To determine the elastic modulus of biologic tissue, a sequence of elasticity images and a sequence of B-mode ultrasound images are acquired simultaneously. Then, at least one sub-sequence of the B-mode ultrasound images representing a resting state is generated from said sequence of B-mode ultrasound images. Based on the sub-sequence of the B-mode ultrasound images, a subsequence of the elasticity images is generated by selecting and/or modifying those elasticity images. Finally, the elastic modulus is determined based on the sub-sequence of the elasticity images. Also disclosed are a method for determining changes of the elastic modulus of a tissue, a method of identifying biological tissue based on the determined elastic modulus and a device for determining the elastic modulus of a biological tissue.