Acoustic radiation force impulse elastography for noninvasive assessment of chronic pancreatitis

Background Endoscopic ultrasonography or real-time elastography has been applied for the diagnosis of chronic pancreatitis. Acoustic radiation force impulse (ARFI) imaging is another tissue strain imaging technology, and recent technological advances have enabled quantification of the stiffness of some tissues by measuring the shear wave velocity (SWV) during routine B-mode ultrasonography. Methods ARFI elastography was performed in 52 healthy volunteers and 46 patients with chronic pancreatitis. SWV was measured in the head, body, and tail of the pancreas. The diagnostic performance was assessed using receiver-operating characteristic (ROC) curves. Results SWV in patients with chronic pancreatitis was significantly higher than that in healthy volunteers in each part of the pancreas, although the measurement was difficult in the tail of the pancreas. The area under the ROC curve was 0.78 in the body of the pancreas, with an optimal cut-off value of 1.40 m/s, and the sensitivity, specificity, positive predictive value, and negative predictive value were 75, 72, 69, and 78%, respectively. In the patients with chronic pancreatitis, alcoholic etiology and decreased body mass index (BMI) were associated with high SWV. Conclusions ARFI elastography of the pancreas showed high elasticity in chronic pancreatitis compared to findings in the normal pancreas. This modality is feasible to use for the diagnosis of chronic pancreatitis.