DIAGNOSTIC PERFORMANCE OF CT, MPR AND 3DCT IMAGING IN MAXILLOFACIAL TRAUMA

CT imaging of complex maxillofacial fractures is common practice now, but the relative diagnostic value of spiral computed tomography (CT), multiplanar reformations (MPR), and three-dimensional (3D) reconstruct ions in evaluating maxillofacial fractures is not established with ind ependent validation of correct diagnosis. We studied these modalities and measured their diagnostic value in a carefully controlled observer based rated response experiment. Multiple fractures were created by b lunt experimental trauma in nine adult cadaver heads (five males, four females). Spiral CT scans were performed on all specimens before (con trol) and after trauma. Axial slices (CT), sagittal and coronal multip lanar reconstructions (MPR), and 3D volumetric reconstructions views w ere generated. Truth was determined by defleshing the specimens and di rect inspection of the traumatized skull. Three expert readers separat ely interpreted CT, MPR and 3D film hard copy images presented in rand om order blinded to patient identification or experimental conditions. We measured the time to diagnose each case as recorded by a monitor w ho was present while evaluations were performed. Twenty-eight facial r egions were evaluated using rated response and free response illustrat ive formats. Each region was considered separately. Sensitivity and sp ecificity were calculated to measure observer performance. We found th at 3D and CT had a similar performance in fracture detection and both were markedly better than MPR. For free response illustrative data, CT correctly identified 10% more orbital fractures than 3D, and approxim ately 10% fewer zygomatic fractures. Fracture localization was best wi th 3D. Reader confidence was highest with CT, but assessment time was faster with 3D. We conclude that CT and 3D are comparable in detecting midfacial fractures and both are superior to MPR. 3D reconstructions are superior for localization of complex fractures involving multiple planes. (C) 1996 Elsevier Science Ltd.