Portable, field-based neuroimaging using high-density diffuse optical tomography
Andrew K. Fishell,
Ana María Arbeláez,
Claudia P. Valdés,
Tracy M. Burns-Yocum,
Arefeh Sherafati,
Edward J. Richter,
Margarita Torres,
Adam T. Eggebrecht,
Christopher D. Smyser,
Joseph P. Culver
Affiliations
Andrew K. Fishell
Washington University School of Medicine, Division of Biology and Biomedical Sciences, St. Louis, MO, USA; Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO, USA
Ana María Arbeláez
Washington University School of Medicine, Department of Pediatrics, St. Louis, MO, USA
Claudia P. Valdés
Centro Médico Imbanaco, Cali, Valle del Cauca, Colombia
Tracy M. Burns-Yocum
Indiana University, Department of Psychological and Brain Sciences, Bloomington, IN, USA
Arefeh Sherafati
Washington University School of Medicine, Division of Biology and Biomedical Sciences, St. Louis, MO, USA; Washington University, Department of Physics, St. Louis, MO, USA
Edward J. Richter
Washington University, Electrical and Systems Engineering, St. Louis, MO, USA
Margarita Torres
Centro Médico Imbanaco, Cali, Valle del Cauca, Colombia
Adam T. Eggebrecht
Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO, USA; Washington University School of Medicine, Department of Pediatrics, St. Louis, MO, USA
Christopher D. Smyser
Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO, USA; Washington University School of Medicine, Department of Pediatrics, St. Louis, MO, USA; Washington University School of Medicine, Department of Neurology, St. Louis, MO, USA
Joseph P. Culver
Washington University School of Medicine, Division of Biology and Biomedical Sciences, St. Louis, MO, USA; Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO, USA; Washington University, Department of Physics, St. Louis, MO, USA; Washington University, Department of Biomedical Engineering, MO, St. Louis, USA; Corresponding author. Washington University School of Medicine, Mallinckrodt Institute of Radiology, 660 S. Euclid Ave., St. Louis, MO 63110, USA.
Behavioral and cognitive tests in individuals who were malnourished as children have revealed malnutrition-related deficits that persist throughout the lifespan. These findings have motivated recent neuroimaging investigations that use highly portable functional near-infrared spectroscopy (fNIRS) instruments to meet the demands of brain imaging experiments in low-resource environments and enable longitudinal investigations of brain function in the context of long-term malnutrition. However, recent studies in healthy subjects have demonstrated that high-density diffuse optical tomography (HD-DOT) can significantly improve image quality over that obtained with sparse fNIRS imaging arrays. In studies of both task activations and resting state functional connectivity, HD-DOT is beginning to approach the data quality of fMRI for superficial cortical regions. In this work, we developed a customized HD-DOT system for use in malnutrition studies in Cali, Colombia. Our results evaluate the performance of the HD-DOT instrument for assessing brain function in a cohort of malnourished children. In addition to demonstrating portability and wearability, we show the HD-DOT instrument’s sensitivity to distributed brain responses using a sensory processing task and measurements of homotopic functional connectivity. Task-evoked responses to the passive word listening task produce activations localized to bilateral superior temporal gyrus, replicating previously published work using this paradigm. Evaluating this localization performance across sparse and dense reconstruction schemes indicates that greater localization consistency is associated with a dense array of overlapping optical measurements. These results provide a foundation for additional avenues of investigation, including identifying and characterizing a child’s individual malnutrition burden and eventually contributing to intervention development.
