Abdominal applications of quantitative 4D flow MRI

4D flow MRI is a quantitative MRI technique that allows the comprehensive assessment of time-resolved hemodynamics and vascular anatomy over a 3-dimensional imaging volume. It effectively combines several advantages of invasive and non-invasive imaging modalities like ultrasound, angiography, and computed tomography in a single MRI acquisition and provides an unprecedented characterization of velocity fields acquired non-invasively in vivo. Functional and morphological imaging of the abdominal vasculature is especially challenging due to its complex and variable anatomy with a wide range of vessel calibers and flow velocities and the need for large volumetric coverage. Despite these challenges, 4D flow MRI is a promising diagnostic and prognostic tool as many pathologies in the abdomen are associated with changes of either hemodynamics or morphology of arteries, veins, or the portal venous system. In this review article, we will discuss technical aspects of the implementation of abdominal 4D flow MRI ranging from patient preparation and acquisition protocol over post-processing and quality control to final data analysis. In recent years, the range of applications for 4D flow in the abdomen has increased profoundly. Therefore, we will review potential clinical applications and address their clinical importance, relevant quantitative and qualitative parameters, and unmet challenges.

Congenital right internal mammary artery to portal vein arteriovenous malformation

Neonatal cases of systemic artery to portal venous system arteriovenous malformations (AVMs) can present unique challenges in terms of diagnosis, management, and treatment. Prompt identification of these AVMs is necessary for minimizing long-term sequelae and optimizing prognosis. Our report describes the diagnosis and successful endovascular coil embolization of a congenital right internal mammary artery (IMA) to portal vein AVM in a young infant initially presenting during routine fetal screening with an incidentally discovered congenital thoracic vascular abnormality.

Liver segmentation: practical tips

The liver segmentation system, described by Couinaud, is based on the identification of the three hepatic veins and the plane passing by the portal vein bifurcation. Nowadays, Couinaud's description is the most widely used classification since it is better suited for surgery and more accurate for the localisation and monitoring of intra-parenchymal lesions. Knowledge of the anatomy of the portal and venous system is therefore essential, as is knowledge of the variants resulting from changes occurring during the embryological development of the vitelline and umbilical veins. In this paper, the authors propose a straightforward systematisation of the liver in six steps using several additional anatomical points of reference. These points of reference are simple and quickly identifiable in any radiological examination with section imaging, in order to avoid any mistakes in daily practice. In fact, accurate description impacts on many diagnostic and therapeutic applications in interventional radiology and surgery. This description will allow better preparation for biopsy, portal vein embolisation, transjugular intrahepatic portosystemic shunt, tumour resection or partial hepatectomy for transplantation. Such advance planning will reduce intra- and postoperative difficulties and complications.

Effect of H2-receptor blocker combined with domperidone on the blood flow of portal venous system in patients with liver cirrhosis

AIM: To explore the effect of H2-receptor blocker combined with domperidone on the blood flow of portal venous system in patients with liver cirrhosis.

METHODS: A total of 60 patients with liver cirrhosis were randomly and averagely divided into group A, B, and C, treated with H2-receptor blocker, domperidone, and their combination, respectively. Twenty healthy subjects served as normal controls. Portal venous flow (PVF, mL/min), splenic venous flow (SVF, mL/min) and superior mesenteric venous flow (SMVF, mL/min) were determined using Doppler ultrasonography before and after treatment.

RESULTS: After treatment, PVF was significantly higher than that before treatment (850.23 ± 140.78 vs 695.22 ± 221.44, P < 0.01), while SVF and SMVF were lower (both P > 0.05) in group A. PVF was increased as compared with that before treatment in group B, but there was no significant difference (P > 0.05). However, SVF and SMVF were markedly decreased as compared with those before treatment in group B (SVF: 598.13 ± 272.33 vs 816.40 ± 279.61, P < 0.05; SMVF: 504.23 ± 188.54 vs 640.30 ± 200.12, P < 0.05). PVF was remarkably higher than that before treatment (876.76 ± 178.65 vs 705.34 ± 200.15, P < 0.05), while SVF and SMVF were lower (SVF: 605.33 ± 252.86 vs 798.33 ± 280.45, P < 0.01; SMVF: 503.43 ± 175.25 vs 650.19 ± 190.62, P < 0.01) in group C.

CONCLUSION: H2-receptor blocker and domperidone can improve the blood flow of portal venous system, and their combination is more effective.