Approximately 400,000 people are living with type 1 diabetes mellitus (T1DM) in the United Kingdom: one of the highest rates in the world. It is characterised by autoimmune loss of pancreatic beta cell mass leading to metabolic dysregulation, requiring lifelong insulin therapy. It is now recognised that there are micro-secretors of insulin and that preservation of insulin secretion in these cases is associated with decreased complications. Therefore, recent research has focussed on using immunomodulation to preserve pancreatic beta cell mass. Evaluation of novel therapies for T1DM requires reliable methods to measure beta-cell function, which is unattainable using traditional non-invasive imaging techniques. A new approach is manganese-enhanced magnetic resonance imaging (MEMRI). This proof-of-concept study was designed to investigate whether MEMRI can be used as a measure of beta-cell function in people with T1DM.

Inclusion Criteria:

• Age >18 years
• No regular medications
• No known significant medical conditions

Exclusion Criteria:

• Inability to consent
• Renal failure (eGFR <30 mL/min/1.73 m2)
• Standard MRI contraindications
• Pregnancy or breast feeding

Patients with type 1 diabetes mellitus (with or without detectable C-peptide levels)