Role of 3D FLAIR in demonstration of peripheral lesions of brainstem and cranial neuropathies.

Aim: We present a pictorial review of 3D FLAIR images depicting its importance in demonstrating the peripheral lesions of brainstem particularly in relation to attachment of cranial nerves and cranial neuropathies and particularly in context of patients with multiple sclerosis (MS). Discussion: T2 axials and routine 2D FLAIR have drawbacks in depicting the lesions on the peripheral aspects of brainstem. Such lesions are commonly found in MS. The revised McDonald’s criteria (2010) put equal emphasis on periventricular, juxtacortical, infratentorial and cord lesions. Detection of peripheral lesions thus play important role in fulfilling the criteria of dissemination in space and also provide anatomic correlate in several cranial nerve palsies. In clinically isolated syndromes, demonstration of lesions at the site of affected cranial nerves increase diagnostic confidence and exclude other potential disease processes. Ability to show signal changes at cranial nerve attachment can also potentially prevent a false attribution of symptoms to neurovascular compression. Conclusion: We propose that 3D FLAIR sequence is extremely useful in detecting abnormalities on the surface of brainstem and cranial nerve attachments and should be performed in all patients of MS and cranial nerve palsies.

A rare case of third ventricular epidermoid cyst as seen by newer MRI sequences.

Aim: We describe a 52 year old gentleman who had a third ventricular lesion, presumed to be epidermoid cyst, which is very rare. We also describe the appearances of this rare condition on newer MRI sequences. Presentation of Case: Third ventricle is a rare site of epidermoid cysts and difficult to visualise specially in routine MRI sequences. We used 3D FLAIR sequence as part of routine MRI protocol that was helpful in raising suspicion initially, aided by clinical presentation. Subsequent 3D T2 SPACE sequence confirmed the presence of abnormality. Discussion: The case highlights the importance of high resolution 3D FLAIR sequence as part of initial MRI protocol that is devoid of CSF flow artefacts and therefore helpful for small intraventricular lesions. Importance of 3D T2 SPACE is also highlighted which is another new MRI sequence. It has excellent spatial resolution without artefacts that is helpful in clearly delineating the presence of small lesions such as epidermoid cyst and its relationship with surrounding structures and increasing diagnostic certainty. Conclusion: We present a rare case of presumed third ventricular epidermoid cyst and potential role of newer MRI sequences in small intraventricular lesions.

Sylvian fissure lipoma associated with middle cerebral artery aneurysm – Report of a rare case highlighting imaging pitfalls.

Aim: We describe a 60 year old lady who had a Sylvian fissure lipoma associated with an underlying middle cerebral artery saccular aneurysm which is a rare association and describe its imaging features. Presentation of Case: Due to its rarity and MRI appearances simulating blood products, this case offered an initial diagnostic dilemma to the reporting radiologists, when an incidental lesion like lipoma adjoining an aneurysm was initially misinterpreted as blood products. Discussion and Conclusion: This case highlights potential pitfalls in imaging interpretation even with a newer neuroimaging technique to accurately identify the nature of the lesion that can lead to misdiagnosis with the potential of inappropriate clinical management, at least in some cases.