Differentiating focal pancreatitis from pancreatic carcinoma on ultrasound imaging can be challenging. Focal pancreatic lesions caused by chronic pancreatitis are tumorlike and may often be confused with pancreatic carcinoma.
In China, conventional ultrasound is frequently the first imaging examination performed to diagnose pancreatic lesions. Radiologists from the Peking University Cancer Hospital and Institute in Beijing report in the March issue of the Journal of Ultrasound in Medicine that contrast-enhanced ultrasound (CEUS) greatly increases the diagnostic accuracy over conventional ultrasound.
These findings were determined from a study to analyze the diagnostic efficiency of CEUS enhancement patterns compared to conventional ultrasound with respect to differentiating focal pancreatitis from pancreatic carcinoma. CEUS can display microvascular perfusion of pancreatic lesions, thus providing proof of differentiation.
The study cohort included 305 patients with pancreatic disease who had both examinations identified solid lesions. One hundred-thirty-six patients had final diagnoses, which included pancreatic carcinoma (86 patients), focal pancreatitis (25 patients), neuroendocrine tumors (16 cases), and 9 with other diseases.
Two ultrasound specialists reviewed the CEUS images of the pancreatic lesions, and classified the enhancement patterns into five categories: isoenhancement, isoenhancement with focal hypoenhancement, centripetal enhancement, hypoenhancement, and hyperenhancement. They analyzed the diagnostic sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for diagnosing focal pancreatitis and pancreatic carcinoma.
The diagnostic efficiency of isoenhancement alone independently analyzed with respect to diagnosis of focal pancreatitis. It was compared with the diagnostic efficiency of combining isoenhancement and isoenhancement with focal hypoenhancement. Lead author Yanjie Wang, PhD, and colleagues defined the diagnostic criteria for focal pancreatitis as isoenhancement or isoenhancement with focal hypoenhancement in both the early and late phases of the examination. Focal pancreatitis showed isoenhancement in 32% of the cases and isoenhancement with focal hypoenhancement in 40% in both early and late phases.
The authors stated that the diagnostic sensitivity of isoenhancement or isoenhancement with focal hypoenhancement alone in both the early and late phases with CEUS greatly increased the diagnosis of focal pancreatitis compared to conventional ultrasound. CEUS had an accuracy rate of 85.6% compared to conventional ultrasound at 49.5% with respect to diagnosing the 86 cases of pancreatic cancer and the 25 cases of focal pancreatitis. While they recommend CEUS over conventional ultrasound, and laud its ready availability and economic cost, they also said that CEUS cannot replace contrast-enhanced computed tomography (CT) as the gold standard for diagnosing solid pancreatic lesions.
Diagnosing focal pancreatitis from pancreatic carcinoma with CEUS. Appl Radiol.