3 T MR Perfusion of Solid Pancreatic Lesions Using Dynamic Contrast-enhanced DISCO Sequence: Usefulness of Qualitative and Quantitative Analyses in a Pilot Study

Purpose: To assess the usefulness of qualitative and quantitative analyses of pancreatic focal diseases by using the dynamic contrast-enhanced Differential Subsampling with Cartesian Ordering (DISCO) sequence at 3 T MR device.

Materials And Methods: Ten patients without pancreatic diseases and twenty-five patients with pathologically confirmed pancreatic focal disease (ductal adenocarcinoma, n = 14; endocrine tumour, n = 8; focal chronic pancreatitis, n = 3), underwent MRI by 3 T-device. Multiphasic contrast-enhanced MR perfusion, consisting of a 3D axial navigator, based free-breathing T1-weighted DISCO sequence, was repeated for 5 min. A dose of 0.1 mL/kg of Gadobutrolo with a 20 mL saline flush was injected at a flow rate of 5 mL/s. Perfusion MRI were processed using a dedicated software package (GeniQ; GE Healthcare), obtaining both a time-signal-intensity curve (TSIC) and perfusion maps for each healthy pancreatic parenchyma and focal disease. The TSIC were grouped into four types according to their shapes and the MR perfusion parameters (Ktrans, Kep, Ve, IAUGC) were calculated. The one-way analysis of variance and the Student's t-test were used to correlate the quantitative and qualitative parameters with the tissue histology.

Results: All 10 patients with healthy pancreas presented a TSIC-type 1; TSIC-type 2 was observed in all 14 ductal adenocarcinomas and in one neuroendocrine tumour; TSIC-type 3 was recognized in the remaining 7 neuroendocrine neoplasms; TSIC-type 4 was identified in all 3 focal chronic pancreatitis. All perfusion parameters were significantly different (p < 0.0001) for each type of lesion. Furthermore, Ve was also very useful to discriminate between normal and pathological tissues (p = 0.0005).

Conclusion: Qualitative and quantitative analyses of contrast-enhanced 3 T MR perfusion, using the dynamic contrast-enhanced DISCO sequence, could be considered an interesting tool to improve the diagnosis of focal pancreatic diseases, of solid lesions in particular. Further investigations with prospective larger sample studies are required to confirm these preliminary results.