Document Detail


Reduced transverse relaxation rate (RR2) for improved sensitivity in monitoring myocardial iron in thalassemia.
MedLine Citation:
PMID:  21591022     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: To evaluate the reduced transverse relaxation rate (RR2), a new relaxation index which has been shown recently to be primarily sensitive to intracellular ferritin iron, as a means of detecting short-term changes in myocardial storage iron produced by iron-chelating therapy in transfusion-dependent thalassemia patients.
MATERIALS AND METHODS: A single-breathhold multi-echo fast spin-echo sequence was implemented at 3 Tesla (T) to estimate RR2 by acquiring signal decays with interecho times of 5, 9 and 13 ms. Transfusion-dependent thalassemia patients (N = 8) were examined immediately before suspending iron-chelating therapy for 1 week (Day 0), after a 1-week suspension of chelation (Day 7), and after a 1-week resumption of chelation (Day 14).
RESULTS: The mean percent changes in RR2, R2, and R2* off chelation (between Day 0 and 7) were 11.9 ± 8.9%, 5.4 ± 7.7% and -4.4 ± 25.0%; and, after resuming chelation (between Day 7 and 14), -10.6 ± 13.9%, -8.9 ± 8.0% and -8.5 ± 24.3%, respectively. Significant differences in R2 and RR2 were observed between Day 0 and 7, and between Day 7 and 14, with the greatest proportional changes in RR2. No significant differences in R2* were found.
CONCLUSION: These initial results demonstrate that significant differences in RR2 are detectable after a single week of changes in iron-chelating therapy, likely as a result of superior sensitivity to soluble ferritin iron, which is in close equilibrium with the chelatable cytosolic iron pool. RR2 measurement may provide a new means of monitoring the short-term effectiveness of iron-chelating agents in patients with myocardial iron overload.
Authors:
Jerry S Cheung; Wing-Yan Au; Shau-Yin Ha; Daniel Kim; Jens H Jensen; Iris Y Zhou; Matthew M Cheung; Yin Wu; Hua Guo; Pek-Lan Khong; Truman R Brown; Gary M Brittenham; Ed X Wu
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of magnetic resonance imaging : JMRI     Volume:  33     ISSN:  1522-2586     ISO Abbreviation:  J Magn Reson Imaging     Publication Date:  2011 Jun 
Date Detail:
Created Date:  2011-05-18     Completed Date:  2011-10-03     Revised Date:  2013-06-28    
Medline Journal Info:
Nlm Unique ID:  9105850     Medline TA:  J Magn Reson Imaging     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1510-6     Citation Subset:  IM    
Copyright Information:
Copyright © 2011 Wiley-Liss, Inc.
Affiliation:
Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
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MeSH Terms
Descriptor/Qualifier:
Adult
Blood Transfusion
Chelating Agents / pharmacology
Chelation Therapy / methods
Cytosol / metabolism
Female
Ferritins / chemistry
Hemosiderin / chemistry
Humans
Iron / chemistry
Magnetic Resonance Imaging / methods
Male
Myocardium / pathology*
Thalassemia / diagnosis,  pathology*
Time Factors
Grant Support
ID/Acronym/Agency:
R01 DK049108-10/DK/NIDDK NIH HHS; R01 DK066251-04/DK/NIDDK NIH HHS; R01 DK069373-03/DK/NIDDK NIH HHS; R01-DK049108/DK/NIDDK NIH HHS; R01-DK066251/DK/NIDDK NIH HHS; R01-DK069373/DK/NIDDK NIH HHS; R37 DK049108-17/DK/NIDDK NIH HHS; R37 DK049108-18/DK/NIDDK NIH HHS; R37-DK049108/DK/NIDDK NIH HHS
Chemical
Reg. No./Substance:
0/Chelating Agents; 7439-89-6/Iron; 9007-73-2/Ferritins; 9011-92-1/Hemosiderin
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