Research Interests:
Because public health and innovation are no longer national issues, regulatory authorities must apply a global view to oversight.
Research Interests:
Research Interests:
Research Interests:
Research Interests: Clinical Pharmacology, Translational Research, Medicine, Translational Medicine, Clinical Practice, and 8 moreHumans, Biomedical Research, United States, Diffusion of Innovation, Drug Industry, Translational Science, Clinical Pharmacology and Therapeutics, and Pharmacology and pharmaceutical sciences
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Radiology, Medicine, Humans, Female, Male, and 13 moreUrinary Tract Infections, Clinical Sciences, Aged, Middle Aged, Pelvis, Adult, Urinary System, Retrospective Studies, X ray Computed Tomography, Sexually Transmitted Diseases, Acquired immunodeficiency syndrome, hydronephrosis , and Retroperitoneal space
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Chemistry, Biomedical Engineering, Magnetic Resonance Imaging, Magnetic Resonance Spectroscopy, Medicine, and 15 moreAdenosine, Magnesium, Animals, Male, Heart, Hemoglobin, Myocardium, Blood Flow, Coronary Circulation, Calcium Chloride, Erythrocytes, Heart Ventricles, Hemoglobins, Bicarbonates, and Coronary Vessels
Research Interests: Radiology, Chemotherapy, Radiation Therapy, Adolescent, Medicine, and 15 moreHumans, Liver, Female, Male, Hepatocellular Carcinoma, Clinical Sciences, Angiography, Middle Aged, Carcinoma, Computer Assisted Tomography, Adult, Arteriovenous Malformations, Computer, Liver neoplasms, and Colonic Neoplasms
To determine the feasibility of using hemoglobin (Hb) desaturation as an indicator of myocardial oxygenation. High-resolution gradient-echo nuclear magnetic resonance (MR) images of isolated, blood-perfused rabbit hearts were obtained at... more
To determine the feasibility of using hemoglobin (Hb) desaturation as an indicator of myocardial oxygenation. High-resolution gradient-echo nuclear magnetic resonance (MR) images of isolated, blood-perfused rabbit hearts were obtained at various blood oxygenation levels. The hearts were perfused at 37 degrees C with a Langendorff apparatus modified for nuclear MR imaging. The perfusate contained bovine red blood cells in a cardioplegic solution that eliminated motion artifacts and minimized arteriovenous oxygenation differences. Hb saturation was varied (7%-100%) randomly. Perfusion pressure was continuously monitored, and blood samples were obtained. There was a substantial correlation between image signal intensity in the myocardium and Hb saturation in the blood, believed to be due to susceptibility effects of the paramagnetic species deoxyhemoglobin. Direct and noninvasive determination of regional Hb saturation with susceptibility-dependent MR imaging may provide information regarding regional myocardial O2 content.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The preoperative evaluation of pulmonary sequestration requires delineation of the arterial supply and venous drainage of both the sequestered segment and the neighboring lung. In this case magnetic resonance imaging was the sole modality... more
The preoperative evaluation of pulmonary sequestration requires delineation of the arterial supply and venous drainage of both the sequestered segment and the neighboring lung. In this case magnetic resonance imaging was the sole modality which demonstrated all components of the arterial and venous circulations of a sequestration and the remainder of the ipsilateral lung.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
THE NATIONAL INSTITUTES OF Health (NIH), a component of the US Department of Health and Human Services, supports more biomedical research than any other single entity in the world and plays a key role in shaping future research directions... more
THE NATIONAL INSTITUTES OF Health (NIH), a component of the US Department of Health and Human Services, supports more biomedical research than any other single entity in the world and plays a key role in shaping future research directions and in advancing the health of the biomedical research enterprise. The scope, depth, and momentum of the NIH research portfolio provides me, as director of the agency, with a unique view of the ways in which science is poised to radically transform the practice of medicine. Perhaps the most compelling prospect is the potential to practice preemptive medicine—by making use of precise molecular knowledge to detect disease before symptoms are manifest, and intervening before disease can strike. National Institutes of Health programs both stimulate and complement private-sector medical research and development. In fiscal year (FY) 2004, the $28 billion NIH budget comprised about one third of national biomedical research spending, with pharmaceutical an...
