Simulation study of magnetic resonance imaging-guided cortically constrained diffuse optical tomography of human...

Area of Science:

• Neuroimaging
• Biomedical Optics
• Medical Physics

Background:

• Diffuse optical imaging (DOI) noninvasively measures human brain activity by detecting light modulation through scalp and skull.
• Current DOI methods have limited spatial resolution (~3 cm) and poor depth resolution due to measurement geometry.

Purpose of the Study:

• To improve spatial resolution and localization accuracy in diffuse optical imaging of adult human brain function.
• To address depth resolution challenges in diffuse optical imaging using multimodal approaches.

Main Methods:

• Utilized simulation studies on a 3D human head model.
• Incorporated overlapping tissue sampling measurements to enhance localization accuracy.
• Applied a cortical spatial constraint derived from coregistered structural magnetic resonance imaging (MRI) segmentation.

Main Results:

• Addition of overlapping samples significantly improved localization accuracy.
• Cortical spatial constraints improved absorption contrast amplitude accuracy by enhancing depth localization.
• Despite improvements, absorption contrast deep within the cortex was reconstructed superficially, leading to underestimation.

Conclusions:

• Combining diffuse optical imaging with MRI shows potential for more quantitative estimates of brain activation responses (deoxyhemoglobin).
• Multimodal imaging overcomes limitations of individual methods but depth resolution within the cortex remains a challenge.