Feasibility of using 3D MR elastography to determine pancreatic stiffness in healthy volunteers

Abstract

Purpose To evaluate the feasibility of using 3D Magnetic Resonance Elastography (MRE) to determine the stiffness of the pancreas in healthy volunteers. Materials and Methods Twenty healthy volunteers underwent 1.5-T MRE exams using an accelerated echo planar imaging (EPI) pulse sequence with low-frequency vibrations (40 and 60 Hz). Stiffness was calculated with a 3D direct inversion algorithm. The mean shear stiffness in five pancreatic subregions (uncinate, head, neck, body and tail) and the corresponding liver stiffness were calculated. The intrasubject coefficient of variation (CV) was calculated as a measure of the reproducibility for each volunteer. Results The mean shear stiffness (average of values obtained in different pancreatic subregions) was (1.15±0.17) kPa at 40 Hz, and (2.09±0.33) kPa at 60 Hz. The corresponding liver stiffness was higher than the pancreas stiffness at 40 Hz [(1.60±0.21) kPa, mean pancreas-to-liver stiffness ratio: 0.72], but similar at 60Hz [(2.12±0.23) kPa, mean ratio: 0.95]. The mean intrasubject CV for each pancreatic subregion was lower at 40 Hz than 60 Hz (P<0.05 for all subregions, range: 11.9–15.7% at 40 Hz and 16.5–19.6% at 60 Hz). Conclusion 3D pancreatic MRE can provide promising and reproducible stiffness measurements throughout the pancreas, with more consistent data acquired at 40 Hz.

Cross-vendor validation of liver magnetic resonance elastography

“…While there have been several reports in the literature confirming the high reproducibility of MRE derived liver stiffness values on the same subject performed at different times points, these studies were all performed on the same vendor platform [21,22]. To our knowledge, there have been no reports in the literature demonstrating reproducibility of MRE derived liver stiffness values on the same individual on different platforms.…”

Experimental analysis of the mechanical behavior of the viscoelastic porcine pancreas and preliminary case study on the human pancreas

“…The in vivo shear stiffness of pancreas was for example investigated with the MR elastography technique (Yin et al, 2008) and found to be 2:070:4kPa which is similar to that of hepatic tissue (Rouviere et al, 2006). Similar investigations were conducted (Shi et al, 2014) with a resulting mean shear stiffness of 1.2 kPa at 40 Hz and 2.1 kPa at 60 Hz, respectively.…”

Preoperative imaging evaluation of pancreatic pathologies for the objective prediction of pancreatic fistula after pancreaticoduodenectomy

“…Recent preliminary studies with 20 healthy volunteers have suggested the feasibility of three-dimensional pancreatic MR elastography for quantitatively determining the stiffness of the pancreas [53].…”