Assignment Confidence in Localization of the Hand Motor Cortex: Comparison of Structural Imaging With Functional MRI

Area of Science:

• Neuroimaging
• Neuroanatomy
• Radiology

Background:

• Accurate localization of the primary motor cortex is crucial for clinical and research applications.
• Both structural magnetic resonance imaging (MRI) and functional MRI (fMRI) are used for this purpose, but their reliability varies.

Purpose of the Study:

• To compare the confidence levels of structural MRI and fMRI in localizing the primary motor cortex.
• To evaluate different anatomical landmarks and fMRI for their accuracy and inter-reader reliability.

Main Methods:

• Ninety-one fMRI studies with motor tasks were analyzed.
• Three anatomical assessments (superior frontal sulcus-precentral sulcus relation, cortical thickness, precentral knob configuration) and fMRI were used for localization.
• Confidence ratings (0-5) were assigned, and inter-reader agreement was assessed.

Main Results:

• Cortical thickness provided the highest confidence rating (mean 4.90 ± 0.47) with minimal failure.
• fMRI confidence improved from 4.72 ± 0.54 (single task) to 4.87 ± 0.36 (multiple tasks).
• Cortical thickness showed the least inter-reader differences.

Conclusions:

• Cortical thickness is a more reliable anatomical landmark for primary motor cortex localization confidence than fMRI alone.
• Combining anatomical landmarks with fMRI enhances the specificity of motor function localization.
• Multiple techniques increase confidence in identifying the hand motor cortex.