Postprocessing in Maxillofacial Multidetector Computed Tomography

Abstract

Multidetector computed tomography (CT) and volumetric rendering techniques have always been a useful support for the anatomical and pathological study of the maxillofacial district. Nowadays accessibility to multidetector CT scanners allows the achievement of images with an extremely thin collimation and with high spatial resolution, not only along the axial plane but also along the patient's longitudinal axis. This feature is the main theoretical assumption for multiplanar imaging and for an optimal 3-dimensional postprocessing. Multiplanar reconstruction (MPR) techniques permit images along any plane in the space to be obtained, including curved planes; this feature allows the representation in a single bidimensional image of different anatomical structures that develop on multiple planes. For this reason MPR techniques represent an unavoidable step for the study of traumatic pathology as well as of malformative, neoplastic, and inflammatory pathologies. Among 3-dimensional techniques, Maximum Intensity Projection and Shaded Surface Display are routinely used in clinical practice. In addition, volumetric rendering techniques allow a better efficacy in representing the different tissues of maxillofacial district. Each of these techniques give the radiologist an undoubted support for the diagnosis and the characterization of traumatic and malformative conditions, have a critical utility in the neoplastic evaluation of primary or secondary bone involvement, and are also used in the planning of the most modern radiosurgical treatments. The aim of this article is to define the main technical aspects of imaging postprocessing in maxillofacial CT and to summarize when each technique is indicated, according to the different pathologies of this complex anatomical district.

Keywords: Maxillofacial district; Maximum intensity projection; Multiplanar reconstruction; Shaded surface display; Volume rendering technique.