CT Imaging of facial trauma. Role of different types of reconstruction. Part I – bones

BACKGROUND Injury to the facial skeleton and the adjoining soft tissues is a frequently occurring condition. The main aim of this work was to assess the value of multiplanar and three-dimensional (3D) reconstruction computed tomography (CT) images obtained by using multi-detector row technology in spiral data acquisition in patients with facial skeleton injury. THE AUTHORS ATTEMPTED TO ANSWER THE FOLLOWING QUESTIONS: Are there particular mechanisms and types of injuries or locations of fractures which can be diagnosed significantly more effectively by conducting additional multiplanar image reconstructions? Do 3D image reconstructions contribute to the diagnostic process, to what extent? Compared to other imaging techniques, is the spiral CT data acquisition a more convenient for the patient and a faster investigation method of diagnosing post-injury lesions involving the facial skeleton? MATERIAL/METHODS Sixty-seven patients diagnosed with injury to the facial skeleton were referred for emergent CT scanning. Each patient underwent a CT scan with the use of a GE HiSpeed Qx/i scanner. The scans were conducted with the use of spiral data acquisition technique in the transverse plane. THE FOLLOWING SECONDARY IMAGE RECONSTRUCTIONS WERE CONDUCTED FOR EACH PATIENT: a two-dimensional (2D) multiplanar reconstruction (MPR), maximum intensity projection (MIP), and 3D volume rendering (VR). Post-injury lesions of the facial skeleton were assessed and the presence of any loose displaced bone fragments was taken into consideration. RESULTS As far as fracture imaging is concerned, the 2D image reconstruction and volume rendering proved to be the most effective in the majority of locations. 3D image reconstructions proved the most sensitive in most cases of loose displaced bone fragments, except for fine structures such as the ethmoid bone and the inferior orbital wall. CONCLUSIONS 1. Multiplanar computer reconstructions increase the effectiveness of visualisation of fractures, especially in the case of fractures in the inferior orbital wall. 2. 3D reconstructions are a good complementary technique allowing to locate loose bone fragments precisely and to assess the degree of displacement. 3. Spiral CT data acquisition increases patient's convenience due to shorter time required for examination, and allows to conduct reconstructions of satisfactory value.