title: Blood oxygenation level-dependent magnetic resonance imaging during carbogen breathing: differentiation between prostate cancer and benign prostate hyperplasia and correlation with vessel maturity.
abstract: OBJECTIVE
  The aim of this study was to investigate whether the blood oxygenation level-dependent (BOLD) contrast magnetic resonance imaging (MRI) can evaluate tumor maturity and preoperatively differentiate prostate cancer (PCa) from benign prostate hyperplasia (BPH).
  
  
  METHODS
  BOLD MRI based on transverse relaxation time*-weighted echo planar imaging was performed to assess PCa (19) and BPH (22) responses to carbogen (95% O2 and 5% CO2). The average signal values of PCa and BPH before and after carbogen breathing and the relative increased signal values were computed, respectively. The endothelial-cell marker, CD31, and the pericyte marker, α-smooth muscle actin (mature vessels), were detected with immunofluorescence, and were assessed by microvessel density (MVD) and microvessel pericyte density (MPD). The microvessel pericyte coverage index (MPI) was used to evaluate the degree of vascular maturity. The changed signal from BOLD MRI was correlated with MVD, MPD, and MPI.
  
  
  RESULTS
  After inhaling carbogen, both PCa and BPH showed an increased signal, but a lower slope was found in PCa than that in BPH (P<0.05). PCa had a higher MPD and MVD but a lower MPI than BPH. The increased signal intensity was positively correlated with MPI in PCa and that in BPH (r=0.616, P=0.011; r=0.658, P=0.002); however, there was no correlation between the increased signal intensity and MPD or MVD in PCa than that in BPH (P>0.05).
  
  
  CONCLUSIONS
  Our results confirmed that the increased signal values induced by BOLD MRI well differentiated PCa from BPH and had a positive correlation with vessel maturity in both of them. BOLD MRI can be utilized as a surrogate marker for the noninvasive assessment of the degree of vessel maturity.
authors.affiliation: Department of Radiology, Affiliated Huashan Hospital of Fudan University, Shanghai; Department of Radiology, Binzhou Medical University Affiliated Hospital, Binzhou.
authors.forename: Ningning
authors.initials: N
authors.lastname: Di
authors.affiliation: Department of Radiology, Yantai Yuhangding Hospital, Yantai.
authors.forename: Ning
authors.initials: N
authors.lastname: Mao
authors.affiliation: Department of Pharmacy, Binzhou Medical University Affiliated Hospital, Binzhou.
authors.forename: Wenna
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Department of Radiology, Affiliated Huashan Hospital of Fudan University, Shanghai.
authors.forename: Haopeng
authors.initials: H
authors.lastname: Pang
authors.affiliation: Department of Radiology, Affiliated Huashan Hospital of Fudan University, Shanghai.
authors.forename: Yan
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Department of Radiology, Binzhou Medical University Affiliated Hospital, Binzhou.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.affiliation: Department of Radiology, Binzhou Medical University Affiliated Hospital, Binzhou.
authors.forename: Xinjiang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Medical Imaging and Nuclear Medicine, Binzhou Medical University, Yantai, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
keywords: BOLD; benign prostate hyperplasia; magnetic resonance imaging; prostate carcinoma; vessel maturity