An imaging method carried out by using ultrasound transducers and a processing apparatus comprising: providing ultrasound pulse-echo data of a region in which at least one portion of a blood vessel is located, wherein the pulse-echo data comprises pulse-echo data at a frame rate of at least 100 frames per second, such that measured displacement of the vessel wall defining the at least one portion of the blood vessel and measured average blood flow through the at least one portion of the blood vessel have a quasi-periodic profile over time to allow motion tracking of both the vessel wall and the blood flow simultaneously; applying speckle tracking to the pulse-echo data to generate strain and shear strain image data for the region in which the at least one portion of the vessel is located, wherein the speckle tracking comprises using multi-dimensional correlation of the pulse-echo data of one or more speckle regions undergoing deformation in the region in which the at least one portion of a blood vessel is located, wherein the multi-dimensional correlation comprises determining a cross-correlation peak for the sampled pulse-echo data based on phase and magnitude gradients of the cross-correlated pulse-echo data; and identifying at least one vessel wall boundary of the region in which at least one portion of a blood vessel is located based on the strain and shear strain image data, and characterized in that the speckle tracking further comprises modifying a characteristic, such as location, size or shape of at least one of the one or more speckle regions being tracked based on the one or more vessel wall boundaries identified such that the at least one speckle region is entirely within or outside of the vessel wall. providing ultrasound pulse-echo data of a region in which at least one portion of a blood vessel is located, wherein the pulse-echo data comprises pulse-echo data at a frame rate of at least 100 frames per second, such that measured displacement of the vessel wall defining the at least one portion of the blood vessel and measured average blood flow through the at least one portion of the blood vessel have a quasi-periodic profile over time to allow motion tracking of both the vessel wall and the blood flow simultaneously; applying speckle tracking to the pulse-echo data to generate strain and shear strain image data for the region in which the at least one portion of the vessel is located, wherein the speckle tracking comprises using multi-dimensional correlation of the pulse-echo data of one or more speckle regions undergoing deformation in the region in which the at least one portion of a blood vessel is located, wherein the multi-dimensional correlation comprises determining a cross-correlation peak for the sampled pulse-echo data based on phase and magnitude gradients of the cross-correlated pulse-echo data; and identifying at least one vessel wall boundary of the region in which at least one portion of a blood vessel is located based on the strain and shear strain image data, and characterized in that the speckle tracking further comprises modifying a characteristic, such as location, size or shape of at least one of the one or more speckle regions being tracked based on the one or more vessel wall boundaries identified such that the at least one speckle region is entirely within or outside of the vessel wall.