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Kano Y, Uchida Y, Kan H, Sakurai K, Kobayashi S, Seko K, Mizutani K, Usami T, Takada K, Matsukawa N. Assessing white matter microstructural changes in idiopathic normal pressure hydrocephalus using voxel-based R2* relaxometry analysis. Front Neurol 2023; 14:1251230. [PMID: 37731849 PMCID: PMC10507687 DOI: 10.3389/fneur.2023.1251230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 08/22/2023] [Indexed: 09/22/2023] Open
Abstract
Background R2* relaxometry and quantitative susceptibility mapping can be combined to distinguish between microstructural changes and iron deposition in white matter. Here, we aimed to explore microstructural changes in the white matter associated with clinical presentations such as cognitive impairment in patients with idiopathic normal-pressure hydrocephalus (iNPH) using R2* relaxometry analysis in combination with quantitative susceptibility mapping. Methods We evaluated 16 patients clinically diagnosed with possible or probable iNPH and 18 matched healthy controls (HC) who were chosen based on similarity in age and sex. R2* and quantitative susceptibility mapping were compared using voxel-wise and atlas-based one-way analysis of covariance (ANCOVA). Finally, partial correlation analyses were performed to assess the relationship between R2* and clinical presentations. Results R2* was lower in some white matter regions, including the bilateral superior longitudinal fascicle and sagittal stratum, in the iNPH group compared to the HC group. The voxel-based quantitative susceptibility mapping results did not differ between the groups. The atlas-based group comparisons yielded negative mean susceptibility values in almost all brain regions, indicating no clear paramagnetic iron deposition in the white matter of any subject. R2* and cognitive performance scores between the left superior longitudinal fasciculus (SLF) and right sagittal stratum (SS) were positively correlated. In addition to that, R2* and gait disturbance scores between left SS were negatively correlated. Conclusion Our analysis highlights the microstructural changes without iron deposition in the SLF and SS, and their association with cognitive impairment and gait disturbance in patients with iNPH.
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Affiliation(s)
- Yuya Kano
- Department of Neurology, Toyokawa City Hospital, Toyokawa, Japan
- Department of Neurology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Yuto Uchida
- Department of Neurology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
- The Russell H. Morgan, Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Hirohito Kan
- Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Keita Sakurai
- Department of Radiology, National Center for Geriatrics and Gerontology, Ōbu, Japan
| | - Susumu Kobayashi
- Department of Radiology, Toyokawa City Hospital, Toyokawa, Japan
| | - Kento Seko
- Department of Neurology, Toyokawa City Hospital, Toyokawa, Japan
| | - Keisuke Mizutani
- Department of Neurology, Toyokawa City Hospital, Toyokawa, Japan
| | - Toshihiko Usami
- Department of Neurology, Toyokawa City Hospital, Toyokawa, Japan
| | - Koji Takada
- Department of Neurology, Toyokawa City Hospital, Toyokawa, Japan
| | - Noriyuki Matsukawa
- Department of Neurology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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Kan H, Uchida Y, Ueki Y, Arai N, Tsubokura S, Kunitomo H, Kasai H, Aoyama K, Matsukawa N, Shibamoto Y. R2* relaxometry analysis for mapping of white matter alteration in Parkinson's disease with mild cognitive impairment. Neuroimage Clin 2022; 33:102938. [PMID: 34998126 PMCID: PMC8741619 DOI: 10.1016/j.nicl.2022.102938] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/22/2021] [Accepted: 01/03/2022] [Indexed: 12/01/2022]
Abstract
R2* relaxometry analysis combined with QSM revealed detail of WM alteration in PD-MCI. R2* relaxometry analysis can detect slight demyelination in PD-MCI. R2* value shows potential for early evaluation of cognitive decline in PD.
