Methods of treating using adipose tissue using ultrasonic cavitation to dissociate the fat cells and blood vessels contained within adipose tissue and thereby obtain mesenchymal or stromal vascular fractions for use in human subjects are provided. These methods preferably do not include the use of any exogenous dissociating enzymes such as collagenase and result in increased numbers of the cells which constitute the mesenchymal or stromal vascular fractions (about 10-fold greater) than methods which use collagenase to isolate these cells.