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Bai M, Xiong Z, Zhang Y, Wang Z, Zeng X. Associations between quantitative susceptibility mapping with male obstructive sleep apnea clinical and imaging markers. Sleep Med 2024; 124:154-161. [PMID: 39303362 DOI: 10.1016/j.sleep.2024.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 08/31/2024] [Accepted: 09/12/2024] [Indexed: 09/22/2024]
Abstract
PURPOSE To quantitatively measure and compare whole-brain iron deposition between OSA patients and a healthy control group, we initially utilized QSM and evaluated its correlation with PSG results and cognitive function. MATERIALS AND METHODS A total of 28 OSA patients and 22 healthy control subjects matched in age, education level, and BMI were enrolled in our study. Each participant underwent scanning with 3D T1 and multi-echo GRE sequences. Additionally, PSG results were collected from OSA patients, and they underwent simple cognitive assessments. Finally, we analyzed the relationship between iron content in different brain regions, PSG results, and cognitive ability. RESULTS In OSA patients, iron content increased in the left temporal-pole-sup and right putamen, while it decreased in the left fusiform gyrus, left middle temporal gyrus, right inferior occipital gyrus, and right superior temporal gyrus. The correlation analysis between brain iron content and PSG results/cognitive scales is as follows: left fusiform gyrus and MMSE (r = -0.416, p = 0.028); right superior temporal gyrus and MMSE (r = 0.422, p = 0.025); left middle temporal gyrus and average oxygen saturation (r = -0.418, p = 0.027); left temporal-pole-sup and REM stage (rs = 0.466, p = 0.012); the right putamen and N1 stage (rs = 0.393. p = 0.039). Moreover, both MoCA (r = 0.598, p = 0.001) and MMSE (r = 0.456, p = 0.015) show a positive correlation with average oxygen saturation. CONCLUSION This study is the first to use QSM technology to show abnormal brain iron levels in OSA. Correlations between brain iron content, PSG, and cognition in OSA may reveal neuropathological mechanisms, aiding OSA diagnosis.
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Affiliation(s)
- Mingxian Bai
- GuiZhou University Medical College, Guiyang, China; Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Zhenliang Xiong
- Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China; College of Computer Science and Technology, Guizhou University, Guiyang, China
| | - Yan Zhang
- Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China; College of Computer Science and Technology, Guizhou University, Guiyang, China
| | - Zhongxin Wang
- Department of Pulmonary and Critical Care Medicine, Guizhou Provincial People's Hospital, Guiyang, China
| | - Xianchun Zeng
- GuiZhou University Medical College, Guiyang, China; Department of Radiology, Guizhou Provincial People's Hospital, Guiyang, China.
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Kang M, Behr GG, Jafari R, Gambarin M, Otazo R, Kee Y. Free-breathing high isotropic resolution quantitative susceptibility mapping (QSM) of liver using 3D multi-echo UTE cones acquisition and respiratory motion-resolved image reconstruction. Magn Reson Med 2023; 90:1844-1858. [PMID: 37392413 PMCID: PMC10529485 DOI: 10.1002/mrm.29779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/15/2023] [Accepted: 06/06/2023] [Indexed: 07/03/2023]
Abstract
PURPOSE To enable free-breathing and high isotropic resolution liver quantitative susceptibility mapping (QSM) using 3D multi-echo UTE cones acquisition and respiratory motion-resolved image reconstruction. METHODS Using 3D multi-echo UTE cones MRI, a respiratory motion was estimated from the k-space center of the imaging data. After sorting the k-space data with estimated motion, respiratory motion state-resolved reconstruction was performed for multi-echo data followed by nonlinear least-squares fitting for proton density fat fraction (PDFF),R 2 * $$ {\mathrm{R}}_2^{\ast } $$ , and fat-corrected B0 field maps. PDFF and B0 field maps were subsequently used for QSM reconstruction. The proposed method was compared with motion-averaged (gridding) reconstruction and conventional 3D multi-echo Cartesian MRI in moving gadolinium phantom and in vivo studies. Region of interest (ROI)-based linear regression analysis was performed on these methods to investigate correlations between gadolinium concentration and QSM in the phantom study and betweenR 2 * $$ {\mathrm{R}}_2^{\ast } $$ and QSM in in vivo study. RESULTS Cones with motion-resolved reconstruction showed sharper image quality compared to motion-averaged reconstruction with a substantial reduction of motion artifacts in both moving phantom and in vivo studies. For ROI-based linear regression analysis of the phantom study, susceptibility values from cones with motion-resolved reconstruction (QSM ppm $$ {\mathrm{QSM}}_{\mathrm{ppm}} $$ = 0.31 × gadolinium mM + $$ \times {\mathrm{gadolinium}}_{\mathrm{mM}}+ $$ 0.05,R 2 $$ {R}^2 $$ = 0.999) and Cartesian without motion (QSM ppm $$ {\mathrm{QSM}}_{\mathrm{ppm}} $$ = 0.32× gadolinium mM + $$ \times {\mathrm{gadolinium}}_{\mathrm{mM}}+ $$ 0.04,R 2 $$ {R}^2 $$ = 1.000) showed linear relationships with gadolinium concentrations and showed good agreement with each other. For in vivo, motion-resolved reconstruction showed higher goodness of fit (QSM ppm $$ {\mathrm{QSM}}_{\mathrm{ppm}} $$ = 0.00261 × R 2 s - 1 * - $$ \times {\mathrm{R}}_{2_{{\mathrm{s}}^{-1}}}^{\ast }- $$ 0.524,R 2 $$ {R}^2 $$ = 0.977) compared to motion-averaged reconstruction (QSM ppm $$ {\mathrm{QSM}}_{\mathrm{ppm}} $$ = 0.0021 × R 2 s - 1 * - $$ \times {\mathrm{R}}_{2_{{\mathrm{s}}^{-1}}}^{\ast }- $$ 0.572,R 2 $$ {R}^2 $$ = 0.723) in ROI-based linear regression analysis betweenR 2 * $$ {\mathrm{R}}_2^{\ast } $$ and QSM. CONCLUSION Feasibility of free-breathing liver QSM was demonstrated with motion-resolved 3D multi-echo UTE cones MRI, achieving high isotropic resolution currently unachievable in conventional Cartesian MRI.
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Affiliation(s)
- MungSoo Kang
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Gerald G. Behr
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Ramin Jafari
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Maya Gambarin
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Ricardo Otazo
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Youngwook Kee
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
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Wang C, Reeder SB, Hernando D. Relaxivity-iron calibration in hepatic iron overload: Reproducibility and extension of a Monte Carlo model. NMR IN BIOMEDICINE 2021; 34:e4604. [PMID: 34462976 PMCID: PMC9019851 DOI: 10.1002/nbm.4604] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 07/12/2021] [Accepted: 08/01/2021] [Indexed: 05/04/2023]
Abstract
The aim of this study was to reproduce relaxivity-iron calibration in hepatic iron overload using a Monte Carlo model, and further extend the model with multiple spin echo (MSE) imaging. As previously reported, relationships between relaxation rates ( R2* and single spin echo R2 ) and liver iron concentration (LIC) can be characterized by a Monte Carlo model incorporating realistic liver structure, iron distribution, and proton mobility. In this study, relaxivity-iron calibration curves at 1.5 and 3.0 T were simulated using the Monte Carlo model. Furthermore, the model was extended with MSE imaging, and iron calibrations were evaluated using two different fitting models: mononexponential with a constant offset and nonmonoexponential. Results consistent with previous empirical calibrations and Monte Carlo predictions were accurately reproduced for relaxivity-iron calibration. The predicted R2* and single spin echo R2 increased by a factor of 2.00 and 1.51, respectively, at 1.5 versus 3.0 T. MSE signals and their corresponding R2 depended strongly on LIC, interecho time, and field strength. Preliminary results showed that a nonmonoexponential model accurately characterizes the simulated MSE signals, and that strong correlations were found between predicted relaxation parameters and LIC. In conclusion, relaxivity-iron calibration is reproducible using the proposed Monte Carlo model. Furthermore, this model can be readily extended to other important applications, including predicting signal behavior for MSE imaging.
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Affiliation(s)
- Changqing Wang
- School of Biomedical Engineering, Anhui Medical University, Hefei, China
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
| | - Scott B. Reeder
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
- Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, USA
- Department of Medicine, University of Wisconsin, Madison, Wisconsin, USA
- Department of Emergency Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - Diego Hernando
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
- Corresponding author: Diego Hernando, PhD, Room 2474, Wisconsin Institutes for Medical Research (WIMR-2), 1111 Highland Avenue, Madison, WI 53705, (608) 265-7590,
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Consul N, Javed-Tayyab S, Morani AC, Menias CO, Lubner MG, Elsayes KM. Iron-containing pathologies of the spleen: magnetic resonance imaging features with pathologic correlation. Abdom Radiol (NY) 2021; 46:1016-1026. [PMID: 32915270 DOI: 10.1007/s00261-020-02709-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/17/2020] [Accepted: 07/25/2020] [Indexed: 12/13/2022]
Abstract
Systemic and non-systemic pathologies that involve iron deposition within the spleen have characteristic features on MRI due to the susceptibility properties of deposited iron, or hemosiderin. These lesions will have signal loss on longer echo sequences due to the T2* effect when evaluated with dual-echo gradient-echo sequences. The pathophysiology of systemic and localized iron sequestration disease processes can elucidate an underlying diagnosis based on these imaging features in conjunction with clinical information.