Research Interests:
Centrilobular emphysema (CLE) is a disease defined pathologically. Assessment of the accuracy of high resolution computed tomography (CT) in the diagnosis of centrilobular emphysema has been hampered by a lack of pathologic correlation.... more
Centrilobular emphysema (CLE) is a disease defined pathologically. Assessment of the accuracy of high resolution computed tomography (CT) in the diagnosis of centrilobular emphysema has been hampered by a lack of pathologic correlation. We applied high resolution computed tomography to 20 postmortem lung specimens fixed by a method that allows for direct one-to-one pathologic-radiologic correlation. The degree of centrilobular emphysema was assessed radiologically on a visual grading system based on nonperipheral low-attenuation areas. The lungs were then sectioned along the plane of the CT image, and the degree of centrilobular emphysema was graded pathologically by scoring against a panel of standards. A significant correlation (r = 0.91, p less than 0.005) was found between the pathologic grade and the in vitro CT score.
Research Interests:
Research Interests:
To determine if fluid-fluid levels on horizontal-beam radiographs of posttraumatic knee joints always represent lipohemarthrosis. The files of 41 patients with tibial plateau fracture were reviewed retrospectively. Twelve with fluid-fluid... more
To determine if fluid-fluid levels on horizontal-beam radiographs of posttraumatic knee joints always represent lipohemarthrosis. The files of 41 patients with tibial plateau fracture were reviewed retrospectively. Twelve with fluid-fluid levels on radiographs who underwent computed tomography (CT) or magnetic resonance (MR) imaging were selected; CT attenuation and MR signal intensity patterns were used to assess fluid-fluid levels. Simulated hemarthrosis and lipohemarthrosis underwent plain radiography, CT, and MR imaging. Eight patients showed no evidence of fat in the supernatant fluid with either CT (n = 7) or CT and MR imaging (n = 1). Fluid levels resulted from blood separating into cellular elements and supernatant serum. Four patients showed evidence of lipohemarthrosis with either CT (n = 3) or MR imaging (n = 1); in one of these patients, a double fluid-fluid level could be demonstrated retrospectively on plain radiographs. Single fluid-fluid levels in posttraumatic knee ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Background Contrast-enhanced fast magnetic resonance (MR) images of acute, reperfused human infarcts demonstrate regions of hypoenhancement and hyperenhancement. The relations between the spatial extent and time course of these... more
Background Contrast-enhanced fast magnetic resonance (MR) images of acute, reperfused human infarcts demonstrate regions of hypoenhancement and hyperenhancement. The relations between the spatial extent and time course of these enhancement patterns to myocardial risk, infarct, and no-reflow regions have not been well characterized. Methods and Results The proximal left anterior descending coronary artery was occluded in 11 closed-chest dogs for 90 minutes followed by 2 days of reperfusion. Regional blood flow was determined by use of radioactive microspheres. The animals were studied at the 2-day time point with contrast-enhanced fast MRI (Signa 1.5 T, General Electric). Thioflavin-S was administered to demarcate no-reflow regions. The hearts were then excised, sectioned into five base-to-apex slices, stained with 2,3,5-triphenyltetrazolium chloride (TTC), and photographed under room light (for TTC) and ultraviolet light (for thioflavin). The spatial extents of thioflavin-negative, ...
Research Interests: Cardiology, Magnetic Resonance Imaging, Medicine, Dogs, Animals, and 15 moreExploration, Clinical Sciences, Myocardial Infarction, Gadolinium, Myocardium, Public health systems and services research, Time Factors, Circulation, Coronary Circulation, Microspheres, Nuclear Magnetic Resonance Imaging, Organometallic Compounds, Heterocyclic compounds, Contrast Media, and Cardiovascular medicine and haematology
BACKGROUND Measurement of regional left ventricular (LV) function is predicted on the ability to compare equivalent LV segments at different time points during the cardiac cycle. Standard techniques of short-axis acquisition in... more
BACKGROUND Measurement of regional left ventricular (LV) function is predicted on the ability to compare equivalent LV segments at different time points during the cardiac cycle. Standard techniques of short-axis acquisition in two-dimensional echocardiography, cine computed tomography, and standard magnetic resonance imaging (MRI) acquire images from a fixed plane and fail to compensate for through-plane motion. The shortening of the left ventricle along its long axis during systole results in planar images of two different levels of the ventricle, leading to error in any derived functional measurements. LV systolic long-axis motion was measured in 19 normal volunteers using MRI. METHODS AND RESULTS With a selective radio frequency (RF) tissue-tagging technique, three short-axis planes were labeled at end diastole and standard spin-echo images were acquired at end systole in the two- and four-chamber orientations. Persistence of the tags through systole allowed visualization of the...