Research
The Unit is active in a number research areas including:
- the development and evaluation of new magnetic resonance imaging and spectroscopy techniques for the investigation of brain disease;
- the use of these techniques to investigate focal brain damage and its functional consequences in several groups of patients, including children with epilepsy, children with cerebrovascular disease, and children with specific types of cognitive impairment;
- applications of imaging techniques in (a) haematological and oncological disorders, (b) disorders of growth and nutrition, and (c) congenital and genetic conditions;
- classification of dysplasias and malformation syndromes, involving the development of a computer image database and knowledge-based (expert) diagnostic system;
Research in Magnetic Resonance
The magnetic resonance imaging (MRI) and spectroscopy (MRS) programme focuses on the development and application of a wide range of techniques for the assessment of brain structure, biochemistry, and function, including morphometric analyses, relaxometry, functional MRI, 1H MRS, diffusion imaging and perfusion imaging. This research involves extensive collaboration with colleagues in a number of other Units within the Institute, including the Neurosciences Unit, the Developmental Cognitive Neuroscience Unit, the MRC Childhood Nutrition Research Centre, and the Medical Molecular Biology Unit. One of the important features of the programme is that, in addition to increasing our understanding of disease processes, the research findings also readily translated into improvements in clinical practice. The clinical research is complemented by a thriving basic research programme, thus providing a broad multidisciplinary environment; indeed many of the students are jointly supervised with colleagues in other Units. A brief outline of the research is given below; for further details contact Professor David Gadian.
Children with epilepsy form the largest patient group so
far investigated in our collaborative programme with the Neurosciences
and Developmental
Cognitive Neuroscience Units. The development and
application of new magnetic resonance techniques now allows
identification of the brain damage underlying seizure activity in many
of these children, and this has made a major contribution to the
establishment of a highly successful epilepsy surgery programme at Great
Ormond Street for the treatment of children with intractable epilepsy.
Structural and functional MRI techniques are also helping us to
understand the cognitive and behavioural difficulties experienced by
some of these children.
|
Functional MRI scans of a candidate for epilepsy surgery. The regions that are activated on performance of a verb generation task are displayed in colour, and they indicate left hemisphere lateralization of language function. |
Stroke is another major area of interest within this programme.
Although stroke is primarily a disease of adulthood, some groups of
children are at particular risk; for example, children with sickle cell
disease have an incidence of stroke similar to that in a general elderly
adult population. The development of diffusion and perfusion imaging is
proving invaluable in identifying brain abnormalities that may reflect
tissue which is at risk, but which has not undergone irreversible
damage. The non-invasive identification of such tissue, prior to the
occurrence of a stroke, could in turn lead to developments in the
management of these patients, including the development of preventative
strategies.
|
Images from a boy with sickle cell disease. The T2-weighted structural image (a) shows no abnormalities; the ‘mean-transit-time’ image (b) reveals extensive blood flow abnormalities as areas of abnormally high signal intensity throughout the hemisphere on the left side of the image and in the posterior region on the right. |
The third major area involves the use of magnetic resonance techniques to investigate brain structure-function relationships in selected groups of children with specific types of cognitive impairment, including children with memory or speech and language impairments (with the Developmental Cognitive Neuroscience Unit). Here, the main focus is to relate abnormalities seen on MRI to those seen on neuropsychological testing. Many children with learning difficulties are survivors of preterm birth, and further investigations of a large cohort of children born preterm (in collaboration with the MRC Childhood Nutrition Research Centre) are providing us with important new information about the neural bases of learning problems.
All of this clinical research is complemented by an extensive programme of basic research aimed at understanding the pathophysiological basis of disease. This research includes a number of investigations of experimental models of brain disease, including models of stroke and of epilepsy. The stroke studies are exemplified by a project investigating the neuroprotective effects of virally-delivered heat shock proteins (in collaboration with the Medical Molecular Biology Unit). Our epilepsy research includes investigations of the chain of events whereby a prolonged seizure may cause temporal lobe damage and subsequent epilepsy.
Skeletal Dysplasias and Malformation Syndromes
Professor Christine Hall is involved in the classification of skeletal dysplasias and malformation syndromes and systems aimed at improving diagnostic accuracy by general clinicians and radiologists of these many rare conditions. Currently about 250 dysplasias are recognised and 2000 malformation syndromes with skeletal involvement. The research has centred on the development of a knowledge-based expert system for diagnosis, in collaboration with John Washbrook and other colleagues in the Department of Computer Science, UCL London. This work has had the support of The Leverhulme Trust.
The work has led to the creation and publication of a Radiological Electronic Atlas of Malformation Syndromes and Skeletal Dysplasias (REAMS), a database of 7000 radiographic images of these rare conditions and their radiological findings. The database incorporates abstracts of the conditions, lists of findings and comprehensive references and has a powerful search facility on multiple parameters. The database is published on CD-ROM by Oxford University Press. The work has been undertaken in collaboration with John Washbrook, Department of Computer Science, UCL, Professor Andrew Todd-Pokropek, Department of Medical Physics and Bioengineering, UCL, and the late Professor Robin Winter, Department of Clinical Genetics, ICH London. The development of REAMS has been supported by Oxford University Press and The Dunhill Medical Trust.
Ongoing work involves clinical trials and evaluation of the role of the Knowledge-based system and of the electronic database in influencing clinical accuracy among general clinicians.
The Department of Paediatric Radiology under Professor Christine Hall provides a service to the courts on behalf of Great Ormond Street Children's Hospital in the field of the radiological findings of physical child abuse (non-accidental injury). Data from many hundreds of cases have been collated and evaluated .
Research in Nuclear Medicine
Nuclear medicine investigations are led by Professor Isky Gordon. Research in nephro-urology has focused on the clinical problems of urinary tract infection, prenatal diagnosis of renal pelvic dilatation, assessment of children following renal transplantation and assessment of children with sustained systemic hypertension.
In the brain the focus has been on children with intractable epilepsy attempting to help define whether surgery is a feasible solution as well as in Anorexia Nervosa trying to understand the cortical involvement in the disease process.
In oncology combining functional data with structural information is assisting in both the management as well as the understanding of childhood malignancy.
Page last modified on 18 mar 11 10:10
