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Venkatakrishna SSB, Otero HJ, Khrichenko D, Serai SD. Can Automated 3-Dimensional Dixon-Based Methods Be Used in Patients With Liver Iron Overload? J Comput Assist Tomogr 2024; 48:343-353. [PMID: 38595087 DOI: 10.1097/rct.0000000000001574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
PURPOSE Accurate quantification of liver iron concentration (LIC) can be achieved via magnetic resonance imaging (MRI). Maps of liver T2*/R2* are provided by commercially available, vendor-provided, 3-dimensional (3D) multiecho Dixon sequences and allow automated, inline postprocessing, which removes the need for manual curve fitting associated with conventional 2-dimensional (2D) gradient echo (GRE)-based postprocessing. The main goal of our study was to investigate the relationship among LIC estimates generated by 3D multiecho Dixon sequence to values generated by 2D GRE-based R2* relaxometry as the reference standard. METHODS A retrospective review of patients who had undergone MRI scans for estimation of LIC with conventional T2* relaxometry and 3D multiecho Dixon sequences was performed. A 1.5 T scanner was used to acquire the magnetic resonance studies. Acquisition of standard multislice multiecho T2*-based sequences was performed, and R2* values with corresponding LIC were estimated. The comparison between R2* and corresponding LIC estimates obtained by the 2 methods was analyzed via the correlation coefficients and Bland-Altman difference plots. RESULTS This study included 104 patients (51 male and 53 female patients) with 158 MRI scans. The mean age of the patients at the time of scan was 15.2 (SD, 8.8) years. There was a very strong correlation between the 2 LIC estimation methods for LIC values up to 3.2 mg/g (LIC quantitative multiecho Dixon [qDixon; from region of interest R2*] vs LIC GRE [in-house]: r = 0.83, P < 0.01; LIC qDixon [from segmentation volume R2*] vs LIC GRE [in-house]: r = 0.92, P < 0.01); and very weak correlation between the 2 methods at liver iron levels >7 mg/g. CONCLUSION Three-dimensional-based multiecho Dixon technique can accurately measure LIC up to 7 mg/g and has the potential to replace 2D GRE-based relaxometry methods.
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Affiliation(s)
| | | | - Dmitry Khrichenko
- From the Department of Radiology, Children's Hospital of Philadelphia
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Brendel JM, Kratzenstein A, Berger J, Hagen F, Nikolaou K, Gawaz M, Greulich S, Krumm P. T2* map at cardiac MRI reveals incidental hepatic and cardiac iron overload. Diagn Interv Imaging 2023; 104:552-559. [PMID: 37550171 DOI: 10.1016/j.diii.2023.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 07/27/2023] [Accepted: 07/31/2023] [Indexed: 08/09/2023]
Abstract
PURPOSE The purpose of this study was to assess the diagnostic capabilities of cardiac magnetic resonance (CMR) T2* mapping in detecting incidental hepatic and cardiac iron overload. MATERIALS AND METHODS Patients with various clinical indications for CMR examination were consecutively included at a single center from January 2019 to April 2023. All patients underwent T2* mapping at 1.5 T in a single mid-ventricular short-axis as part of a comprehensive routine CMR protocol. T2* measurements were performed of the heart (using a region-of-interest in the interventricular septum) and the liver, categorized according to the severity of iron overload. The degree of cardiac iron overload was categorized as mild (15 ms < T2* < 20 ms), moderate (10 ms < T2* < 15 ms) and severe (T2* < 10 ms). The degree of hepatic iron overload was categorized as mild (4 ms < T2* < 8 ms), moderate (2 ms < T2* < 4 ms), severe (T2* < 2 ms). Image quality and inter-reader agreement were assessed using intraclass correlation coefficient (ICC). RESULTS CMR examinations from 614 patients (374 men, 240 women) with a mean age of 50 ± 18 (standard deviation) years were fully evaluable. A total of 24/614 patients (3.9%) demonstrated incidental hepatic iron overload; of these, 22/614 patients (3.6%) had mild hepatic iron overload, and 2/614 patients (0.3%) had moderate hepatic iron overload. Seven out of 614 patients (1.1%) had incidental cardiac iron overload; of these, 5/614 patients (0.8%) had mild iron overload, 1/614 patients (0.2%) had moderate iron overload, and 1/614 patients (0.2%) had severe iron overload. Good to excellent inter-reader agreement was observed for the assessment of T2* values (ICC, 0.90 for heart [95% confidence interval: 0.88-0.91]; ICC, 0.91 for liver [95% confidence interval: 0.89-0.92]). CONCLUSION Analysis of standard CMR T2* maps detects incidental cardiac and hepatic iron overload in 1.1% and 3.9% of patients, respectively, which may have implications for further patient management. Therefore, despite an overall low number of incidental abnormal findings, T2* imaging may be included in a standardized comprehensive CMR protocol.
