Reproducibility of 3D chemical exchange saturation transfer (CEST) contrasts in the healthy brain at 3T.

Chemical exchange saturation transfer (CEST) imaging may provide novel contrast for the diagnosis, prognosis, and monitoring of the progression or treatment of neurological applications. However, the reproducibility of prominent CEST contrasts like amide CEST and nuclear Overhauser enhancement (NOE) CEST must be characterized in healthy brain gray matter (GM) and white matter (GM) prior to clinical implementation. The objective of this study was to characterize the reproducibility of four different CEST contrasts in the healthy human brain.

Reproducibility of 3D pH-weighted chemical exchange saturation transfer contrast in the healthy cervical spinal cord.

Spinal cord ischemia and hypoxia can be caused by compression, injury, and vascular alterations. Measuring ischemia and hypoxia directly in the spinal cord noninvasively remains challenging. Ischemia and hypoxia alter tissue pH, providing a physiologic parameter that may be more directly related to tissue viability.

Characterizing mJOA-defined post-surgical recovery patterns in patients with degenerative cervical myelopathy.

Background: Degenerative cervical myelopathy is a spinal disorder resulting in progressive cord compression and neurological deficits that are assessed using the modified Japanese Orthopedic Association (mJOA) questionnaire. It is difficult to predict which patients will recover neurological function after surgery, making it challenging for clinicians to set postoperative patient expectations. In this study, we used mJOA subscores to identify patterns of recovery and recovery timelines in patients with moderate and severe myelopathy.

Spinal cord compression is associated with brain plasticity in degenerative cervical myelopathy.

The impact of spinal cord compression severity on brain plasticity and prognostic determinates is not yet fully understood. We investigated the association between the severity of spinal cord compression in patients with degenerative cervical myelopathy, a progressive disease of the spine, and functional plasticity in the motor cortex and subcortical areas using functional magnetic resonance imaging. A 3.

Reducing unnecessary testing in the emergency department: The case for INR and aPTT.

Objective: Routine coagulation testing is rarely indicated in the emergency department. Our goal is to determine the combined effects of uncoupling routine coagulation testing (i.e.

Does the Neurological Examination Correlate with Patient-Perceived Outcomes in Degenerative Cervical Myelopathy?

Background: In patients with neurological disorders, a divergence can exist between patients' perceptions regarding the outcomes and the objective neurological findings. Degenerative cervical myelopathy (DCM), a prevalent condition characterized by progressive compression of the cervical spinal cord, can produce debilitating symptoms and profound neurological findings. The purpose of the present study was to determine whether the physician-derived neurological examination findings, as recorded by American Spine Injury Association (ASIA) summary score, correlated with the patient-derived outcome measures for DCM.

Current State of Point-of-care Ultrasound Usage in Canadian Emergency Departments.

Background Point-of-care ultrasound (POCUS) has many applications in emergency medicine, which have been proven to improve patient outcomes. Training programs and well-established guidelines for its use are available, but Canadian adoption rates and attitudes toward this technology have not been recently assessed. Objectives This study aimed to provide a national assessment of the current use of POCUS in Canadian emergency departments (ED) including patterns of use, attitudes towards its role, descriptors of training experience, as well as barriers to increased utilization.

Application of 3-d echocardiography and gated micro-computed tomography to assess cardiomyopathy in a mouse model of duchenne muscular dystrophy.

The purpose of this study was to measure changes in cardiac function as cardiomyopathy progresses in a mouse model of Duchenne muscular dystrophy using 3-D ECG-gated echocardiography. This study is the first to correlate cardiac volumes acquired using 3-D echocardiography with those acquired using retrospectively gated micro-computed tomography (CT). Both were further compared with standard M-mode echocardiography and histologic analyses.

Three-dimensional imaging of the mouse heart and vasculature using micro-CT and whole-body perfusion of iodine or phosphotungstic acid.

Recent studies have investigated histological staining compounds as micro-computed tomography (micro-CT) contrast agents, delivered by soaking tissue specimens in stain and relying on passive diffusion for agent uptake. This study describes a perfusion approach using iodine or phosphotungstic acid (PTA) stains, delivered to an intact mouse, to capitalize on the microvasculature as a delivery conduit for parenchymal staining and direct contact for staining artery walls. Twelve C57BL/6 mice, arterially perfused with either 25% Lugol's solution or 5% PTA solution were scanned intact and reconstructed with 26 µm isotropic voxels.

