Possibility of modern ultrasound imaging of portal venous system

Abstract

During the past few years, there have been a number of new technical developments in the field of high-performance ultrasound diagnostics, which should help us to better assess dynamic vascular changes with ultrasound. BMUS enables us to get important anatomical variants with regard to the portal venous vessels and the hepatic veins. With color-coded duplex sonography (CCDS), and power Doppler (PD), examiners can carry out a comprehensive hemodynamic assessment of the portal venous. However, low flow settings in the vein have always been a particular challenge for CCDS, since the examiner requires special experience and artefacts often occur. In this review article, we reviewed the technical basics and diagnostic possibilities of new digital vascular ultrasound methods, 3D flow methods and contrast enhanced ultrasound (CEUS) in the assessment of portal venous flow changes.

Keywords: CEUS; assessment; digital flow; liver; portal vein; vascularization.

Figure 1.

A case of a 68-year-old female patient. Thrombosis happened during severe COVID 19 infection. Contrast enhanced CT scan shows thrombosis of the portal vein (a & b, arrow). Color-coded Duplex sonography (CCDS) and power Doppler including Glazing Flow (c) and HR Flow (d) show flow separation within the lumen of the portal vein (arrow). Contrast enhanced ultrasound (CEUS) could clearly detect the lower echogenic thrombosis without artefacts (e & f, arrow).

Figure 2.

A case of a 55year old male patient with pancreatitis after gallbladder surgery. Contrast enhanced CT scan shows drainage of the gallbladder system (a, arrow) and stenosis of the portal vein (b, arrow). Color-coded Duplex sonography (CCDS) shows portal vein stenosis with enlarged velocities up to 90 cm/s (c) with elevated blood velocity measured by Doppler spectrum (d). Power Doppler including Glazing Flow (e) and HR Flow (f) show lumen narrowing of the portal vein.

Figure 3.

A case of a 24-year-old female patient with portal hypertension by liver fibrosis. CT scan showed Budd Chiari Syndrome (a & b). MRI showed dilatation of the portal vein (c), occlusion of the hepatic veins (d). B mode ultrasound showed occlusion of the liver veins (e). Shear wave elastography showed higher shear wave velocity of liver fibrosis, > 2,2 m/s (f). After transjugular intrahepatic portosystemic shunt (TIPS) treatment, color-coded duplex sonography (CCDS) with HR Glazing Flow showed the blood flow signals in hepatic veins (f). Doppler spectrum evaluated by CCDS (g). High frame rate contrast enhanced ultrasound (HIFR CEUS) showed hyperenhancement of hepatic veins during arterial phase (i) and late phase (j).

Figure 4.

Shunt from the mesenteric vein to the left renal vein (a, arrow) after thrombotic occlusion of the portal vein. The shuntvein showed enhancement on contrast enhanced CT scan (b, arrow).

Figure 5.

A 56-year-old male patient with mesenterico-renal shunts after thrombosis of the portal vein. Color-coded Duplex sonography (CCDS) showed radiant flow in both superior mesenteric vein (a) and left renal vein (b).

Figure 6.

A case of an 82-year-old male patient with thrombosis of the right femoral and iliac vein after COVID-19 infection. HR-Flow showed the hypoechoic thrombosis with peripheral short-line color blood flow signal (a). Elastography showed a clear boundary of thrombosis (b). On V-Flow scan, only tiny vector flow signals could be detected on the peripheral area of thrombosis (c).