The serial effect of iodinated contrast media on renal hemodynamics and oxygenation as evaluated by ASL and BOLD MRI

Contrast Media Mol Imaging. Jul-Aug 2012;7(4):418-25. doi: 10.1002/cmmi.1468.

Abstract

Contrast-induced nephropathy is a prevalent cause of renal failure, and the mechanisms underlying this injury are not fully understood. We utilized noninvasive functional MRI in order to determine the serial effect of a single administration of iodinated contrast media (CM) on renal hemodynamics and oxygenation. Fifteen rabbits were randomized to receive an intravenous injection of CM (i.e. iopamidol-370; 6 ml kg(-1) body weight) or an equivalent amount of 0.9% saline. Both arterial spin-labeling and blood oxygen level-dependent imaging sequences were performed at 24 h before and at intervals of 1, 24, 48 and 72 h after injection to obtain serial renal blood flow (RBF) and relative spin-spin relaxation rate (R(2)*). Results showed that, in the iopamidol group, the mean cortical RBF decreased at 1 h (p = 0.04 vs baseline), reached its minimum at 24 h (p = 0.01) and gradually returned to baseline by 48 h (p = nonsignificant, NS). The outer medullary RBF decreased to its minimum by 24 h (p = 0.00) and remained less than baseline until 72 h. R(2)* in inner stripes was dramatically increased at 1 h (p = 0.00), remained elevated at 24 h (p = 0.05), but returned to baseline by 48 h (p = NS). R(2)* values within the cortex and outer stripes and inner medulla were slightly increased, but the changes did not reach a statistical significance (p = NS). Saline did not produce positive change in either RBF or R(2)* within different compartments of the kidney. We conclude that iopamidol is associated with a relatively longer-term hypoperfusion in whole kidney and decreased oxygen level in the inner stripes of the outer medulla.

MeSH terms

  • Animals
  • Contrast Media / administration & dosage
  • Contrast Media / pharmacology
  • Hemodynamics / drug effects*
  • Iodine / administration & dosage
  • Iodine / pharmacology
  • Iopamidol / administration & dosage
  • Iopamidol / pharmacology*
  • Magnetic Resonance Imaging / methods*
  • Male
  • Oxygen / blood*
  • Perfusion
  • Rabbits
  • Renal Artery / drug effects*
  • Renal Artery / metabolism
  • Renal Circulation / drug effects*
  • Spin Labels*

Substances

  • Contrast Media
  • Spin Labels
  • Iodine
  • Iopamidol
  • Oxygen