title: Comparison of 1H blood oxygen level-dependent (BOLD) and 19F MRI to investigate tumor oxygenation.
abstract: Fluorine-19 [(19)F] MRI oximetry and (1)H blood oxygen level-dependent (BOLD) MRI were used to investigate tumor oxygenation in rat breast 13762NF carcinomas, and correlations between the techniques were examined. A range of tissue oxygen partial pressure (pO(2)) values was found in the nine tumors while the anesthetized rats breathed air, with individual tumor pO(2) ranging from a mean of 1 to 36 torr and hypoxic fraction (HF10) (<10 torr) ranging from 0% to 75%, indicating a large intra- and intertumor heterogeneity. Breathing oxygen produced significant increase in tumor pO(2) (mean DeltapO(2) = 50 torr) and decrease in HF(10) (P < 0.01). (1)H BOLD MRI observed using a spin echo-planar imaging (EPI) sequence revealed a heterogeneous response and significant increase in mean tumor signal intensity (SI) (DeltaSI = 7%, P < 0.01). R(2)* measured by multigradient-echo (MGRE) MRI decreased significantly in response to oxygen (mean DeltaR(2)* = -4 s(-1); P < 0.05). A significant correlation was found between changes in mean tumor pO(2) and mean EPI BOLD DeltaSI accompanying oxygen breathing (r(2) > 0.7, P < 0.001). Our results suggest that BOLD MRI provides information about tumor oxygenation and may be useful to predict pO(2) changes accompanying interventions. Significantly, the magnitude of the BOLD response appears to be predictive for residual tumor HFs.
authors.affiliation: Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9058, USA.
authors.forename: Dawen
authors.initials: D
authors.lastname: Zhao
authors.forename: Lan
authors.initials: L
authors.lastname: Jiang
authors.forename: Eric W
authors.initials: EW
authors.lastname: Hahn
authors.forename: Ralph P
authors.initials: RP
authors.lastname: Mason
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D005462:Fluorine Radioisotopes; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000032:analysis* / Q000097:blood / Q000378:metabolism*; D011522:Protons; D019275:Radiopharmaceuticals; D051381:Rats; D011916:Rats, Inbred F344; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D005462:Fluorine Radioisotopes; D011522:Protons; D019275:Radiopharmaceuticals; D010100:Oxygen