Assessment of cardiac iron by MRI susceptometry and R2* in patients with thalassemia

Wang, Zhiyue J.; Fischer, Roland; Chu, Zili; Mahoney, Donald H.; Mueller, Brigitta U.; Muthupillai, Raja; James, Ellen B.; Krishnamurthy, Rajesh; Chung, Taylor; Padua, Eric; Vichinsky, Elliott; Harmatz, Paul

doi:10.1016/j.mri.2009.12.001

« Previous Next »Magnetic Resonance Imaging
Volume 28, Issue 3 , Pages 363-371, April 2010

Assessment of cardiac iron by MRI susceptometry and R2* in patients with thalassemia

Zhiyue J. Wang
- Texas Children's Hospital, Houston, TX 77030, USA
- Baylor College of Medicine, Houston, TX 77030, USA
- Corresponding author. Children's Medical Center Dallas, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA. Tel.: +1 214 456 1479; fax: +1 214 456 6015.
Roland Fischer
- Children's Hospital and Research Center Oakland, Oakland, CA 94609, USA
- University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
Zili Chu
- Texas Children's Hospital, Houston, TX 77030, USA
- Baylor College of Medicine, Houston, TX 77030, USA
Donald H. Mahoney Jr.
- Texas Children's Hospital, Houston, TX 77030, USA
- Baylor College of Medicine, Houston, TX 77030, USA
Brigitta U. Mueller
- Texas Children's Hospital, Houston, TX 77030, USA
- Baylor College of Medicine, Houston, TX 77030, USA
Raja Muthupillai
- Baylor College of Medicine, Houston, TX 77030, USA
- Philips Medical Systems, Cleveland, OH 44143, USA
- St. Luke's Episcopal Hospital, Houston, TX 77030, USA
Ellen B. James
- Children's Hospital and Research Center Oakland, Oakland, CA 94609, USA
Rajesh Krishnamurthy
- Texas Children's Hospital, Houston, TX 77030, USA
- Baylor College of Medicine, Houston, TX 77030, USA
Taylor Chung
- Texas Children's Hospital, Houston, TX 77030, USA
- Baylor College of Medicine, Houston, TX 77030, USA
- Children's Hospital and Research Center Oakland, Oakland, CA 94609, USA
Eric Padua
- Children's Hospital and Research Center Oakland, Oakland, CA 94609, USA
Elliott Vichinsky
- Children's Hospital and Research Center Oakland, Oakland, CA 94609, USA
Paul Harmatz
- Children's Hospital and Research Center Oakland, Oakland, CA 94609, USA

Received 5 February 2009; received in revised form 7 July 2009; accepted 6 December 2009. published online 11 January 2010.

Abstract

A magnetic resonance imaging cardiac magnetic susceptometry (MRI-CS) technique for assessing cardiac tissue iron concentration based on phase mapping was developed. Normal control subjects (n=9) and thalassemia patients (n=13) receiving long-term blood transfusion therapy underwent MRI-CS and MRI measurements of the cardiac relaxation rate R2*. Using MRI-CS, subepicardium and subendocardium iron concentrations were quantified exploiting the hemosiderin/ferritin iron specific magnetic susceptibility. The average of subepicardium and subendocardium iron concentrations and R2* of the septum were found to be strongly correlated (r=0.96, P<.0001), and linear regression analysis yielded CIC (μg Fe/g_{wet tissue})=(6.4±0.4)·R2* _septum (s⁻¹) − (120±40). The results demonstrated that septal R2* indeed measures cardiac iron level.

Keywords: Iron overload, Heart, Thalassemia, Magnetic susceptibility, R2*, MRI