Use of two-dimensional ultrasonic imaging to measure pharmacologically induced vasomotion in rabbit aorta

We have developed a novel method combining two-dimensional ultrasonic imaging and computerized edge detection to study the vasomotor responses of isolated arterial vessels to various pharmacological agents. Using this in vitro system, we studied the contraction and relaxation of rabbit aorta, respectively, to phenylephrine and acetylcholine. Quantification of these drug-induced changes in vessel wall diameter was achieved by computerized edge detection processing of the two-dimensional ultrasonic vessel wall images. Resolution of this imaging system was determined to be +/- 0.27 mm. Dose-response curves obtained via this new method showed a high degree of correlation with data obtained by classical tissue bath techniques using ring segments. Two-dimensional ultrasonic imaging combined with computerized edge detection is a new and sensitive method to study vasoreactivity of whole, isolated arterial vessels to pharmacological agents.