Papilloedema: diffusion-weighted imaging of optic nerve head.

Area of Science:

• Neuroradiology
• Ophthalmology
• Neurology

Background:

• Papilledema, characterized by optic nerve head (ONH) swelling, is a clinical sign of elevated intracranial pressure.
• Accurate assessment of papilledema severity is crucial for timely intervention and management.
• Diffusion-weighted imaging (DWI) offers a non-invasive method to evaluate tissue microstructural changes.

Purpose of the Study:

• To investigate the correlation between the clinical grading of papilledema and diffusion abnormalities in the ONH using DWI.
• To determine if DWI-derived parameters can serve as objective markers for papilledema severity and intracranial pressure.

Main Methods:

• Brain MRI with DWI was performed on 32 patients with papilledema and 32 controls.
• Clinical grading of papilledema utilized the modified Frisen scale.
• ONH hyperintensity and apparent diffusion coefficient (ADC) values were analyzed, with statistical comparisons using Chi-square, Fisher's exact, ANOVA, and Student's t-tests. ROC analysis determined cut-off ADC values.

Main Results:

• A significant correlation was observed between ONH hyperintensity and ADC values with clinical papilledema grades.
• ONH hyperintensity demonstrated high sensitivity (87.5%) and specificity (>97%) for detecting papilledema.
• A mean cut-off ONH ADC value showed high sensitivity (96.83%) and specificity (95.31%) in differentiating cases from controls.

Conclusions:

• Diffusion parameters of the ONH are significantly correlated with the clinical grading of papilledema.
• DWI-derived ONH diffusion parameters show potential as non-invasive surrogate markers for elevated intracranial pressure.
• These findings support the utility of DWI in the objective assessment of papilledema.