title: Accurate liver T2 measurement of iron overload: a simulations investigation and in vivo study.
abstract: OBJECTIVE
  To investigate the accuracy of T 2 liver iron quantification using different curve-fitting models under varying acquisition conditions, and to compare in iron-overloaded patients the reliability of rapid T 2 measurements against approved and slower T(2) protocols.
  
  
  METHODS
  Simulations were conducted to assess the influence of various factors on the accuracy of T 2 measurement: curve-fitting model, signal-to-noise ratio (SNR), and echo time (TE) spacing. Fifty-four iron-overloaded pediatric patients were assessed using a standard T(2) and two variations of T 2 acquisitions. In both simulations and in vivo data, three analysis models were evaluated: monoexponential, constant offset, and truncated.
  
  
  RESULTS
  Simulations show the truncated model provides the best accuracy but is susceptible to underestimating high iron species under low SNR or high minimum TE. In contrast, the offset model tends to overestimate but maintains the most reliable measurements across the relevant range of iron levels. Furthermore, a much lower SNR can be tolerated if the acquisition uses a low minimum TE. In vivo results confirm theoretical findings and show that T 2 measurements can be as reliable as those from approved and slower T(2) protocols.
  
  
  CONCLUSIONS
  Guidelines are provided on choosing an appropriate model under specific noise conditions and acquisition schemes to ensure accurate and rapid T2 liver iron quantification.
authors.affiliation: The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Marine
authors.initials: M
authors.lastname: Beaumont
authors.forename: Isaac
authors.initials: I
authors.lastname: Odame
authors.forename: Paul S
authors.initials: PS
authors.lastname: Babyn
authors.forename: Logi
authors.initials: L
authors.lastname: Vidarsson
authors.forename: Melanie
authors.initials: M
authors.lastname: Kirby-Allen
authors.forename: Hai-Ling Margaret
authors.initials: HL
authors.lastname: Cheng
mesh_terms: D000293:Adolescent; D000465:Algorithms; D003198:Computer Simulation; D005260:Female; D006801:Humans; D019190:Iron Overload / Q000175:diagnosis*; D008099:Liver / Q000737:chemistry*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012016:Reference Values