The use of conventional and advanced magnetic resonance techniques in the assessment of primary brain tumours

The aim of the work described in this thesis was to investigate the value of conventional, perfusion- and diffusion-weighted magnetic resonance imaging (MRI) in patients with histology-proven low-grade gliomas (LGG), and the potential role of these methods in the management of patients with these brain tumours. Thirty-six patients were studied at the National Hospital for Neurology and Neurosurgery using conventional, perfusion-weighted and diffusion-weighted MRI at study entry and 6 monthly intervals thereafter. At each visit, tumour volume, maximum rCBV and ADC histogram measures were calculated. This is a unique cohort, as patients were treatment free until malignant transformation was diagnosed, which translates the natural history of these brain tumours. It is unlikely to find such a specific cohort as most of the patients receive treatment after the initial diagnosis of low grade gliomas. Chapters 1 and 2 of this thesis describe the theoretical basis of the MRI techniques used, and summarise the natural history and imaging aspects of cerebral gliomas. Chapter 3 describes a methodological study relating to tumour perfusion measurement: since the inclusion or exclusion of intratumoural vessels may influence the quantification of relative cerebral blood volume (rCBV), a study was conducted to choose the best ROI placement technique to be used for the rCBV measurements included in this thesis. It was shown that only the approach which excluded intratumoural vessels demonstrated a significant association between rCBV values and tumour subtypes (astrocytomas, oligodendrogliomas and oligoastrocytomas) and therefore this technique was used in all subsequent rCBV measurements.

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

UCL (University College London)

Year dc:date.issued

2008

Author dc:creator

• Caseiras, G.D.B.

• Department of Headache, Brain Injury and Rehabilitation

Language dc:language

en, eng