Put your head on my shoulder…
We started digging in to the humerus and shoulder positioning techniques in lab today. The positions we studied are:
AP Humerus
Lateral Humerus
Transthoracic Lateral Humerus
AP Internal Shoulder
AP External Shoulder
Superoinferior Axial Shoulder
Scapular Y Lateral Shoulder
All of these views are 40″ SID with the CR perpendicular to the image receptor, except for the suproinferior axial shoulder, which uses a 40″ SID with a 5 to 15-degree angle on the tube towards the elbow. The AP and Lateral Humerus views use a 14×17 image receptor in most cases, while the rest can use 10×12 (or possibly 8×10 depending on the patient.)
These positions aren’t too difficult. The transthoracic lateral humerus requires an interesting breathing technique, because it’s a rather long exposure at 4-5 seconds. The technique is rapid and shallow breathing to blur out some of the anatomy in the picture. The patient positioning for the AP and Lateral Humerus is practically identical to the positioning for the AP Internal and External shoulder. The only difference is where you are centering your beam and what you are actually looking at. We spent about two hours in lab practicing these positions. Each student took a turn at positioning another student for these routines.
I really wish we were actually able to make some radiographs. Our instructor is watching what we do and telling us where our problems may be, but executing a positioning routine and then not having a radiograph to see afterwards still feels strange to me. We don’t really know how good our positioning technique is without being able to see a resulting image. I do realize that we can’t radiate each other all semester :)
I’m having a test in the morning on imaging concepts. This test is covering a lot of general topics such as the inverse square law, density maintenance formula, mAs calculations, photographic and geometric properties of images, contrast, density, film (what it’s made of and how it works), intensifying screens, grids, grid ratios, grid frequencies, et cetera. I don’t think it’s going to be too difficult, but I’m going to spend an hour or two studying anyway.