Background R2* relaxometry analysis combined with quantitative susceptibility mapping (QSM), which has high sensitivity to iron deposition, can distinguish microstructural changes of the white matter (WM) and iron deposition, thereby providing a sensitive and biologically specific measure of the WM owing to the changes in myelin and its surrounding environment. This study aimed to explore the microstructural WM alterations associated with cognitive impairment in patients with Parkinson’s disease (PD) using R2* relaxometry analysis combined with QSM. Materials and methods We enrolled 24 patients with PD and mild cognitive impairment (PD-MCI), 22 patients with PD and normal cognition (PD-CN), and 19 age- and sex-matched healthy controls (HC). All participants underwent Montreal Cognitive Assessment (MoCA) and brain magnetic resonance imaging, including structural three-dimensional T1-weighted images and multiple spoiled gradient echo sequence (mGRE). The R2* and susceptibility maps were estimated from the multiple magnitude images of mGRE. The susceptibility maps were used for verifying iron deposition in the WM. The voxel-based R2* of the entire WM and its correlation with cognitive performance were analyzed. Results In the voxel-based group comparisons, the R2* in the PD-MCI group was lower in some WM regions, including the corpus callosum, than R2* in the PD-CN and HC groups. The mean susceptibility values in almost all brain regions were negative and close-to-zero values, indicating no detectable paramagnetic iron deposition in the WM of all subjects. There was a significant positive correlation between R2* and MoCA in some regions of the WM, mainly the corpus callosum and left hemisphere. Conclusion R2* relaxometry analysis for WM microstructural changes provided further biologic insights on demyelination and changes in the surrounding environment, supported by the QSM results demonstrating no iron existence. This analysis highlighted the potential for the early evaluation of cognitive decline in patients with PD.
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Affiliation(s)
- Hirohito Kan
- Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Japan; Department of Radiology, Nagoya City University, Graduate School of Medical Sciences, Japan.
| | - Yuto Uchida
- Department of Neurology, Nagoya City University, Graduate School of Medical Sciences, Japan; Department of Neurology, Toyokawa City Hospital, Japan.
| | - Yoshino Ueki
- Department of Rehabilitation Medicine, Nagoya City University, Graduate School of Medical Sciences, Japan.
| | - Nobuyuki Arai
- Department of Radiology, Suzuka University of Medical Science, Japan.
| | | | - Hiroshi Kunitomo
- Department of Radiology, Nagoya City University Hospital, Japan.
| | - Harumasa Kasai
- Department of Radiology, Nagoya City University Hospital, Japan
| | - Kiminori Aoyama
- Department of Rehabilitation Medicine, Nagoya City University, Graduate School of Medical Sciences, Japan
| | - Noriyuki Matsukawa
- Department of Neurology, Nagoya City University, Graduate School of Medical Sciences, Japan.
| | - Yuta Shibamoto
- Department of Radiology, Nagoya City University, Graduate School of Medical Sciences, Japan.
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Lan L, Lu X, Shu J. T 2 Values for Diagnosing Acute-on-Chronic Liver Failure in Hepatitis B Patients. Curr Med Imaging 2021; 17:129-135. [PMID: 32586254 DOI: 10.2174/1573405616666200625152357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/09/2020] [Accepted: 04/25/2020] [Indexed: 11/22/2022]
Abstract
OBJECTIVES The aim of this study was to investigate the value of hepatic T2 imaging for the evaluation of chronic hepatitis-B-related acute-on-chronic liver failure (HBV-ACLF). METHODS Three groups of patients underwent liver MRI utilising m-GRASE sequence (multi-echo gradient and spin echo): HBV-ACLF patients (n = 28), chronic hepatitis B patients (n = 11), and healthy control patients (n = 14). A T2 image was produced using post-processing software, and the mean T2 (relaxation time) value was calculated. Blood biochemical indices for the HBV-ACLF and Chronic Hepatitis B were obtained within 2 days pre- or post-MR scanning. The patients' T2 values, and the correlation between their biochemical indices and T2 values were analysed. A receiver operating characteristic curve was employed to evaluate the efficiency of utilising T2 values in the diagnosis of HBV-ACLF. RESULTS There were significant variations in the T2 values (χ2 = 19.074, P < 0.001) among the 3 groups. The AUC of T2 values for diagnosing HBV-ACLF was 0.86 (P < 0.001), with a cut-off value of 57.73 ms. A moderately positive correlation was observed between the T2 value and the international normalised ratio, prothrombin time, and hyaluronic acid values (rs = 0.65, P < 0.001; rs = 0.67, P < 0.001; rs = 0.39, P = 0.025). A moderately negative correlation was observed between the T2 value and the prothrombin activity, albumin, and prealbumin values (rs = -0.67, P < 0.001; rs = -0.48, P = 0.004; rs = -0.37, P = 0.030). CONCLUSION T2 values could accurately reflect liver function state, as they correlated well with certain biochemical indices, illustrating good diagnostic efficiency for diagnosing HBV-ACLF.
