MR MEASUREMENT OF TIME-DEPENDENT BLOOD-PRESSURE VARIATIONS

An MR imaging method for measuring intravascular pressure variations i s introduced, The technique is based on estimates of vascular complian ce and vessel distension, which are obtained from a correlation of spa tial and temporal velocity derivatives and measurements of the velocit y gradient in the direction of how, respectively, The accuracy of the technique was determined in vitro through a comparison of MR and trans ducer pressure measurements obtained in distensible vessel phantoms un dergoing pulsatile flow, Results indicated that a Toot-mean-square err or of 4-12% can be expected in phantoms covering a physiological range of compliance, In vivo feasibility was demonstrated by thoracic aorta pressure measurements, which produced pressure waveforms with an expe cted shape and magnitude.