Quantitative analysis of tissue perfusion using contrast-enhanced transabdominal ultrasound (CEUS) in the evaluation of the severity

Introduction: contrast enhanced ultrasound provides information on the vascularization of the pancreatic parenchyma, detecting areas of inflammation, necrosis, as well as the residual parenchyma in acute pancreatitis. The aim of our study was to assess the role of contrast enhanced ultrasound in appreciating the severity of acute pancreatitis by quantitative analysis of the degree of vascularization and the areas of pancreatic parenchymal necrosis. Material and methods: The study was prospective (December 2008 April 2010) and included 25 patients with acute pancreatitis. CEUS examination was performed with a Logiq 7 ultrasound machine, using the afferent software for the quantitative analysis of the acoustic signal. Results: The analysis of the average value of the maximum acoustic signal intensity (max I) after contrast injection, and of the mean time to signal enhancement appearance (mT): a) superior mesenteric artery: max I 19.37 ± 8.53 dB, mT 15.85 ± 4.6 sec; b) inflammation area: max I 14.76 ± 6.7 dB, mT 15.15 ± 3.6 sec; c) necrosis area: max I 8.89 ± 9.91 dB, mT 22.17 ± 7.9 sec; d) structural ill-defined hypoechoic area: max I 12.03 ± 5.4 dB, mT 21.67 ± 4.47 sec. The comparison of pancreatic necrosis area measured with contrast enhanced ultrasound and CT revealed a 62.5% concordance. Conclusions: Our study attests the usefulness of CEUS in quantifying the necrosis area in acute pancreatitis, with similar results to those obtained by CT.