Magnetic resonance microscopy detects pancreatic architecture
MedWire News: US research shows that magnetic resonance microscopy (µMRI) can be used to visualize individual components of a healthy mouse pancreas including acini, islets, blood vessels, and stroma.
"Clinically, changes in any of these cellular compartments can result in pathological states, including pancreatitis (acini), cancer (ductal), and diabetes (islets), and the ability to detect architectural changes will likely improve diagnostic capabilities for these diseases," remark Paul Grippo (Northwestern University, Chicago, Illinois) and colleagues.
The researchers explain that, as pancreatic diseases are often difficult to detect and/or stage in humans, there is need for a technology that can visualize tissue changes in the pancreas, and thus improve understanding of disease progression, and facilitate earlier detection.
In recent years, the advent of high field strength (>9.4 T) magnetic resonance imaging systems has allowed imaging of diseases in mouse models, using µMRI (ie, imaging at microscopic spatial resolution, typically around 50 µm).
The greater sensitivity of high field strength imaging systems can be used to image the pancreas at a high spatial resolution and to visualize tissue microstructure that is not visible at lower field strengths, the researchers note.
Before this technique can be applied in vivo, however, it is necessary to understand the µMRI phenotype of the exocrine and endocrine components of the mouse pancreas, they say.
Grippo and team therefore evaluated the use of high field strength (14.1 T) µMRI, without contrast agents, to capture the 3D structure and morphology of cellular and anatomical components, ex vivo, in a normal mouse pancreas.
They report that the images demonstrated excellent contrast between various structures within the pancreas, based on their T2 and proton density differences.
Broad regions of low signal intensity corresponded to acinar cells, while small elliptical structures distributed throughout the acinar cells with focal, moderate signal intensity, were consistent with the arrangement of islets.
Regions of high signal intensity that cut through the organ, often connecting with one another, were identified as blood vessels.
When the researchers compared the 3D-µMRI images with histological images, they observed good correspondence between the locations and dimensions of pancreatic components.
Grippo and team say that longitudinal studies are now required to expand on the use of in vivo µMRI in mouse models of pancreatic diseases.
"Capturing three-dimensional structural changes through µMRI could help to identify early cellular and tissue changes associated with pancreatic disease, serving as a mode of improved detection in the clinic for endocrine and exocrine pathologies," they conclude in the American Journal of Pathology.
By Laura Dean