Search results for "RESONANCE"
showing 10 items of 6625 documents
Characterization of normal regional myocardial function by MRI cardiac tagging
2013
Purpose The aim of this study was to establish reference values for segmental myocardial strain measured by magnetic resonance (MR) cardiac tagging in order to characterize the regional function of the heart. Material and Methods We characterized the left ventricular (LV) systolic deformation in 39 subjects (26 women and 13 men, age 58.8 ± 11.6 years) whose cardiological study had not revealed any significant abnormality. The deformation was measured from MR-tagged (Siemens 1.5T MR) images using an algorithm based on sine wave modeling. Circumferential and radial peak systolic strain values along with the torsion angle and circumferential-longitudinal (CL) shear were determined in 16 LV seg…
MRI of the inner ear: use of modified GRASS and fast spin-echo sequences
1996
We report our experience with MRI of the normal and pathological inner ear with fast spin-echo and modified gradient recalled at steady state sequences. Although earlier studies on temporal bone MRI were discouraging, improvements in MR technology combined with the use of paramagnetic contrast media can make MRI a useful diagnostic tool for the assessment of inner ear pathology. Conventional spin-echo imaging seems not to be the modality of choice because of the relatively thick slices and the long acquisition times.
Remodeling of Cortical Structural Networks in Multiple Sclerosis
2019
Multiple sclerosis (MS) is one of the most frequent immune-mediated disorders of the central nervous system. Pathological events occurring within the white matter and gray matter compartments can be reliably tracked in vivo by magnetic resonance imaging (MRI) but conventional imaging parameters do not reflect the remodeling processes of the brain. Here, we sought to investigate the reorganization of cortical structural networks in a group of patients with MS. For this, 40 patients (mean age ± standard deviation 31.2 ± 7.0 years, 14 males) with relapsing-remitting MS and 40 healthy subjects (27.1 ± 5.0 years, 14 males) were included in the study. From T1-weighted MR image-derived cortical th…
Temperature Measurement by Diffusion-Weighted Imaging
2021
Diffusion-weighted imaging (DWI) thermometry is a magnetic resonance-based imaging tool that allows the noninvasive measurement of brain core temperature. Although only applicable to cerebrospinal fluid, it is thought to be potentially useful in assessing the thermal pathophysiology of the brain in both patients and healthy subjects. The objective of this article is to provide a concise but thorough review of the basic physical principles and the principal applications of DWI thermometry as a potential method to elucidate the pathophysiology of several brain diseases and neurologic syndromes.
Comment on “Computer-Extracted Texture Features to Distinguish Cerebral Radionecrosis from Recurrent Brain Tumors on Multiparametric MRI: A Feasibili…
2017
We have read with great interest the article published by Tiwari et al, “Computer-Extracted Texture Features to Distinguish Cerebral Radionecrosis from Recurrent Brain Tumors on Multiparametric MRI: A Feasibility Study.”[1][1] In their article, they refer to our work regarding brain metastasis
Variación de tamaño de la hiperplasia nodular focal mediante resonancia magnética
2013
Objective: To evaluate the changes in the size of focal nodular hyperplasia (FNH) during longterm magnetic resonance imaging (MRI) follow-up.
Study of CT/MRI mutual information based registration applied in brachytherapy
2016
The present work aims to include magnetic resonance imaging (MRI) in a Medical Image-based Graphical platfOrm - Brachytherapy module (AMIGOBrachy) which coupled to the Monte Carlo N-Particle (MCNP6) code allows absorbed dose calculations. Computed tomography (CT) and MRI images were registered using mutual information algorithms to improve tissue segmentation potentially leading to a more accurate treatment planning system.
Visualization of inert gas wash-out during high-frequency oscillatory ventilation using fluorine-19 MRI
2010
High-frequency oscillatory ventilation is looked upon as a lung-protective ventilation strategy. For a further clarification of the physical processes promoting gas transport, a visualization of gas flow and the distribution of ventilation are of considerable interest. Therefore, fluorine-19 magnetic resonance imaging of the imaging gas octafluorocyclobutane (C(4) F(8) ) during high-frequency oscillatory ventilation was performed in five healthy pigs. For that, a mutually compatible ventilation-imaging system was set up and transverse images were acquired every 5 sec using FLASH sequences on a 1.5 T scanner. Despite a drop in signal-to-noise ratio after the onset of high-frequency oscillato…
A Combined Behavioral and Neuroimaging Battery to Test Positive Appraisal Style Theory of Resilience in Longitudinal Studies
2018
AbstractResilience is the maintenance or rapid recovery of mental health during and after stressor exposure. It is becoming increasingly clear that resilience results from a complex and dynamic process of adaptation to stressors involving the biological, psychological and social levels. Positive appraisal style theory of resilience (PASTOR) claims that the common final pathway to maintained mental health lies in the non-negative (non-catastrophizing, non-pessimistic) appraisal of potential stressors, permitting the organism to fine-tune stress responses to optimal levels, thus avoiding unnecessary stress, inefficient deployment of resources and concomitant deleterious allostatic load effect…
Optical biosensor-based characterization of anti-double-stranded DNA monoclonal antibodies as possible new standards for laboratory tests.
2009
The serum determination of circulating anti-double-stranded (ds)DNA autoantibodies is a routine measure for the laboratory diagnosis of systemic lupus erythematosus. Since available assays differ substantially and no feasible calibrator is available, the aim of this study was to evaluate a recently introduced surface plasmon resonance (SPR) biosensor chip for binding studies between dsDNA and anti-dsDNA autoantibodies and to demonstrate its usefulness for the characterization of new monoclonal antibody (mAb) standards and standardization of assays. We characterized two human and one murine monoclonal anti-dsDNA antibodies by measuring the kinetic on- and off-rates using the biosensor and ca…