Interobserver Variation of the Bolus-and-Burst Method for Pancreatic Perfusion with Dynamic – Contrast-Enhanced Ultrasound

Abstract

AbSTR Ac TPurpose Dynamic contrast-enhanced ultrasound (DCE-US) can be used for calculating organ perfusion. By combining bolus injection with burst replenishment, the actual mean transit time (MTT) can be estimated. Blood volume (BV) can be obtained by scaling the data to a vessel on the imaging plane. The study aim was to test interobserver agreement for repeated recordings using the same ultrasound scanner and agreement between results on two different scanner systems. Materials and MethodsTen patients under evaluation for exocrine pancreatic failure were included. Each patient was scanned two times on a GE Logiq E9 scanner, by two different observers, and once on a Philips IU22 scanner, after a bolus of 1.5 ml Sonovue. A 60-second recording of contrast enhancement was performed before the burst and the scan continued for another 30 s for reperfusion. We performed data analysis using MATLAB-based DCE-US software. An artery in the same depth as the region of interest (ROI) was used for scaling. The measurements were compared using the intraclass correlation coefficient (ICC) and Bland Altman plots.Results The interobserver agreement on the Logiq E9 for MTT (ICC = 0.83, confidence interval (CI) 0.46-0.96) was excellent. There was poor agreement for MTT between the Logiq E9 and the IU22 (ICC = − 0.084, CI − 0.68-0.58). The interobserver agreement for blood volume measurements was excellent on the Logiq E9 (ICC = 0.9286,) and between scanners (ICC = 0.86, CI = 0.50-0.97).Conclusion Interobserver agreement was excellent using the same scanner for both parameters and between scanners for BV, but the comparison between two scanners did not yield acceptable agreement for MTT. This was probably due to incomplete bursting of bubbles in some of the recordings on the IU22.

Interobserver Analysis of CEUS-Derived Perfusion in Fibrotic and Inflammatory Crohn’s Disease

“…Jirik et al [24] combined bolus injection and burst replenishment in a new model to solve this problem, thereby providing a robust AIF estimate and enabling the estimation of absolute perfusion. Recently presented data indicates that this method performs well also for repeated measurements [25].…”

Ultrasound imaging for assessing functions of the GI tract

“…The measurements using absolute perfusion estimation should be independent of patient-and equipmentrelated factors. Though not demonstrated in the bowel, studies suggest that the interobserver data for this method is promising (Engjom et al 2018) and that you can indeed compare perfusion parameters between different scanners (Stangeland et al 2017). Currently there are no commercial systems providing these data and since the post-processing is cumbersome, it is primarily a research tool.…”