Assessing whether the plane of section on CT affects accuracy in demonstrating facial fractures in 3-D reconstruction when using a dried skull.

CT slice thickness and threshold value are well-known determinants of accuracy in three-dimensional (3-D) CT image reconstruction. The purpose of this study was to assess whether the plane selected for primary CT data acquisition, axial vs coronal, might also contribute to the accuracy and ease of identification of abnormalities in 3-D image reconstruction independent of the 3-D processing system used. Two sets of 10 observers evaluated fractures created in a dried skull and corresponding 3-D image data. A General Electric 9800 scanner was used to acquire the two-dimensional CT data. The 3D98 Quick software and ISG Camra Allegra workstation were used for two sets of 3-D reconstructions. The expected result was that fractures oriented perpendicularly to the initial plane of CT section would be better reconstructed on 3-D than when the initial plane of CT imaging paralleled the fracture. Our results indicate that Le Fort fractures (types I and III) are better displayed with coronal CT data and that zygomatic tripod fractures may be better displayed in 3-D with axial CT image data.