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OBJECTIVE: This multicenter prospective cohort study compared pancreas volume as assessed by MRI, metabolic scores derived from oral glucose tolerance testing (OGTT), and a combination of pancreas volume and metabolic scores for predicting progression to stage 3 type 1 diabetes (T1D) in individuals with multiple diabetes-related autoantibodies. RESEARCH DESIGN AND METHODS: Pancreas MRI was performed in 65 multiple autoantibody-positive participants enrolled in the Type 1 Diabetes TrialNet Pathway to Prevention study. Prediction of progression to stage 3 T1D was assessed using pancreas volume index (PVI), OGTT-derived Index60 score and Diabetes Prevention Trial–Type 1 Risk Score (DPTRS), and a combination of PVI and DPTRS. RESULTS: PVI, Index60, and DPTRS were all significantly different at study entry in 11 individuals who subsequently experienced progression to stage 3 T1D compared with 54 participants who did not experience progression (P < 0.005). PVI did not correlate with metabolic testing across individual study participants. PVI declined longitudinally in the 11 individuals diagnosed with stage 3 T1D, whereas Index60 and DPTRS increased. The area under the receiver operating characteristic curve for predicting progression to stage 3 from measurements at study entry was 0.76 for PVI, 0.79 for Index60, 0.79 for DPTRS, and 0.91 for PVI plus DPTRS. CONCLUSIONS: These findings suggest that measures of pancreas volume and metabolism reflect distinct components of risk for developing stage 3 type 1 diabetes and that a combination of these measures may provide superior prediction than either alone. [ABSTRACT FROM AUTHOR]

Objective: This study investigated the temporal dynamics of pancreas volume and microstructure in children and adolescents with recent-onset type 1 diabetes (T1D) and individuals without diabetes, including a subset expressing autoantibodies associated with the early stages of T1D.Research Design and Methods: MRI was performed in individuals with recent-onset stage 3 T1D (n = 51; median age 13 years) within 100 days after diagnosis (mean 67 days), 6 months, and 1 year postdiagnosis. Longitudinal MRI measurements were also made in similarly aged control participants (n = 57) and in autoantibody-positive individuals without diabetes (n = 20). The MRI protocol consisted of anatomical imaging to determine pancreas volume and quantitative MRI protocols interrogating tissue microstructure and composition.Results: Within 100 days of diabetes onset, individuals with T1D had a smaller pancreas (median volume 28.6 mL) than control participants (median volume 48.4 mL; P < 0.001), including when normalized by individual weight (P < 0.001). Longitudinal measurements of pancreas volume increased in control participants over the year, consistent with adolescent growth, but pancreas volume declined over the first year after T1D diagnosis (P < 0.001). In multiple autoantibody-positive individuals, the pancreas volume was significantly larger than that of the T1D cohort (P = 0.017) but smaller than that of the control cohort (P = 0.04). Diffusion-weighted MRI showed that individuals with recent-onset T1D had a higher apparent diffusion coefficient (P = 0.012), suggesting a loss of cellular structural integrity, with heterogeneous pancreatic distribution.Conclusions: These results indicate that pancreas volume is decreased in stages 1, 2, and 3 of T1D and decreases during the first year after diabetes onset and that this loss of pancreatic volume is accompanied by microstructural changes. [ABSTRACT FROM AUTHOR]

Pancreas volume, as measured by magnetic resonance imaging (MRI), is smaller in individuals with newly-diagnosed type 1 diabetes (T1D) and declines over the first year after diagnosis. However, the repeatability and reproducibility of these MRI measurements is not established, and for MRI to be utilized to measure pancreas volume, the variation between measurements of pancreas volume must be determined. To determine the test-retest repeatability of pancreas volume measurements by MRI, we performed two or three same-day repeat MRIs in the same individuals with or without T1D (n = 8, mean age 24 y, range 11-40 y). A single radiologist, blinded to whether the subject had T1D or not, outlined the pancreas on these repeat images. Pancreas volume was determined by multiplying the area of the pancreatic regions of interest by the MRI slice volume (5 mm). The repeatability of test-retest scans had an intraclass correlation coefficient (ICC) of 0.979 (95% CI 0.928 to 0.996). To determine the inter-reader reliability of pancreas volume measurements, the pancreas was independently outlined by two board-certified radiologists (n = 11). Comparing results from multiple radiologists yielded an ICC of 0.931 (95% CI 0.776 to 0.981), with greater differences in measurement in larger pancreases (p < 0.005). The mean DICE coefficient, a measurement of the degree overlap between pancreas regions of interest between the two readers, was 0.77. These data show that measurements of pancreas volume obtained using MRI are both repeatable and reproducible across multiple readers with ICCs corresponding to excellent clinical significance (ICC > 0.9). These results indicate that MRI measurements of T1D pancreatic volume can be reliably determined and could be useful for clinical investigation. Disclosure: J.M. Williams: None. M.A. Hilmes: None. B.T. Archer: None. L. Du: None. H. Kang: None. W.E. Russell: None. D.J. Moore: None. A.C. Powers: None. J. Virostko: None. Funding: JDRF (3-SRA-2015-102-M-B) [ABSTRACT FROM AUTHOR]