Artifacts in Cone Beam Computed Tomography Image Volumes: An Illustrative Depiction

The evolution of cone beam computed tomography (CBCT) has brought about a paradigm shift in radiographic evaluation of the maxillofacial skeleton. Because of its low cost, high resolution, and relatively low-radiation dose, CBCT is fast becoming the 3-D imaging modality of choice in dentistry. The ubiquitous availability of this new imaging modality poses unique challenges in understanding this technology and recognizing the associated artifacts that present themselves in the acquired image volumes. There are several artifacts that are inherent to CBCT scans by virtue of the physics behind their acquisition and image reconstruction algorithms.

An image artifact may be defined as a visualized structure in the reconstructed data that was not originally present in the object or the imaged area of interest. It can be explained as any distortion or error in the image that is unrelated to the subject being studied. Artifacts are induced by discrepancies between the physical conditions of the measuring setup, which is usually the CBCT scanner's technical composition and position of the object under investigation.

The objective of this study is to present an illustrative depiction of the most commonly encountered CBCT artifacts with an explanation of how each artifact is caused and how it presents itself in CBCT image volumes.

Because these artifacts cause significant image degradation and often misrepresent the region of interest, they should be recognized, understood, and taught along with normal CBCT anatomy to facilitate accurate evaluation of the image volumes and prevent inaccurate diagnoses.