title: Evaluation of tumour vascular distribution and function using immunohistochemistry and BOLD fMRI with carbogen inhalation.
abstract: OBJECTIVE
  To evaluate oxygenation changes in rat subcutaneous C6 gliomas using blood-oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI) combined with non-haemodynamic response function (non-HRF) analysis.
  
  
  METHODS
  BOLD fMRI were performed during carbogen inhalation in 20 Wistar rats bearing gliomas. Statistical maps of spatial oxygenation changes were computed by a dedicated non-HRF analysis algorithm. Three types of regions of interest (ROIs) were defined: (1) maximum re-oxygenation zone (ROImax), (2) re-oxygenation zones that were less than the maximum re-oxygenation (ROInon-max), and (3) zones without significant re-oxygenation (ROInone). The values of percent BOLD signal change (PSC), percent enhancement (ΔSI), and significant re-oxygenation (T) were extracted from each ROI. Tumours were sectioned for histology using the fMRI scan orientation and were stained with haematoxylin and eosin and CD105. The number of microvessels (MVN) in each ROI was counted. Differences and correlations among the values for T, PSC, ΔSI, and MVN were determined.
  
  
  RESULTS
  After carbogen inhalation, the PSC significantly increased in the ROImaxareas (p<0.01) located in the tumour parenchyma. No changes occurred in any of the ROInoneareas (20/20). Some changes occurred in a minority of the ROInon-maxareas (3/60) corresponding to tumour necrosis. MVN and PSC (R=0.59, p=0.01) were significantly correlated in the ROImaxareas. In the ROInon-maxareas, MVN was significantly correlated with PSC (R=0.55, p=0.00) and ΔSI (R=0.37, p=0.00).
  
  
  CONCLUSIONS
  Statistical maps obtained via BOLD fMRI with non-HRF analysis can assess the re-oxygenation of gliomas.
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: J
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: A
authors.initials: A
authors.lastname: Chen
authors.affiliation: Department of Radiology, The Central Hospital of Wuhan, Wuhan, China.
authors.forename: J
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Soochow University, Suzhou, China; Institute of Radiotherapy & Oncology, Soochow University, Suzhou, China. Electronic address: j102@163.com.
authors.forename: Z
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Institute of Radiotherapy & Oncology, Soochow University, Suzhou, China; Suzhou Key Laboratory for Radiation Oncology, Suzhou, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Department of Radiology, Wuxi People's Hospital, Wuxi, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Tang
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: P
authors.initials: P
authors.lastname: Cao
authors.affiliation: Magnetic Resonance Imaging Institute for Biomedical Research, Wayne State University, Detroit, MI, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Dai
authors.affiliation: Department of Neuroradiology and MRI, CHU Grenoble-IFR1, Grenoble, France.
authors.forename: A
authors.initials: A
authors.lastname: Krainik
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: J
authors.initials: J
authors.lastname: Shen
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D001931:Brain Mapping / Q000379:methods; D001932:Brain Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002245:Carbon Dioxide / Q000008:administration & dosage*; D004195:Disease Models, Animal; D005260:Female; D005910:Glioma / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D000860:Hypoxia / Q000150:complications / Q000175:diagnosis*; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010100:Oxygen / Q000008:administration & dosage*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D012119:Respiration
chemical_list: D011838:Radiation-Sensitizing Agents; D002245:Carbon Dioxide; C011700:carbogen; D010100:Oxygen