Investigating hyperostosis frontalis interna: a computed tomography analysis and predictive model for Hershkovitz classification

BackgroundAxial computed tomography (CT) cross-sections offer an accessible model for assessing diverse pathologies associated with hyperostosis frontalis interna (HFI) based on the Hershkovitz classification.PurposeTo delineate the CT characteristics of HFI, emphasizing a radiological description using the Hershkovitz classification. It investigated whether the Hershkovitz classification can be predicted using density, a variable unexplored in the literature. HFI thickness and the presence of concurrent hyperostosis beyond the frontal bone (HBFB) were evaluated across varying degrees of the Hershkovitz classification.Material and MethodsThis retrospective study evaluated characteristics of HFI on CT. Each case was assigned a Hershkovitz classification. Density and thickness of the HFI along with the presence of concurrent HBFB were evaluated and correlated with the Hershkovitz classification.ResultsAxial CT of 77 patients with HFI was evaluated. Patient characteristics including sex were uncorrelated with CT measurements (<i>P</i> > 0.25) and Hershkovitz classification (<i>P</i> > 0.06). Increasing HFI thickness was associated with a higher Hershkovitz classification (odds ratio [OR] = 1.863, 95% confidence interval [CI] = 1.452-2.389; <i>P</i> < 0.001), and increasing density of HFI was associated with a lower Hershkovitz classification (OR = 0.995, 95% CI = 0.992-0.998; <i>P</i> = 0.002). Higher Hershkovitz classification was also found to be associated with the presence of concurrent HBFB (OR = 31.694, 95% CI = 6.483-154.938; <i>P</i> < 0.001).ConclusionIn our cohort, Hershkovitz classification on axial CT correlated with increased HFI thickness, presence of HBFB, and lower HFI density.