Prediction of detectability of the mandibular canal by quantitative image quality evaluation using cone beam CT.

Prediction of detectability of the mandibular canal by quantitative image quality evaluation using cone beam CT.

Dentomaxillofac Radiol. 2018 Jan 29;:20170369

Authors: Takeshita Y, Shimizu M, Jasa GR, Weerawanich W, Okamura K, Yoshida S, Tokumori K, Asaumi J, Yoshiura K

Abstract
OBJECTIVES: To compare the results of a new quantitative image quality evaluation method that requires no observers with the results of receiver operating characteristic (ROC) analysis in detecting the mandibular canal in cone beam CT (CBCT) images.
METHODS: A Teflon (polytetrafluoroethylene) plate phantom with holes of different depths was scanned with two CBCT systems. One CBCT system was equipped with an image intensifier (Experiment 1), and the other was equipped with a flat panel detector (Experiment 2). Holes that were above the threshold gray value (ΔG), calculated using just-noticeable difference (JND), were extracted. The number of extracted holes was used as the index of the image quality, and was compared with the Az values calculated by ROC analysis to detect the mandibular canal.
RESULTS: The number of extracted holes reflected the influence of different scanning conditions, and showed a strong correlation with the Az values calculated by ROC analysis. Indices of the number of extracted holes corresponding to high Az values for detecting the mandibular canal were obtained in both experiments.
CONCLUSIONS: Our image quality evaluation method applying JND to images of a standardized phantom is a quantitative method that could be useful for evaluating the detectability of the mandibular canal in CBCT images.

PMID: 29376745 [PubMed - as supplied by publisher]

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