Artifacts and Technical Restrictions in 2D Shear Wave Elastography.

2 D shear wave elastography (2D-SWE) is the latest evolution of elastography techniques and allows real-time quantitative assessment of the medium stiffness. The aim of this review is to identify, describe, explain and illustrate some technical restrictions and artifacts in 2D-SWE. Encountered artifacts and technical restrictions may be categorized according to acquisition technique, medium, or operator: · Acquisition technique: B-mode & SWE entanglement, transducer frequency, posterior elastographic shadowing artifact, mirrored elastogram artifact, "vertical striped" artifact, resolution limits in SWE, non-equivalence of elastographic devices. · Medium: SWE in liquid medium, "black hole phenomenon", pseudo-liquid lesions, musculotendinous anisotropy, intrinsic stiffness variations of tendons and muscles, depth of analysis, movement artifacts. · Operator: Region of interest compression, acquisition and measurement parameters (ROI size, ROI location, elastogram acquisition time). Clear knowledge of the underlying physical basis is necessary in 2D-SWE because radiologists have to deal with technical restrictions and a wide range of artifacts. Proper use of 2D-SWE ensures the reliability and reproducibility of the technique.