MRI Studies of Blood-Retina-Barrier Breakdown and ADC in rd1 Mice

Abstract

Methods: : Both diffusion- and T₁-weighted MRI were performed on the control and rd1 mice at 1- and 3-month old (four groups, n = 5 each). The apparent diffusion coefficient (ADC) from age-matched control and rd1 mice was evaluated. The BRB integrity was assessed with T₁-weighted MRI signal changes in vitreous resulting from the extravasations of the blood-pool MR contrast agent Gd-DTPA.

Results: : The ADC was significantly higher in the retina of 3-month comparing with that of 1-month old rd1 mice (A, p < 0.05). Comparable inner retina ADC was observed in 1- and 3-month old control mice (A). In the 1-month old rd1 and all controls, only ~10% increase in vitreous (arrow) signal intensity was seen 30 min after Gd-DTPA injection (B & D). In contrast, a 40% increase of vitreous signal (C & D, p<0.05) was observed in 3-month old rd1,suggesting BRB breakdown and resulting substantial leakage of Gd-DTPA into the vitreous.

Keywords: retina • retinal pigment epithelium