What are the differential diagnoses of cerebral ring enhancing lesions?
The causes of cerebral ring enhancing lesions can be remembered using mnemonic ( MAGICAL DR): - M: metastasis. - A: abscess. - G: glioblastoma. - I: infarct (subacute phase), inflammatory - neurocysticercosis, tuberculoma. - C: contusion. - A: AIDS-related CNS disease. - L: lymphoma (more common in immunocompromised patients). - D: demyelinating disease (classically incomplete ring enhancement). - R: radiation necrosis or resolving haematoma.
How can MRI differentiate a cerebral abscess from a high grade glioma?
The MRI findings that favors a cerebral abscess rather than a high grade glioma are: - restricted diffusion of the cystic/necrotic component. - presence of satellite lesions. - reduced perfusion of the lesion and asscoiated edema. - low signal rim on T2.
Images from MRI study of the brain that was done at the initial presentation of the patient showing ethmoidal and to a lesser extent frontal and right maxillary sinusitis as well as small retention cyst at the left maxillary sinus.