[Ultrasound artifacts and their diagnostic significance in internal medicine and gastroenterology - part 2: color and spectral Doppler artifacts].

Artifacts in ultrasonographic diagnostics are a result of the physical properties of the ultrasound waves and are caused by interaction of the ultrasound waves with biological structures and tissues of the body and with foreign materials. On the one hand, they may be diagnostically helpful. On the other hand, they may be distracting and may lead to misdiagnosis. Profound knowledge of the causes, avoidance, and interpretation of artifacts is a necessary precondition for correct clinical appraisal of ultrasound images. Part 1 of this review commented on the physics of artifacts and described the most important B-mode artifacts. Part 2 focuses on the clinically relevant artifacts in Doppler and color-coded duplex sonography. Problems and pitfalls of interpretation arising from artifacts, as well as the diagnostic use of Doppler and colour-coded duplex sonography, are discussed. © Georg Thieme Verlag KG Stuttgart · New York.