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Affiliation(s)
- Lianjun Lan
- Department of Radiology, Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
| | - Xiaofei Lu
- Department of Radiology, Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
| | - Jian Shu
- Department of Radiology, Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
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Simchick G, Liu Z, Nagy T, Xiong M, Zhao Q. Assessment of MR-based R2* and quantitative susceptibility mapping for the quantification of liver iron concentration in a mouse model at 7T. Magn Reson Med 2018; 80:2081-2093. [PMID: 29575047 PMCID: PMC6107404 DOI: 10.1002/mrm.27173] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 02/15/2018] [Accepted: 02/15/2018] [Indexed: 01/19/2023]
Abstract
PURPOSE To assess the feasibility of quantifying liver iron concentration (LIC) using R2* and quantitative susceptibility mapping (QSM) at a high field strength of 7 Tesla (T). METHODS Five different concentrations of Fe-dextran were injected into 12 mice to produce various degrees of liver iron overload. After mice were sacrificed, blood and liver samples were harvested. Ferritin enzyme-linked immunosorbent assay (ELISA) and inductively coupled plasma mass spectrometry were performed to quantify serum ferritin concentration and LIC. Multiecho gradient echo MRI was conducted to estimate R2* and the magnetic susceptibility of each liver sample through complex nonlinear least squares fitting and a morphology enabled dipole inversion method, respectively. RESULTS Average estimates of serum ferritin concentration, LIC, R2*, and susceptibility all show good linear correlations with injected Fe-dextran concentration; however, the standard deviations in the estimates of R2* and susceptibility increase with injected Fe-dextran concentration. Both R2* and susceptibility measurements also show good linear correlations with LIC (R2 = 0.78 and R2 = 0.91, respectively), and a susceptibility-to-LIC conversion factor of 0.829 ppm/(mg/g wet) is derived. CONCLUSION The feasibility of quantifying LIC using MR-based R2* and QSM at a high field strength of 7T is demonstrated. Susceptibility quantification, which is an intrinsic property of tissues and benefits from being field-strength independent, is more robust than R2* quantification in this ex vivo study. A susceptibility-to-LIC conversion factor is presented that agrees relatively well with previously published QSM derived results obtained at 1.5T and 3T.
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Affiliation(s)
- Gregory Simchick
- Physics and Astronomy, University of Georgia, Athens, GA, United States
- Bio-Imaging Research Center, University of Georgia, Athens, GA, United States
| | - Zhi Liu
- Pharmaceutical & Biomedical Sciences, University of Georgia, Athens, GA United States
| | - Tamas Nagy
- Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA United States
| | - May Xiong
- Pharmaceutical & Biomedical Sciences, University of Georgia, Athens, GA United States
| | - Qun Zhao
- Physics and Astronomy, University of Georgia, Athens, GA, United States
- Bio-Imaging Research Center, University of Georgia, Athens, GA, United States
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Vanhoutte L, Gerber BL, Gallez B, Po C, Magat J, Balligand JL, Feron O, Moniotte S. High field magnetic resonance imaging of rodents in cardiovascular research. Basic Res Cardiol 2016; 111:46. [PMID: 27287250 DOI: 10.1007/s00395-016-0565-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 06/01/2016] [Indexed: 02/07/2023]
Abstract
Transgenic and gene knockout rodent models are primordial to study pathophysiological processes in cardiovascular research. Over time, cardiac MRI has become a gold standard for in vivo evaluation of such models. Technical advances have led to the development of magnets with increasingly high field strength, allowing specific investigation of cardiac anatomy, global and regional function, viability, perfusion or vascular parameters. The aim of this report is to provide a review of the various sequences and techniques available to image mice on 7-11.7 T magnets and relevant to the clinical setting in humans. Specific technical aspects due to the rise of the magnetic field are also discussed.
