Comparison is made with previous studies. An extra-axial lesion is demonstrated overlying the right frontal lobe. It follows CSF on all sequences and has maximum measurements of 45 mm (AP) x 15mm (trans) x 41 mm (SI), stable. No evidence of diffusion restriction. Remodelled bone overlying the lesion again noted. Localised mass-effect with effacement of the underlying cerebral sulci. No effacement of the ventricular system or evidence of midline shift. No abnormal susceptibility.
Conclusion: Stable findings with features consistent with a right frontal arachnoid cyst.