Dr. Dale is founding Co-Director of the Multimodal Imaging Laboratory, an interdisciplinary initiative of the Departments of Neurosciences and Radiology. He is highly skilled in the development and utilization of multimodality imaging technologies.
Within both departments, Dr. Dale is the designated point person for integrating the various modes and methods of collecting imaging data, including functional MRI (fMRI), magnetoencephalography (MEG), electroencephalography (EEG), and optical imaging. His efforts are directed in three areas: continuing development and refinement of accurate and automated algorithms for evaluation subjects using multimodality approaches to data collection; statistical analysis of data; and conducting studies in animal models using optical imaging, high field fMRI, and electrophysiological recordings to enhance the interpretation of neuroimaging studies.
Correct modeling of EEG/MEG and optical signals requires an accurate segmentation of the tissues within the head. A major component of Dr. Dale's laboratory effort has been on developing accurate and automated algorithms for head segmentation. This work began while he was a graduate student at UCSD and continued with Dr. Bruce Fischl and Dr. Eric Halgren at Harvard Medical School. Efforts to date have resulted in the development of software tools that enable the automated segmentation of the entire head and brain, including the neocortex and subcortical structures, from MRI data. As Dr. Dale notes, "The task of automated structure segmentation of human brain anatomy has been a Holy Grail for years."
Investigators at the Multimodal Imaging Lab are currently involved in several clinical research studies, applying these methods to assessment of regional morphometric changes associated with normal and abnormal development, aging, and brain-related diseases such as schizophrenia, Alzheimer's disease, and Huntington's disease.
Multimodal Imaging Laboratory
Dr. Dale brings together bench research, technology development and clinical applications for a complete research portfolio. At its most basic level, the focus of Dr. Dale’s research is to develop and apply imaging technologies in order to improve understanding of brain function and structure in both health and disease. One of his larger research focuses is in the area of the Blood Oxygenation Level Dependent (BOLD) signal, as measured by functional MRI (fMRI). Through the use of electrophysiological recordings (laminar electrodes, single-unit, and patch), optical imaging (intrinsic signal CCD, speckle CCD, two-photon laser scanning microscopy, voltage sensitive dyes, calcium yes), and fMRI (BOLD and ASL), his laboratory has yielded important new insights into the effect of neuronal excitation and inhibition on arteriolar dilation and constriction. Further Dr. Dale’s laboratory has been developing biophysical models of neuronal population activity and electrophysiological measures. To this end his laboratory collaborated to develop a method called Laminar Population Analysis, which allows the firing rates of cortical neuronal populations to be estimated from laminar electrode recordings of multi-unit activity (MUA) and the local field potential (LFP). This work was further extended to allow estimation of thalamocortical and intracortical network models in the rat barrel system.
The current review period has also seen several technological developments emerge from Dr. Dale’s laboratory. These include a method for tracking and correcting for head motion, in real time, during MRI scans; a fully automated method for identifying white matter tracts from MRI scans; and a method for quantifying longitudinal anatomical change from serial MRI scans. This is of particular importance in detection and quantification of regionally-specific anatomical changes associated with disease progression and normal- and abnormal brain development.
One important technology produced by Dr. Dale’s laboratory is a free software program that aids in the study of anatomical changes associated with early stages of Alzheimer’s disease and Mild Cognitive Impairment (MCI). This technology, developed for the Alzheimer’s Disease Neuroimaging Initiative (ADNI), involves longitudinal MRI and PET scans as well as CSF biomarkers in a large number of patients. The benefit of the software is that it controls and improves the accuracy of the assessment of change across time, and allows pooling of data across sites and instruments.
Dr. Dale also initiated several large, multi-site, collaborative efforts using neuroimaging methods to study the genetic and environmental influences on brain structure and development. Finally, Dr. Dale is very interested in translating technologies and scientific findings into clinical routine applications. An FDA-approved version of his automated segmentation technology is now in routine use for quantitative assessment of regional atrophy in patients under clinical evaluation for AD/MCI at UCSD. The technology is also routinely used to assess structural asymmetry of the medial temporal lobe in patients with epilepsy.
Dr. Dale’s productivity in the review period has been outstanding. Since his last review, Dr. Dale published 42 new research articles, with seven more in press in refereed journals. These articles appear in well-established reputable journals such as PNAS, The Journal of Neuroscience, Neurology, and Neurobiology of Aging. He also has one book chapter which was in press at the time the review materials were collected.