Search results for "Aging"

Linking immune-mediated damage to neurodegeneration in multiple sclerosis: could network-based MRI help?

2021

Abstract Inflammatory demyelination characterizes the initial stages of multiple sclerosis, while progressive axonal and neuronal loss are coexisting and significantly contribute to the long-term physical and cognitive impairment. There is an unmet need for a conceptual shift from a dualistic view of multiple sclerosis pathology, involving either inflammatory demyelination or neurodegeneration, to integrative dynamic models of brain reorganization, where, glia-neuron interactions, synaptic alterations and grey matter pathology are longitudinally envisaged at the whole-brain level. Functional and structural MRI can delineate network hallmarks for relapses, remissions or disease progression, …

Autogreffe chondrocostale pour lésion latérale ostéochondrale de la tête métacarpienne

2020

Abstract Osteochondral injuries of the metacarpal head require anatomical restoration to prevent limitations in range of motion and osteoarthritis. Osteochondral bone grafting is a viable option, especially in younger patients. Central injuries allow for different types of grafting, but when the injured area is on the lateral portion of the metacarpal head, the graft must include both a cortical and a cartilaginous portion. We present here the pearls and pitfalls in the surgical technique of chondrocostal grating from the 6th rib and an example of its use within a case of comminuted fracture of the metacarpal head. This technique provides a graft with cortical bone that allows for a stable …

Seizure following the Use of the COX-2 Inhibitor Etoricoxib

2017

We describe a case of epileptic seizures occurring after the use of a COX-2 inhibitor. A 61-year-old man was admitted to our department because of a generalized tonic-clonic seizure. EEG showed generalized slowdown of the activity. Neuroimaging and blood samples studies did not evidence alterations, but a careful pharmacological history revealed that the patient had taken the COX-2 inhibitor etoricoxib to treat lumbago few days before the onset of clinical symptoms. No seizures were reported after etoricoxib discontinuation and an EEG resulted to be normal two months after this. Conclusion. Knowing the pharmacological history of a patient is important for understanding the clinical presenta…

Clustering Algorithms for MRI

1991

Magnetic Resonance Imaging (MRI) plays a relevant role in the design of systems for computer assisted diagnosis. MR-images are multi-dimensional in nature; physicians have to combine several perceptual information images to perform the tissue classification needed for diagnosis. Automatic clustering methods help to discriminate relevant features and to perform a preliminary segmentation of the image; it can guide the final manual classification of body-tissues. Three clustering techniques and their integration in a MRI-system are described. Their performance and accuracy was evaluated on synthetic and real image-data. A comparison of our approach with the tissue-classification done by a rad…

Classification of Schizophrenia Patients and Healthy Controls Using ICA of Complex-Valued fMRI Data and Convolutional Neural Networks

2019

Deep learning has contributed greatly to functional magnetic resonance imaging (fMRI) analysis, however, spatial maps derived from fMRI data by independent component analysis (ICA), as promising biomarkers, have rarely been directly used to perform individualized diagnosis. As such, this study proposes a novel framework combining ICA and convolutional neural network (CNN) for classifying schizophrenia patients (SZs) and healthy controls (HCs). ICA is first used to obtain components of interest which have been previously implicated in schizophrenia. Functionally informative slices of these components are then selected and labelled. CNN is finally employed to learn hierarchical diagnostic fea…

Confocal microscopy: is there a future in view of current results?

2005

Bestimmung der myokardialen Perfusionsreserve bei KHK-Patienten mit der kontrastmittelverstärkten MRT: Ein Vergleich zwischen semiquantitativer und q…

2002

OBJECTIVE Comparison between two semiquantitative methods and a quantitative evaluation of myocardial blood flow (MBF) for assessment of myocardial perfusion reserve (MPR) in patients with CAD. MATERIAL AND METHODS 9 patients with coronary stenoses > 50 % were examined with an ECG-gated Saturation Recovery Turbo FLASH sequence by using Gd-DTPA as contrast agent (CA). The entive measurements were performed both during rest and hyperemia induced by adenosine. The up-slopes of the signal-time S(t) curves in the myocardium and left ventricular (LV) cavity were evaluated by a linear fit. MPR was calculated from the original up-slopes of the myocardial S(t) curves and from the up-slopes, which we…

Diagnostische Aussagekraft von Sonographie und Computertomographie bei Lebermetastasen

1988

The diagnostic accuracy of sonography and computed tomography for detecting liver metastases was analysed in 526 patients with tumors and the findings were compared with those at laparotomy and at post mortem. The surgical protocols were analysed in respect of the primary tumour, the frequency of metastases and the number, localisation and size of metastases. A comparison of sonography and CT showed a higher sensitivity for CT (57.1%) compared with sonography (52.3%) although specificity was slightly higher for sonography. Liver metastases greater than 15 mm were detected by sonography (80.5%) and CT (92%), with much higher sensitivity. CT also proved superior, since the results depended le…

Comparison of the quantitative first pass myocardial perfusion MRI with and without prospective slice tracking: Comparison between breath-hold and fr…

2010

Physiologic motion of the heart is one of the major problems of myocardial blood flow quantification using first pass perfusion-MRI method. To overcome these problems, a perfusion pulse sequence with prospective slice tracking was developed. Cardiac motion was monitored by a navigator directly positioned at heart's basis to overcome no additional underlying model calculations connecting diaphragm and cardiac motion. Additional prescans were used before the perfusion measurement to detect slice displacements caused by remaining cardiac motion between navigator and the perfusion slice readout. The pulse sequence and subsequent quantification of myocardial blood flow was tested in healthy pigs…

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…