THE RELATIONSHIP BETWEEN BLOOD-FLOW AND PULSATILITY INDEX IN THE SUPERIOR MESENTERIC-ARTERY AT REST AND DURING CONSTRICTOR STIMULI IN NORMAL SUBJECTS

The relationships between superior mesenteric artery blood flow (SMABF ) and pulsatility index (PI) measurement during rest (25 subjects) and stimuli constricting the SMA (16 subjects) have been studied in norma l subjects. At rest and during constrictor stimuli, SMABF and PI were highly reproducible (r = 0.89, p < 0.01 for SMABF, and r = 0.97, p < 0 .001 for PI) between two observers. There was significant correlation between changes in SMABF, PI, and SMA vascular resistance during-the c onstrictor stimuli, except during head-up tilt when PI was unchanged. Both PI and SMABF measurements are reproducible and can be used to mon itor physiological changes in suitable (18 of 25) subjects. PI measure ment, although semiquantitative, by itself can also be used to monitor these changes. This may be also of importance in pathological situati ons such as intestinal ischemia, where measurement of volume blood flo w may be less accurate due to irregularities of the vessel wall. PI me asurement, however, ideally should not be used in studies involving po stural change. (C) 1994 John Wiley & Sons, Inc.