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Affiliation(s)
- Nikita Consul
- Department of Diagnostic Radiology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Sidra Javed-Tayyab
- Department of Radiology, Memorial-Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Ajaykumar C Morani
- Department of Abdominal Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | | | - Meghan G Lubner
- Department of Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI, 53726, USA
| | - Khaled M Elsayes
- Department of Diagnostic Radiology, Mayo Clinic, Scottsdale, AZ, USA.
- Department of Radiology, Unit 1473, The University of Texas MD Anderson Cancer Center, 1400 Pressler Street, Houston, TX, 77030, USA.
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Colgan TJ, Knobloch G, Reeder SB, Hernando D. Sensitivity of quantitative relaxometry and susceptibility mapping to microscopic iron distribution. Magn Reson Med 2020; 83:673-680. [PMID: 31423637 PMCID: PMC7041893 DOI: 10.1002/mrm.27946] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/27/2019] [Accepted: 07/23/2019] [Indexed: 01/19/2023]
Abstract
PURPOSE Determine the impact of the microscopic spatial distribution of iron on relaxometry and susceptibility-based estimates of iron concentration. METHODS Monte Carlo simulations and in vitro experiments of erythrocytes were used to create different microscopic distributions of iron. Measuring iron with intact erythrocyte cells created a heterogeneous distribution of iron, whereas lysing erythrocytes was used to create a homogeneous distribution of iron. Multi-echo spin echo and spoiled gradient echo acquisitions were then used to estimate relaxation parameters ( R 2 and R 2 * ) and susceptibility. RESULTS Simulations demonstrate that R 2 and R 2 * measurements depend on the spatial distribution of iron even for the same iron concentration and volume susceptibility. Similarly, in vitro experiments demonstrate that R 2 and R 2 * measurements depend on the microscopic spatial distribution of iron whereas the quantitative susceptibility mapping (QSM) susceptibility estimates reflect iron concentration without sensitivity to spatial distribution. CONCLUSIONS R 2 and R 2 * for iron quantification depend on the spatial distribution or iron. QSM-based estimation of iron concentration is insensitive to the microscopic spatial distribution of iron, potentially providing a distribution independent measure of iron concentration.
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Affiliation(s)
- Timothy J. Colgan
- Department of Radiology, University of Wisconsin, Madison, Wisconsin
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin
| | - Gesine Knobloch
- Department of Radiology, University of Wisconsin, Madison, Wisconsin
| | - Scott B. Reeder
- Department of Radiology, University of Wisconsin, Madison, Wisconsin
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin
- Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin
- Department of Medicine, University of Wisconsin, Madison, Wisconsin
- Department of Emergency Medicine, University of Wisconsin, Madison, Wisconsin
| | - Diego Hernando
- Department of Radiology, University of Wisconsin, Madison, Wisconsin
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin
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Barrera CA, Khrichenko D, Serai SD, Hartung HD, Biko DM, Otero HJ. Biexponential R2* relaxometry for estimation of liver iron concentration in children: A better fit for high liver iron states. J Magn Reson Imaging 2019; 50:1191-1198. [PMID: 30950562 DOI: 10.1002/jmri.26735] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/15/2019] [Accepted: 03/18/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND R2* relaxometry's capacity to calculate liver iron concentration (LIC) is limited in patients with severe overload. Hemosiderin increases in these patients, which exhibits a non-monoexponential decay that renders a failed R2* analysis. PURPOSE/HYPOTHESIS To evaluate a biexponential R2* relaxometry model in children with different ranges of iron overload. STUDY TYPE Retrospective. POPULATION In all, 181 children with different conditions associated with iron overload. FIELD STRENGTH/SEQUENCE 1.5T, T2 *-weighted gradient echo sequence. ASSESSMENT Bi- and monoexponential R2* relaxometry were measured in the liver using two regions of interest (ROIs) using a nonproprietary software: one encompassing the whole liver parenchyma (ROI-1) and the other only the periphery (ROI-2). These were drawn by a single trained observer. The residuals for each fitting model were estimated. A ratio between the residuals of the mono- and biexponential models was calculated to identify the best fitting model. Patients with 1) residual ratio ≥1.5 and 2) R2*fast ≥R2*slow were considered as having a predominant biexponential behavior. STATISTICAL TESTS Nonparametric tests, Bland-Altman plots, linear correlation, intraclass correlation coefficient. Patients were divided according to their LIC into stable (n = 23), mild (n = 58), moderate (n = 61), and severe (n = 39). RESULTS The biexponential model was more suitable for patients with severe iron overload when compared with the other three LIC categories (P < 0.001) for both ROIs. For ROI-1, 37 subjects met criteria for a predominant biexponential behavior. The slow component (5.7%) had a lower fraction than the fast component (94.2%). For ROI-2, 22 subjects met criteria for a predominant biexponential behavior. The slow component (4.7%) had a lower fraction than the fast component (95.2%). The intraobserver variability between both ROIs was excellent. DATA CONCLUSION The biexponential R2* relaxometry model is more suitable in children with severe iron overload. LEVEL OF EVIDENCE 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:1191-1198.
