The Significance of Diffusion-Weighted Imaging and Apparent Diffusion Coefficient in the Diagnosis of Early Acute Interstitial Edematous Pancreatitis.

The study assessed the diagnostic value of diffusion-weighted imaging (DWI) and mean apparent diffusion coefficient (ADC) in early acute interstitial edematous pancreatitis (AIEP). Fifty-six AIEP patients and 60 healthy controls underwent an upper abdominal magnetic resonance (MR) examination. The pancreas diameter and ADC values were measured and analyzed across age and gender groups. Results showed that the pancreas diameter varied with sex and age, with smaller diameters in females and the elderly. Mean ADC values were not significantly affected by age or sex. Signal changes were observed in AIEP patients' images, with DWI showing a higher positive rate than T1WI and T2WI. Comparing the control and AIEP groups, the pancreas diameter was significantly larger in AIEP patients, particularly the pancreatic tail in males. ADC values were significantly lower in AIEP patients, and the difference was more pronounced at b=800 s/mm² compared to b=500 s/mm². Mean ADC exhibited good diagnostic potential for early AIEP, with higher sensitivity and specificity values than serum amylase levels. The area under the receiver operating characteristic (ROC) curve (AUC) indicated that the diagnostic value was better at b=800 s/mm² than at b=500 s/mm². In conclusion, the study found that normal pancreas diameter is influenced by sex and age, with smaller diameters in females and the elderly. Mean ADC values were not affected by these factors. Early AIEP could not be diagnosed solely based on pancreas diameter changes. DWI combined with Mean ADC demonstrated high diagnostic value for early AIEP.