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Affiliation(s)
- Jan M Brendel
- Department of Radiology, Diagnostic and Interventional Radiology, University of Tübingen, 72076 Germany
| | - Alina Kratzenstein
- Department of Radiology, Diagnostic and Interventional Radiology, University of Tübingen, 72076 Germany
| | - Josephine Berger
- Department of Radiology, Diagnostic and Interventional Radiology, University of Tübingen, 72076 Germany
| | - Florian Hagen
- Department of Radiology, Diagnostic and Interventional Radiology, University of Tübingen, 72076 Germany
| | - Konstantin Nikolaou
- Department of Radiology, Diagnostic and Interventional Radiology, University of Tübingen, 72076 Germany
| | - Meinrad Gawaz
- Department of Internal Medicine III, Cardiology and Angiology, University of Tübingen, 72076 Germany
| | - Simon Greulich
- Department of Internal Medicine III, Cardiology and Angiology, University of Tübingen, 72076 Germany.
| | - Patrick Krumm
- Department of Radiology, Diagnostic and Interventional Radiology, University of Tübingen, 72076 Germany
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Wang L, Wang D, Chen J, Sun M, Nickel D, Kannengiesser S, Qu F, Zhu J, Ren C, Zhang Y, Cheng J. Preliminary Study of Confounder-Corrected Fat Fraction and R2* Mapping of Bone Marrow in Children With Acute Leukemia. J Magn Reson Imaging 2023; 58:1353-1363. [PMID: 37154163 DOI: 10.1002/jmri.28755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/10/2023] [Accepted: 04/10/2023] [Indexed: 05/10/2023] Open
Abstract
BACKGROUND The bone marrow (BM) evaluation of acute leukemia (AL) mainly depends on invasive BM puncture biopsy. Noninvasive and accurate MR examination technology has potential clinical application value in the BM evaluation of AL patients. Multi-gradient-echo (MGRE) has been found useful to evaluate changes in BM fat and iron content, but has not yet been applied in AL. PURPOSE To explore the diagnostic capability of BM infiltration of quantitative BM fat fraction (FF) and R2* values obtained from a 3D MGRE sequence in children with primary AL. STUDY TYPE Prospective. POPULATION/SUBJECTS Sixty-two pediatric patients with untreated AL and 68 healthy volunteers. AL patients were divided into acute lymphoblastic leukemia (ALL) (n = 39) and acute myeloid leukemia (AML) (n = 23) groups. FIELD STRENGTH/SEQUENCE 3T, 3D chemical-shift-encoded multi-gradient-echo, T1WI, T2WI, T2_STIR. ASSESSMENT BM FF and R2* values were assessed by manually drawing regions of interest at the L3, L4, ilium, and 1 cm below the bilateral trochanter of the femur (upper femur). STATISTICAL TESTS Independent sample t-tests, variance analysis, Spearman correlation. RESULTS BM FF and R2* at L3, L4, ilium, and upper femur, FFtotal and R2*total were significantly lower in the AL than control group. BM FF did not significantly differ between ALL and AML groups (PL3 = 0.060, PL4 = 0.086, Pilium = 0.179, Pupper femur = 0.149, and Ptotle = 0.097, respectively). The R2* was significantly lower in ALL group than AML group for L3, L4, and R2*total . BM FF was moderately positively correlated with R2* in ALL group, and strongly positively correlated in AML group. Area under the receiver operating characteristic curves showed that BM FF had higher AUC in AL, ALL, and AML (all AUC = 1.000) than R2* (0.976, 0.996, and 0.941, respectively). DATA CONCLUSION MGRE-MRI mapping can be applied to measure BM FF and R2* values, and help evaluate BM infiltration and iron storage in children with AL. EVIDENCE LEVEL 1 Technical Efficacy: 2.
