Metal artefact reduction with cone beam CT: anin vitrostudy

Abstract

Background: Metal in a patient's mouth has been shown to cause artefacts that can interfere with the diagnostic quality of cone beam CT. Recently, a manufacturer has made an algorithm and software available which reduces metal streak artefact (Picasso Master 3DH machine; Vatech, Hwaseong, Republic of Korea). Objectives: The purpose of this investigation was to determine whether or not the metal artefact reduction algorithm was effective and enhanced the contrast-to-noise ratio. Methods: A phantom was constructed incorporating three metallic beads and three epoxy resin-based bone substitutes to simulate bone next to metal. The phantom was placed in the centre of the field of view and at the periphery. 10 data sets were acquired at 50-90 kVp. The images obtained were analysed using a public domain software ImageJ (NIH Image, Bethesda, MD). Profile lines were used to evaluate grey level changes and area histograms were used to evaluate contrast. The contrast-to-noise ratio was calculated. Results: The metal artefact reduction option reduced grey value variation and increased the contrast-to-noise ratio. The grey value varied least when the phantom was in the middle of the volume and the metal artefact reduction was activated. The image quality improved as the peak kilovoltage increased. Conclusion: Better images of a phantom were obtained when the metal artefact reduction algorithm was used.

Diagnostic accuracy of cone beam computed tomography with and without metal artifact reduction algorithm in detection of vertical root fractures of teeth with metallic posts

“…Teeth roots were covered by wax to simulate soft tissue. [9] Only single-rooted teeth included in the study to avoid the superimposition of other endodontically treated roots.…”

Cone-beam CT to assess bony fusion following anterior cervical interbody fusion

“…Another advantage of CBCT is that metal artefacts do not influence CBCT image quality as much as they do with classical CT [12,13]. Most ACIF procedures will use some manner of metal implant, either stainless steel or titanium, in the procedure.…”

Identification of occlusal prematurity by clinical examination and cone-beam computed tomography

“…The result is the pronounced presence of radiopaque and bright bands in the form of rays, marginal non-linear gradients and errors in the samples of surface restoration. Consequently, this creates serious difficulties of interpretation in the researched areas by the presence of artifacts (25). For this reason, many professionals justified the impossibility to determine the existence or absence of occlusal prematurity due to the presence of artifacts and lack of sharpness in the images.…”