Quantitative analysis of endosonographic parenchymal echogenicity in patients with chronic pancreatitis

Background and Aim: The aim of the study was to develop a method of quantitation of endoscopic ultrasonography (EUS) changes of chronic pancreatitis (CP). Methods: Twenty-three patients with chronic pancreatitis by EUS were compared with nine normal subjects. Hyperechogenicity was evaluated as the size of the hyperechoic area that was over a threshold echogenicity level. Mean echo density was expressed using the average gray-scale value within the region of interest. The quantitative data were compared with the diagnosis using conventional EUS criteria. Results: The size of the hyperechoic area over the threshold level was 0.86 ± 0.67 mm² (mean ± SD) in the normal pancreas using EUS criteria. In chronic pancreatitis, the size of the hyperechoic area was 7.28 ± 2.98 mm² in patients with mild CP, 18.12 ± 2.56 mm² in patients with moderate CP, and 18.02 ± 10.81 mm² in patients with severe CP, respectively. These changes in hyperechoic size area were statistically significant in all patients having mild to severe CP when compared with normal controls. Conclusion: Computer analysis of EUS images may provide objective information for the diagnosis of CP and may be useful in quantitating the severity of disease and overcoming interobserver variability in analyzing individual echo features supporting the diagnosis of CP.