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Magnetic resonance imaging

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Articles 1 - 12 of 12

Full-Text Articles in Anatomy

Magnetic Resonance Imaging-Derived Microvascular Perfusion Modeling To Assess Peripheral Artery Disease, Olga A. Gimnich, Tatiana Belousova, Christina M. Short, Addison A. Taylor, Vijay Nambi, Joel D. Morrisett, Christie M. Ballantyne, Jean Bismuth, Dipan J. Shah, Gerd Brunner Jan 2023

Magnetic Resonance Imaging-Derived Microvascular Perfusion Modeling To Assess Peripheral Artery Disease, Olga A. Gimnich, Tatiana Belousova, Christina M. Short, Addison A. Taylor, Vijay Nambi, Joel D. Morrisett, Christie M. Ballantyne, Jean Bismuth, Dipan J. Shah, Gerd Brunner

School of Medicine Faculty Publications

BACKGROUND: Computational fluid dynamics has shown good agreement with contrast-enhanced magnetic resonance imaging measurements in cardiovascular disease applications. We have developed a biomechanical model of microvascular perfusion using contrast-enhanced magnetic resonance imaging signal intensities derived from skeletal calf muscles to study peripheral artery disease (PAD). METHODS AND RESULTS: The computational microvascular model was used to study skeletal calf muscle perfusion in 56 in-dividuals (36 patients with PAD, 20 matched controls). The recruited participants underwent contrast-enhanced magnetic resonance imaging and ankle-brachial index testing at rest and after 6-minute treadmill walking. We have determined associations of microvascular model parameters including the transfer …


Atlas-Based Shared-Boundary Deformable Multi-Surface Models Through Multi-Material And Two-Manifold Dual Contouring, Tanweer Rashid, Sharmin Sultana, Mallar Chakravarty, Michel Albert Audette Jan 2023

Atlas-Based Shared-Boundary Deformable Multi-Surface Models Through Multi-Material And Two-Manifold Dual Contouring, Tanweer Rashid, Sharmin Sultana, Mallar Chakravarty, Michel Albert Audette

Electrical & Computer Engineering Faculty Publications

This paper presents a multi-material dual “contouring” method used to convert a digital 3D voxel-based atlas of basal ganglia to a deformable discrete multi-surface model that supports surgical navigation for an intraoperative MRI-compatible surgical robot, featuring fast intraoperative deformation computation. It is vital that the final surface model maintain shared boundaries where appropriate so that even as the deep-brain model deforms to reflect intraoperative changes encoded in ioMRI, the subthalamic nucleus stays in contact with the substantia nigra, for example, while still providing a significantly sparser representation than the original volumetric atlas consisting of hundreds of millions of voxels. The …


Pineal Cyst Apoplexy And Memory Loss: A Novel Complication, Areez Shafqat, Hanin Jaber Algethami, Shameel Shafqat, Syed Shafqat Ul Islam Aug 2022

Pineal Cyst Apoplexy And Memory Loss: A Novel Complication, Areez Shafqat, Hanin Jaber Algethami, Shameel Shafqat, Syed Shafqat Ul Islam

Medical College Documents

An 8-year-old boy presented to our hospital complaining of a bilateral headache associated with episodes of anterograde amnesia. He had a road traffic accident 3 years ago when a computed tomography (CT) scan revealed traumatic brain injury. In addition, a small pineal cyst (PC) was noted with minor intramural calcifications. A follow-up CT a day later demonstrated increased density in the pineal gland of 60 Hounsfield Units, suggestive of apoplectic changes in the PC. However, the patient was lost to follow-up and presented with memory loss a year and a half later, upon which CT and magnetic resonance imaging revealed …


Automation Through Deep-Learning To Quantify Ventilation Defects In Lungs From High-Resolution Isotropic Hyperpolarized 129xe Magnetic Resonance Imaging, Tuneesh Kaur Ranota Jun 2022

Automation Through Deep-Learning To Quantify Ventilation Defects In Lungs From High-Resolution Isotropic Hyperpolarized 129xe Magnetic Resonance Imaging, Tuneesh Kaur Ranota

Electronic Thesis and Dissertation Repository

Obstructive lung diseases are characterized by heterogenous ventilation. Hyperpolarized 129Xe gas lung magnetic resonance imaging (MRI) can examine lung ventilation heterogeneity by acquiring high-resolution isotropic images. The current gold standard of semi-automated (SA) segmentation can be used to quantify non-isotropic 129Xe lung images to generate ventilation defect percent (VDP), however, this method is not suitable for analysis of isotropic voxel 129Xe images due to the large number of slices. Therefore, we used a fully automated deep learning-based (DL) lung algorithm to calculate VDP from isotropic images. SNR, SA and DL-based VDP were calculated, showing a strong positive …


