ABSTRACT
Introduction: Functional magnetic resonance imaging (fMRI) is a neuroradiological technique for the localisation of cortical function. FMRI made its debut in cognitive neuroscience and then eventually to other clinical applications. We report our experience with pre-surgical fMRI on a high field scanner, based purely on a clinical platform. Materials and Methods: The protocols included motor, auditory, visual and language fMRI. The choice of protocols was dependant on clinical request and lesion locale. Results: Retrospective analysis and audit of the f rst 30 consecutive patients over a 12-month period revealed that about 85% of patients had a successful examination. In a pictorial essay, we demonstrate that patients with weakness in performing a motor task showed abnormal activations of the pre-motor and supplementary motor areas. Conclusion: FMRI data greatly enhances the pre-surgical planning process and the conduct of surgery when it is incorporated into the surgical navigation system in the operating theatre.
It is pertinent to mention Pierre Paul Broca’s historical report from 1861 and state-of-the-art functional neuronavigation in the same sentence as it illustrates the continuous efforts expended by investigations in refining the golden rules for identifying locations of functional areas.1 One remarkable example is the visualisation of the omega-like shape of the part of the primary motor cortex that involves hand movement. Susceptibility-weighted imaging (SWI), one of the latest developments in magnetic resonance imaging (MRI), monitors sensitively the amount of iron in the brain which is presumably higher in gray matter compared to white matter, and thus provides increased contrast between the two tissues compared to conventional images.2 The ‘omega’ in SWI, identifies the motor hand area with ease (Fig. 1), in contrast to the ‘knob’ on the precentral sulcus, which may be visualised with difficulty in T1-weighted studies.3
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