Improved Image Quality in Head and Neck CT Using a 3D Iterative Approach to Reduce Metal Artifact.
OBJECTIVE
Metal artifacts from dental fillings and other devices degrade image quality and may compromise the detection and evaluation of lesions in the oral cavity and oropharynx by CT. The aim of this study was to evaluate the effect of iterative metal artifact reduction on CT of the oral cavity and oropharynx.


METHODS
Data from 50 consecutive patients with metal artifacts from dental hardware were reconstructed with standard filtered back-projection, linear interpolation metal artifact reduction (LIMAR), and iterative metal artifact reduction. The image quality of sections that contained metal was analyzed for the severity of artifacts and diagnostic value.


RESULTS
A total of 455 sections (mean ± standard deviation, 9.1 ± 4.1 sections per patient) contained metal and were evaluated with each reconstruction method. Sections without metal were not affected by the algorithms and demonstrated image quality identical to each other. Of these sections, 38% were considered nondiagnostic with filtered back-projection, 31% with LIMAR, and only 7% with iterative metal artifact reduction. Thirty-three percent of the sections had poor image quality with filtered back-projection, 46% with LIMAR, and 10% with iterative metal artifact reduction. Thirteen percent of the sections with filtered back-projection, 17% with LIMAR, and 22% with iterative metal artifact reduction were of moderate image quality, 16% of the sections with filtered back-projection, 5% with LIMAR, and 30% with iterative metal artifact reduction were of good image quality, and 1% of the sections with LIMAR and 31% with iterative metal artifact reduction were of excellent image quality.


CONCLUSIONS
Iterative metal artifact reduction yields the highest image quality in comparison with filtered back-projection and linear interpolation metal artifact reduction in patients with metal hardware in the head and neck area.
From the Radiological Institute (W.W., M.S.M., M.B., N.B., M.U., M.L.), Friedrich-Alexander-University-Erlangen-Nuremberg, Erlangen, Germany wolfgang.wuest@uk-erlangen.de.
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Wuest
From the Radiological Institute (W.W., M.S.M., M.B., N.B., M.U., M.L.), Friedrich-Alexander-University-Erlangen-Nuremberg, Erlangen, Germany.
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MS
May
From the Radiological Institute (W.W., M.S.M., M.B., N.B., M.U., M.L.), Friedrich-Alexander-University-Erlangen-Nuremberg, Erlangen, Germany.
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Brand
From the Radiological Institute (W.W., M.S.M., M.B., N.B., M.U., M.L.), Friedrich-Alexander-University-Erlangen-Nuremberg, Erlangen, Germany.
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Bayerl
Medical Imaging (A.K.), Siemens Healthcare, Erlangen, Germany.
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Krauss
From the Radiological Institute (W.W., M.S.M., M.B., N.B., M.U., M.L.), Friedrich-Alexander-University-Erlangen-Nuremberg, Erlangen, Germany.
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Uder
From the Radiological Institute (W.W., M.S.M., M.B., N.B., M.U., M.L.), Friedrich-Alexander-University-Erlangen-Nuremberg, Erlangen, Germany.
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http://orcid.org/0000-0002-4800-4428
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Lell
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016477:Artifacts; D003287:Contrast Media; D003793:Dental Restoration, Permanent; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007479:Iopamidol / Q000031:analogs & derivatives; D008297:Male; D008670:Metals; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000000981:diagnostic imaging*; D009959:Oropharyngeal Neoplasms / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D008670:Metals; C057937:iomeprol; D007479:Iopamidol