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Affiliation(s)
- Christian A Barrera
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Dmitry Khrichenko
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Suraj D Serai
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Helge D Hartung
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - David M Biko
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Hansel J Otero
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
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Why should neuroscientists worry about iron? The emerging role of ferroptosis in the pathophysiology of neuroprogressive diseases. Behav Brain Res 2017; 341:154-175. [PMID: 29289598 DOI: 10.1016/j.bbr.2017.12.036] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 12/23/2017] [Accepted: 12/27/2017] [Indexed: 12/12/2022]
Abstract
Ferroptosis is a unique form of programmed death, characterised by cytosolic accumulation of iron, lipid hydroperoxides and their metabolites, and effected by the fatal peroxidation of polyunsaturated fatty acids in the plasma membrane. It is a major driver of cell death in neurodegenerative neurological diseases. Moreover, cascades underpinning ferroptosis could be active drivers of neuropathology in major psychiatric disorders. Oxidative and nitrosative stress can adversely affect mechanisms and proteins governing cellular iron homeostasis, such as the iron regulatory protein/iron response element system, and can ultimately be a source of abnormally high levels of iron and a source of lethal levels of lipid membrane peroxidation. Furthermore, neuroinflammation leads to the upregulation of divalent metal transporter1 on the surface of astrocytes, microglia and neurones, making them highly sensitive to iron overload in the presence of high levels of non-transferrin-bound iron, thereby affording such levels a dominant role in respect of the induction of iron-mediated neuropathology. Mechanisms governing systemic and cellular iron homeostasis, and the related roles of ferritin and mitochondria are detailed, as are mechanisms explaining the negative regulation of ferroptosis by glutathione, glutathione peroxidase 4, the cysteine/glutamate antiporter system, heat shock protein 27 and nuclear factor erythroid 2-related factor 2. The potential role of DJ-1 inactivation in the precipitation of ferroptosis and the assessment of lipid peroxidation are described. Finally, a rational approach to therapy is considered, with a discussion on the roles of coenzyme Q10, iron chelation therapy, in the form of deferiprone, deferoxamine (desferrioxamine) and deferasirox, and N-acetylcysteine.
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Genetically encoded iron-associated proteins as MRI reporters for molecular and cellular imaging. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2017; 10. [DOI: 10.1002/wnan.1482] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 04/18/2017] [Accepted: 05/04/2017] [Indexed: 02/06/2023]
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Coates TD, Carson S, Wood JC, Berdoukas V. Management of iron overload in hemoglobinopathies: what is the appropriate target iron level? Ann N Y Acad Sci 2017; 1368:95-106. [PMID: 27186942 DOI: 10.1111/nyas.13060] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/04/2016] [Accepted: 03/09/2016] [Indexed: 01/19/2023]
Abstract
Patients with thalassemia become iron overloaded from increased absorption of iron, ineffective erythropoiesis, and chronic transfusion. Before effective iron chelation became available, thalassemia major patients died of iron-related cardiac failure in the second decade of life. Initial treatment goals for chelation therapy were aimed at levels of ferritin and liver iron concentrations associated with prevention of adverse cardiac outcomes and avoidance of chelator toxicity. Cardiac deaths were greatly reduced and survival was much longer. Epidemiological data from the general population draw clear associations between increased transferrin saturation (and, by inference, labile iron) and early death, diabetes, and malignant transformation. The rate of cancers now seems to be significantly higher in thalassemia than in the general population. Reduction in iron can reverse many of these complications and reduce the risk of malignancy. As toxicity can result from prolonged exposure to even low levels of excess iron, and survival in thalassemia patients is now many decades, it would seem prudent to refocus attention on prevention of long-term complications of iron overload and to maintain labile iron and total body iron levels within a normal range, if expertise and resources are available to avoid complications of overtreatment.
