Search results for "MAGNETIC RESONANCE"
showing 10 items of 4721 documents
Facilitating cartilage volume measurement using MRI.
2010
To compare quantitative cartilage volume measurement (CVM) using different slice thicknesses.Ten knees were scanned with a 1.5T MRI (Sonata, Siemens, Erlangen, Germany) using a 3D gradient echo sequence (FLASH, fast low-angle shot). Cartilage volume of the medial and lateral tibial plateau was measured by two independent readers in 1.5mm, 3.0mm and 5.0mm slices using the Argus software application. Accuracy and time effectiveness served as control parameters.Determining cartilage volume, time for calculation diminished for the lateral tibial plateau from 384.6+/-127.7s and 379.1+/-117.6s to 214.9+/-109.9s and 213.9+/-102.2s to 122.1+/-60.1s and 126.8+/-56.2s and for the medial tibial platea…
Magnetic resonance chondro-crassometry (MR CCM): a method for accurate determination of articular cartilage thickness?
1996
A method for the assessment of articular cartilage thickness based on MRI is presented and its accuracy and reproducibility tested. Six specimens of human patellae were imaged, using a fat-suppressed FLASH 3D sequence, and sectioned with a high-precision band saw. The regional distribution of articular cartilage thickness was determined from the MR images and from the anatomical sections (intervals of 0.5 mm). With image analysis 50-90% of the image points were found to lie within exactly the same thickness interval in corresponding patterns, and less than 17% deviated more than 0.5 mm. More than 85% of all pixels were reproducible with MRI after new positioning of the joint. No influence o…
Repeatability of patellar cartilage thickness patterns in the living, using a fat-suppressed magnetic resonance imaging sequence with short acquisiti…
1998
A fast, reproducible, and noninvasive method is required for quantifying cartilage thickness clinically and for studying the deformation of articular cartilage during and after mechanical loading in vivo. The objective of the current investigation was to test the repeatability of regional distribution patterns of patellar cartilage thickness in the living on the basis of a fat-suppressed magnetic resonance imaging sequence with a short acquisition time and three-dimensional digital data processing. The knees of eight healthy volunteers were transversally imaged with a fat-suppressed FLASH-3D (fast low angle shot) sequence (acquisition time: 4 minutes and 10 seconds). In each case, the joint…
Determination of knee joint cartilage thickness using three-dimensional magnetic resonance chondro-crassometry (3D MR-CCM)
1996
The objective of this article was to analyze the accuracy and precision with which the quantitative distribution of articular cartilage can be determined in the knee joint using MRI. A three-dimensional (3D) technique that accounts for the out-of-plane deviation of the interface normal in strongly curved joint surfaces (3D MR-CCM) has been developed for cartilage thickness measurements. Eight cadaveric knee-joint specimens and six volunteers were imaged using a fat-suppressed gradient-echo sequence at a resolution of 2 x 0.31 x 0.31 mm3. Cartilage volumes and topographical thickness maps were obtained and compared with those derived from anatomical sections by image analysis. The deviation …
Non-invasive determination of cartilage thickness throughout joint surfaces using magnetic resonance imaging.
1997
Abstract Data on articular cartilage thickness in the living are important for the design of computer models, aimed at preoperatively assessing the effect of surgical procedures on joint contact and load transmission, and for the calculation of cartilage material properties from its deformational behavior as determined during arthroscopy. A non-invasive method for measuring cartilage thickness in living subjects is, however, not available. A technique based on magnetic resonance imaging has therefore been tested for assessing articular cartilage thickness throughout joint surfaces. The accuracy is determined by comparing cartilage thickness maps obtained from three patellar specimens with a…
Thoracic spinal cord cavernous angioma: a case report and review of the literature
2014
Introduction: Cavernous angiomas of the spinal cord are rare vascular malformations, which account for approximately 5 to 12 percent of spinal cord vascular lesions. They usually originate in the vertebrae, with occasional extension into the extradural space, and intramedullary cavernomas, even if reported in the literature, are very rare. Case presentation: We report the case of a 34-year-old Caucasian woman affected by a thoracic intramedullary cavernous angioma. Our patient complained of 10-day history of acute dorsal pain, progressive weakness of both lower extremities, worse on the right side, a ‘pins and needles’ sensation in the abdominal region and bladder dysfunction. Magnetic reso…
Neurochemical alterations in women with borderline personality disorder and comorbid attention-deficit hyperactivity disorder
2010
Borderline personality disorder (BPD) is associated with structural and functional brain changes. Recent models and findings refer to alterations of glutamate and total N-acetylaspartate (tNAA) in this condition.Absolute quantities of tNAA, creatine, glutamate, glutamine, myoinositol and total choline were measured using 3 Tesla magnetic resonance spectroscopy of the left anterior cingulate cortex and the left cerebellum in 14 unmedicated women with BPD and comorbid attention-deficit hyperactivity disorder (ADHD) and 18 healthy women. Both groups were matched with respect to age, education and premorbid intelligence.In the anterior cingulate, we found significantly higher tNAA and glutamate…
Reduced interhemispheric structural connectivity between anterior cingulate cortices in borderline personality disorder
2008
Functional and structural alterations of the anterior cingulate cortex (ACC), a key region for emotional and cognitive processing, are associated with borderline personality disorder (BPD). However, the interhemispheric structural connectivity between the left and right ACC and between other prefrontal regions in this condition is unknown. We acquired diffusion-tensor imaging data from 20 healthy women and 19 women with BPD and comorbid attention-deficit hyperactivity disorder (ADHD). Interhemispheric structural connectivity between both sides of the ACC, dorsolateral prefrontal cortices and medial orbitofrontal cortices was assessed by a novel probabilistic diffusion tensor-based fiber tra…
Cognitive priming in sung and instrumental music: Activation of inferior frontal cortex
2006
Neural correlates of the processing of musical syntax-like structures have been investigated via expectancy violation due to musically unrelated (i.e., unexpected) events in musical contexts. Previous studies reported the implication of inferior frontal cortex in musical structure processing. However - due to the strong musical manipulations - activations might be explained by sensory deviance detection or repetition priming. Our present study investigated neural correlates of musical structure processing with subtle musical violations in a musical priming paradigm. Instrumental and sung sequences ended on related and less-related musical targets. The material controlled sensory priming com…
Seeking the “Beauty Center” in the Brain: A Meta-Analysis of fMRI Studies of Beautiful Human Faces and Visual Art
2020
AbstractThe existence of a common beauty is a long-standing debate in philosophy and related disciplines. In the last two decades, cognitive neuroscientists have sought to elucidate this issue by exploring the common neural basis of the experience of beauty. Still, empirical evidence for such common neural basis of different forms of beauty is not conclusive. To address this question, we performed an activation likelihood estimation (ALE) meta-analysis on the existing neuroimaging studies of beauty appreciation of faces and visual art by non-expert adults (49 studies, 982 participants, meta-data are available at https://osf.io/s9xds/). We observed that perceiving these two forms of beauty a…