The pancreas-to-muscle signal intensity ratio on T1-weighted MR images of the pancreas may be a potential biomarker for assessment of pancreatic fibrosis and prediction of postoperative pancreatic fistula, according to a study published in the March issue of Radiology.
By assessing preoperative features of pancreatic parenchymal texture that are linked to the occurrence of postoperative pancreatic fistula, researchers may be able to prevent the development of secondary complications. However, literature is scarce regarding relationships between the findings of MR imaging, pancreatic stellate cell expression, pancreatic fibrosis progression and postoperative pancreatic fistula development.
Lead author Haruo Watanabe, MD, of the Gifu University Hospital in Japan, and colleagues investigated the potential value of MRI in assessing degrees of pancreatic fibrosis and expression of activated pancreatic stellate cells. They also examined its feasibility in predicting postoperative pancreatic fistula development.
The retrospective study evaluated MR images of 29 patients who underwent pancreatectomy. The researchers measured the pancreas-to-muscle signal intensity ratio on unenhanced T1- and T2-weighted, dynamic contrast material-enhanced, and diffusion-weighted images, as well as the apparent diffusion coefficient of the pancreas.
Analysis revealed that the pancreas-to-muscle signal intensity ratios on T1-weighted images and apparent diffusion coefficient values were independently associated with pancreatic fibrosis and activated pancreatic stellate cell expression. The mean pancreas-to-muscle signal intensity ratio on T1-weighted images was higher for patients with postoperative pancreatic fistula. Lastly, the odds ratio for postoperative pancreatic fistula was 21.3 in patients with a signal intensity ratio of 1.41 and higher.
“Our results suggest that T1-weighted and diffusion-weighted MR imaging with concomitant SI ratio and ADC measurements could serve as preoperative noninvasive biomarkers to efficiently detect advanced pancreatic fibrosis, which is highly linked to the occurrence of postoperative pancreatic fistula,” wrote Watanabe and colleagues. “We believe that the measurement of these simple parameters at routine unenhanced MR imaging may enhance the value of pancreatic MR imaging.”