An integrated measurement system for simultaneous functional magnetic resonance imaging and diffuse optical tomography in human brain mapping.

An integrated measurement system is described for performing simultaneous functional magnetic resonance imaging (fMRI) and diffuse optical tomography (DOT) for human brain mapping experiments. The components of this system consist of an MRI-compatible multi-overlapping-channel optical probe, methods for co-registration of optical and fMRI measurements, and DOT reconstruction algorithms with structural and physiological constraints derived from the MRI data. The optical probe is fully MRI-compatible in the sense that it produces negligible MR image distortion and does not require any modification to the MRI scanner or data acquisition protocol. The probe can be attached to any part of the head without posing any limitation on optical data acquisition. Co-registration of images from fMRI and optical measurements was achieved by localizing the positions of the optical fibers using MRI markers. Human studies show successful implementation of the entire system.