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Affiliation(s)
- Linlin Wang
- MRI Department of the First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
| | - Dao Wang
- Department of Paediatrics of the First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
| | - Jiao Chen
- Department of Paediatrics of the First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
| | - Mengtian Sun
- MRI Department of the First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
| | - Dominik Nickel
- MR Application Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany
| | | | - Feifei Qu
- MR Collaboration, Siemens Healthcare Ltd., Beijing, China
| | - Jingxia Zhu
- MR Collaboration, Siemens Healthcare Ltd., Beijing, China
| | - Cuiping Ren
- MRI Department of the First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
| | - Yong Zhang
- MRI Department of the First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
| | - Jingliang Cheng
- MRI Department of the First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
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Venkatakrishna SSB, Otero HJ, Ghosh A, Khrichenko D, Serai SD. Rate of Change of Liver Iron Content by MR Imaging Methods: A Comparison Study. Tomography 2022; 8:2508-2521. [PMID: 36287808 PMCID: PMC9608976 DOI: 10.3390/tomography8050209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/23/2022] [Accepted: 09/27/2022] [Indexed: 11/05/2022] Open
Abstract
Objective: Magnetic resonance imaging (MRI) can accurately quantify liver iron concentration (LIC), eliminating the need for an invasive liver biopsy. Currently, the most widely used relaxometry methods for iron quantification are R2 and R2*, which are based on T2 and T2* acquisition sequences, respectively. We compared the rate of change of LIC as measured by the R2-based, FDA-approved commercially available third-party software with the rate of change of LIC measured by in-house analysis using R2*-relaxometry-based MR imaging in patients undergoing follow-up MRI scans for liver iron estimation. Methods: We retrospectively included patients who had undergone serial MRIs for liver iron estimation. The MR studies were performed on a 1.5T scanner; standard multi-slice, multi-echo T2- and T2*-based sequences were acquired, and LIC was estimated. The comparison between the rate of change of LIC by R2 and R2* values was performed via correlation coefficients and Bland−Altman difference plots. Results: One hundred and eighty-nine MR abdomen studies for liver iron evaluation from 81 patients (male: 38; female: 43) were included in the study. Fifty-nine patients had two serial scans, eighteen patients had three serial scans, three patients had four serial scans, and one patient had five serial scans. The average time interval between the first and last scans for each patient was 13.3 months. The average rates of change of LIC via R2 and R2* methods were −0.0043 ± 0.0214 and −0.0047 ± 0.012 mg/g per month, respectively. There was no significant difference in the rate of change of LIC observed between the two methods. Linearity between the rate of change of LIC measured by R2 (LIC R2) and R2* (LIC R2*) was strong, showing a correlation coefficient of r = 0.72, p < 0.01. A Bland−Altman plot between the rate of change of the two methods showed that the majority of the plotted variables were between two standard deviations. Conclusion: There was no significant difference in the rate of change of LIC detected between the R2 method and the R2* method that uses a gradient echo (GRE) sequence acquired with breath-hold. Since R2* is relatively faster and less prone to motion artifacts, R2*-derived LIC is recommended for iron homeostasis follow-up in patients with liver iron overload.
