NMR imaging of changes in vascular morphology due to tumor angiogenesis

Magn Reson Med. 1998 Dec;40(6):793-9. doi: 10.1002/mrm.1910400602.


Tumor-sprouted vessels are greater in both number and diameter in comparison to their healthy counterparts. A novel technique based on magnetic susceptibility contrast mechanisms that are sensitive to varying sizes of blood vessels is presented to measure differences between the relaxation rates (1/T2 and 1/T2*) in a rat glioma model and normal cerebral cortex. deltaR2 and deltaR2*, the differences between relaxation rates precontrast and postcontrast agent injection, were measured for an intravascular equilibrium contrast agent (MION) at various echo times. Since deltaR2*/deltaR2 increases as vessel size increases, this ratio can be used as a measure of the average vessel size within an ROI or a voxel. The stability and longevity of the contrast agent within the vasculature were verified (n = 2 trials), and the ratio of deltaR2*/deltaR2 between the tumor and normal cortex was measured to be 1.9+/-0.2 (n = 4, echo time = 20 ms, and susceptibility difference (deltachi) approximately 10(-6)). This ratio compared favorably to a predicted ratio determined using histologically determined vessel sizes and theoretical Monte Carlo modeling results (1.9+/-0.1). Maps of the ratio of deltaR2*/deltaR2 were also made on a pixel-by-pixel basis. These techniques support the hypothesis that susceptibility contrast MRI can provide useful quantitative metrics of in vivo tumor vascular morphology.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Brain Neoplasms / blood supply*
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology
  • Contrast Media
  • Ferrosoferric Oxide
  • Gadolinium DTPA
  • Glioma / blood supply*
  • Glioma / metabolism
  • Glioma / pathology
  • Immunohistochemistry
  • Iron
  • Magnetic Resonance Spectroscopy / instrumentation
  • Magnetic Resonance Spectroscopy / methods*
  • Microcirculation / metabolism
  • Microcirculation / pathology
  • Monte Carlo Method
  • Neovascularization, Pathologic / metabolism
  • Neovascularization, Pathologic / pathology*
  • Oxides
  • Random Allocation
  • Rats


  • Contrast Media
  • Oxides
  • Iron
  • Gadolinium DTPA
  • Ferrosoferric Oxide