title: Gas challenge-blood oxygen level-dependent (GC-BOLD) MRI in the rat Novikoff hepatoma model.
abstract: OBJECTIVE
  The purpose of the study was to investigate the relationship between gas challenge-blood oxygen level-dependent (GC-BOLD) response angiogenesis and tumor size in rat Novikoff hepatoma model.
  
  
  METHODS
  Twenty adult male Sprague-Dawley rats (weighting 301-325 g) were used for our Animal Care and Use Committee-approved experiments. N1-S1 Novikoff hepatomas were grown in 14 rats with sizes ranging from 0.42 to 2.81 cm. All experiments were performed at 3.0 T using a custom-built rodent receiver coil. A multiple gradient-echo sequence was used for R2* measurements, first during room air (78% N(2)/20% O(2)) breathing and then after 10 min of carbogen (95% O(2)/5% CO(2)) breathing. After image acquisition, rats were euthanized, and the tumors were harvested for histological evaluation.
  
  
  RESULTS
  The R2* change between air and carbogen breathing for small hepatomas was positive; R2* changes changed to negative values for larger hepatomas. We found a significant positive correlation between tumor R2* change and tumor microvessel density (MVD) (r=0.798, P=.001) and a significant inverse correlation between tumor R2* change and tumor size (r=-0.840, P<.0001).
  
  
  CONCLUSIONS
  GC-BOLD magnetic resonance imaging measurements are well correlated to MVD levels and tumor size in the N1-S1 Novikoff hepatoma model; GC-BOLD measurements may serve as noninvasive biomarkers for evaluating angiogenesis and disease progression and/or therapy response.
authors: Department of Radiology, Northwestern University, Chicago, IL 60611, USA.
authors: Yang
authors: Y
authors: Guo
authors: Ning
authors: N
authors: Jin
authors: Rachel
authors: R
authors: Klein
authors: Jodi
authors: J
authors: Nicolai
authors: Guang-Yu
authors: GY
authors: Yang
authors: Reed A
authors: RA
authors: Omary
authors: Andrew C
authors: AC
authors: Larson
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000150:complications / Q000378:metabolism* / Q000473:pathology*; D045744:Cell Line, Tumor; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009389:Neovascularization, Pathologic / Q000378:metabolism* / Q000473:pathology*; D010100:Oxygen / Q000097:blood*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D010100:Oxygen