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Affiliation(s)
| | - Hansel J. Otero
- Department of Radiology, Children’s Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd, Philadelphia, PA 19104, USA
| | - Adarsh Ghosh
- Department of Radiology, Children’s Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104, USA
| | - Dmitry Khrichenko
- Department of Radiology, Children’s Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104, USA
| | - Suraj D. Serai
- Department of Radiology, Children’s Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd, Philadelphia, PA 19104, USA
- Correspondence:
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Hepatic manifestations of systemic disease: an imaging-based review. Pediatr Radiol 2022; 52:852-864. [PMID: 34797394 DOI: 10.1007/s00247-021-05222-5] [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: 06/20/2021] [Revised: 08/28/2021] [Accepted: 10/05/2021] [Indexed: 10/19/2022]
Abstract
The liver is responsible for many processes that maintain human metabolic homeostasis and can be affected by several pediatric systemic diseases. In this manuscript, we explore key pathological findings and imaging features across multiple modalities of a spectrum of congenital, metabolic and autoimmune disorders. Strengthening the radiologists' knowledge regarding potential hepatic manifestations of these systemic diseases will ultimately lead to improved care for pediatric patients.
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6
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Serai SD. Basics of magnetic resonance imaging and quantitative parameters T1, T2, T2*, T1rho and diffusion-weighted imaging. Pediatr Radiol 2022; 52:217-227. [PMID: 33856502 DOI: 10.1007/s00247-021-05042-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/18/2021] [Accepted: 03/01/2021] [Indexed: 01/27/2023]
Abstract
Magnetic resonance imaging is widely available and accepted as the imaging method of choice for many pediatric body imaging applications. Traditionally, it has been used in a qualitative way, where the images are reported non-numerically by radiologists. But now MRI machines have built-in post-processing software connected to the scanner and the database of MR images. This setting enables and encourages simple quantitative analysis of MR images. In this paper, the author reviews the fundamentals of MRI and discusses the most common quantitative MRI techniques for body imaging: T1, T2, T2*, T1rho and diffusion-weighted imaging (DWI). For each quantitative imaging method, this article reviews the technique, its measurement mechanism, and selected clinical applications to body imaging.
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Affiliation(s)
- Suraj D Serai
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA. .,Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
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7
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Lindquist DM, Dillman JR, Tkach JA. Editorial for "Hepatic Iron Quantification Using a Free-Breathing 3D Radial Gradient Echo Technique and Validation with a 2D Biopsy-Calibrated R2* Relaxometry Method". J Magn Reson Imaging 2021; 55:1417-1418. [PMID: 34523184 DOI: 10.1002/jmri.27904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 08/18/2021] [Indexed: 11/06/2022] Open
Affiliation(s)
- Diana M Lindquist
- Department of Radiology, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Jonathan R Dillman
- Department of Radiology, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Jean A Tkach
- Department of Radiology, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
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8
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Yoshikawa M, Kudo K, Harada T, Harashima K, Suzuki J, Ogawa K, Fujiwara T, Nishida M, Sato R, Shirai T, Bito Y. Quantitative Susceptibility Mapping versus R2*-based Histogram Analysis for Evaluating Liver Fibrosis: Preliminary Results. Magn Reson Med Sci 2021; 21:609-622. [PMID: 34483224 DOI: 10.2463/mrms.mp.2020-0175] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE The staging of liver fibrosis is clinically important, and a less invasive method is preferred. Quantitative susceptibility mapping (QSM) has shown a great potential in estimating liver fibrosis in addition to R2* relaxometry. However, few studies have compared QSM analysis and liver fibrosis. We aimed to evaluate the feasibility of estimating liver fibrosis by using QSM and R2*-based histogram analyses by comparing it with ultrasound-based transient elastography and the stage of histologic fibrosis. METHODS Fourteen patients with liver disease were enrolled. Data sets of multi-echo gradient echo sequence with breath-holding were acquired on a 3-Tesla scanner. QSM and R2* were reconstructed by water-fat separation method, and ROIs were analyzed for these images. Quantitative parameters with histogram features (mean, variance, skewness, kurtosis, and 1st, 10th, 50th, 90th, and 99th percentiles) were extracted. These data were compared with the elasticity measured by ultrasound transient elastography and histological stage of liver fibrosis (F0 to F4, based on the new Inuyama classification) determined by biopsy or hepatectomy. The correlation of histogram parameters with intrahepatic elasticity and histologically confirmed fibrosis stage was examined. Texture parameters were compared between subgroups divided according to fibrosis stage. Receiver operating characteristic (ROC) analysis was also performed. P < 0.05 indicated statistical significance. RESULTS The six histogram parameters of both QSM and R2*were significantly correlated with intrahepatic elasticity. In particular, three parameters (variance, percentiles [90th and 99th]) of QSM showed high correlation (r = 0.818-0.844), whereas R2* parameters showed a moderate correlation with elasticity. Four parameters of QSM were significantly correlated with fibrosis stage (ρ = 0.637-0.723) and differentiated F2-4 from F0-1 fibrosis and F3-4 from F0-2 fibrosis with areas under the ROC curve of > 0.8, but those of R2* did not. CONCLUSION QSM may serve as a promising surrogate indicator in detecting liver fibrosis.
