TIPS Doppler US (last edited 08/08/2018)
(last reviewed 08/08/2018)
(last reviewed 08/08/2018)
Main Portal vein gray scale, color, and spectral Doppler
- document peak velocity
- document direction (normal = hepatopedal, abnl = hepatofugal, bidirectional, absent)
TIPS gray scale, color, spectral Doppler
- velocity proximal
- velocity mid
- velocity distal
- Most commonly TIPS extends from right portal vein --> right hepatic vein
Left, middle, right hepatic veins gray scale, color, and spectral Doppler
Intrahepatic IVC gray scale, color, and spectral Doppler
Reference/interpretation:
- Normal velocity in TIPS 90 to 200 cm/sec
- Normal portal vein velocity (proximal to TIPS) typically 30 to 45 cm/sec
- Normal TIPS waveform is phasic
- Normally velocity is fairly uniform across TIPS
- Portal venous branches adjacent may reverse their flow, to flow toward TIPS (path of least resistance)
- Abnormal if focal/disproportionate significant aliasing at site of narrowing in TIPS
- Abnormal TIPS velocity >200 cm/sec
- Abnormal TIPS velocity <90 cm/sec
- Abnormal absent color flow within TIPS
- Low velocity proximal to stent in portal vein (<30 cm/sec) can support abnormal TIPS
- Change in velocity over course of TIPS >50 cm/sec point to point
- Change in velocity over time of TIPS >50 cm/sec from prior study
- Loss of pulsatility/resp variation (nonspecific)