What advantage does MRI have over CT in assessing for/assessing an inverted papilloma?
As this case shows CT is poor as assessing the detail of the mass, relationship to the turbinates and whether opacification in the maxillary sinus is papilloma or fluid from an obstructed osteomeatal complex. The T2 weighted images exquisitly show where the tumour ends and which is fluid or mucosal thickening.
What is the characteristi MRI appearance of an inverted papilloma?
Upto 80% demonstrate the so-called convoluted cerebriform pattern - alternating roughly parallel lines of high and low signal intensity on T2. This is equally well observed on the post-contrast sequences.
A mass with alternating roughly parallel lines of high and low signal intensity is present on T2. The mass avidly enhanced following contrast.
The left maxillary sinus contains only a small amount of tumour, but contains fluid as the osteomeatal complex is obstructed by the papilloma.
The inferior turbinate is displaced, but not involved.