Dynamic Susceptibility Contrast Perfusion Imaging of Radiation Effects in Normal-Appearing Brain Tissue: Changes in the First-Pass and Recirculation Phases

J Magn Reson Imaging. 2005 Jun;21(6):683-93. doi: 10.1002/jmri.20298.

Abstract

Purpose: To identify radiation-induced changes in the cerebral vasculature of healthy tissue in the first four months following radiotherapy through the analysis of dynamic-susceptibility contrast perfusion imaging.

Materials and methods: Dynamic gradient-echo imaging was performed on 22 patients during injection of a bolus of Gd-DTPA contrast. The relative cerebral blood volume (rCBV), maximum DeltaR2* of the first passage of the bolus, and a recirculation parameter were derived from gamma-variate fits of the dynamic data. The white matter (WM) rCBV and peak heights were estimated through correlation with segmented T1-weighted images. A percent recovery to baseline was also computed to further describe the recirculation phase.

Results: A significant elevation of the recirculation phase was observed at doses>15 Gy at two months following radiotherapy. This was reflected in an increased recirculation parameter in the fitted curves in the 15-30, 30-45, and >45 Gy dose groups to 2.8%, 3.8%, and 2.4% above the <15 Gy voxels, as well as in a decline in percent recovery to baseline. A trend toward lower rCBV and peak heights was observed at that same time point.

Conclusion: The observed results suggest a dose-dependent decline in vessel density and increase in vascular permeability and/or tortuosity in irradiated normal-appearing brain tissue at two months following radiotherapy.

Publication types

  • Clinical Conference
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Blood Volume / radiation effects*
  • Brain / blood supply
  • Brain / radiation effects*
  • Brain Neoplasms / physiopathology
  • Brain Neoplasms / radiotherapy*
  • Cerebrovascular Circulation*
  • Contrast Media
  • Dose-Response Relationship, Radiation
  • Female
  • Gadolinium DTPA
  • Glioma / physiopathology
  • Glioma / radiotherapy*
  • Humans
  • Image Processing, Computer-Assisted
  • Male
  • Middle Aged
  • Monte Carlo Method
  • Statistics, Nonparametric

Substances

  • Contrast Media
  • Gadolinium DTPA