A prospective evaluation of liver and spleen shearwave elastography measurements in patients with chronic liver disease

Background: Prompt assessment of the degree of severity of fibrosis is important in guiding management of therapy in chronic liver disease. In the last years ultrasound based non invasive tests for liver fibrosis have completely changed clinical practice in hepatology. There are several available equipment in the market using the shear wave elastography (SWE) technology. Despite the great interest on SWE, knowledge of the different techniques is still incomplete. Portal hypertension is a major complication of cirrhosis that is associated with significant morbidity and mortality. Aim of this study is to assess the diagnostic accuracy of spleen stiffness, area and diameter in predicting the presence of portal hypertension. Methods: 160 patients underwent same-day liver biopsy, and measurement of liver fibrosis on the right and left lobe of the liver, with the 3 shear wave elastography methods Philips Affiniti 70TM ultrasound system, Siemens Acuson (ARFI) ultrasound system, and Echosens FibroscanTM. Results: Spearman correlation between TE, ElastPQ, and VTQ results with histological fibrosis stage demonstrated a good correlation with r2 = 0.569, 0.556 and 0.448 respectively (p = 0.0001). ElastPQ L (r2= 0.411, p = 0.001), VTQ L (r2= 0.336, p = 0.001). Areas under the Curve (AUC) were: TE 0.810; ElastPQ 0.828; VTQ 0.741 for fibrosis F 0/1; TE 0.970; ElastPQ 0.832; VTQ 0.782 for fibrosis F 3/4 and TE 0.939; ElastPQ 0.856; VTQ 0.826 for cirrhosis F4. Diagnostically, there was a better accuracy of measurements of the right lobe (ElastPQ R and VTQ R) compared to measurements in the left lobe (ElastPQ L and VTQ L). Compared with 10 measurements, a minimum of six SWV measurements was required. The overall area under the curve for diagnosing mild and severe fibrosis or cirrhosis did not differ according to number of measurements (six vs 10). Significant fibrosis B, 0.567; standard error, 0.331; hazard ratio, 2.10; p= 0.010 was an independentpredictor for lower reliability. On univariate and individual performance, platelet count [area under the receiver operating characteristic (AUROC) 0.846, p value < 0.001], spleen area (AUROC 0.828, p value = 0.002) and APRI score (AUROC 0.827, p value < 0.001) were the most accurate variables in identifying the presence of portal hypertension. Conclusions: TE and ElastPQ achieved good diagnostic performance, whereas VTQ showed a lower diagnostic accuracy with AUROC ranging from 0.733 to 0.818. The data would support the best practice guidance on the utility of LSM values in aiding the clinical management of patients. Ordinal logistic regression corrected for age to assess if steatosis, ballooning, portal inflammation and lobular inflammation have an influence on the relation between SWE measurements and histology findings, showed that there is a significant interaction between steatosis (p = 0.008) and lobular inflammation and VTQ (p = 0.04) and between lobular inflammation and TE (p = 0.006). Cut off value for fibrosis F0/1 were significantly lower in the sub-group of patients with viral aetiologies compared to cut off value for fibrosis F0/1 in other aetiologies. The number of measurements required for a reliable study using the latest SWE technologies can be reduced to 6 for ElastPQ and to 7 for VTQ from the standard recommendation of 10. Spleen area, spleen stiffness and platelet count may be useful markers to assess the presence of portal hypertension in patients of various etiologies.Open Acces