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Affiliation(s)
- Laetitia Vanhoutte
- Department of Paediatric Cardiology, Cliniques universitaires Saint Luc, Université Catholique de Louvain (UCL), Brussels, Belgium. .,Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain (UCL), Brussels, Belgium.
| | - Bernhard L Gerber
- Division of Cardiology, Cliniques universitaires Saint Luc, Université Catholique de Louvain (UCL), Brussels, Belgium.,Pole of Cardiovascular Research (CARD), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Bernard Gallez
- Biomedical Magnetic Resonance Unit (REMA), Louvain Drug Research Institute (LDRI), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Chrystelle Po
- CNRS, ICube, FMTS, Institut de Physique Biologique, Faculté de Médecine, Université de Strasbourg, Strasbourg, France
| | - Julie Magat
- L'Institut de RYthmologie et de Modélisation Cardiaque (LIRYC), Inserm U1045, Bordeaux, France
| | - Jean-Luc Balligand
- Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Olivier Feron
- Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Stéphane Moniotte
- Department of Paediatric Cardiology, Cliniques universitaires Saint Luc, Université Catholique de Louvain (UCL), Brussels, Belgium
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Comparison of Utility of Histogram Apparent Diffusion Coefficient and R2* for Differentiation of Low-Grade From High-Grade Clear Cell Renal Cell Carcinoma. AJR Am J Roentgenol 2015. [PMID: 26204307 DOI: 10.2214/ajr.14.13802] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Hocq A, Luhmer M, Saussez S, Louryan S, Gillis P, Gossuin Y. Effect of magnetic field and iron content on NMR proton relaxation of liver, spleen and brain tissues. CONTRAST MEDIA & MOLECULAR IMAGING 2014; 10:144-52. [PMID: 24954138 DOI: 10.1002/cmmi.1610] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 05/02/2014] [Accepted: 05/22/2014] [Indexed: 12/13/2022]
Abstract
Iron accumulation is observed in liver and spleen during hemochromatosis and important neurodegenerative diseases involve iron overload in brain. Storage of iron is ensured by ferritin, which contains a magnetic core. It causes a darkening on T2 -weighted MR images. This work aims at improving the understanding of the NMR relaxation of iron-loaded human tissues, which is necessary to develop protocols of iron content measurements by MRI. Relaxation times measurements on brain, liver and spleen samples were realized at different magnetic fields. Iron content was determined by atomic emission spectroscopy. For all samples, the longitudinal relaxation rate (1/T1 ) of tissue protons decreases with the magnetic field up to 1 T, independently of iron content, while their transverse relaxation rate (1/T2 ) strongly increases with the field, either linearly or quadratically, or a combination thereof. The extent of the inter-echo time dependence of 1/T2 also varies according to the sample. A combination of theoretical models is necessary to describe the relaxation of iron-containing tissues. This can be due to the presence, inside tissues, of ferritin clusters of different sizes and densities. When considering all samples, a correlation (r(2) = 0.6) between 1/T1 and iron concentration is observed at 7.0 T. In contrast the correlation between 1/T2 and iron content is poor, even at high field (r(2) = 0.14 at 7.0 T). Our results show that MRI methods based on T1 or T2 measurements will easily detect an iron overloading at high magnetic field, but will not provide an accurate quantification of tissue iron content at low iron concentrations.