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Affiliation(s)
- Masato Yoshikawa
- Department of Diagnostic Imaging, Hokkaido University Graduate School of Medicine
| | - Kohsuke Kudo
- Department of Diagnostic Imaging, Hokkaido University Graduate School of Medicine.,Global Center for Biomedical Science and Engineering, Hokkaido University Faculty of Medicine
| | - Taisuke Harada
- Center for Cause of Death Investigation, Hokkaido University Faculty of Medicine.,Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital
| | - Kazutaka Harashima
- Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital
| | - Jun Suzuki
- Department of Radiation Oncology, Hakodate Municipal Hospital
| | - Koji Ogawa
- Department of Gastroenterology and Hepatology, Hokkaido University Graduate School of Medicine
| | - Taro Fujiwara
- Department of Radiology, Division of Medical Imaging and Technology, Hokkaido University Hospital
| | - Mutsumi Nishida
- Diagnostic Center for Sonography, Hokkaido University Hospital
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9
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Muehler MR, Vigen K, Hernando D, Zhu A, Colgan TJ, Reeder SB. Reproducibility of liver R2* quantification for liver iron quantification from cardiac R2* acquisitions. Abdom Radiol (NY) 2021; 46:4200-4209. [PMID: 33982186 PMCID: PMC8346410 DOI: 10.1007/s00261-021-03099-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/14/2021] [Accepted: 04/21/2021] [Indexed: 01/19/2023]
Abstract
OBJECTIVES To evaluate the reproducibility of liver R2* measurements between a 2D cardiac ECG-gated and a 3D breath-hold liver CSE-MRI acquisition for liver iron quantification. METHODS A total of 54 1.5 T MRI exams from 51 subjects (18 women, 36 men, age 35.2 ± 21.8) were included. These included two sub-studies with 23 clinical MRI exams from 19 patients identified retrospectively, 24 participants with known or suspected iron overload, and 7 healthy volunteers acquired prospectively. The 2D cardiac and the 3D liver R2* maps were acquired in the same exam. Either acquisitions were reconstructed using a complex R2* algorithm that accounts for the presence of fat and residual phase errors due to eddy currents. Data were analyzed using colocalized ROIs in the liver. RESULTS Linear regression analysis demonstrated high Pearson's correlation and Lin's concordance coefficient for the overall study and both sub-studies. Bland-Altman analysis also showed good agreement, except for a slight increase of the mean R2* value above ~ 400 s-1. The Kolmogorow-Smirnow test revealed a non-normal distribution for (R2* 3D-R2* 2D) values from 0 to 600 s-1 in contrast to the 0-200 s-1 and 0-400 s-1 subpopulations. Linear regression analysis showed no relevant differences other than the intercept, likely due to only 7 measurements above 400 s-1. CONCLUSIONS The results demonstrate that R2*-measurements in the liver are feasible using 2D cardiac R2* maps compared to 3D liver R2* maps as the reference. Liver R2* may be underestimated for R2* > 400 s-1 using the 2D cardiac R2* mapping method.
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Affiliation(s)
- M R Muehler
- Department of Radiology, Wisconsin Institutes of Medical Research, University of Wisconsin, Room 2478, 1111 Highland Avenue, Madison, WI, 53705, USA.
