ABSTRACT
We present a novel method for preoperative computer-assisted deep brain stimulation (DBS) electrode targeting that takes into account the multiplicity of available contacts and their polarity. Our framework automatically evaluates the efficacy of many possible electrode orientations to optimize the interplay between the extracellular electric field, created from distinct arrangements of active contacts, and anatomical structures responsible for therapeutic and potential side effects. Experimental results on subthalamic DBS cases suggest bipolar configurations provide more flexibility and control on the spread of electric field and, consequently, are most robust to targeting imprecision. Visualization of predicted efficacy maps provides surgeons with complementary feedback that can bridge the gap between insertion safety and optimal therapeutic efficacy. Overall, this work adds a new dimension to preoperative DBS planning and suggests new insights regarding multi-target stimulation.
Subject(s)
Deep Brain Stimulation/instrumentation , Deep Brain Stimulation/methods , Neurosurgery/methods , Parkinson Disease/therapy , Surgery, Computer-Assisted/methods , Algorithms , Brain/pathology , Brain Mapping/methods , Computer Simulation , Electrodes , Humans , Magnetic Resonance Imaging/methods , Models, Statistical , Signal Processing, Computer-Assisted , SoftwareABSTRACT
In studies of the human brain, a standard stereotaxic space such as the Montreal Neurological Institute (MNI space) is widely used to provide a common reference for the three-dimensional localization of functional activation foci and anatomical structures, enabling the comparison of results obtained across different studies. Here we present a standard macaque monkey brain MRI template that offers a common stereotaxic reference frame to localize anatomical and functional information in an organized and reliable way for comparison across individual monkeys and studies. We have used MRI volumes from a group of 25 normal adult macaque monkeys (18 cynomolgus and 7 rhesus) to create a common standard macaque monkey brain as well as atlases for each of these species separately. In addition, the digital macaque monkey volume was subjected to 3D volumetric analysis and comparison of brain structures between the individual brains and the average atlas. Furthermore, we provide a means of transforming any macaque MRI volume into MNI monkey space coordinates in 3D using simple web based tools. Coordinates in MNI monkey space can also be transformed into the coordinate system of a detailed neuroanatomical paper atlas (Paxinos et al., 2008), enabling researchers to identify and delineate cortical and subcortical structures in their individual macaque monkey brains.
Subject(s)
Brain/anatomy & histology , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Macaca/anatomy & histology , Magnetic Resonance Imaging/methods , Models, Anatomic , Subtraction Technique , Animals , Brain Mapping/methods , Computer Simulation , Image Enhancement/methods , Reproducibility of Results , Sensitivity and Specificity , Stereotaxic TechniquesABSTRACT
A novel method is presented for creating a probability map from histologically defined cytoarchitectonic data, customised for the anatomy of individual fMRI volunteers. Postmortem structural and cytoarchitectonic information from a published dataset is combined with high resolution structural MR images using deformable registration of a region of interest. In this paper, we have targeted the three sub-areas of the primary auditory cortex (located on Heschl's gyrus); however, the method could be applied to any other cytoarchitectonic region. The resulting probability maps show a significantly higher overlap than previously generated maps using the same cytoarchitectonic data, and more accurately span the macroanatomical structure of the auditory cortex. This improvement indicates a high potential for spatially accurate fMRI analysis, allowing more reliable correlation between anatomical structure and function. We validate the approach using fMRI data from nine individuals, taken from a published dataset. We compare activation for stimuli evoking a pitch percept to activation for acoustically matched noise, and demonstrate that the primary auditory cortex (Te1.0) and the lateral region Te1.2 are sensitive to pitch, whereas Te1.1 is not.
Subject(s)
Auditory Cortex/physiology , Brain Mapping/methods , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Magnetic Resonance Imaging/methods , Models, Neurological , Subtraction Technique , Algorithms , Artificial Intelligence , Humans , Image Enhancement/methods , Models, Anatomic , Models, Statistical , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
OBJECTIVES: To examine the role and responsibilities of the nurse as a fact witness and an expert witness in legal proceedings, and provide practical instruction regarding testifying in either capacity. DATA SOURCES: Federal rules, legal literature, and nursing articles. CONCLUSIONS: The nursing professional can serve the health care profession and the justice system by participating in the legal process. IMPLICATIONS FOR NURSING PRACTICE: By participating in the legal process, nurses define and uphold the appropriate standard of care, and in so doing, preserve quality health care.
