UGI Image Evaluation

One of the things I used to do multiple times per day as a radiologic technologist was upper GI's.  Though they're still being done quite a lot these days, I often forget how much effort we spent in x-ray school to learn how to properly tell them apart for hanging protocols.  We can distinguish our views by evaluating three things:

1. Location of barium within the stomach
2. Location of air within stomach
3. The spatial relationship between the stomach and spine

If you take the first image below, it's easy to look at the radiograph and think it was performed supine, when in fact, it was exposed with the patient prone.  The original x-ray may have been flipped horizontally upon first glance, but we are required to hang images in the anatomical position so it has been flipped.  The fundus of the stomach is full of air, while the body contains barium.  It is also superimposed over a non-rotated spine.  This tells me the patient was prone.

On a double-contrast study, we need to remember how the anatomy lies in relationship to other structures to tell the difference.  The fundus is superior to the body and also rests more posterior.  I can tell it is prone because the air will rise to the most posterior anatomy when prone.  I know this is not an upright exposure because while it would also demonstrate the barium in the body of the stomach, there would be more of a horizontal line separating the air/fluid level.

The lateral stomach view below demonstrates how the fundus is posterior to the body.  I know different hospitals can have different hanging protocols for lateral views.  So if I'm going to evaluate the image below to tell which lateral was performed, I could also reference the picture above knowing that the fundus lies to the patient's left side while the body and pylorus are more midline.  If we remember that the air will rise while barium settles, it should be easy to differentiate between a right and left lateral.  Since the barium is exiting the body and collecting in the pylorus and duodenum, we know that the patient's right side is down and a right lateral was performed.

Now, lets talk about oblique views.  Still referencing the first image, we can tell that if an RPO is performed, the stomach should superimpose the spine, which is typically undesirable for UGI studies.  The same would hold true for the opposite LAO.  We almost always perform RAO or LPO views of the stomach to free the pylorus, body and duodenum from superimposition of the spine.  That being said, look at the next image.  We can tell it is LPO because the stomach is free of the spine, and the body is full of air.  This is actually one of the radiologist's spot views.  After the stomach drains some of the contrast, the barium coats and we can rotate the patient to allow air to accumulate at the juncton.  Unfortunately, we cannot visualize the fundus, which is most likely full of barium, which would support our claim that this is an LPO.

*Tip: although the textbooks say "rotate 45 degrees," we should be mindful as technologists of the reasons for the rotation.  In this case, the radiologist needs to visualize gastric emptying function in profile while not being superimposed by the spine.  Some times we need to rotate more or less depending on patient body habitus, so keep an eye on the fluoro monitor when assisting the patient while rotating.  If you rotate 45 degrees, it may not be enough to adequately allow for an optimum view.  When contrast is involved, we need to be efficient, so we don't want to stand there waiting for the radiologist to tell us to turn the patient more while we're missing a good opportunity to image the stomach emptying.

Compared to the image above, the next set of images differs in that the barium is in the body, while air is in the fundus.  This tells us the fundus is superior to the body, but we also know it's an oblique due to several give-aways.  The fundus and body are free of superimposition of the spine, and you can also notice rotation of the spine itself.  For these reasons, we know these are RAO views.  They were taken in the position of the bottom left image below (where the fundus is closer to the x-ray tube/superior to the rest of the stomach).  The images were then flipped horizontally to represent anatomical position like in the bottom right image.

Evaluating UGI images can be somewhat confusing at first, but once you get it, it's like riding a bike.  If you can visualize how the stomach lies within the abdominal cavity, it's not so difficult.  Acquiring that knowledge early on in your studies will make a huge difference later when you're in the middle of a procedure.

*if you like the virtual images I posted, check out the interactive anatomy site, https://www.biodigitalhuman.com/.  There is an interactive anatomy skeleton with all body tissues which gives you the opportunity to isolate tissues of interest, rotate, zoom, and a few other helpful tools.