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Affiliation(s)
- Thomas D Coates
- Section of Hematology, Children's Center for Cancer, Blood Diseases and Bone Marrow Transplantation
| | - Susan Carson
- Section of Hematology, Children's Center for Cancer, Blood Diseases and Bone Marrow Transplantation
| | - John C Wood
- Division of Cardiology, Children's Hospital Los Angeles, University of Southern California, Keck School of Medicine, Los Angeles, California
| | - Vasilios Berdoukas
- Section of Hematology, Children's Center for Cancer, Blood Diseases and Bone Marrow Transplantation
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10
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Walker T, Michaelides C, Ekonomou A, Geraki K, Parkes HG, Suessmilch M, Herlihy AH, Crum WR, So PW. Dissociation between iron accumulation and ferritin upregulation in the aged substantia nigra: attenuation by dietary restriction. Aging (Albany NY) 2016; 8:2488-2508. [PMID: 27743512 PMCID: PMC5115902 DOI: 10.18632/aging.101069] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/26/2016] [Indexed: 01/13/2023]
Abstract
Despite regulation, brain iron increases with aging and may enhance aging processes including neuroinflammation. Increases in magnetic resonance imaging transverse relaxation rates, R2 and R2*, in the brain have been observed during aging. We show R2 and R2* correlate well with iron content via direct correlation to semi-quantitative synchrotron-based X-ray fluorescence iron mapping, with age-associated R2 and R2* increases reflecting iron accumulation. Iron accumulation was concomitant with increased ferritin immunoreactivity in basal ganglia regions except in the substantia nigra (SN). The unexpected dissociation of iron accumulation from ferritin-upregulation in the SN suggests iron dyshomeostasis in the SN. Occurring alongside microgliosis and astrogliosis, iron dyshomeotasis may contribute to the particular vulnerability of the SN. Dietary restriction (DR) has long been touted to ameliorate brain aging and we show DR attenuated age-related in vivo R2 increases in the SN over ages 7 - 19 months, concomitant with normal iron-induction of ferritin expression and decreased microgliosis. Iron is known to induce microgliosis and conversely, microgliosis can induce iron accumulation, which of these may be the initial pathological aging event warrants further investigation. We suggest iron chelation therapies and anti-inflammatory treatments may be putative 'anti-brain aging' therapies and combining these strategies may be synergistic.
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Affiliation(s)
- Thomas Walker
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Christos Michaelides
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Antigoni Ekonomou
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Kalotina Geraki
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - Harold G Parkes
- CR-UK Clinical MR Research Group, Institute of Cancer Research, London, United Kingdom
| | - Maria Suessmilch
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | | | - William R Crum
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Po-Wah So
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
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Comparison of myocardial T1 and T2 values in 3 T with T2* in 1.5 T in patients with iron overload and controls. Int J Hematol 2016; 103:530-6. [PMID: 26872908 DOI: 10.1007/s12185-016-1950-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 01/26/2016] [Accepted: 01/26/2016] [Indexed: 12/31/2022]
Abstract
Myocardial iron quantification remains limited to 1.5 T systems with T2* measurement. The present study aimed at comparing myocardial T2* values at 1.5 T to T1 and T2 mapping at 3.0 T in patients with iron overload and healthy controls. A total of 17 normal volunteers and seven patients with a history of myocardial iron overload were prospectively enrolled. Mid-interventricular septum T2*, native T1 and T2 times were quantified on the same day, using a multi-echo gradient-echo sequence at 1.5 T and T1 and T2 mapping sequences at 3.0 T, respectively. Subjects with myocardial iron overload (T2* < 20 ms) in comparison with those without had significantly lower mean myocardial T1 times (868.9 ± 120.2 vs. 1170.3 ± 25.0 ms P = 0.005 respectively) and T2 times (34.9 ± 4.7 vs. 45.1 ± 2.0 ms P = 0.007 respectively). 3 T T1 and T2 times strongly correlated with 1.5 T, T2* times (Pearson's r = 0.95 and 0.91 respectively). T1 and T2 measures presented less variability than T2* in inter- and intra-observer analysis. Native myocardial T1 and T2 times at 3 T correlate closely with T2* times at 1.5 T and may be useful for myocardial iron overload quantification.
