 Secretin test dose will be given intravenously 0.2mcg 0.1ml. If no reaction is noted after one minute, then Secretin will be given intravenously 0.2 mcgkg IV slowly over one minute. If an allergic reaction is noted, the patient will not have a CT scan performed as part of this study protocol, and that participant will be ineligible to participant with this study. Secretin bolus will be terminated if Systolic BP 90mmHg is not corrected with IV fluids. 