One of our students brought this to my attention today, and I thought it would be a great example to share here. The first image was the lateral chest view that I was asked to look at. The technical factors used were 120 kVp, 32 mAs (320 mA at 0.1 sec) which produced an S# of 459:
Let's zoom in to the lower lungs and diaphragm:
This is one of the reasons it is good to magnify your images (if possible) when you QC your work. You can tell that there is motion blur in the lung markings, lower ribs, and the diaphragm. We agreed to repeat the image and we made some changes to the technical factors. We decided to use 130 kVp at 32 mAs and change the mA and time stations (640 mA at 0.05 sec) which produced an S# of 373. Here is image 2:
It is obvious that the patient had a larger breath in this time, and we are starting to see more density through the lung bases. Even without zooming, you can see a large improvement in visualization of lung detail, ribs and diaphragm. I'm going to window/level adjust and zoom in to compare to the prior zoomed image:
The difference is clearly noted with this magnified image. Lung markings have clear, crisp detail, as well as well defined diaphragm margins and ribs. You even notice far less visualization of the thoracic spine - another great example of why we do a breathing technique for T-spine.
I know that it doesn't take long to spot this after a couple of years experience as a technologist, but I have often heard students who say they have difficulty spotting motion on lateral chests. This is a great example of how motion normally appears - little or no motion toward the apices and motion more exaggerated toward the bases. Make sure to watch your patients' breathing and keep those time stations low!