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Affiliation(s)
- Aline Hocq
- Biomedical Physics Department, UMONS, 7000, Mons, Belgium
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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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Jin N, Guo Y, Zhang Z, Zhang L, Lu G, Larson AC. GESFIDE-PROPELLER approach for simultaneous R2 and R2* measurements in the abdomen. Magn Reson Imaging 2013; 31:1760-5. [PMID: 24041478 DOI: 10.1016/j.mri.2013.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 07/22/2013] [Accepted: 08/13/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE To investigate the feasibility of combining GESFIDE with PROPELLER sampling approaches for simultaneous abdominal R2 and R2* mapping. MATERIALS AND METHODS R2 and R2* measurements were performed in 9 healthy volunteers and phantoms using the GESFIDE-PROPELLER and the conventional Cartesian-sampling GESFIDE approaches. RESULTS Images acquired with the GESFIDE-PROPELLER sequence effectively mitigated the respiratory motion artifacts, which were clearly evident in the images acquired using the conventional GESFIDE approach. There was no significant difference between GESFIDE-PROPELLER and reference MGRE R2* measurements (p=0.162) whereas the Cartesian-sampling based GESFIDE methods significantly overestimated R2* values compared to MGRE measurements (p<0.001). CONCLUSION The GESFIDE-PROPELLER sequence provided high quality images and accurate abdominal R2 and R2* maps while avoiding the motion artifacts common to the conventional Cartesian-sampling GESFIDE approaches.
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Affiliation(s)
- Ning Jin
- Department of Biomedical Engineering, Northwestern University Chicago, IL, USA; Department of Radiology, Northwestern University Chicago, IL, USA; Siemens Medical Solutions USA, Inc., Chicago, IL, USA.
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Abstract
Many studies show that hepatic iron overload has a close association with hepatitis, hepatic fibrosis, cirrhosis, and hepatic tumors. Methods currently used for detection of hepatic iron overload, such as plasma ferritin detection, liver biopsy, and superconducting quantum interface device, have some limitations. Improvement in software and hardware has enabled MRI to become a safe, noninvasive and accurate method for detecting hepatic iron overload. This article aims to summarize the performance and application of MRI in the evaluation of hepatic iron overload.
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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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Brain iron deposition and sequence characteristics in Parkinsonism: comparison of SWI, T₂* maps, T₂-weighted-, and FLAIR-SPACE. Invest Radiol 2011; 45:795-802. [PMID: 20829707 DOI: 10.1097/rli.0b013e3181ec9c96] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To compare quantitatively T2- and T2*-based magnetic resonance imaging sequences in patients with symptoms of Parkinson disease and to evaluate the information content of those sequences regarding brain iron concentration. MATERIALS AND METHODS We imaged 51 patients with symptoms of Parkinson disease on 3-T magnetic resonance imaging with T2-weighted sampling perfection with application optimized contrasts using different flip-angle evolution (SPACE), fluid attenuation inversion recovery (FLAIR)-SPACE, susceptibility-weighted imaging (SWI), and parametric T2* sequence (MapIt). Signal analysis was performed in 22 regions of interest in the brain. RESULTS Correlations (r2 = 0.82...0.96) with brain iron concentration were excellent. Contrast and tissue separability ratios were best in the T2* maps and FLAIR-SPACE, respectively. Good correlations of contrast were reached between SWI and both T2-weighted SPACE and FLAIR-SPACE. Their relation to quantitative T2* values was reminiscent of a quadratic curve shape. However, separation into gray and white matter revealed a linear positive and negative correlation, respectively. CONCLUSIONS SWI showed potential in differentiating illnesses characterized by brain iron deposition. Closely similar information was given by T2-weighted SPACE and FLAIR-SPACE, whereas other sequence comparisons revealed dispersion from intersequence agreement.
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