Lordotic Much???

One of the most common errors I was guilty of as a student (and as a new technologist) was having a lordotic chest x-ray any time I did an AP view in the stretcher. There is a simple fix to this that I have yet to see in a textbook, but I have heard literally dozens of technologists use this tip: angle perpendicular to the sternum. Here's what your AP chest should look like; with emphasis on curvature of the ribs and the amount that the clavicles dip down into the apices:



And how here's what a portable chest sometimes looks like if you make your central ray perpendicular to the cassette:



I know what you're thinking... "Why is it that in a PA standing chest, this doesn't happen and I'm using a perpendicular beam?" Well, when you perform the PA standing chest, what do you do? You roll the patient's shoulders foreward so that the sternum is up against the bucky, making it parallel to the IR. Think about this... if you were to leave the patient in the same position and simply turn them around to be facing the tube, you would probably be able to make a fist and place it between their shoulders and the bucky. Let's look at this lateral projection for a point of reference:



The red line indicates the central ray passing through the sterno-clavicular joints. This patient's back is almost vertical, as it would be if placing a film behind them for the AP sitting chest, and there is not much lung field above the sterno-clavicular joint. You might have to lean this patient forward for the AP projection to demonstrate the clavicles in the lung field at all. Now if I angle perpendicular to the sternum, it will project the clavicles down into the apices as it would if I were rolling the shoulders forward for a PA projection:



Another common error that produces similar results is patient positioning in the stretcher. Ideally, you need the patient sitting upright with the stretcher at 90 degrees with your cassette behind the patient. What you want to do is have the patient scoot (or you may need to slide them before you sit them up) so that they are bending at the waist with the stretcher. You don't want a gap between their hips and the upright portion of the stretcher. This elevates the clavicles, making a lordotic position similar to the standing lordotic chest we all learned about in school and shown here:



If you combine this error with the previous error of not angling to the sternum, the resulting image could be horrid. Check out the following picture:



The first central ray would produce a lordotic image with a foreshortened lung field due to the angulation of the patient (caused by not having the hips flush against the stretcher). The second central ray would project the clavicles downward into the apices as needed, but would probably produce an elongated effect due to the patient's hips being away from the IR. The lower lung fields have increased OID, causing magnification which may cause the radiographer to be unable to include the entire lung field on the image.

For best results, keep it simple: sit the patient up as much as possible, bending at the waist where the stretcher flexes. Prevent OID on all of your film, and angle perpendicular to the sternum to avoid a lordotic projection (and don't forget to shield).