MRI techniques: bilateral findings and "normal findings".

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Computed tomography (CT) and other non-invasive methods have limitations in temporal lobe imaging.
• Magnetic resonance imaging (MRI) provides superior visualization of temporal lobe structures.
• Accurate diagnosis of temporal lobe pathologies is crucial for effective treatment.

Purpose of the Study:

• To highlight the advantages of MRI over CT for temporal lobe imaging.
• To outline optimal MRI sequences for detecting mesial temporal sclerosis.
• To discuss the role of magnetic resonance spectroscopy (MRS) and functional MRI (fMRI) in temporal lobe evaluation.

Main Methods:

• Comparison of MRI and CT imaging capabilities for temporal lobe assessment.
• Description of optimal MRI sequences including T1-weighted volumetric, T2-weighted coronal, FLAIR, and gradient echo scans.
• Inclusion of magnetic resonance spectroscopy (MRS) for biochemical analysis and functional MRI (fMRI) for functional localization.

Main Results:

• MRI significantly surpasses CT in imaging the temporal lobe and detecting foreign tissue lesions.
• Specific MRI sequences are recommended for maximizing the yield in detecting mesial temporal sclerosis.
• MRS may reveal decreased N-acetyl aspartate (NAA) or altered NAA ratios, indicating neuronal dysfunction.

Conclusions:

• MRI is the preferred modality for detailed temporal lobe imaging, especially for detecting lesions and mesial temporal sclerosis.
• A combination of advanced MRI sequences and MRS provides comprehensive diagnostic information.
• Functional MRI shows potential for localizing hemispheric functions, though its role in pre-operative evaluation of temporal lobe seizures is still under investigation.