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12
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Puliyel M, Mainous AG, Berdoukas V, Coates TD. Iron toxicity and its possible association with treatment of Cancer: lessons from hemoglobinopathies and rare, transfusion-dependent anemias. Free Radic Biol Med 2015; 79:343-51. [PMID: 25463277 DOI: 10.1016/j.freeradbiomed.2014.10.861] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 10/22/2014] [Accepted: 10/30/2014] [Indexed: 01/19/2023]
Abstract
Exposure to elevated levels of iron causes tissue damage and organ failure, and increases the risk of cancer. The toxicity of iron is mediated through generation of oxidants. There is also solid evidence indicating that oxidant stress plays a significant role in a variety of human disease states, including malignant transformation. Iron toxicity is the main focus when managing thalassemia. However, the short- and long-term toxicities of iron have not been extensively considered in children and adults treated for malignancy, and only recently have begun to draw oncologists' attention. The treatment of malignancy can markedly increase exposure of patients to elevated toxic iron species without the need for excess iron input from transfusion. This under-recognized exposure likely enhances organ toxicity and may contribute to long-term development of secondary malignancy and organ failure. This review discusses the current understanding of iron metabolism, the mechanisms of production of toxic free iron species in humans, and the relation of the clinical marker, transferrin saturation (TS), to the presence of toxic free iron. We will present epidemiological data showing that high TS is associated with poor outcomes and development of cancer, and that lowering free iron may improve outcomes. Finally, we will discuss the possible relation between some late complications seen in survivors of cancer and those due to iron toxicity.
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Affiliation(s)
- Mammen Puliyel
- Section of Hematology, Childrens Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles California, USA
| | - Arch G Mainous
- Department of Health Services Research, Management and Policy, University of Florida, Gainesville, Fla. USA
| | - Vasilios Berdoukas
- Section of Hematology, Childrens Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles California, USA
| | - Thomas D Coates
- Section of Hematology, Childrens Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles California, USA.
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13
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Adachi Y, Sato N, Saito Y, Kimura Y, Nakata Y, Ito K, Kamiya K, Matsuda H, Tsukamoto T, Ogawa M. Usefulness of SWI for the Detection of Iron in the Motor Cortex in Amyotrophic Lateral Sclerosis. J Neuroimaging 2014; 25:443-51. [PMID: 24888543 DOI: 10.1111/jon.12127] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 01/07/2014] [Accepted: 03/02/2014] [Indexed: 11/28/2022] Open
Abstract
PURPOSE The purpose of the present retrospective study was to evaluate the sensitivity of susceptibility-weighted imaging (SWI) compared to conventional spin-echo T2-weighted and T2*-weighted images in detecting iron deposition in the motor cortex of amyotrophic lateral sclerosis (ALS) patients in comparison with age-matched normal controls. We also investigated the etiology of the low signal referring to the pathology of one autopsy case. METHODS This retrospective magnetic resonance (MR) study included 23 ALS patients and 28 age-matched normal controls. The signal intensity of the motor cortex was scored by SWI, conventional T2-weighted images and T2*-weighted images. A postmortem study of one patient was also performed. RESULTS On SWI, there was a significant difference between the precentral cortical signal intensity scores in the ALS patients and the controls (P < .0001). The total scores of signal intensities of the precentral cortex were positively correlated with age in the normal controls (r = .494), but no correlation was observed in the ALS patients. The postmortem study showed intensely stained microglias and macrophages after antiferritin antibody staining in the precentral cortices. CONCLUSIONS Decreased signal intensity of the motor cortex on SWI may serve a useful role in ALS diagnoses, particularly in young patients. MR images were also helpful for speculating on the etiology of ALS.
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Affiliation(s)
- Yuko Adachi
- National Center Hospital of Neurology and Psychiatry Radiology, Kodaira, Tokyo, Japan
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14
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Abstract
Liver fat, iron, and combined overload are common manifestations of diffuse liver disease and may cause lipotoxicity and iron toxicity via oxidative hepatocellular injury, leading to progressive fibrosis, cirrhosis, and eventually, liver failure. Intracellular fat and iron cause characteristic changes in the tissue magnetic properties in predictable dose-dependent manners. Using dedicated magnetic resonance pulse sequences and postprocessing algorithms, fat and iron can be objectively quantified on a continuous scale. In this article, we will describe the basic physical principles of magnetic resonance fat and iron quantification and review the imaging techniques of the "past, present, and future." Standardized radiological metrics of fat and iron are introduced for numerical reporting of overload severity, which can be used toward objective diagnosis, grading, and longitudinal disease monitoring. These noninvasive imaging techniques serve an alternative or complimentary role to invasive liver biopsy. Commercial solutions are increasingly available, and liver fat and iron quantitative imaging is now within reach for routine clinical use and may soon become standard of care.
