Metallic dental artifact reduction in computed tomography (Smart MAR): Improvement of image quality and diagnostic confidence in patients with suspected head and neck pathology and oral implants

• Published in: European journal of radiology Vol. 118; pp. 153 - 160
• Main Authors: Feldhaus, Felix, Böning, Georg, Jonczyk, Martin, Kahn, Johannes, Fehrenbach, Uli, Maurer, M., Renz, D., Hamm, Bernd, Streitparth, Florian
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01-09-2019
• Subjects: Aged; Algorithms; Computer-assisted image processing; Dental Implants; Female; Head and Neck Neoplasms - diagnostic imaging; Humans; Male; Metals; Neck; Radiographic Image Interpretation, Computer-Assisted - methods; Reproducibility of Results; Signal-To-Noise Ratio; Squamous cell carcinoma; Tomography, X-Ray Computed - methods; Squamous cell carcinoma; DE-CT; CNR; SS-CT; Computer-assisted image processing; CTDI; DLP; IQR; HU; ROI; CT; SD; Artifacts; IJV; SNR; MS-CT; Neck; MAR
• ISSN: 0720-048X; 1872-7727
• DOI: 10.1016/j.ejrad.2019.07.015

We determined whether the Smart MAR metal artifact reduction tool - a three-stage, projection-based, post processing algorithm - improves subjective and objective image quality and diagnostic confidence in patients with dental artifacts and suspected head and neck pathology compared to standard adaptive statistical iterative reconstructions (ASIR V) alone.
The study included 100 consecutive patients with nonremovable oral implants or dental fillings and suspected oropharyngeal cancer or abscess. CT raw data of a single-source multislice CT scanner were postprocessed using ASIR V alone and with additional Smart MAR reconstruction. Image quality of baseline ASIR V and Smart MAR-based reconstruction series was compared both quantitatively (5 regions of interest, ROIs) and qualitatively (two independent raters).
Additional Smart MAR reconstruction significantly seems to improve both attenuation and noise adjacent to implants and in more distant areas (all p < 0.001) compared to standard ASIR V reconstructions alone. Signal-to-noise ratio (SNR; p = 0.001) and contrast-to-noise ratio were improved significantly (CNR; p = 0.001). Smart MAR improved visualization of tumor/abscess (detected in 36 of 100 patients, 36%) and representative oropharyngeal tissue (p < 0.001). In 8 of 36 patients (22%), tumor was only detected in Smart MAR series. Mean total DLP was 506.8mGy*cm; average CTDIvol was 5.5 mGy.
The supplementary use of the Smart MAR post-processing tool seems to significantly improve both subjective and objective image quality as well as diagnostic confidence and lesion detection in CT of the head and neck. In 22% of cases, the tumor was detected only in Smart MAR reconstructed images.