30° tilt axial computed tomography imaging of the facial skeleton: Normal anatomy

An optimal computed tomography (CT) evaluation of the facial skeleton requires both axial and coronal sections. The axial sections are needed for the evaluation of vertical structures (anterior and posterior frontal sinus walls, zygoma, ethmoido-sphenoidal junction). The coronal sections are most helpful in accurately depicting horizontal structures (anterior skull base, orbital floor). In the coronal projection, however, the patient must be positioned with overextension of the head. Not all patients can tolerate or are medically amenable to this position.We describe a CT technique that is capable of producing excellent imaging combining the axial and coronal incidences. The patient is placed supine and the gantry is tilted at 30°. All components of the bony and adjacent soft tissue structures in their spatial relations are visualized by this technique.Although this technique provides no substantial improvement in the diagnosis when compared with axial and coronal sections together, it can be easily done and it visualizes the anatomic profile in all patients including the uncooperative, obtunded, or critically ill. This technique is described and the normal anatomy is discussed.