Series 1: In Pursuit of the Pancreas
The elusive pancreas?? – oh but it is there right in front of us if we know the landmarks, where to look, what to look for, how to train the eye to look for the key features (JUST like with the phrenic veins of the adrenals). The SDEP abdominal progression teaches one how to image the pancreas whether you recognize it or not – but you need to recognize it so that you can optimize your images and recognize pathology. Anatomy and normal pretty pancs first, then on to pancreatitis, abscesses, neoplasia, necrosis in cats and dogs later in the series.
Start with an ANATOMY REVIEW and then the imaging landmarks will make sense. The left limb of the pancreas extends caudally from the gastric fundus and is located medial to the spleen in an open space of the left cranial abdomen. The right limb and right base run along the pylorus and descending duodenum.
In the dog, the left limb is blunted, will stop around the splenic hilus. In the cat, the left limb will extend very long to the left kidney and maybe beyond if inflamed.
- Go medial to the spleen, stomach on the left, colon on the right, and the left pancreatic limb will be in between.
- Follow the duodenum: from the “C-Loop” on the SDEP protocol, the pancreas will be right next to it.
- If you find the duodenal flexure, the pancreas will running right alongside the pyloric outflow.
- If you can see the pyloris, follow it to the duodenum and the panc will be just to the right “hugging” it. come off the right kidney and fan medially.
- Go sub xiphoid, point to the right shoulder and find the gallbladder.
- Go caudally to the pyloris, and the pancreatic body is to the right of that.
- From here you can often change your probe orientation and get the left and right limb.
Look for 4 HYPERECHOIC LINES:
- Two of them are the dual lines in the center (“railroad tracks”) representing the pancreatic duct- look for these 1st. They generally stand out from the isoechoic parenchyma, in the center.
- Two of them are the capsule – look for these next, equidistant from the duct, and continuous throughout the contour of the pancreas.
Canine Left Pancreatic Limb: The left limb is generally isoechoic to surrounding fat.
The spleen is placed long at the top of the image; the left limb is medial to the spleen (see diagram above) so start looking there. The stomach is imaged on the left; often the colon or the left kidney will appear on the right and possibly obscure the pancreas. The trick is to make room to visualize the pancreas between the stomach and the colon. Use the back of your probe hand to exert gentle pressure, spread your fingers and push aside the stomach and colon. Then release pressure just a bit to let the pancreas fall into place. Slide or fan up and down; the pancreas is right there. A normal pancreas will be curvilinear without deviation.
OPEN THAT WINDOW BETWEEN STOMACH AND COLON LOOK FOR THE DUAL LINE IN THE CENTER, THEN THE 2 LINES OF THE CAPSULE. ALWAYS KEEP MOVING WITH MICROMANEUVERS; nothing will magically appear by staring at a still image! When you are learning to see the pancreas, video clip or freeze and scroll back so you can look for the lines. Do this when you are done scanning so as not to take up time during the scan.
At first everything will look like hyperechoic capsule and dual hyperechoic lines
but keep pursuing this and look EVERY TIME ON EVERY ANIMIAL and it will start to get clearer.
The hyperechoic serosal capsule (C) and parallel hyperechoic lines of the pancreatic duct (PD) allow one to distinguish the pancreas from surrounding isoechoic fat in the normal dog. In this image, the hyperechoic nodule at the cranial pole of the spleen (large arrow) is an incidental finding in the near field.
Let’s look at the right pancreatic limb. As you can see in the diagram above, it parallels the descending duodenum (D), and is similar in appearance to the left limb. After you image the right liver and move caudally, start looking for the duodenum which is a reliable landmark. The pancreatic duct is the hyperechoic dual line in the middle (long arrow) of the linear hyperechoic serosa in the near and far field (small arrows).
Here is another view of the right pancreatic limb and duodenum, with the pancreas running alongside. This image shows proper measurement, from serosa to serosa with the duct in the center.
Not sure if you are looking at pancreatic duct or vessel? Put color flow on it; the duct has no color.
This image shows duodenal (D) and gas artifact coming in from the left trying to obscure the view, which is common. Use manual, widespread pressure with the back of the scanning hand to displace the artifact. Release pressure just a bit to allow the pancreas to fall into view. Note the thin hyperechoic line of the capsule is your landmark! Sometimes on the right, you will only see one line of the capsule.
- Using the key landmarks and scanning techniques discussed above, try to identify the pancreas in every scan you do.
- Annotate your images if you can, and send in to the forum under the post “Pancreatic campaign”.
- We will let you know if you are correct, and archive all of your images to a library for future training!
Go series 2: Review and more normal images.