Metal artifact reduction in dental CT images using polar mathematical morphology

Abstract

ElsevierNaranjo Ornedo, V.; Lloréns Rodríguez, R.; Alcañiz Raya, ML.; López-Mir, F. (2011). Metal artifact reduction in dental CT images using polar mathematical morphology. Computer Methods and Programs in Biomedicine. 102 (1) AbstractMost dental implant planning systems use a 3D representation of the CT scan of the patient under study as it provides a more intuitive view of the human jaw. The presence of metallic objects in human jaws, such as amalgam or gold fillings, provokes several artifacts like streaking and beam hardening which makes the reconstruction process difficult. In order to reduce these artifacts, several methods have been proposed using the raw data, directly obtained from the tomographs, in different ways. However, in DICOM-based applications this information is not available, and thus the need of a new method that handles this task in the DICOM domain. The presented method performs a morphological filtering in the polar domain yielding output images less affected by artifacts (even in cases of multiple metallic objects) without causing significant smoothing of the anatomic structures, which allows a great improvement in the 3D reconstruction. The algorithm has been automated and compared to other image denoising methods with successful results.

Accuracy of linear intraoral measurements using cone beam CT and multidetector CT: a tale of two CTs

“…39 Implants, dental reconstructions and orthodontic appliances may cause beam hardening and streaking artefacts, thus decreasing image quality. 40 To determine image quality in our study, we have evaluated the number of NASs due to metallic dental reconstructions. The results show that, compared with the CBCT scans, MDCT scans showed more NASs because of the close proximity of the measured area to the metal reconstructions.…”

Improved Image Quality in Head and Neck CT Using a 3D Iterative Approach to Reduce Metal Artifact

“…More elaborate strategies include monoenergetic processing of dual-energy CT data, which works nicely for surgical plates and implants, 11,12 but its effect is limited with dental hardware. Sinogram in-painting methods 8,13,14 and iterative, 15,16 statistical, 17,18 and filtering methods 13,19 have been suggested, but for various reasons, they have not made their way into clinical practice. NMAR is an in-painting-based MAR method that is designed to reduce metal artifacts and to prevent the introduction of new artifacts by replacing raw data from the metal trace more reliably.…”

Can MRI accurately detect pilon articular malreduction? A quantitative comparison between CT and 3T MRI bone models

“…Metallic implants generate metal artefacts on CT and MRI, which can be reduced to some extent using postprocessing algorithms (13) and specific scanning protocols (14,15). A recent study by the authors quantifying metal artefacts had reported that if metal screws are ~2 or ~3 mm away from the ankle joint for CT and MRI respectively, a clear visualisation of the ankle joint can be obtained (16).…”