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Affiliation(s)
- Takeshi Yokoo
- From the *Department of Radiology, †Advanced Imaging Research Center, and ‡Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
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15
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Tang H, Jensen JH, Sammet CL, Sheth S, Swaminathan SV, Hultman K, Kim D, Wu EX, Brown TR, Brittenham GM. MR characterization of hepatic storage iron in transfusional iron overload. J Magn Reson Imaging 2013; 39:307-16. [PMID: 23720394 DOI: 10.1002/jmri.24171] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 03/15/2013] [Indexed: 01/09/2023] Open
Abstract
PURPOSE To quantify the two principal forms of hepatic storage iron, diffuse, soluble iron (primarily ferritin), and aggregated, insoluble iron (primarily hemosiderin) using a new MRI method in patients with transfusional iron overload. MATERIALS AND METHODS Six healthy volunteers and 20 patients with transfusion-dependent thalassemia syndromes and iron overload were examined. Ferritin- and hemosiderin-like iron were determined based on the measurement of two distinct relaxation parameters: the "reduced" transverse relaxation rate, RR2 , and the "aggregation index," A, using three sets of Carr-Purcell-Meiboom-Gill (CPMG) datasets with different interecho spacings. Agarose phantoms, simulating the relaxation and susceptibility properties of tissue with different concentrations of dispersed (ferritin-like) and aggregated (hemosiderin-like) iron, were used for validation. RESULTS Both phantom and in vivo human data confirmed that transverse relaxation components associated with the dispersed and aggregated iron could be separated using the two-parameter (RR2 , A) method. The MRI-determined total hepatic storage iron was highly correlated (r = 0.95) with measurements derived from biopsy or biosusceptometry. As total hepatic storage iron increased, the proportion stored as aggregated iron became greater. CONCLUSION This method provides a new means for noninvasive MRI determination of the partition of hepatic storage iron between ferritin and hemosiderin in iron overload disorders.
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Affiliation(s)
- Haiying Tang
- Imaging, Discovery Medicine & Clinical Pharmacology, Bristol Myers Squibb, Princeton, New Jersey, USA
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16
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Sammet CL, Swaminathan SV, Tang H, Sheth S, Jensen JH, Nunez A, Hultman K, Kim D, Wu EX, Brittenham GM, Brown TR. Measurement and correction of stimulated echo contamination in T2-based iron quantification. Magn Reson Imaging 2012; 31:664-8. [PMID: 23260394 DOI: 10.1016/j.mri.2012.10.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 10/11/2012] [Accepted: 10/30/2012] [Indexed: 11/17/2022]
Abstract
The purpose of this study was to characterize the effects of stimulated echo contamination on MR-based iron measurement derived from quantitative T2 images and develop a method for retrospective correction. Two multiple spin-echo (MSE) pulse sequences were implemented with different amounts of stimulated echo contamination. Agarose-based phantoms were constructed that simulate the relaxation and susceptibility properties of tissue with different concentrations of dispersed (ferritin-like) and aggregated (hemosiderin-like) iron. Additionally, myocardial iron was assessed in nine human subjects with transfusion iron overload. These data were used to determine the influence of stimulated echoes on iron measurements made by an MR-based iron quantification model that can separately measure dispersed and aggregated iron. The study found that stimulated echo contamination caused an underestimation of dispersed (ferritin-like) iron and an overestimation of aggregated (hemosiderin-like) iron when applying this model. The relationship between the measurements made with and without stimulated echo appears to be linear. The findings suggest that while it is important to use MSE sequences with minimal stimulated echo in T2-based iron quantification, it appears that data acquired with sub-optimal sequences can be retrospectively corrected using the methodology described here.
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17
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Nienhuis AW, Nathan DG. Pathophysiology and Clinical Manifestations of the β-Thalassemias. Cold Spring Harb Perspect Med 2012; 2:a011726. [PMID: 23209183 DOI: 10.1101/cshperspect.a011726] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The β-thalassemia syndromes reflect deficient or absent β-globin synthesis usually owing to a mutation in the β-globin locus. The relative excess of α-globin results in the formation of insoluble aggregates leading to ineffective erythropoiesis and shortened red cell survival. A relatively high capacity for fetal hemoglobin synthesis is a major genetic modifier of disease severity, with polymorphisms in other genes also having a significant role. Iron overload secondary to enhanced absorption and red cell transfusions causes an increase in liver iron and in various other tissues, leading to endocrine and cardiac dysfunction. Modern chelation regimens are effective in removing iron and preserving or restoring organ function.