- Department of Radiology and Neuroradiology, University Greifswald, Greifswald, Germany.
| | - K Vigen
- Department of Radiology, Wisconsin Institutes of Medical Research, University of Wisconsin, Room 2478, 1111 Highland Avenue, Madison, WI, 53705, USA
- Department of Medical Physics, University of Wisconsin, Madison, WI, USA
| | - D Hernando
- Department of Radiology, Wisconsin Institutes of Medical Research, University of Wisconsin, Room 2478, 1111 Highland Avenue, Madison, WI, 53705, USA
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA
- Department of Medical Physics, University of Wisconsin, Madison, WI, USA
- Department of Electrical and Computer Engineering, University of Wisconsin, Madison, WI, USA
| | - A Zhu
- Department of Radiology, Wisconsin Institutes of Medical Research, University of Wisconsin, Room 2478, 1111 Highland Avenue, Madison, WI, 53705, USA
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA
| | - T J Colgan
- Department of Radiology, Wisconsin Institutes of Medical Research, University of Wisconsin, Room 2478, 1111 Highland Avenue, Madison, WI, 53705, USA
| | - S B Reeder
- Department of Radiology, Wisconsin Institutes of Medical Research, University of Wisconsin, Room 2478, 1111 Highland Avenue, Madison, WI, 53705, USA
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA
- Department of Medical Physics, University of Wisconsin, Madison, WI, USA
- Department of Electrical and Computer Engineering, University of Wisconsin, Madison, WI, USA
- Department of Medicine, University of Wisconsin, Madison, WI, USA
- Department of Emergency Medicine, University of Wisconsin, Madison, WI, USA
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Jiang X, Hintenlang DE, White RD. Lower limit of iron quantification using dual-energy CT - a phantom study. J Appl Clin Med Phys 2020; 22:299-307. [PMID: 33369002 PMCID: PMC7856509 DOI: 10.1002/acm2.13124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/08/2020] [Accepted: 11/20/2020] [Indexed: 11/29/2022] Open
Abstract
Purpose Dual‐energy computed tomography (DECT) has been proposed for quantification of hepatic iron concentration (IC). However, the lower limit of quantification (LLOQ) has not been established, limiting the clinical adoption of this technology. In this study, we aim to (a) establish the LLOQ using phantoms and (b) investigate the effects of patient size, dose level, energy combination, and reconstruction method. Methods Three phantom sizes and eight vials of ferric nitrate solution with IC ranging from 0 to 10 mg/ml were used. DECT scans were performed at 80/140 and 100/140Sn kVp, and using five different levels of CT dose index (CTDI). An image‐domain three‐material‐decomposition algorithm was used to calculate the IC. The LLOQ was determined based on the coefficient of variation from repeated measurements. Results The measured IC correlated strongly with the true IC in the small and medium phantoms (R2 of linear regression > 0.99) and moderately in the large phantom (0.8 < R2<0.9). The LLOQ improved with increased CTDI. At 30 mGy, the LLOQ was found to be 0.50/1.73/6.25 mg/ml in the small/medium/large phantoms, respectively. 80/140Sn kVp resulted in superior LLOQ for all phantom sizes compared to 100/140Sn kVp, primarily due to the difference in their iron enhancement ratios (1.94 and 1.55, respectively). Iterative reconstruction was found to further improve the LLOQ (by ~ 11%), whereas reconstruction kernel smoothness had negligible effect. The LLOQ of iron was significantly higher than that of iodine due to its lack of a useful k‐edge and lower enhancement ratio. Conclusion Iron quantification at clinically important levels was achieved in a small‐ and a medium‐sized phantom using DECT, but proved challenging in a large phantom. Wide spectral separation and accurate calibration were found to be critical to the success of the technology.
