Post processing “collimation”, shuttering or cropping seemed to be one of the greatest features of digital radiography. With our first CR unit we were taking badly collimated chest x-rays and then with a couple of mouse and key strokes turning in images that looked like we were the best collimating super techs in the world!!
After almost two years of this one of our radiologist’s finally realized something weird was gong on and asked what we were doing. When we told and showed him, he couldn’t believe it. He immediately told us that what were doing was basically illegal as the radiologist is legally responsible for every bit of anatomy that was radiated and appeared on the image receptor (IR). This rule has not changed one bit since the film days.
The predicament we have with this is no one even knows it’s a problem. I know for a fact that in one somewhat large U.S. city two different hospitals were sued because the radiographer cropped out anatomy that was later proven to have shown a tumor.
Picture this: You take a lateral C-spine and get almost the entire mandible on the image. You don’t notice that there is a small tumor in the mandibular body so you crop out almost the entire mandible, leaving just a perfect looking lateral C-spine. Six months later lawyers looking through every image taken on their client sees that your images would have shown the tumor half a year ago. Six weeks ago the patient had to have a huge part of their mandible excised in surgery because of the fast growing cancer. Your hospital is now being sued for five or ten million dollars and they are not even going to try to fight it because it would be impossible to win. It was completely your fault and everyone knows it.
Now I know you haven’t heard about these two cases. Also if it’s happened twice in this city, what are the odds it hasn’t happened countless times in cities all over the country? The reason this is still a secret is because the hospital is willing to hand over this incredibly large sum of money with one stipulation, and that is a gag order is invoked whereby no one is allowed to talk about the case. So until the day a patient decides to have their day in court, we are not going to read or hear about this.
So there are only two ways you can post “collimate” and have it still be legal. First is to only crop out areas that are outside the border of the body tissue (white or black areas). Second is to make a copy of the original image and turn it in along with the cropped version.