Ultra-high-field MR imaging in polymicrogyria and epilepsy.

Area of Science:

• Neurology
• Medical Imaging
• Neuroscience

Background:

• Polymicrogyria is a brain malformation affecting cortical development, often linked to epilepsy and developmental delays.
• Conventional 3T MRI has limitations in fully characterizing polymicrogyria.

Purpose of the Study:

• To investigate the utility of 7T MRI in characterizing polymicrogyria.
• To identify additional imaging features of polymicrogyria at 7T compared to 3T.

Main Methods:

• Ten adult patients with polymicrogyria underwent 7T MRI, including 3D T2* susceptibility-weighted angiography and 2D tissue border enhancement.
• Polymicrogyria was assessed for pattern, extent, symmetry, and morphology.

Main Results:

• 7T MRI revealed more detailed topographic patterns and extent of polymicrogyria, with some bilateral cases initially misclassified as unilateral on 3T.
• Susceptibility-weighted angiography showed a uniform ribbonlike pattern and numerous dilated superficial veins in polymicrogyric areas.
• Tissue border enhancement imaging improved visualization of the gray-white matter interface, enhancing polymicrogyric cortex detection.

Conclusions:

• 7T MRI provides superior anatomical detail of polymicrogyria compared to 3T MRI.
• Enhanced characterization has potential implications for diagnosis, genetic studies, and surgical planning for epilepsy.
• Observed cortical vein abnormalities suggest a possible role for vascular dysgenesis in polymicrogyria pathogenesis.