Somebody Stop Me! Post Processing Radiographic Images

Digital Radiography (DR) brought us many features and most are an improvement from where we were with film. The DR dark side began to show almost immediately upon implementation.  As we recovered from the astonishment of having the digital image at our fingertips as soon as we could say “SHAZAM” we began to see the downsides. Controversy is never very far away in health care and this new practice pattern began to make itself known. What is the problem? Manipulating the image after the radiation exposure has been delivered to the patient.

Digital radiography eliminated repeat images because of equipment failure or processing mistakes. Acceptable repeat rates for film imaging departments were usually monitored to a benchmark of 5%. The increased dynamic range of a digital image receptor in comparison to a film product allows greater flexibility in the amount of radiation exposure required to get a diagnostic image.  If you do not approve of exposure, the equipment allows you to “window” or “post process” the image to the correct level. If digital radiography was supposed to reduce the radiation dose to the patient, it has not reached the goal. And, if you do not like the image, just erase it! Yes, hit the delete button and the record of the patient’s radiation exposure disappears. When you add in the capability to hide the lack of primary beam collimation, the DR image receptor is the same size for all exams whether it is a finger or a pelvis. The reduction of the radiation exposure is strictly in the hands of the radiologic technologist or physician who controls the exposure switch. The rules for collimation and restriction of the radiation field have disappeared. What happened to ALARA? New regulations have been appearing for patient radiation dose and monitoring, but unless someone is in charge of Policy and Procedures and Quality Assurance, the problem exists without anyone’s knowledge. White papers from various radiology professional organizations have started to address this issue, but no impact from the opinions has been noticed.

AHEC did a survey this month to ask our readers and attendees what was really happening in the clinical situation.  We do have some interesting facts to report from our survey group. Our survey group reported 66% were working in an outpatient facility and the group was 63% females.

In our group 14% of the respondents used post processing every day instead of collimation. Only 12% said it was forbidden at their facility to use post processing instead of collimation. Another 37% said they did it sometimes. On a bad day over half of our respondents were not restricting the beam or the radiation dose.

When asked who is responsible for quality control of radiographic images at their facility 21% said no one. The majority listed the manager, chief tech, supervisor or the RSO as the person or job description who was responsible. Only 18% listed or identified the radiologist as the responsible person. However, when asked if the radiologist or group of radiologists were concerned about clinical issues or radiation exposure of patients 40% said their radiologist was concerned. Another 31% said the radiologist would interpret any image that was put into the PACS system. And 24% said the radiologists were not on site and the facility was using interpretation services.

The question about seeing a white line around the perimeter of the image to demonstrate collimation brought an overwhelming response that this practice has disappeared except for a small 23% of facilities. A separate question asked about state or federal regulations for ALARA was answered by 49% that they knew about regulations, but their facility had never been inspected by any agency. The remainder answered they were unfamiliar or did not have any knowledge.

When an x-ray tube beam restrictor device or collimator is opened to the fullest extent, the beam is magnified according to how far the x-ray tube is from the image receptor. If the image receptor is electronic, it has the capability to record an extremely wide range of radiation exposures. Opened to maximum width for a chest x-ray, it can deliver 200X the amount of radiation necessary for the actual procedure. The radiation creates more radiation as it interacts with the wall, table, floor, etc. Protecting the newborn from whole body exposure is important as it is with all children.  X-ray beams should be contained in procedures to only the area of diagnostic interest.

As we become more and more concerned about radiation exposure and keeping it As Low As Is Reasonably Achievable (ALARA), the newest radiation imaging technology definitely has a dark side Primary beam collimation to expose only the pertinent anatomy is an ethical responsibility of the radiographer. The following example of the overexposure of this child’s body including the reproductive organs and the body outside the chest and lungs is a perfect storm of mistakes forgiven by post processing an image to remove or restrict the field electronically.

Please! Somebody Stop Me!

This is an impossible dilemma.

Leave a Reply