Gastrointestinal imaGinG

Doppler ultrasonography (US) is usually the first-line modality for evaluating flow in native liver vessels and transjugular intrahepatic portosystemic shunts (TIPS). Waveforms, which represent flow in each of the major vessels and in TIPS, have been well described. The appearance of these waveforms should be recognized, and the mechanisms behind their generation should be understood by those interpreting these examinations. Understanding how waveforms are formed—that is, their mechanisms for generation— is predicated on knowing basic vascular Doppler concepts and established nomenclature. This article is a review of these basic concepts and nomenclature as applied to the interpretation of liver Doppler US waveforms.