Extended Functional Connectivity Of Convergent Structural Alterations Among Individuals With Ptsd: A Neuroimaging Meta-Analysis, Brianna S. Pankey, Michael C. Riedel, Isis Cowan, Jessica E. Bartley, Rosario Pintos Lobo, Lauren D. Hill-Bowen, Taylor Sato, Erica D. Musser, Matthew T. Sutherland, Angela R. Laird Jan 2022

Extended Functional Connectivity Of Convergent Structural Alterations Among Individuals With Ptsd: A Neuroimaging Meta-Analysis, Brianna S. Pankey, Michael C. Riedel, Isis Cowan, Jessica E. Bartley, Rosario Pintos Lobo, Lauren D. Hill-Bowen, Taylor Sato, Erica D. Musser, Matthew T. Sutherland, Angela R. Laird

Psychology Faculty Publications

Background: Post-traumatic stress disorder (PTSD) is a debilitating disorder defined by the onset of intrusive, avoidant, negative cognitive or affective, and/or hyperarousal symptoms after witnessing or experiencing a traumatic event. Previous voxel-based morphometry studies have provided insight into structural brain alterations associated with PTSD with notable heterogeneity across these studies. Furthermore, how structural alterations may be associated with brain function, as measured by task-free and task-based functional connectivity, remains to be elucidated.

Methods: Using emergent meta-analytic techniques, we sought to first identify a consensus of structural alterations in PTSD using the anatomical likelihood estimation (ALE) approach. Next, we generated functional …


Diagnostic Accuracy Of Mcmurry’S Test In The Diagnosis Of Meniscal Tears, Jessica Smyth, Hartwell Rainey Dec 2020

Diagnostic Accuracy Of Mcmurry’S Test In The Diagnosis Of Meniscal Tears, Jessica Smyth, Hartwell Rainey

Physician Assistant Capstones, 2020-current

No abstract provided.


Does An Acute Achilles Tendon Rupture Become A Patient's Achilles Heel In The Long-Term?, Michaela Cm Khan Nov 2019

Does An Acute Achilles Tendon Rupture Become A Patient's Achilles Heel In The Long-Term?, Michaela Cm Khan

Electronic Thesis and Dissertation Repository

It is unknown if deficits in the involved limb following acute Achilles tendon rupture (AATR) persist in the long-term, or differ between patients treated operatively or non-operatively. This study investigated 43 patients 15±1 years post-AATR from a previous randomized controlled trial (RCT) that compared operative and non-operative treatment. Structural characteristics in the Achilles tendon and surrounding musculature were assessed using magnetic resonance imaging. We also performed physical examinations and evaluated performance-based and patient-reported outcomes. Overall, there were substantial differences between the involved and uninvolved limbs in most outcomes. Some outcomes improved over time from the initial RCT to the final …


Ultra-High Field Magnetic Resonance Imaging For Stereotactic Neurosurgery, Jonathan Lau Apr 2019

Ultra-High Field Magnetic Resonance Imaging For Stereotactic Neurosurgery, Jonathan Lau

Electronic Thesis and Dissertation Repository

Stereotactic neurosurgery is a subspecialty within neurosurgery concerned with accurate targeting of brain structures. Deep brain stimulation (DBS) is a specific type of stereotaxy in which electrodes are implanted in deep brain structures. It has proven therapeutic efficacy in Parkinson’s disease and Essential Tremor, but with an expanding number of indications under evaluation including Alzheimer’s disease, depression, epilepsy, and obesity, many more Canadians with chronic health conditions may benefit. Accurate surgical targeting is crucial with millimeter deviations resulting in unwanted side effects including muscle contractions, or worse, vessel injury. Lack of adequate visualization of surgical targets with conventional lower field …


A Descriptive Study To Find Possible Correlation Between Mri Findings Of Pituitary Gland And Serum Prolactin Level, Muhammad Azeemuddin, Rohana Naqi, Mohammad Wasay Jun 2013

A Descriptive Study To Find Possible Correlation Between Mri Findings Of Pituitary Gland And Serum Prolactin Level, Muhammad Azeemuddin, Rohana Naqi, Mohammad Wasay

Department of Medicine

Objective: To explore equation, if any, between findings of magnetic resonance imaging of pituitary gland and serum prolactin level.

Methods: The retrospective, descriptive study was conducted at the Department of Radiology, Aga Khan University Hospital, Karachi, and related to patients\' records from April 19, 2006 to April 23, 2009. Seventy patients underwent magnetic resonance imaging of brain for pituitary gland. Inclusion criteria were all patients referred with relevant clinical symptoms or deranged serum prolactin level. Patients who were claustrophobic or had a pacemaker, aneurysm clip, metallic foreign body in the orbit or with no laboratory investigation were excluded from the …


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.


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. …


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.