What are the differential for peripheral or ring enhancing cerebral lesions?
The differential for peripheral or ring enhancing cerebral lesions includes: cerebral abscess, tuberculoma, neurocysticercosis, metastasis, glioblastoma, subacute infarct / haemorrhage / contusion, demyelination (incomplete ring), tumefactive demyelinating lesion (incomplete ring), radiation necrosis, postoperative change and lymphoma - in immunocompromised patient.
What is the role of DWI in cerebral abscess diagnosis?
Bacterial abscesses reliably demonstrate restricted diffusion, and DWI has proved useful in distinguishing abscesses from necrotic tumors, resolving haematomas, and other fluid-filled cavities.
How to differentiate between the cytotoxic and vasogenic brain edema?
The vasogenic edema do not show restricted diffusion while the cytotoxic cerebral oedema shows diffusion restriction.
A Well defined left high parietal thick-walled cystic lesion showing the following criteria: central high intensity in T2WI and FLAIR while low signal thin rim abscess capsule; restriction of diffusion of its central content with low ADC value while high signal capsule; peripheral enhancement in post-contrast study; associated with perilesional vasogenic oedema that facilitated in DWI.
Right temporoparietal white matter vasogenic oedema exhibiting hypointense signal in T1Wi and hyperintense signal in T2WI with no definite enhancement and no restriction in DWI suggestive of multiple areas of cerebritis.