BOLD MRI response to hypercapnic hyperoxia in patients with meningiomas: correlation with Gadolinium-DTPA uptake rate

The Blood Oxygen Level–Dependent Functional MR Imaging Signal Can Be Used to Identify Brain Tumors and Distinguish Them from Normal Tissue

“…15,17,20,31 Mathematic models have been designed to map the microvasculature that develops in brain neoplasms, 30 and there are numerous articles citing the effect of endothelial growth factors in increasing tumor angiogenesis. 17,18,32,33,34 The effect on the BOLD signal intensity of varying tumor oxygenation has been studied in animals 3,24,25 and patients 27 while breathing various gases; these studies have shown a significant enhancement in T2 of the tumor but not of the normal tissue. The authors suggested that oxygen consumption in tumor tissue may be different from that in normal brain.…”

“…[20][21][22][23] In this study, we focused on 2 questions: Do brain tumors have a unique BOLD signal intensity, and if so, can we use this signal intensity to distinguish the tumor from the surrounding normal brain? Recent studies have attempted to distinguish brain tumors from normal tissue by using the BOLD fMRI signal intensity; several of these required having animals 3,[24][25][26] or patients 27 breathe carbogen or other hypoxic gases while blood flow was monitored. A more recent study used the BOLD signal intensity itself to distinguish brain tumors from the surrounding edematous tissue.…”

Quantification of the magnetic resonance signal response to dynamic (C)O2‐enhanced imaging in the brain at 3 T: R*2 BOLD vs. balanced SSFP

“…The high clinical impact of this method in oncologic applications is underlined by numerous animal studies investigating tumor hypoxia (2,3,(16)(17)(18) and vessel maturation and function (19)(20)(21). The feasibility of respiratory challenges in clinical settings has been further demonstrated in several tumor studies in humans (22)(23)(24)(25)(26)(27).The response to hyperoxia and hypercapnia, affecting both oxygenation and blood flow and volume, can be measured using magnetic resonance imaging (MRI), because the related changes in deoxyhemoglobin concentration (dHb) ultimately manifest in changes in the reversible transverse relaxation rate R* 2 (1,28), a relation that is known as the blood-oxygenation-level-dependent (BOLD) effect (29). Furthermore, an increased blood flow also leads to an accelerated inflow of unsaturated spins in slice-selective MR sequences.…”

Using magnetic resonance imaging and spectroscopy in cancer diagnostics and monitoring

“…In a study on meningiomas, it was observed that BOLD response to carbogen was seen only in areas with leakage of injected Gd-based contrast agent, demonstrating that BOLD response is an index of vascular reactivity (and thus, perfusion in the tumor stroma). 82 The BOLD MRI data from respiratory challenges are promising pointing to an imminent potential of BOLD MRI in monitoring tumor vasoreactivity and oxygenation in a clinical setting. In animal models drugs have also been used to cause vasodilation, such as nicotinamide.…”