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Magnetic resonance imaging

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Articles 301 - 309 of 309

Full-Text Articles in Medicine and Health Sciences

Neuroanatomical Structure Of The Spinner Dolphin (Stenella Longirostris Orientalis) Brain From Magnetic Resonance Images, Lori Marino, Keith Sudheimer, William A. Mclellan, John I. Johnson Jul 2004

Neuroanatomical Structure Of The Spinner Dolphin (Stenella Longirostris Orientalis) Brain From Magnetic Resonance Images, Lori Marino, Keith Sudheimer, William A. Mclellan, John I. Johnson

Veterinary Science and Medicine Collection

High-resolution magnetic resonance (MR) images of the brain of an adult spinner dolphin (Stenella longirostris orientalis) were acquired in the coronal plane at 55 antero-posterior levels. From these scans a computergenerated set of resectioned virtual images in the two remaining orthogonal planes was constructed with the use of the VoxelView and VoxelMath (Vital Images, Inc.) programs. Neuroanatomical structures were labeled in all three planes, providing the first labeled anatomical description of the spinner dolphin brain.


Bilateral Internuclear Ophthalmoplegia As A Presenting Sign Of Multiple Sclerosis: An Interdisciplinary Approach To Diagnosis And Management, Sherrol A. Reynolds, Joseph Pizzimenti, Albert D. Woods Jul 2004

Bilateral Internuclear Ophthalmoplegia As A Presenting Sign Of Multiple Sclerosis: An Interdisciplinary Approach To Diagnosis And Management, Sherrol A. Reynolds, Joseph Pizzimenti, Albert D. Woods

Internet Journal of Allied Health Sciences and Practice

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system with various neurological and ocular manifestations. Ocular involvement occurs in approximately 80% of patients sometime during the course of the illness, and may be the presenting sign in about 50% of the patients with this disease. Bilateral internuclear ophthalmoplegia (BINO) is a common ocular complication of MS, occurring in up to one third of all MS patients. BINO is an ocular motility impairment characterized by a total or partial inability to adduct each eye accompanied by a concomitant nystagmus of the abducting eye on lateral gaze and …


Neuroanatomy Of The Common Dolphin (Delphinus Delphis) As Revealed By Magnetic Resonance Imaging (Mri), L. Marino, Keith Sudheimer, D. Ann Pabst, William A. Mclellan, David Filsoof, John I. Johnson Dec 2002

Neuroanatomy Of The Common Dolphin (Delphinus Delphis) As Revealed By Magnetic Resonance Imaging (Mri), L. Marino, Keith Sudheimer, D. Ann Pabst, William A. Mclellan, David Filsoof, John I. Johnson

Veterinary Science and Medicine Collection

In this study, magnetic resonance (MR) images of the brain of an adult common dolphin (Delphinus delphis) were acquired in the coronal plane at 66 antero-posterior levels. From these scans a computer-generated set of resectioned virtual images in orthogonal planes was constructed using the programs VoxelView and VoxelMath (Vital Images, Inc., Michigan State Univ.). Sections in all three planes reveal major neuroanatomical structures. These structures in the adult common dolphin brain are compared with those from a fetal common dolphin brain from a previously published study as well as with MR images of adult brains of other odontocetes. …


Description Of A Poorly Differentiated Carcinoma Within The Brainstem Of A White Whale (Delphinapterus Leucas) From Magnetic Resonance Images And Histological Analysis, Sam H. Ridgway, Lori Marino, T. P. Lipscomb Dec 2002

Description Of A Poorly Differentiated Carcinoma Within The Brainstem Of A White Whale (Delphinapterus Leucas) From Magnetic Resonance Images And Histological Analysis, Sam H. Ridgway, Lori Marino, T. P. Lipscomb

Veterinary Science and Medicine Collection

In this study we used magnetic resonance imaging (MRI) to investigate neuroanatomical structure in the brain of a white whale (Delphinapterus leucas) that died from a large tumor within the brainstem. This specimen was also compared with a normal white whale brain using MRI. MRI scans of the white whale specimen show how the tumor deformed surrounding brain structure. Histopathological analysis indicated a poorly differentiated carcinoma of uncertain origin. These analyses demonstrate the usefulness of supplementing histological analyses of pathology with studies of gross morphology facilitated by MRI.


