CHRONIC MESENTERIC ISCHEMIA - USE OF IN-VIVO MR-IMAGING MEASUREMENTS OF BLOOD-OXYGEN SATURATION IN THE SUPERIOR MESENTERIC VEIN FOR DIAGNOSIS

PURPOSE: To determine if dogs and humans with chronic mesenteric ische mia demonstrate a decrease in the percentage of oxygenated hemoglobin (%Hbo(2)) in the superior mesenteric vein (SMV) after a meal. MATERIAL S AND METHODS: In 10 dogs, ameroid rings were surgically implanted aro und the superior mesenteric arteries to create gradual stenosis. Pre- and postoperative angiograms and pre- and postprandial magnetic resona nce (MR) oximetry measurements of the SMV %Hbo(2), with now-independen t T2 measurements of venous blood, were obtained at different times. I n 10 patients with atherosclerotic disease and six patients with sympt omatic chronic mesenteric ischemia, the same measurements were obtaine d after at least 6 hours of fasting and at 15, 35, and 45 minutes afte r ingestion of a liquid nutritional supplement. RESULTS: In seven dogs , the postprandial SMV %Hbo(2) increased an average of 2.5% +/- 0.8 be fore surgery and decreased an average of 6.3% +/- 2.1 when hemodynamic ally significant (> 70%) stenosis of the superior mesenteric artery de veloped 7-14 days after surgery. In the 10 patients without ischemia, the SMV %Hbo(2) increased by 4.6% +/- 0.6, whereas in the symptomatic patients a postprandial decrease of 8.8% +/- 0.7 occurred (P < .0001). CONCLUSION: Measurement of the SMV %Hbo(2) with MR oximetry is a prom ising test for diagnosis of chronic mesenteric ischemia.