CT perfusion and diffusion-weighted MR imaging of pancreatic adenocarcinoma: can we predict tumor grade using functional parameters?

Background: Pancreatic adenocarcinoma is a highly lethal disease even in initially resectable patients. Functional imaging procedures such as diffusion-weighted imaging (DWI) and computed tomography (CT)-perfusion might facilitate preoperative prediction of factors influencing prognosis in patients with pancreatic adenocarcinoma. Purpose: To evaluate CT-perfusion and DWI quantitative parameters of pancreatic adenocarcinoma and to assess their correlation with clinicopathological features. Material and Methods: Forty-four patients with histopathologically proven pancreatic adenocarcinoma underwent CT-perfusion and DWI for estimating blood volume (BV), blood perfusion (BF), mean transit time (MTT), time to peak (TTP), and apparent diffusion coefficient (ADC) values. The statistical analysis was performed using Wilcoxon matched-pairs test, t-test for independent samples, Spearman's rank correlation coefficient (r_s), and receiver operating characteristic analysis. Results: The mean CT-perfusion parameters and ADCs were significantly different in pancreatic adenocarcinoma versus healthy parenchyma. BV (2.66 ± 0.98 mL/100g), BF (17.45 ± 4.06 mL/min/100g), and ADCs (0.91 ± 0.15 × 10⁻³mm/s²) in high-grade tumors were significantly lower in comparison to low-grade tumors (BV = 5.35 ± 1.36 mL/100g, BF = 28.51 ± 7.73 mL/min/100g, ADC = 1.07 ± 0.21 × 10⁻³mm/s²). For prediction of high-grade tumors, the sensitivity and specificity were 79.2% and 82.4% for BF and 87.5% and 88.2% for BV, respectively. A significant negative correlation was found between BV and tumor size (r_s = −0.445, P = 0.029), MTT and tumor size (r_s = −0.330, P = 0.043), BV and M-stage (r_s = −0.286, P = 0.049), and ADC and M-stage (r_s = −0.274, P = 0.038). Moreover, BF and BV values were significantly associated with ADCs. Conclusion: CT-perfusion parameters and ADC values could improve preoperative assessment of pancreatic adenocarcinoma with possibility of tumor grade prediction. [ABSTRACT FROM AUTHOR]