Emergency magnetic resonance of the brain

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Magnetic resonance (MR) imaging is crucial for assessing acute neurological abnormalities.
• A key challenge is the perceived insensitivity of MR to hyperacute (<12 hours) intracranial hemorrhage and acute subarachnoid hemorrhage (SAH).

Purpose of the Study:

• To review the role of MR in evaluating patients with acute neurological abnormalities.
• To highlight MR's capabilities in detecting conditions previously challenging for computed tomography (CT).

Main Methods:

• Review of MR imaging characteristics for hyperacute hemorrhage, including T1-weighted, T2-weighted, and gradient-echo sequences.
• Evaluation of fast fluid-attenuated inversion recovery (FLAIR) sequences for detecting SAH.
• Assessment of MR's utility in diagnosing hypertensive encephalopathy, venous thrombosis, and acute intracranial infections.

Main Results:

• Hyperacute hematomas exhibit characteristic iso-to hyperintense T1 and hyperintense T2 signal, with gradient-echo scans showing peripheral hypointensity.
• Fast FLAIR sequences demonstrate high sensitivity for SAH, comparable to or exceeding CT.
• MR aids in diagnosing conditions like hypertensive encephalopathy, venous thrombosis, and infections (abscess, empyema, encephalitis).

Conclusions:

• MR is sensitive to hyperacute intracranial hemorrhage and SAH.
• Advanced MR techniques enhance diagnostic accuracy for a range of acute neurological emergencies.
• Improved diagnostic capabilities with MR facilitate timely treatment and better patient prognoses.