Pancreatic perfusion of healthy individuals and type 1 diabetic patients as assessed by magnetic resonance perfusion imaging

Abstract

Aims/hypothesis Loss of pancreatic beta cell mass and function leads to the development of diabetes mellitus. Currently there is no technical way to non-invasively image islet function and mass. Murine models suggest that islets are highly vascularised organs that make a significant contribution to the total pancreatic blood flow. The current study was undertaken to test with arterial spin labelling (ASL) magnetic resonance imaging if islet mass and/or stimulation of human pancreatic islets by hyperglycaemia can differentially increase whole-pancreas perfusion, thereby distinguishing non-diabetic from type 1 diabetic patients. Methods We assessed pancreatic blood flow using ASL at baseline, during a hyperglycaemia clamp study (glucose at 11 mmol/l) and during recovery to euglycaemia. Results Seventeen healthy volunteers and seven type 1 diabetic patients were studied. In healthy volunteers we observed no change in pancreatic blood flow during the three phases of the study. A trend for an increase in blood flow was observed in the two control tissues, the liver and kidney. Similarly, there was no significant difference in blood flow during the three stages (baseline, hyperglycaemia and recovery) in diabetic patients and there was no significant difference observed between diabetic patients and normal volunteers. Conclusions/interpretation Our data suggest that in humans neither increased demand nor islet mass has a substantial influence on pancreatic perfusion. It is possible, however, that the current state-of-the art imaging technology employed in this study might not be sensitive enough to distinguish between a true effect and noise.Trial registration: ClinicalTrials.gov NCT00280085 Funding: This study was fully funded by a grant from Pfizer.

Pancreatic perfusion and subsequent response to glucose in healthy individuals and patients with type 1 diabetes

“…Future studies in large animals may be of value to increase our understanding of the partial contribution of islet blood flow increase and general increase in blood perfusion of splanchnic organs. In contrast to our results, a previous study of human pancreatic blood flow did not show any difference between individuals with type 1 diabetes and healthy individuals, neither at baseline nor after glucose administration [7]. This disparity in findings could be due to the limitations of the technique that was used; arterial spin labelling MRI is a technique that has a high noise to signal ratio, where artefacts are induced by surrounding organ movements and where there are an insufficient number of voxels for sensitive analysis.…”

“…In previous investigations, pancreatic perfusion in individuals with type 1 diabetes has been shown either not to change or to have a tendency to decrease [2,7]. Experience from animal studies [4][5][6] is suggestive that the perfusion difference between insulin-deficient and healthy animals mainly reflects the islet vascular component.…”

Positron Emission Tomography Ligand [11C]5-Hydroxy-Tryptophan Can Be Used as a Surrogate Marker for the Human Endocrine Pancreas

“…Rodent studies show that the islet blood flow normally constitutes ;10% of the total pancreatic blood flow even though the islet tissue comprises only 1-2% of the total pancreatic volume (23). In humans, no techniques are available for specific studies of islet blood perfusion, but the perfusion of the whole pancreas in HVs and T1D subjects, as measured by magnetic resonance perfusion imaging, did not differ (32). In the current study, a tendency to a decrease in mean pancreatic blood flow by 20% was recorded.…”

Temporal assessment of pancreatic blood flow and perfusion following secretin stimulation using noninvasive MRI

“…However, this technique requires the injection of a gadolinium-based contrast agent from which the first pass is measured and quantified for perfusion, 7,8 which again limits repeat measures. Arterial spin labeling (ASL) has been used previously to measure perfusion in the pancreas 9,10 as well as several other abdominal organs [11][12][13] without administration of contrast agent, thus allowing for repeated measures and enables the assessment of temporal changes in pancreatic perfusion, without the risks associated with intravenous contrast agents.…”