; you’ll maximize the detail you can see. The focal zone should be in the middle of the area of interest. The arrow on the scale tells you where the ultrasound beam is thinnest, and where on the screen you’ll get the best resolution. Gain can be adjusted for different attenuating tissues like liver and bladder to reduce artifacts.
Get out the anatomy atlas
Half of being able to do abdominal ultrasound is knowing where the organs are. It’s been a long time since first year veterinary school, and sometimes the details are fuzzy. You need a 3D map of the abdomen in your head to be able to find the organs, and to recognize them from different angles. Looking at some photographs or drawings of the relationships between the abdominal organs is a big help.
Try one of these tips at a time, and soon you’ll notice an improvement in your confidence and skill. What problems do you have with abdominal ultrasound? Post a comment!