MESENTERIC ISCHEMIA DUE TO HEMORRHAGIC-SHOCK - MR-IMAGING DIAGNOSIS AND MONITORING IN A CANINE MODEL

PURPOSE: To test whether changes in the percentage of oxygenated hemog lobin (%Hbo(2)) and blood flow in the superior mesenteric vein (SMV), as measured with magnetic resonance (MR) imaging in vivo, can be used to diagnose and monitor mesenteric ischemia due to hemorrhagic shock i n a canine model. MATERIALS AND METHODS: Eight mongrel dogs (weight ra nge, 20-30 kg) underwent fasting for 24 hours before the experiments. MR imaging measurements of SMV %Hbo(2) and volume flow rate were obtai ned at the resting state and after 5%, 10%, and 15% of the blood volum e of the dogs had been removed sequentially, which led to a total bloo d volume depletion of 30%. In four dogs, resuscitation was performed w ith normal saline solution in a volume equal to the total volume of bl ood removed. RESULTS: SMV %Hbo(2) and SMV flow measurements at the dif ferent stages of blood removal were all significantly different (P < . 05) from baseline measurements and from each other. After volume repla cement with normal saline solution, SMV %Hbo(2) and flow were not sign ificantly different (P > .05) from the baseline values. CONCLUSION: SM V %Hbo(2) and volume flow rate, as measured with MR imaging in vivo, c an be used to diagnose and monitor mesenteric ischemia due to hemorrha gic shock in a canine model.