Ivan Amat-Roldan PhD, Presenter: Nothing to Disclose

Annalisa Berzigotti MD, PhD, Abstract Co-Author: Nothing to Disclose

Rosa Gilabert MD, Abstract Co-Author: Nothing to Disclose

Jaime Bosch MD, Abstract Co-Author: Nothing to Disclose

The liver vascular network is characterized by a highly organized structure. This is progressively deranged due to fibrosis and hepatocyte drop-out in patients with chronic liver diseases, leading to portal hypertension. We hypothesised that graph analysis of vascular images obtained by dynamic contrast-enhanced ultrasound (DCE-US), would allow calculating the hepatic vascular network connectivity, which would predict the degree of organization of the liver circulation, and that this would mirror the severity of portal hypertension.

This pilot study includes 4 healthy subjects and 15 well characterized patients with liver cirrhosis who underwent DCE-US and hepatic venous pressure gradient measurement (HVPG; gold standard method to assess portal hypertension in cirrhosis). Individual graph models ('vascular connectomes') were computed based on time series analysis of video sequences of DCE-US examination (disruption-reperfusion technique). Graph analysis was carried out by calculation of clustering coefficient; according to graph theory a higher clustering coefficient indicates a more organized network. Based on clustering coefficient we calculated statistical models to predict HVPG from DCE-US video sequences.

Healthy subjects had a high clustering coefficient of vascular connectome suggesting a highly organized liver vascular network. Patients with cirrhosis showed a lower clustering coefficient indicating disruption of normal anatomy. Clustering coefficient decreased as HVPG increased. The correlation between the best model derived from distribution of clustering coefficient (10 bins) of vascular 4 connectome and HVPG had a Pearson's correlation of 0.977 and a root mean square error of 1.57 evaluated by leave one out cross-validation.

Computer based graph-analysis of video sequences generated by DCE-US permits to calculate a vascular connectome that reflects the degree of organization of hepatic microvascular network

This non-invasive method is able to quantify automatically the degree of liver vascular derangement and accurately mirrors the severity of portal hypertension in patients with cirrhosis.

Amat-Roldan, I, Berzigotti, A, Gilabert, R, Bosch, J, Assessment of Hepatic Vascular Network Connectivity by Automated Graph Analysis of Dynamic Contrast Enhanced Ultrasound to Evaluate Portal Hypertension in Patients with Cirrhosis: A Pilot Study.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013845.html