Radiomic Parameters in Periapical Lesions: A CBCT Analysis Evaluating Volumetric Size, Cortical Expansion, Erosion, and Shape

Objective: To investigate significant differences in selected radiomic parameters when classifying periapical lesions based on volumetric size, expansion, erosion, and shape using Cone Beam Computed Tomography (CBCT).
Methods: A retrospective, analytical, and comparative study of 100 small field of view (FOV) 50mm x 50mm CBCT scans was conducted. The CBCT scans were collected between 2018 and 2023. Periapical lesions were qualitatively classified, followed by segmentation and radiomic parameter extraction using 3D Slicer and Pyradiomics. To determine the normal distribution of the variables, the Shapiro-Wilk test was used. To assess significant differences, tests such as Student's t-test, Mann-Whitney U test, ANOVA and Tukey's post hoc analysis were employed.
Results: When classifying periapical lesions according to their volumetric size, significant differences were observed in the following parameters among the classification levels. There were significant differences in “Firstorder_Energy” with a p-value of 0.001 and “Firstorder_TotalEnergy” with a p-value of 0.02. “Texture_NGTD Contrast” also showed a significant difference with a p-value of 0.001. Larger volumetric size is associated with greater energy and lower contrast. Significant differences in periapical lesions with erosion were found in shape sphericity (mean 0.34, SD 0.10, p=0.01), first-order energy (mean 3.73E+10, SD 4.52E+10, p=0.002), and texture NGTD contrast (mean 0.05, SD 0.02, p=0.001), compared to lesions without erosion. GLCM contrast was lower in erosive lesions (mean 18.94, SD 6.81, p=0.03) than in non-erosive ones (mean 22.28, SD 8.48). Regular-shaped periapical lesions demonstrated significantly greater elongation (mean 0.794, SD 0.115, p=0.006) and flatness (mean 0.614, SD 0.107, p=0.005) compared to irregular-shaped lesions. These findings suggest that regular-shaped periapical lesions tend to be more elongated and flatter compared to irregular ones. No significant differences were found in radiomic features depending on the presence or absence of expansion in the periapical lesion.
Conclusions: There are significant differences in texture and first-order radiomic features in periapical lesions classified based on size, erosion, and shape. These findings can enhance the Funderstanding of periapical lesions and potentially contribute to their diagnosis and treatment in clinical practice. (EEJ-2023-11-159)