2024年4月25日 · The normal velocity of portal venous flow is 20cm/s to 40cm/s on spectral Doppler ultrasound. The waveform shows gentle undulations with hepatopetal flow direction 12. CT. Mean portal vein diameter is typically larger on CT, measuring up to 1.55 cm and enhanced portal vein is typically 0.6 mm larger than unenhanced portal vein 13. Development

2024年7月8日 · Portal venous flow is normally towards the liver (hepatopetal), with the normal main portal vein peak systolic velocities usually measuring 20-40 cm/s 1,3. The mean flow velocity of portal vein in adults is 19.3 cm/s 6 .

2024年9月30日 · The hepatic veins have a characteristic spectral Doppler waveform. Alterations in the normal hepatic vein waveform may reveal or confirm abnormalities in the heart or liver.

2024年10月25日 · The normal TIPS should show color Doppler flow throughout its length. The in-stent velocities are typically higher than in a native portal vein 1 . Trending stent velocities over multiple exams adds specificity to a single evaluation.

2024年5月11日 · A pulsatile portal venous flow pattern is an abnormal form of portal venous flow and can result from both physiological and pathological causes. In well subjects, mild to marked pulsatility has been described.

A normal portal vein Doppler trace should be monophasic with a little variation in maximum and minimum velocity, with no reversal of flow. In this particular case, when the line drops below the 0 cm/s level, there is reversal of flow.

2024年8月28日 · Ultrasound is able to identify a normal portal vein in almost all cases when present (97%) 3, and therefore is a good first-order examination. Doppler examination can be carried out at the same time to evaluate for portal hypertension. Cavernous transformation appears as numerous tortuous vessels occupying the portal vein bed.

2024年12月2日 · Portal hypertension is defined as a hepatic venous pressure gradient (HVPG) >5 mmHg, which is a surrogate for the portosystemic pressure gradient. Clinically significant portal hypertension is defined as a gradient >10 mmHg, and variceal bleeding may …

2025年1月8日 · Color Doppler should be able to demonstrate absent flow in the portal vein and even to detect partial thrombosis, but attention to the Doppler gain and filters is necessary to avoid color overwrite of partial thrombosis.

Diagram showing normal hepatic spectral Doppler waveform. A wave - atrial contraction causes retrograde flow back to liver, then rapid RV filling; S wave - ventricular systole, antegrade flow into right atrium against closed TV; V wave - opening of tricuspid, followed by rush of antegrade flow; D wave - ventricular diastole, antegrade flow into RV