Type:
Educational Exhibit
Keywords:
Vascular, Veins / Vena cava, Ultrasound, Ultrasound-Colour Doppler, Ultrasound-Spectral Doppler, Technical aspects, Education and training
Authors:
W. Sim, A. Mohamed Afif, Q. Soh, S. Y. Lim; Singapore/SG
DOI:
10.26044/ecr2019/C-0959
Background
The portal vein (PV) supplies nearly 75% of blood to the liver while the hepatic arteries supply the remaining 25%.
The main PV is formed at the confluence of the superior mesenteric and splenic veins at the level of L1/L2 [1].
As it enters the liver,
the main PV bifurcates into right and left,
with the right further dividing into anterior and posterior branches,
while the left into medial and lateral branches.
The PV measures up to 12.6 + 1.7mm in diameter and nearly 8cm in length [2].
Fig. 1 shows the anatomy of the PV system.
Fig. 1: Anatomy of the portal venous system
References: Sim Wanjou, 2019
Ultrasound is the modality of choice for evaluation of the PV.
It is easily accessible and has a high safety profile compared to computed tomography (CT) and magnetic resonance imaging (MRI),
where there is risk with the use of intravenous contrast.
In addition to flow detection,
Doppler ultrasound is able to assess the haemodynamics status of the PV,
in terms of its flow direction and velocity.
Understanding and familiarity with the various colour spectral patterns is crucial to ensure accurate diagnosis.
In this poster,
the normal and abnormal waveforms are presented,
and the mechanisms behind these waveforms are explained.