Search results for "Echo time"
showing 6 items of 6 documents
Stronger proprioceptive BOLD-responses in the somatosensory cortices reflect worse sensorimotor function in adolescents with and without cerebral pal…
2020
Graphical abstract
Mathematical models for the diffusion magnetic resonance signal abnormality in patients with prion diseases
2014
In clinical practice signal hyperintensity in the cortex and/or in the striatum on magnetic resonance (MR) diffusion-weighted images (DWIs) is a marker of sporadic Creutzfeldt–Jakob Disease (sCJD). MR diagnostic accuracy is greater than 90%, but the biophysical mechanisms underpinning the signal abnormality are unknown. The aim of this prospective study is to combine an advanced DWI protocol with new mathematical models of the microstructural changes occurring in prion disease patients to investigate the cause of MR signal alterations. This underpins the later development of more sensitive and specific image-based biomarkers. DWI data with a wide a range of echo times and diffusion weightin…
MRI of inner ear fluids using modified GRASS sequences: a useful tool in the assessment of the normal and pathological labyrinth
1995
MRI is acquiring a progressively more important role in the investigation of petrous bone disease. Nevertheless, despite the extensive use of MRI in the detection of inflammatory or neoplastic involvement of the seventh and eighth cranial nerves, conventional spinecho images cannot be considered the modality of choice in inner ear imaging “Steady-state sequences” are known to be motion sensitive. By setting a very short repetition time, a large flip angle and a long echo time, one can obtain a sequence sufficiently sensitive to the slow movement of endo- and perilymph. We report our experience in MRI of normal and pathological inner ear with modified GRASS sequences.
Students’ experiences of reflective writing in physiotherapy education
2015
band through the big fingers and the first toes and instructed them to extend the band as much as possible (band exercise). Each exercise was to be performed on alternate days. Before exrcise, we obtained MR imaging using Achieva 3.0T MRI (Philips Medical Systems, Best, Netherland). The imaging technique was T2 star (repetition time, 500ms; echo time, 0.703ms; field-of-view, 480mm). After scanning, participants performed each exercise in the MRI machine. For a duration of 5min, each exercise was performed at an interval of 10 s; MRI was conducted immediately after exercise. The OsiriX imaging software was used for analysis, and we circled region of interest (ROI) multifidus muscles and the …
Increased cortical curvature reflects white matter atrophy in individual patients with early multiple sclerosis
2014
Objective White matter atrophy occurs independently of lesions in multiple sclerosis. In contrast to lesion detection, the quantitative assessment of white matter atrophy in individual patients has been regarded as a major challenge. We therefore tested the hypothesis that white matter atrophy (WMA) is present at the very beginning of multiple sclerosis (MS) and in virtually each individual patient. To find a new sensitive and robust marker for WMA we investigated the relationship between cortical surface area, white matter volume (WMV), and whole-brain-surface-averaged rectified cortical extrinsic curvature. Based on geometrical considerations we hypothesized that cortical curvature increa…
Accurate classification of childhood brain tumours by in vivo H-1 MRS - A multi-centre study
2013
Aims: To evaluate the accuracy of single-voxel Magnetic Resonance Spectroscopy (1H-MRS) as a non-invasive diagnostic aid for pediatric brain tumours in a multi-national study. Our hypotheses are (1) that automated classification based on 1H-MRS provides an accurate non-invasive diagnosis in multi-centre datasets and (2) using a protocol which increases the metabolite information improves the diagnostic accuracy. Methods: 78 patients under 16 years old with histologically proven brain tumours from 10 international centres were investigated. Discrimination of 29 medulloblastomas, 11 ependymomas and 38 pilocytic astrocytomas was evaluated. Single-voxel MRS was undertaken prior to diagnosis (1.…