MRI physics research and development
The research and development work carried by the MRI physics group is concerned with the application and development of advanced MRI techniques. Some of this work involves developing new MRI techniques or applications, whereas other areas are more related to the transfer of research techniques into the clinical domain.
MRI research areas
The assessment of cerebral autoregulation using MRI
This project involves using advanced MRI techniques to try and assess cerebral autoregulation. Autoregulation is the mechanism by which blood flow to the brain is maintained at a constant rate despite variations in the pressure of blood supplying the vessels. These vessels achieve flow regulation by altering their resistance accordingly. This mechanism can become impaired. The measurement and spatial localisation of the autoregulation mechanism across the brain is not currently possible but could provide insight into a wide range of neurological disorders and conditions. This work is being carried out in collaboration with the neurological physics group within the department.
The imaging of musculoskeletal characteristics using advanced MRI techniques
The main aspect of this project involves using MRI to examine the structure and function of the intra-articular synovial folds (IASFs) in the cervical spine. This work is currently being carried out on healthy volunteers. These are thought to be involved in pain associated with whiplash injuries and not much is known about their composition. Some quantification is being carried out to determine the shape and size of these folds and it is hoped that the project will eventually look at how the IASFs changed with age and injury.
Other aspects of this project have involved looking at the morphology of the talus bone in the ankle and see if the ‘squatting facet’ can be determined from 3D reconstructions. The presence of this feature may provide further information about the function of the ankle joint complex.
Clinical validation of MRI techniques in temporal lobe epilepsy
This project mainly involves using functional MRI to assess language function in temporal lobe epilepsy patients. This is essential prior to surgery and is currently carried out using the WADA test, an invasive and time-consuming procedure. We want to develop a consistent and reliable procedure for testing language using fMRI that should be much easier to carry out than the WADA test. The techniques has initially been optimised on healthy volunteers and is now being used on patients where these is ambiguity in the lateralisation of language function. The results from this study can be validated against the WADA testing that the patient will undergo.
There are plans to extend this work to investigate the use of functional MRI to test memory function in the same cohort of patients. This will involve developing new paradigms and methods of image analysis.
The assessment of body fat volume and distribution in obese men
The aim of this project was to quantify the volume and distribution of subcutaneous and visceral fat in a group of obese men using a set of non-contiguous T1 – weighted abdominal MRI images. These measurements could then be related to other obesity related parameters to predict the presence of fatty liver (hepatic steatosis) in obese patients. Quantification was carried out using a program called Mimics (Materialise LV, Leuven, Belgium) and this involved creating ‘masks’ that isolated areas of visceral and subcutaneous fat. Quantitative information could be extracted from these masks to allow percentages of visceral and subcutaneous fat volume to be calculated.
The automated diagnosis of emphysema in COPD from high resolution CT images of the lungs
This project used high-resolution CT images to try and come up with a quantitative measure of emphysema based on the percentage of lung voxels that were below a certain threshold of Hounsfield Units (HU). This measure was compared to other measures of lung function and quality of life. An automated analysis method was devised using IDL (Interactive Data Language, Research Systems Inc, Boulder, CO, USA).
Development of cardiac MRI techniques
This area of research and development has arisen due to the recent installation of a dedicated cardiac MRI scanner (Siemens Avanto 1.5T) at Southampton General Hospital. The MR physics service will be supporting this new development and this will involve optimising pulse sequences and developing image-processing techniques. The unit will scan a large range of patients with both congenital and acquired heart conditions and this should provide an opportunity to develop a nationally leading cardiac MRI service.
Contact
Email Angela Darekar Angela.darekar@suht.swest.nhs.uk|