CT Scans of Maxillofacial Trauma Can Be Taken At Lower Radiation Doses Without Loss of Diagnostic Accuracy
Computed tomography scans can reveal the fine detail of anatomical features, but they expose the patient to levels of ionizing radiation that are increasingly worrying, given the dramatic growth of CT technologies in medical diagnostics. For midfacial fractures, multidetector and cone beam CTs are the preferred diagnostic methods; of the two methods, cone beam CT scans use less radiation, but the machines are less common in emergency rooms and only multidetector scans can reveal soft tissue injuries.
Males are particularly vulnerable to maxillofacial injuries. A 2011 study found that they comprised 68 percent of such patients in emergency rooms. To determine how much radiation doses could be lowered and still provide accurate diagnoses of maxillofacial injuries, Romke Rozema and colleagues at the University Medical Center in Groningen, Netherlands, took four multidetector and two cone beam images of four cadaver heads with maxillofacial traumas and two uninjured heads. After constructing fictional patient histories, they randomly assigned analysis of the images to 16 radiologists and eight oral-maxillofacial surgeons. All reviewers examined all images but not in the same order.
All 24 observers correctly detected fractures in four specimens, one misdiagnosed one of the unfractured specimens, and less than half correctly diagnosed the second unfractured specimen. There were also some differences in identifying the correct site of injury, with zygomatic arch fractures most often identified correctly and zygomatic alveolar crest fractures least often. However, dose reduction did not reduce the reviewers’ ability to diagnose whether a fracture was dislocated or comminuted (broken into small fragments), or affect interpretation of soft tissue images.
The researchers note that their study confirms two earlier studies that had the same results but lacked the randomized blinded structure of the current experiment, demonstrating that lower doses of radiation do not reduce accuracy of diagnosis or application of test results to treatment plans for maxillofacial trauma.
The study was published May 31 in Dentomaxillofacial Radiology.