Pancreatic iron and fat assessment by MRI-R2 in patients with iron overload diseases

• Published in: Journal of magnetic resonance imaging Vol. 42; no. 1; pp. 196 - 203
• Main Authors: Pfeifer, Charlotte D., Schoennagel, Bjoern P., Grosse, Regine, Wang, Zhiyue J., Graessner, Joachim, Nielsen, Peter, Adam, Gerhard, Fischer, Roland, Yamamura, Jin
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.07.2015; Wiley Subscription Services, Inc
• Subjects: Adiposity; Adult; Aged; fat infiltration; Female; Humans; Iron - analysis; iron overload; Iron Overload - metabolism; Iron Overload - pathology; Lipids - analysis; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Magnetic Resonance Spectroscopy - methods; Male; Middle Aged; Molecular Imaging - methods; pancreas; Pancreas - chemistry; Pancreas - pathology; pancreatic tail; Reproducibility of Results; Sensitivity and Specificity; thalassemia; Tissue Distribution; R2; iron overload; thalassemia; pancreatic tail; fat infiltration; pancreas
• DOI: 10.1002/jmri.24752
• ISSN: 1053-1807; 1522-2586

Background To determine the pancreatic iron (R2*) and fat content (FC) in comparison to hepatic and cardiac R2* in patients with iron overload disorders like β‐thalassemia major (TM), Diamond‐Blackfan anemia (DBA) or hereditary hemochromatosis. Methods R2* rates were assessed in the liver, heart and pancreas of 42 patients with TM, 29 subjects with other iron overload diseases, and 10 controls using an ECG‐gated breathhold sequence (12 echo time [TE] = 1.3–25.7 ms, readout repetition time [TR] = 244 ms). Pancreatic R2* and FC were assessed from TE dependent region of interest based signal intensities performing water−fat chemical shift relaxometry and were compared with laboratory parameters (glucose, HbA1c, amylase and lipase). Results A pancreatic iron gradient from tail (R2* = 122 s−1) to head (R2* = 114 s−1, P < 10−4) was found. The close association between cardiac and pancreatic R2* was also confirmed in patients with TM and other iron overload diseases (rs = 0.64, P < 10−4). Receiver operator characteristic analysis (area: 0.89, P < 10−4) identified patients with elevated cardiac iron at a pancreatic R2* cut‐off level of 131s−1 (sensitivity = specificity at 81%). Highest pancreatic R2* (211s−1) and FC (36%) were found in the tail region of diabetic patients with TM. Conclusion Pancreatic tail showed highest R2* rates and fat contents, especially in patients with thalassemia. Besides iron accumulation fatty degeneration might be an additional risk factor for the development of diabetes in β‐thalassemia major, but this hypothesis needs further studies in prediabetic patients. J. Magn. Reson. Imaging 2015;42:196–203. © 2014 Wiley Periodicals, Inc.