Anatomy And Three-Dimensional Reconstructions Of The Brain Of A Bottlenose Dolphin (Tursiops Truncatus) From Magnetic Resonance Images, Lori Marino, Keith D. Sudheimer, Timothy L. Murphy, Kristina K. Davis, D. Ann Pabst, William A. Mclellan, James K. Rilling, John I. Johnson Dec 2001

Anatomy And Three-Dimensional Reconstructions Of The Brain Of A Bottlenose Dolphin (Tursiops Truncatus) From Magnetic Resonance Images, Lori Marino, Keith D. Sudheimer, Timothy L. Murphy, Kristina K. Davis, D. Ann Pabst, William A. Mclellan, James K. Rilling, John I. Johnson

Veterinary Science and Medicine Collection

Cetacean (dolphin, whale, and porpoise) brains are among the least studied mammalian brains because of the formidability of collecting and histologically preparing such relatively rare and large specimens. Magnetic resonance imaging offers a means of observing the internal structure of the brain when traditional histological procedures are not practical. Furthermore, internal structures can be analyzed in their precise anatomic positions, which is difficult to accomplish after the spatial distortions often accompanying histological processing. In this study, images of the brain of an adult bottlenose dolphin, Tursiops truncatus, were scanned in the coronal plane at 148 antero-posterior levels. From these scans …


Methods For Volume Measurement In 3d Images, Kevin J. Black Jan 2001

Methods For Volume Measurement In 3d Images, Kevin J. Black

Kevin J. Black, MD

This letter attempted to politely direct readers of a later, remarkably similar publication to my original publication. The full text as submitted is attached as a PDF file.
The poster cited in the attached letter is available here.
ADDENDUM: Approximately the same work as the article discussed in this letter was also published as: Rajapakse JC: Random-grid stereologic volumetry of MR head scans. J Magn Reson Imaging 12:833-841, 2000. I wrote a similar, unpublished letter to the editor of JMRI in 12/2000.


Results Of Acute Cerebral Anoxia In Adults: Is It A Reversal Sign?, Nai̇l Bulakbaşi, Yüksel Pabuşçu, H. Kemal Kurtaran, Cem Tayfun, Mustafa Taşar, Taner Üçöz Jan 2000

Results Of Acute Cerebral Anoxia In Adults: Is It A Reversal Sign?, Nai̇l Bulakbaşi, Yüksel Pabuşçu, H. Kemal Kurtaran, Cem Tayfun, Mustafa Taşar, Taner Üçöz

Turkish Journal of Medical Sciences

Objective: The aim of this study is to describe the results of acute cerebral anoxia in adults as a reversal sign. Methods: We retrospectively examined the CT and MR images of 9 patients in a vegetative state due to acute prolonged anoxia. Each of them had at least one MRI and 4 CT exams 6-12 hours, 10-14 days, 6-8 months and 1 year after the anoxic event. The degree of the cerebral atrophy and the mean density values of cerebral white matter were measured and calculated to demonstrate quantitative changes over time. Results: We detected a diffuse density decrease of …


Magnetic Resonance Imaging Analysis Of Molecular Mobility During Dissolution Of Poly(Vinyl Alcohol) In Water, Balaji Narasimhan, J. E.M. Snaar, R. W. Bowtell, S. Morgan, C. D. Melia, N. A. Peppas Jan 1999

Magnetic Resonance Imaging Analysis Of Molecular Mobility During Dissolution Of Poly(Vinyl Alcohol) In Water, Balaji Narasimhan, J. E.M. Snaar, R. W. Bowtell, S. Morgan, C. D. Melia, N. A. Peppas

Balaji Narasimhan

Magnetic resonance imaging is used to study changing microstructure and molecular motion during dissolution of poly(vinyl alcohol) (PVA) in water. One-dimensional water concentration profiles were measured as a function of distance from the polymer-solvent interface. Diffusion-weighted profiles were used to calculate the spatial variation of the self-diffusion coefficient of water. The results indicate that diffusion coefficient values decrease toward the glassy core of the polymer. Self-diffusion coefficient values within the dissolving polymer increase with increasing dissolution time, while those near the polymer-solvent interface remain fairly constant. The effect of PVA molecular weight on the dissolution mechanism was investigated, with MÌ„n …


Roc Curve Regression Analysis: The Use Of Ordinal Regression Models For Diagnostic Test Assessment, Anna N.A. Tosteson, Milton C. Weinstein, Jack Wittenberg, Colin B. Begg Nov 1994

Roc Curve Regression Analysis: The Use Of Ordinal Regression Models For Diagnostic Test Assessment, Anna N.A. Tosteson, Milton C. Weinstein, Jack Wittenberg, Colin B. Begg

Dartmouth Scholarship

Diagnostic tests commonly are characterized by their true positive (sensitivity) and true negative (specificity) classification rates, which rely on a single decision threshold to classify a test result as positive. A more complete description of test accuracy is given by the receiver operating characteristic (ROC) curve, a graph of the false positive and true positive rates obtained as the decision threshold is varied. A generalized regression methodology, which uses a class of ordinal regression models to estimate smoothed ROC curves has been described. Data from a multi-institutional study comparing the accuracy of magnetic resonance (MR) imaging with computed tomography (CT) …