Thomas J. Brady

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The borders of human visual areas V1, V2, VP, V3, and V4 were precisely and noninvasively determined. Functional magnetic resonance images were recorded during phase-encoded retinal stimulation. This volume data set was then sampled with a cortical surface reconstruction, making it possible to calculate the local visual field sign (mirror image versus(More)
The stages of integration leading from local feature analysis to object recognition were explored in human visual cortex by using the technique of functional magnetic resonance imaging. Here we report evidence for object-related activation. Such activation was located at the lateral-posterior aspect of the occipital lobe, just abutting the posterior aspect(More)
Using noninvasive functional magnetic resonance imaging (fMRI) technique, we analyzed the responses in human area MT with regard to visual motion, color, and luminance contrast sensitivity, and retinotopy. As in previous PET studies, we found that area MT responded selectively to moving (compared to stationary) stimuli. The location of human MT in the(More)
Functional magnetic resonance imaging (fMRI) was used to measure local haemodynamic changes (reflecting electrical activity) in human visual cortex during production of the visual motion aftereffect, also known as the waterfall illusion. As in previous studies, human cortical area MT (V5) responded much better to moving than to stationary visual stimuli.(More)
Knowledge of regional cerebral hemodynamics has widespread application for both physiological research and clinical assessment because of the well-established interrelation between physiological function, energy metabolism, and localized blood supply. A magnetic resonance technique was developed for quantitative imaging of cerebral hemodynamics, allowing(More)
Knowledge of regional hemodynamics has widespread application for both physiological research and clinical assessment. Here we review the use of MR contrast agents to measure tissue perfusion. Two primary mechanisms of image contrast are discussed: relaxivity and susceptibility effects. Relaxivity effects result from dipolar enhancement of T1 and T2 rates.(More)
BACKGROUND We investigated the ability of multidetector spiral computed tomography (MDCT) to detect atherosclerotic plaque in nonstenotic coronary arteries. METHODS AND RESULTS In 22 patients without significant coronary stenoses, contrast-enhanced MDCT (0.75-mm collimation, 420-ms rotation) and intravascular ultrasound (IVUS) of one coronary artery were(More)
OBJECTIVES This study sought to determine the feasibility of performing a comprehensive cardiac computed tomographic (CT) examination incorporating stress and rest myocardial perfusion imaging together with coronary computed tomography angiography (CTA). BACKGROUND Although cardiac CT can identify coronary stenosis, very little data exist on the ability(More)
OBJECTIVES This study was designed to determine the usefulness of coronary computed tomography angiography (CTA) in patients with acute chest pain. BACKGROUND Triage of chest pain patients in the emergency department remains challenging. METHODS We used an observational cohort study in chest pain patients with normal initial troponin and nonischemic(More)
PURPOSE To prospectively compare 64-section multidetector computed tomography (CT) and cardiac magnetic resonance (MR) imaging for the early assessment of myocardial enhancement and infarct size after acute reperfused myocardial infarction (MI). MATERIALS AND METHODS The study was HIPAA compliant and was approved by the institutional review board. All(More)