Issues in GRE & SE magnetic resonance imaging to probe tumor oxygenation.
Tumor oxygenation determines the efficacy of radiotherapy, but there is no non-invasive way to image this parameter. Since gradient recalled echo (GRE) images are sensitive to blood deoxyhaemoglobin concentration ([dHb]) they could have a role in assessing tumor oxygenation. In brain, linear relationships have been demonstrated between brain tissue R2* relaxation rate and tissue [dHb] or oxygen saturation, but in tumors, vascular and tissue heterogeneity, and the presence of simultaneous oxidative and glycolytic metabolism, complicate the analysis. We have studied the effects of vascular challenge in a rat prolactinoma tumor model by MR imaging and spectroscopy and comment on the implications of these results for calibrating GRE images for blood or tissue pO2.
Howe
Franklyn A
FA
Cancer Research, UK Biomedical Magnetic Resonance Research Group, Dept. Biochemistry and Immunology, St. George's Hospital Medical School, London, SW17 ORE, England.
Robinson
Simon P
SP
Rodrigues
Loreta M
LM
Stubbs
Marion
M
Griffiths
John R
JR
D000818:Animals; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009369:Neoplasms / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D015175:Prolactinoma / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar
D010100:Oxygen