Accurate estimate of pancreatic T2* values: how to deal with fat infiltration Antonella Meloni, 1,2 Daniele De Marchi, 1 Vincenzo Positano, 1,2 Maria Giovanna Neri, 1 Maurizio Mangione, 3 Petra Keilberg, 1 Maddalena Lendini, 4 Carla Cirotto, 5 Alessia Pepe 1 1 CMR Unit, Fondazione G. Monasterio CNR-Regione Toscana, Area della Ricerca S. Cataldo, Via Moruzzi, 1, 56124 Pisa, Italy 2 U.O.C. Bioingegneria e Ingegneria Clinica, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy 3 U.O.S. Sistemi Informatici, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy 4 Centro Trasfusionale, Osp. Giovanni Paolo II, Olbia, Italy 5 Servizio Trasfusionale, Azienda USL n° 1, Sassari, Italy Abstract Purpose: We examined different approaches aimed to deal with the signal fluctuation of pancreatic T2* values due to fat infiltration in order to obtain accurate estimates of iron overload. Methods: Pancreatic T2* values were assessed in 20 patients (13 females, 37.24 ± 9.12 years) enrolled in the Myocardial Iron Overload in Thalassemia network without and with the application of fat suppression-FS (T2*-NoFS and T2*-FS). T2* values were assessed in three different ways: (1) from the immediate fit (original T2*); (2) discarding the echoes until the achievement of a good visual concordance between the signal and the model (final_vis T2*); (3) eliminating the echoes until the achievement of a fitting error (known) <5% (final_thres T2*). Results: For the T2*-NoFS sequence the original T2* values were significantly higher than the final_vis T2* values (difference:4.8 ± 6.1 ms; P < 0.0001) and the final_thres T2* values (difference:4.3 ± 6.1 ms; P = 0.006). For the T2*-FS sequence the original T2* values were comparable to final_vis and final_thres T2* values. The original T2*-FS values were significantly different from the original T2*-NoFS values. The final_vis T2*-FS values were comparable to the final_vis T2*-NoFS values and the final_thresh T2*-FS values were comparable to the final_thresh T2*-NoFS values. For both T2*-FS and T2*-NoFS sequences, the final_thres T2* values were not significantly different from the final_vis T2* values and no bias was present. Conclusions: In the clinical practice, an accurate pancre- atic iron overload assessment should be done by applying FS and, when needed, by discarding the TEs until the fitting error goes below 5%. Key words: Magnetic resonance imaging—Pancreas T2*—Iron overload—Fat suppression Regular and frequent red blood cell transfusions have significantly increased the life expectancy of patients with chronic diseases associated with excess destruction or ineffective production of erythrocytes, such as tha- lassemia major (TM), sickle cell disease, extreme pre- maturity, and certain malignancies. However, since the human body has no physiologic mechanism for removing excess iron, once the body’s natural ability to store iron is exceeded, chronic transfusions result in accumulation of iron in vital organs [1, 2]. The iron accumulates primarily in the liver and spleen, later on in the heart and the endocrine glands [3]. Increased iron deposit is cytotoxic and may cause organ dysfunction [4]. Magnetic resonance imaging (MRI) by the T2* technique has been proved to be an effective, reliable, and reproducible means to non-invasively assess tissue iron overload. T2* is inversely proportional to iron concentration and is obtained by fitting the MRI signal monitored at several gradient echo times (TEs) to an appropriate exponential decay model [5–7]. Despite extensive research on hepatic and cardiac T2* MRI, there are still few reports on the use of MRI to study iron deposits in the pancreas [8, 9]. The pancreas of patients with iron overload patho- logic conditions is frequently affected by severe fatty infiltration [10, 11]. Fat infiltration can generate a sinu- Correspondence to: Antonella Meloni; email: antonella.meloni@ftgm.it ª Springer Science+Business Media New York 2015 Published online: 20 August 2015 Abdominal Imaging Abdom Imaging (2015) 40:3129–3136 DOI: 10.1007/s00261-015-0522-9