Multiple push-detect acquisitions are typically required in current acoustic radiation force based shear wave elasticity imaging methods to reconstruct a full FOV elasticity map, which can result in potential motion artifacts and difficulties in studying tissue dynamic mechanical properties. Comb-push Ultrasound Shear Elastography (CUSE) is a novel and fast shear elasticity imaging technique which utilizes the comb-push to produce a complex shear wave field with shear waves propagating through all imaging pixels so that a full FOV shear elasticity map can be reconstructed with only one rapid data acquisition (less than 25 ms). Three versions of CUSE are presented in this paper: Unfocused CUSE (U-CUSE), Focused CUSE (F-CUSE), and Marching CUSE (M-CUSE). Homogeneous and inclusion phantom experiments showed that all CUSE methods produced accurate and smooth shear elasticity maps with excellent contrast between the inclusion and background. Comparable elasticity maps to Supersonic Shear Imaging (SSI) could be obtained using CUSE, with low MI and heating. Finally, the feasibility of using CUSE in clinical studies was demonstrated by promising results from preliminary in vivo case studies on human biceps muscle, thyroid, breast and liver.