Diffusion-weighted Imaging: New Paradigm in Diagnosis of Early Acute Pancreatitis.

Abstract

Diffusion-weighted imaging (DWI) has come up as a newer diagnostic modality for the diagnosis of early functional changes in various organs including the pancreas. DWI has shown the ability of early and accurate diagnosis of inflammatory pathologies, before the appearance of morphological changes on imaging. The objectives of this study were to study the diagnostic accuracy of DWI in the diagnosis of early acute interstitial pancreatitis. The present retrospective observational study was conducted at the department of radiodiagnosis of a tertiary teaching hospital for 1 year. Fifty patients who underwent magnetic resonance imaging of the pancreas with clinical or laboratory diagnosis of early pancreatitis were included in the study. The diagnostic accuracy of DWI was analyzed on the basis of quantitative (apparent diffusion coefficient [ADC] values) evaluation in the diagnosis of early acute pancreatitis. Threshold values for ADC were derived for differentiation of inflamed versus normal pancreas. Sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV) were obtained by drawing the receiver operating characteristic (ROC) curve. The mean ADC values in the patient group (0.882 × 10 -3 mm 2 /s ± 0.102) were significantly lower than the control group (1.178 × 10 -3 mm 2 /s ± 0.232) with P < 0.001. The ROC curve deciphered a cutoff value of 0.937 × 10 -3 mm 2 /s with a sensitivity of 84%, specificity of 86%, PPV of 85.71%, and NPV of 84.31% for diagnosis of acute pancreatitis using quantitative ADC values. DWI can thus be a succinct modality for early diagnosis of pancreatitis with excellent diagnostic accuracy and superlative advantage of lack of contrast and radiation in comparison to computed tomography scan.