Biomedical subjects

Stephen J Price

Publications and source records attributed to Stephen J Price.

3 recordsLinked to original sources

PubMed2007

Predicting patterns of glioma recurrence using diffusion tensor imaging.

Although multimodality therapy for high-grade gliomas is making some improvement in outcome, most patients will still die from their disease within a short time. We need tools that allow treatments to be tailored to an individual. In this study we used diffusion tensor imaging (DTI), a technique sensitive to subtle disruption of white-matter tracts due to tumour infiltration, to see if it can be used to predict patterns of glioma recurrence. In this study we imaged 26 patients with gliomas using DTI. Patients were imaged after 2 years or on symptomatic tumour recurrence. The diffusion tensor was split into its isotropic (p) and anisotropic (q) components, and these were plotted on T(2)-weighted images to show the pattern of DTI abnormality. This was compared to the pattern of recurrence. Three DTI patterns could be identified: (a) a diffuse pattern of abnormality where p exceeded q in all directions and was associated with diffuse increase in tumour size; (b) a localised pattern of abnormality where the tumour recurred in one particular direction; and (c) a pattern of minimal abnormality seen in some patients with or without evidence of recurrence. Diffusion tensor imaging is able to predict patterns of tumour recurrence and may allow better individualisation of tumour management and stratification for randomised controlled trials.

Adult↗

PubMed2004

Tissue signature characterisation of diffusion tensor abnormalities in cerebral gliomas.

The inherent invasiveness of malignant cells is a major determinant of the poor prognosis of cerebral gliomas. Diffusion tensor MRI (DTI) can identify white matter abnormalities in gliomas that are not seen on conventional imaging. By breaking down DTI into its isotropic (p) and anisotropic (q) components, we can determine tissue diffusion "signatures". In this study we have characterised these abnormalities in peritumoural white matter tracts. Thirty-five patients with cerebral gliomas and seven normal volunteers were imaged with DTI and T2-weighted sequences at 3 T. Displaced, infiltrated and disrupted white matter tracts were identified using fractional anisotropy (FA) maps and directionally encoded colour maps and characterised using tissue signatures. The diffusion tissue signatures were normal in ROIs where the white matter was displaced. Infiltrated white matter was characterised by an increase in the isotropic component of the tensor (p) and a less marked reduction of the anisotropic component (q). In disrupted white matter tracts, there was a marked reduction in q and increase in p. The direction of water diffusion was grossly abnormal in these cases. Diffusion tissue signatures may be a useful method of assessing occult white matter infiltration.

Adult↗

PubMed2003

Have ATLS and national transfer guidelines improved the quality of resuscitation and transfer of head-injured patients? A prospective survey from a Regional Neurosurgical Unit.

High-quality resuscitation and care during transfer of head-injured patients is essential to prevent secondary brain injury. We have prospectively assessed the standard of resuscitation in 50 consecutive head-injured patients transferred to our unit, and compared our findings with previous studies performed before the advanced trauma life support course (ATLS) had become widespread and national guidelines on the transfer of head injuries had been produced by the Association of Anaesthetists of Great Britain and Ireland (AAGBI). Delays in transfer, management of the airway, adequate cervical spine assessment, hypoxia (P(a)O(2) <13 kPa), hypotension (systolic BP <90 mmHg), missed injuries and the experience of the medical escort were compared against the standards laid out in ATLS and AAGBI Guidelines. The mean, unavoidable delay from arrival at the local accident and emergency unit to arrival was 7.4+/-1.9h (mean+/-95%CI) with most of the delay being prior to initial referral. Two patients arrived with an unsecured airway with a GCS=8/15; 26 had inadequate cervical spine imaging; 7 patients arrived hypoxic and 2 patients arrived hypotensive; most of these insults occurred during the transfer. Forty-six percent of medical escorts did not fulfil the minimum standard of experience. ATLS and AAGBI guidelines have provided only modest improvements in patient care at the expense of long delays in transfer. The incidence of hypoxia and hypotension remains unacceptably high.

Adolescent↗