Quantitative parameters for diagnosis of idiopathic intracranial hypertension on brain MRI

Purpose: Aim of this study was to develop quantitative parameters for diagnosing Idiopathic Intracranial Hypertension (IIH) using brain MRI scans.

Methods: This is a case control study with 48 cases and 192 matched controls. Optic nerve diameter (OND), Pituitary height (PH), Meckel's cave diameter (MCD), and Neck fat thickness (NFT) were measured for both groups. Consequently, means were obtained for the different parameters in both groups with subsequent establishment of best cutoffs using Receiver Operator Curve (ROC) analysis.

Results: For IIH patients the means of OND, PH, MCD, and NFT were 6.2 mm, 3.9 mm, 5 mm, 1.4 cm, respectively while for controls the means were 4.6 mm, 4.5 mm, 4.3 mm, and 0.8 cm with statistical significance between the two groups. ROC analysis showed the cutoff points with best accuracy for the above parameters in diagnosing IIH to be 5.4 mm for OND with sensitivity of 0.77 and specificity of 0.85 representing high accuracy, while for PH a cutoff point of 3 mm showed low accuracy with sensitivity of 0.54 and specificity of 0.7, and a MCD cutoff of 4.5 mm also showed low accuracy with sensitivity of 0.6 and specificity of 0.59, meanwhile a cutoff point of 1.1 cm for NFT was moderately accurate with sensitivity of 0.70 and specificity of 0.81.

Conclusion: Statistical difference in the means for OND, PH, MCD, and NFT between IIH patients and controls is established. Also, we provide cut off points for these parameters to diagnose IIH on brain MRI.