Improving Endodontic Radiograph Interpretation with TV-CLAHE for Enhanced Root Canal Detection

Area of Science:

• Dentistry
• Medical Imaging
• Image Processing

Background:

• Accurate visualization of root canal systems is crucial for successful endodontic treatment.
• Periapical radiographs are commonly used, but limitations in visualizing root canal configurations exist.
• Cone-beam computed tomography (CBCT) provides detailed 3D imaging but is more costly and involves higher radiation doses.

Purpose of the Study:

• To evaluate and compare the effectiveness of various image enhancement algorithms in improving root canal detectability in mandibular incisors on periapical radiographs.
• To assess a novel Total Variation-Contrast-Limited Adaptive Histogram Equalization (TV-CLAHE) technique against existing methods.
• To determine if enhancement techniques can improve diagnostic accuracy compared to original radiographs, using CBCT as the gold standard.

Main Methods:

• Retrospective analysis of 60 periapical radiographs of mandibular incisors.
• Application of seven image enhancement techniques: HE, CLAHE, CLAHE-POA, G-CLAHE, KCFDO, and TV-CLAHE.
• Independent assessment of root canal visibility by four experienced observers, compared against CBCT findings.
• Quantitative analysis using PSNR, SNR, entropy, and SSIM to objectively evaluate image quality.

Main Results:

• All enhancement methods improved root canal detection accuracy.
• The proposed TV-CLAHE algorithm achieved the highest accuracy (93-98%), closely matching CBCT visualization.
• Global CLAHE (G-CLAHE) also demonstrated significant improvement (up to 92%).
• Statistical analysis showed significant differences between methods (p < 0.001), with TV-CLAHE outperforming others in subjective ratings and objective metrics (SNR, entropy).

Conclusions:

• Advanced image enhancement, especially TV-CLAHE, significantly enhances root canal visibility on 2D radiographs.
• These techniques offer a practical, cost-effective alternative to CBCT for routine endodontic diagnostics.
• Integrating optimized contrast enhancement into endodontic imaging workflows can reduce missed canals and improve treatment outcomes.