RESUMO
OBJECTIVES: To compare the diagnostic success rate of acoustic radiation force impulse (ARFI) elastography with those of sonography and computed tomography (CT) for acute pancreatitis at hospital admission. METHODS: B-mode sonography and ARFI elastography were performed on 88 patients with symptoms of acute pancreatitis and 50 healthy control participants who were admitted to our hospital between February 2013 and July 2013. Acute pancreatitis was verified in the 88 patients based on clinical and laboratory findings. Computed tomography was performed on 41 patients, and the CT results from these patients were compared with those of ARFI elastography. The appearances of the pancreases of the patients were classified into 6 groups using visual color encodings obtained with ARFI elastography. The elasticity values of pancreatic head, body, and tail regions were evaluated with Virtual Touch imaging and Virtual Touch tissue quantification (Siemens Medical Solutions, Mountain View, CA). The success rates of sonography, CT, and ARFI elastography for diagnosing acute pancreatitis at hospital admission were compared. RESULTS: Forty-six of the 88 patients had a diagnosis of pancreatitis by B-mode sonography; pancreatitis was diagnosed in all patients by ARFI elastography; and 10 of 41 patients could not be diagnosed by CT. The sensitivity and specificity of Virtual Touch tissue quantification were 100% and 98%, respectively, when a cutoff value of 1.63 m/s was used. The control group had color scores of 1 or 2, whereas all patients with pancreatitis had color scores of 3 to 6 on color scale evaluation with Virtual Touch imaging. CONCLUSIONS: Acoustic radiation force impulse elastography is a rapid, radiation-free, and noninvasive tool for diagnosis of acute pancreatitis at initial hospital admission, with a higher success rate for diagnosis of acute pancreatitis than the grayscale sonography and CT.
