In vivo flow-independent T2 measurements of superior mesenteric vein bloodin diagnosis of chronic mesenteric ischemia: A preliminary evaluation

Rationale and Objectives. The authors attempted to determine whether the T2 relaxation time of superior mesenteric vein (SMV) blood would decrease in patients with chronic mesenteric ischemia after a meal. Materials and Methods. Thirty-two patients without chronic mesenteric ische mia and eight patients with symptomatic chronic mesenteric ischemia underwe nt magnetic resonance (MR) imaging. All examinations were performed with a 1.5-T unit, a modified Carr-Purcell-Meiboom-Gill sequence, final section-se lective pulse of 180 degrees. and spiral readout gradients. Measurements of SMV blood T2 were obtained after at least 6 hours of fasting and 15 and 35 minutes after ingestion of 240 mt of a liquid nutritional supplement. Maxi mal change of the SMV blood T2 was expressed as a percentage of the fasting T2 in all patients. Results. In control patients, SMV blood T2 increased postprandially by 9.4% +/- 1.3 (95% confidence level; range, 6.8% 1.9%) (data range, -7.3% to 25. 6%) compared with fasting T2. In symptomatic patients, SMV blood T2 decreas ed postprandially by 15.8% +/- 2.2 (95% confidence level, range, -20.1% to -10.7%) (data range, -7.9% to -25.3%). The difference between the two group s was statistically significant (P < .0001 by Student unpaired t test). Conclusion. Measurement of SMV blood T2 is a promising test for chronic mes enteric ischemia diagnosis. Therefore, conversion of T2 measurements to est imate oxygen saturation may not be necessary for all cases of this clinical indication.