High-resolution magnetic resonance imaging quantitatively detects individual pancreatic islets

Diabetes. 2011 Nov;60(11):2853-60. doi: 10.2337/db11-0726. Epub 2011 Sep 16.

Abstract

Objective: We studied whether manganese-enhanced high-field magnetic resonance (MR) imaging (MEHFMRI) could quantitatively detect individual islets in situ and in vivo and evaluate changes in a model of experimental diabetes.

Research design and methods: Whole pancreata from untreated (n = 3), MnCl(2) and glucose-injected mice (n = 6), and mice injected with either streptozotocin (STZ; n = 4) or citrate buffer (n = 4) were imaged ex vivo for unambiguous evaluation of islets. Exteriorized pancreata of MnCl(2) and glucose-injected mice (n = 6) were imaged in vivo to directly visualize the gland and minimize movements. In all cases, MR images were acquired in a 14.1 Tesla scanner and correlated with the corresponding (immuno)histological sections.

Results: In ex vivo experiments, MEHFMRI distinguished different pancreatic tissues and evaluated the relative abundance of islets in the pancreata of normoglycemic mice. MEHFMRI also detected a significant decrease in the numerical and volume density of islets in STZ-injected mice. However, in the latter measurements the loss of β-cells was undervalued under the conditions tested. The experiments on the externalized pancreata confirmed that MEHFMRI could visualize native individual islets in living, anesthetized mice.

Conclusions: Data show that MEHFMRI quantitatively visualizes individual islets in the intact mouse pancreas, both ex vivo and in vivo.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Algorithms
  • Animals
  • Chlorides / administration & dosage
  • Contrast Media / administration & dosage
  • Diabetes Mellitus, Type 1 / chemically induced
  • Diabetes Mellitus, Type 1 / metabolism
  • Diabetes Mellitus, Type 1 / pathology*
  • Glucagon / metabolism
  • Glucagon-Secreting Cells / metabolism
  • Glucagon-Secreting Cells / pathology
  • Glucose / administration & dosage
  • Glucose / metabolism
  • Image Enhancement / methods*
  • Immunohistochemistry
  • Infusions, Intravenous
  • Injections, Intraperitoneal
  • Insulin / metabolism
  • Insulin-Secreting Cells / metabolism
  • Insulin-Secreting Cells / pathology
  • Islets of Langerhans / metabolism
  • Islets of Langerhans / pathology*
  • Magnetic Resonance Imaging*
  • Manganese Compounds / administration & dosage
  • Mice
  • Mice, Inbred C57BL
  • Organ Size
  • Streptozocin / toxicity

Substances

  • Chlorides
  • Contrast Media
  • Insulin
  • Manganese Compounds
  • Streptozocin
  • Glucagon
  • Glucose
  • manganese chloride