Virtual monoenergetic imaging for metal artifact reduction in dental implant surgery using photon-counting detector...

This ex vivo study was performed to determine the optimal energy level for virtual monoenergetic images (VMIs) generated with photon-counting detector computed tomography (PCD-CT) to minimize metal artifacts from dental implants.

Twelve implants from various manufacturers were placed in 6 pig mandibles and scanned with PCD-CT. VMIs were reconstructed at energy levels from 70 keV to 150 keV in 20-keV increments. Three readers with varying experience qualitatively assessed the image quality, artifact burden, and diagnostic interpretability of peri-implant soft and hard tissues using a 5-point discrete visual scale. Objective analyses included quantitative line profile analysis of implant-induced artifacts. Descriptive statistics were calculated, and inter-reader agreement was assessed using percentage agreement and the Krippendorff alpha coefficient.

Qualitative analysis demonstrated excellent image quality for VMIs at ≥110 keV (median=5), with minimal artifacts observed at 130-150 keV. In contrast, lower-energy VMIs (70-90 keV) showed inferior performance due to artifact-related limitations in diagnostic interpretability. Inter-reader agreement ranged from moderate to perfect, with perfect reliability (α=1) for VMIs ≥110 keV. Quantitative line-profile analysis confirmed reduced artifact burden at higher energy levels, particularly for VMIs ≥110 keV.

VMI at energy levels ≥110 keV on PCD-CT reduced dental implant-related metal artifacts and offered excellent image quality, including assessment of both peri-implant soft and hard tissues. These findings suggest that optimized PCD-CT VMI may enhance postoperative follow-up imaging. Future in vivo studies are warranted to validate these findings in clinical practice.