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Our algorithm contains two major steps: the intervertebral disk localization step, and the vertebra detection and segmentation step. In the first step, we apply a model-based searching method to approximately locate all the intervertebral disk clues between adjacent vertebrae of the whole spine and the best slice selection. A new approach using an intensity(More)
OBJECTIVE To determine whether cortical changes occur following participation in a program of modified constraint-induced movement therapy (mCIMT). DESIGN Pre-post, case series. SETTING Outpatient rehabilitation hospital. PARTICIPANTS Two men and 2 women with unilateral stroke occurring more than 1 year prior to study entry and moderate stable motor(More)
AIMS Impulsivity is common in bipolar disorder, especially during mania. Understanding the functional neuroanatomy of response inhibition, one component of impulsivity, might clarify the neural substrate of bipolar disorder. METHODS Sixteen DSM-IV first-episode, manic bipolar patients and 16 matched healthy subjects were examined during a first manic(More)
The purpose of this work is to study computationally the possibility of the application of a hybrid active noise control technique for magnetic resonance imaging (MRI) acoustic noise reduction. A hybrid control system combined with both feedforward and feedback loops embedded is proposed for potential application on active MRI noise reduction. A set of(More)
A general picture is presented of the implications for diffusion-weighted NMR signals of the parsimonious two-site-exchange (2SX) paradigm. In particular, it is shown that the diffusigraphic "shutter-speed," tau(-1) identical with |q(2)(D(A) - D(B))|, is a useful concept. The "wave-number" q has its standard definition (given in the text), and D(A) and D(B)(More)
BACKGROUND Bipolar I disorder is defined by the occurrence of mania. The presence of mania, coupled with a course of illness characterized by waxing and waning of affective symptoms, suggests that bipolar disorder arises from dysfunction of neural systems that maintain emotional arousal and homeostasis. We used functional magnetic resonance imaging (fMRI)(More)
UNLABELLED The use of mice with targeted gene deletions (knockouts [KOs]) provides an important tool to investigate the mechanisms underlying behavior, neuronal development, and the sequella of neuropsychiatric diseases. MRI has been used to image brain structural changes in KO mice but, to our knowledge, the feasibility of using PET to investigate brain(More)
The standard pharmacokinetic model for the analysis of MRI contrast reagent (CR) bolus-tracking (B-T) data assumes that the mean intracellular water molecule lifetime (tau(i)) is effectively zero. This assertion is inconsistent with a considerable body of physiological measurements. Furthermore, theory and simulation show the B-T time-course shape to be(More)
Split RF coils offer improved patient access by eliminating the need for the coil to be slid over the region of interest. For unshielded birdcage coils, the presence of end ring currents necessitates a direct electrical connection between two halves of the coil. For high-field (>3T) shielded birdcage coils, both the shield and the coil must be split and(More)
Chronic cocaine abuse has been associated with cerebrovascular pathology. This is likely to reflect its vasoactive effects; cocaine produces vasoconstriction and reduces cerebral blood flow. We propose that cerebrovascular pathology in chronic cocaine abusers would result in abnormal BOLD [blood oxygenation level dependent] responses to activation stimuli.(More)