MR imaging of blood oxygenation-dependent changes in focal renal ischemia and transplanted liver tumor in rat.

The potential of using fast magnetic resonance (MR) imaging in conjunction with apnea-induced blood deoxygenation for the noninvasive monitoring of relative perfusion in the rat abdomen has been studied with two experimental models: glycerol-induced focal renal ischemia and transplanted liver tumor. Gradient-echo echo-planar imaging (GRE-EPI) (TE of 20 msec at 2T) of liver and kidney was performed before, during, and after a 60-second apnea episode and then was followed in the same rat by contrast-enhanced (a) GRE-EPI and (b) T1-weighted spin-echo imaging (TR msec/TE msec = 200/6) with polylysine-(gadolinium-DTPA [diethylenetriaminepentaacetic acid]). The results indicate that a noninvasive vascular challenge due to apnea can be used for the detection of focal tissue perfusion abnormalities in rat kidney and liver tumor.