Multitasking dynamic contrast enhanced magnetic resonance imaging can accurately differentiate chronic pancreatitis from pancreatic ductal adenocarcinoma

Abstract

Background and aims: Accurate differentiation of chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC) is an area of unmet clinical need. In this study, a novel Multitasking dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) technique was used to quantitatively evaluate the microcirculation properties of pancreas in CP and PDAC and differentiate between them.

Methods: The Multitasking DCE technique was able to acquire one 3D image per second during the passage of MRI contrast agent, allowing the quantitative estimation of microcirculation properties of tissue, including blood flow F_p, plasma volume fraction v_p, transfer constant K^trans, and extravascular extracellular volume fraction v_e. Receiver operating characteristic (ROC) analysis was performed to differentiate the CP pancreas, PDAC pancreas, normal control pancreas, PDAC tumor, PDAC upstream, and PDAC downstream. ROCs from quantitative analysis and conventional analysis were compared.

Results: Fourteen PDAC patients, 8 CP patients and 20 healthy subjects were prospectively recruited. The combination of F_p, v_p, K^trans, and v_e can differentiate CP versus PDAC pancreas with good AUC (AUC [95% CI] = 0.821 [0.654 - 0.988]), CP versus normal pancreas with excellent AUC (1.000 [1.000 - 1.000]), PDAC pancreas versus normal pancreas with excellent AUC (1.000 [1.000 - 1.000]), CP versus PDAC tumor with excellent AUC (1.000 [1.000 - 1.000]), CP versus PDAC downstream with excellent AUC (0.917 [0.795 - 1.000]), and CP versus PDAC upstream with fair AUC (0.722 [0.465 - 0.980]). This quantitative analysis outperformed conventional analysis in differentiation of each pair.

Conclusion: Multitasking DCE MRI is a promising clinical tool that is capable of unbiased quantitative differentiation between CP from PDAC.

Keywords: Multitasking DCE; differential diagnosis of chronic pancreatitis and pancreatic ductal adenocarcinoma; dynamic contrast enhanced magnetic resonance imaging; microcirculation properties; quantitative imaging.

Figure 1

Flow chart for subject recruitment and grouping.

Figure 2

Example microcirculation parametric maps. (A) Example maps from 72-year-old patient with PDAC, whose tumor is located at the neck of pancreas. First panel shows a gray-scale Multitasking image at the arterial phase at the center slice of the tumor. The tumor was labeled by the red solid boundary. Downstream was visible in this slice. The second panel shows estimated microcirculation parametric maps. PDAC tumor showed lower F_p, lower v_p, and elevated v_e compared to downstream. The third panel shows the averaged contrast agent concentration curves for blood, PDAC tumor, and PDAC downstream. (B) Example maps from a 65-year-old patient with CP. The pancreas was labeled by the yellow dashed boundary. (C) Representative maps of a 32-year-old subject in the normal control group.

Figure 3

Bar graphs for the mean and standard deviation (error bar on top of each bar) for F_p, v_p, K^trans, and v_e for all types of tissues (normal, normal control pancreas; PDAC, PDAC pancreas; CP, CP pancreas).

Figure 4

ROC curves and the sensitivity (SEN), specificity (SPE), and AUC to differentiate between (A) CP (N = 8) versus PDAC pancreas (N = 14), (B) CP (N = 8) versus normal control pancreas (N = 20), (C) PDAC pancreas (N = 14) versus normal control pancreas (N = 20), (D) CP (N = 8) versus PDAC tumor (N = 14), (E) CP (N = 8) versus PDAC downstream (N = 10), and (F) CP (N = 8) versus PDAC upstream (N = 9) using each single microcirculation parameter or the combination of all the four parameters. SEN, sensitivity; SPE, specificity; AUC, area under ROC curve.

Figure 5

ROC curves and the sensitivity, specificity, and AUC using TIC analysis to differentiate between (A) CP versus PDAC pancreas, (B) CP versus normal control pancreas, (C) PDAC pancreas versus normal control pancreas, (D) CP versus PDAC tumor, (E) CP versus PDAC downstream, and (F) CP versus PDAC upstream. SEN, sensitivity; SPE, specificity; AUC, area under ROC curve; TIC, time-signal intensity curve.