Quantitative characterization of hemodynamic properties and vasculature dysfunction of high‐grade gliomas

Abstract

Aberrations in tumor and peritumoral vasculature may not be distinguishable by cerebral blood flow (CBF) or cerebral blood volume (CBV) alone. The relationships between CBF and CBV were examined to estimate vasculature-specific hemodynamic characteristics. Twenty glioma patients were studied with dynamic susceptibility T2*-weighted MRI [(dynamic contrast-enhanced magnetic resonance imaging (DSC-MRI)] before and during week 1 and 3 of radiotherapy (RT). CBF and CBV were calculated from DSC-MRI, and relationships between the two were evaluated: the physiological measure of mean transit time (MTT) = CBV/CBF; empirical fitting using the power law CBV = constant x (CBF)(beta). Three different tissue types were assessed: the Gd-enhancing tumor volume (GEV); non-enhanced abnormal tissue located beyond GEV but within the abnormal hyperintense region on FLAIR images (NEV); normal tissue in the hemisphere contralateral to the tumor (CNT). The effects of tissue types, CBV magnitudes (low, medium and high), before and during RT, on MTT and beta were analyzed by analysis of variance (ANOVA). The MTT and beta for the three tissue types were significantly different (p < 0.009). MTT increased from CNT (1.60 s) to NEV (1.93 s) to GEV (2.28 s) (p < 0.0005). beta was significantly greater in GEV (1.079) and NEV (1.070) than in CNT (1.025). Beta increased with increasing CBV magnitude while MTT was independent of CBV magnitude. There was a significant decrease in MTT of NEV and GEV during week 3 of RT compared with pre-RT values for all CBV magnitudes. There was a significant increase in beta during RT in the tumor and peritumor. Progressive abnormalities in vasculature and hemodynamic characteristics of the vascular bed were delineated, with significant disorder in the tumor but mild abnormality in peritumoral tissue.

Reduced resolution transit delay prescan for quantitative continuous arterial spin labeling perfusion imaging

“…To the extent that transit through the microvascular arterial blood volume does contribute to transit delay, the literature suggests that microvascular transit delays are fairly constant across tissue types. For example, MTT measurements performed with contrast typically show similar values in grey and nearby white matter (45), as well as in tumors (46). Certainly any differences are much smaller than the 3–5 fold greater blood flow in grey matter relative to white matter.…”

A Fully Automated Method for Quantitative Cerebral Hemodynamic Analysis Using DSC–MRI

“…Absolute CBV and cerebral blood flow (CBF) derived from DSC imaging have been monitored in tumoral, peri-tumoral, and normal-appearing brain tissue before, during, and after radiation treatment, and some preliminary studies already indicate that the tracer mean transit time (MTT) may provide important information on treatment response (Nagesh et al, 2007). Other studies have shown that early CBV changes during radiotherapy in gliomas predicted different physiological responses to treatment, and this information may help identify tumor sub-volumes that are radioresistant and might benefit from intensified radiation (Fuss et al, 2000).…”

Newcastle Disease Virus Interaction in Targeted Therapy against Proliferation and Invasion Pathways of Glioblastoma Multiforme

“…Due to the massive growth of the brain cancer focus, peripheral cancerous cells invade the adjacent brain parenchyma, and the core of the tumour becomes necrotic, forming a region in which tumour cells, oedema, and normal tissue coexist, making it difficult to estimate the tumour margin to ensure complete therapeutic removal [5, 19]. The tumour is also surrounded by a penumbra of invasive tumour cells that are detectable several centimetres away from the main tumour mass.…”