title: MR quantitative susceptibility imaging for the evaluation of iron loading in the brains of patients with β-thalassemia major.
abstract: OBJECTIVE
  Patients with β-thalassemia require blood transfusion to prolong their survival, which could cause iron overload in multiple organs, including the heart, liver, and brain. In this study, we aimed to quantify iron loading in the brains of patients with β-thalassemia major through the use of MR quantitative susceptibility imaging.
  
  
  METHODS
  Thirty-one patients with thalassemia with a mean (± standard deviation) age of 25.3 (±5.9) years and 33 age-matched healthy volunteers were recruited and underwent MR imaging at 3T. Quantitative susceptibility images were reconstructed from a 3D gradient-echo sequence. Susceptibility values were measured in the caudate nucleus, putamen, globus pallidus, red nucleus, substantia nigra, dentate nucleus, and choroid plexus. General linear model analyses were performed to compare susceptibility values of different ROIs between the patients with thalassemia and healthy volunteers.
  
  
  RESULTS
  Of the 31 patients, 27 (87.1%) had abnormal iron deposition in one of the ROIs examined. Significant positive age effect on susceptibility value was found in the putamen, dentate nucleus, substantia nigra, and red nucleus (P = .002, P = .017, P = .044, and P = .014, respectively) in the control subjects. Compared with healthy control subjects, patients with thalassemia showed significantly lower susceptibility value in the globus pallidus (P < .001) and substantia nigra (P = .003) and significantly higher susceptibility value in the red nucleus (P = .021) and choroid plexus (P < .001).
  
  
  CONCLUSIONS
  A wide range of abnormal susceptibility values, indicating iron overloading or low iron content, was found in patients with thalassemia. MR susceptibility imaging is a sensitive method for quantifying iron concentration in the brain and can be used as a potentially valuable tool for brain iron assessment.
authors.affiliation: From the Departments of Diagnostic Radiology (D.Q, P.-L.K.)Department of Radiology and Imaging Sciences (D.Q.), Emory University, Atlanta, Georgia qiudeqiang@gmail.com plkhong@hkucc.hku.hk.
authors.forename: D
authors.initials: D
authors.lastname: Qiu
authors.affiliation: Pediatrics and Adolescent Medicine (G.C.-F.C., S.-Y.H.), The University of Hong Kong, Hong Kong, China.
authors.forename: G C-F
authors.initials: GC
authors.lastname: Chan
authors.affiliation: Department of Radiology (J.C.), First Affiliated Hospital of Sun Yat Sen University, Guangzhou, China.
authors.forename: J
authors.initials: J
authors.lastname: Chu
authors.affiliation: Philips Healthcare Hong Kong (Q.C.), Hong Kong, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Chan
authors.affiliation: Pediatrics and Adolescent Medicine (G.C.-F.C., S.-Y.H.), The University of Hong Kong, Hong Kong, China.
authors.forename: S-Y
authors.initials: SY
authors.lastname: Ha
authors.affiliation: Department of Radiology (M.E.M.), Stanford University, Stanford, California.
authors.forename: M E
authors.initials: ME
authors.lastname: Moseley
authors.affiliation: From the Departments of Diagnostic Radiology (D.Q, P.-L.K.) qiudeqiang@gmail.com plkhong@hkucc.hku.hk.
authors.forename: P-L
authors.initials: PL
authors.lastname: Khong
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D002614:Chelating Agents / Q000627:therapeutic use; D003676:Deferoxamine / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007501:Iron / Q000378:metabolism*; D019190:Iron Overload / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism* / Q000517:prevention & control; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D057054:Molecular Imaging / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014018:Tissue Distribution; D016896:Treatment Outcome; D055815:Young Adult; D017086:beta-Thalassemia / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism* / Q000517:prevention & control
chemical_list: D002614:Chelating Agents; D007501:Iron; D003676:Deferoxamine