Monitoring changes in oxygenation of rat thigh muscle and Dunning prostate R3327 prostate MAT-Lu tumors implanted in Copenhagen rat thigh in vivo with respect to oxygen challenge. Spin-echo images of a representative rat thigh muscle (a) and MAT-Lu tumor (f). CHESS spin-echo images of silane injected into thigh muscle (b) and tumor (g) showing the distribution of the injected HMDSO. The corresponding time course PISTOL pO2 maps (c, h, baseline air breathing; d, i, 30 min oxygen; e, j, 30 min after return to air breathing) showing the response to hyperoxic gas intervention in each case.