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Affiliation(s)
- Arthur W Nienhuis
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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18
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Naumova AV, Yarnykh VL, Balu N, Reinecke H, Murry CE, Yuan C. Quantification of MRI signal of transgenic grafts overexpressing ferritin in murine myocardial infarcts. NMR IN BIOMEDICINE 2012; 25:1187-95. [PMID: 22362654 PMCID: PMC3389131 DOI: 10.1002/nbm.2788] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 11/28/2011] [Accepted: 01/15/2012] [Indexed: 05/16/2023]
Abstract
The noninvasive detection of transplanted cells in damaged organs and the longitudinal follow-up of cell fate and graft size are important for the evaluation of cell therapy. We have shown previously that the overexpression of the natural iron storage protein, ferritin, permits the detection of engrafted cells in mouse heart by MRI, but further imaging optimization is required. Here, we report a systematic evaluation of ferritin-based stem cell imaging in infarcted mouse hearts in vivo using three cardiac-gated pulse sequences in a 3-T scanner: black-blood proton-density-weighted turbo spin echo (PD TSE BB), bright-blood T(2) -weighted gradient echo (GRE) and black-blood T(2) -weighted GRE with improved motion-sensitized-driven equilibrium (iMSDE) preparation. Transgenic C2C12 myoblast grafts overexpressing ferritin did not change MRI contrast in the PD TSE BB images, but showed a 20% reduction in signal intensity ratio in black-blood T(2) -weighted iMSDE (p < 0.05) and a 30% reduction in bright-blood T(2) -weighted GRE (p < 0.0001). Graft size measurements by T(2) iMSDE and T(2) GRE were highly correlated with histological assessments (r = 0.79 and r = 0.89, respectively). Unlabeled wild-type C2C12 cells transplanted to mouse heart did not change the MRI signal intensity, although endogenous hemosiderin was seen in some infarcts. These data support the use of ferritin to track the survival, growth and migration of stem cells transplanted into the injured heart.
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Affiliation(s)
- Anna V Naumova
- Department of Radiology, University of Washington, Seattle, WA, USA.
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Taylor BA, Loeffler RB, Song R, McCarville MB, Hankins JS, Hillenbrand CM. Simultaneous field and R2 mapping to quantify liver iron content using autoregressive moving average modeling. J Magn Reson Imaging 2011; 35:1125-32. [PMID: 22180325 DOI: 10.1002/jmri.23545] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 11/29/2011] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To investigate the use of a complex multigradient echo (mGRE) acquisition and an autoregressive moving average (ARMA) model for simultaneous susceptibility and R 2 measurements for the assessment of liver iron content (LIC) in patients with iron overload. MATERIALS AND METHODS Fifty magnetic resonance imaging (MRI) exams with magnitude and phase mGRE images were processed using the ARMA model, which provides fat-separated field maps, R 2 maps, and T(1) -W imaging. The LIC was calculated by measuring the susceptibility between the liver and the right transverse abdominal muscle from the field maps. The relationship between LIC derived from susceptibility measurements and LIC from R 2 measurements was determined using linear least-squares regression analysis. RESULTS LIC measured from R 2 is highly correlated to the LIC with the susceptibility method (mg/g dry = 8.99 ± 0.15 × [mg Fe/mL of wet liver] -2.38 ± 0.29, R(2) = 0.94). The field inhomogeneity in the liver is correlated with R 2 (R(2) = 0.85). CONCLUSION By using the ARMA model on complex mGRE images, both susceptibility and R 2-based LIC measurements can be made simultaneously. The susceptibility measurement can be used to help verify R 2 measurements in the assessment of iron overload.
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Affiliation(s)
- Brian A Taylor
- Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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Cheung JS, Au WY, Ha SY, Kim D, Jensen JH, Zhou IY, Cheung MM, Wu Y, Guo H, Khong PL, Brown TR, Brittenham GM, Wu EX. Reduced transverse relaxation rate (RR2) for improved sensitivity in monitoring myocardial iron in thalassemia. J Magn Reson Imaging 2011; 33:1510-6. [PMID: 21591022 DOI: 10.1002/jmri.22553] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
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.
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Affiliation(s)
- Jerry S Cheung
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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