X-ray dose delivered during a longitudinal micro-CT study has no adverse effect on cardiac and pulmonary tissue in C57BL/6 mice.

Background: Micro-computed tomography (micro-CT) offers numerous advantages for small animal imaging, including the ability to monitor the same animals throughout a longitudinal study. However, concerns are often raised regarding the effects of X-ray dose accumulated over the course of the experiment.

Purpose: To scan C57BL/6 mice multiple times per week for 6 weeks, in order to determine the effect of the cumulative dose on pulmonary and cardiac tissue at the end of the study.

Rapid microcomputed tomography suggests cardiac enlargement occurs during conductance catheter measurements in mice.

Conductance catheters (CC) represent an established method of determining cardiac function in mice; however, the potentially detrimental effects a catheter may have on the mouse heart have never been evaluated. The present study takes advantage of rapid three-dimensional (3D) microcomputed tomography (CT) to compare simultaneously acquired micro-CT and CC measurements of left ventricular (LV) volumes in healthy and infarcted mice and to determine changes in LV volume and function associated with CC insertion. LV volumes were measured in C57BL/6 mice (10 healthy, 10 infarcted, 2% isoflurane anesthesia) using a 1.

Evaluation of eXIA 160 cardiac-related enhancement in C57BL/6 and BALB/c mice using micro-CT.

Evaluation of cardiovascular function in mice using micro-CT requires that a contrast agent be administered to differentiate the blood from the myocardium. eXIA 160, an aqueous colloidal poly-disperse contrast agent with a high iodine concentration (160 mg I ml(-1)), creates strong contrast between blood and tissue with a low injection volume. In this study, the blood-pool enhancement time-course of eXIA 160 is monitored over a 48 h period to determine its optimal use during cardiac function studies in C57BL/6 and BALB/c mice.

Least-error projection sorting to optimize retrospectively gated cardiac micro-CT of free-breathing mice.

Purpose: To develop and characterize a technique for optimizing image quality by eliminating streaking artifacts in retrospectively gated microcomputed tomography (micro-CT) images of mice caused by insufficient and irregular angular sampling.

Methods: A least-error sorting technique was developed to minimize streak artifacts in retrospectively gated cardiac micro-CT images. To ensure complete filling of projection space, for each angular position, the projection acquired closest to the desired cardiac phase is used to reconstruct a volumetric image.

Longitudinal follow-up of cardiac structure and functional changes in an infarct mouse model using retrospectively gated micro-computed tomography.

Objectives: Mouse models of myocardial infarction are valuable in studying the effect of genetic modifications on structural and functional remodeling of the heart. Our group recently developed a method for acquiring three-dimensional images of the beating mouse heart using micro-computed tomography (micro-CT) and retrospective gating. In this study, we evaluated cardiac function in sham and infarcted mice longitudinally, using this novel technique.

Contrast-enhanced microcomputed tomography using intraperitoneal contrast injection for the assessment of tumor-burden in liver metastasis models.

Objectives: To determine if intraperitoneally (IP) administered contrast (iohexol), used in conjunction with a liver-specific agent (Fenestra), can improve measurement precision and accuracy when quantifying tumor volume from micro-CT images of a liver metastasis model.

Materials And Methods: We compared images acquired with Fenestra alone to images acquired with the combination of Fenestra and IP iohexol. The variability in tumor volume and tumor-burden measurement was evaluated for both techniques.

Fast retrospectively gated quantitative four-dimensional (4D) cardiac micro computed tomography imaging of free-breathing mice.

Objective: We sought to demonstrate retrospectively gated dynamic 3D cardiac micro computed tomography (CT) of free-breathing mice.

Materials And Methods: Five C57Bl6 mice were scanned using a cone-beam scanner with a slip-ring-mounted flat-panel detector. After the injection of an intravascular iodinated contrast agent, projection images were acquired over the course of 50 seconds, while the scanner rotated through 10 complete rotations.

Single-strand conformational polymorphism and denaturing gradient gel electrophoresis in screening for variegate porphyria: identification of two new mutations.

Single-strand conformational polymorphism and denaturing gel electrophoresis were used to screen for mutations in the protoporphyrinogen oxidase gene (PPOX) of three patients with clinically and biochemically proven variegate porphyria in order to select genomic regions for specific DNA sequence analysis. Two previously undescribed mutations were identified: PPOX1423-1426-delATCT and PPOX2272insG. Denaturing gel electrophoresis was able to discern the point mutation in exon 5 (PPOX2272insG) of the PPOX gene.