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Affiliation(s)
- Xia Jiang
- Department of Radiology, Ohio State University College of Medicine, Columbus, OH, USA
| | - David E Hintenlang
- Department of Radiology, Ohio State University College of Medicine, Columbus, OH, USA
| | - Richard D White
- Department of Radiology, Ohio State University College of Medicine, Columbus, OH, USA
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Real-World Experience Measurement of Liver Iron Concentration by R2 vs. R2 Star MRI in Hemoglobinopathies. Diagnostics (Basel) 2020; 10:diagnostics10100768. [PMID: 33003498 PMCID: PMC7601611 DOI: 10.3390/diagnostics10100768] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/16/2020] [Accepted: 09/23/2020] [Indexed: 01/19/2023] Open
Abstract
Background: Non-invasive determination of liver iron concentration (LIC) is a valuable tool that guides iron chelation therapy in transfusion-dependent patients. Multiple methods have been utilized to measure LIC by MRI. The purpose of this study was to compare free breathing R2* (1/T2*) to whole-liver Ferriscan R2 method for estimation of LIC in a pediatric and young adult population who predominantly have hemoglobinopathies. Methods: Clinical liver and cardiac MRI scans from April 2016 to May 2018 on a Phillips 1.5 T scanner were reviewed. Free breathing T2 and T2* weighted images were acquired on each patient. For T2, multi-slice spin echo sequences were obtained. For T2*, a single mid-liver slice fast gradient echo was performed starting at 0.6 ms with 1.2 ms increments with signal averaging. R2 measurements were performed by Ferriscan analysis. R2* measurements were performed by quantitative T2* map analysis. Results: 107 patients underwent liver scans with the following diagnoses: 76 sickle cell anemia, 20 Thalassemia, 9 malignancies and 2 Blackfan Diamond anemia. Mean age was 12.5 ± 4.5 years. Average scan time for R2 sequences was 10 min, while R2* sequence time was 20 s. R2* estimation of LIC correlated closely with R2 with a correlation coefficient of 0.94. Agreement was strongest for LIC < 15 mg Fe/g dry weight. Overall bias from Bland–Altman plot was 0.66 with a standard deviation of 2.8 and 95% limits of agreement −4.8 to 6.1. Conclusion: LIC estimation by R2* correlates well with R2-Ferriscan in the pediatric age group. Due to the very short scan time of R2*, it allows imaging without sedation or anesthesia. Cardiac involvement was uncommon in this cohort.
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Acar S, Gözmen S, Bayraktaroğlu S, Acar SO, Tahta N, Aydınok Y, Vergin RC. Evaluation of Liver Iron Content by Magnetic Resonance Imaging in Children with Acute Lymphoblastic Leukemia after Cessation of Treatment. Turk J Haematol 2020; 37:263-270. [PMID: 32077272 PMCID: PMC7702656 DOI: 10.4274/tjh.galenos.2020.2019.0364] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Objective There are a limited number of studies evaluating iron overload in childhood leukemia by magnetic resonance imaging (MRI). The aim of this study was to determine liver iron content (LIC) by MRI in children with acute lymphoblastic leukemia (ALL) who had completed treatment and to compare those values with serum iron parameters. Materials and Methods A total of 30 patients between the ages of 7 and 18 who had completed ALL treatment were included in the study. Serum iron parameters (serum iron, serum ferritin [SF], and total iron-binding capacity) and liver function tests were studied. R2 MRI was performed for determining LIC. Results Normal LIC was detected in 22 (63.4%) of the cases. Seven (23.3%) had mild and 1 (3.3%) had moderate liver iron deposition. In contrast, severe iron overload was not detected in any of the cases. LIC levels were correlated with the numbers of packed red blood cell (pRBC) transfusions (r=0.637, p<0.001), pRBC transfusion volume (r=0.449, p<0.013), SF levels (r=0.561, p=0.001), and transferrin saturation (r=0.353, p=0.044). In addition, a positive correlation was found between the number of pRBC transfusions and SF levels (r=0.595, p<0.001). Conclusion We showed that the frequency of liver iron deposition was low and clinically less significant after the end of treatment in childhood ALL patients. LIC was demonstrated to be related to SF and transfusion history. These findings support that SF and transfusion history may be used as references for monitoring iron accumulation or identifying cases for further examinations such as MRI.
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Affiliation(s)
- Sezer Acar
- Dr. Behçet Uz Child Disease and Pediatric Surgery Training and Research Hospital, Department of Pediatrics, İzmir, Turkey
| | - Salih Gözmen
- Dr. Behcet Uz Child Disease and Pediatric Surgery Training and Research Hospital, Division of Pediatric Hematology and Oncology, İzmir, Turkey
| | | | - Sultan O. Acar
- Dr. Behcet Uz Child Disease and Pediatric Surgery Training and Research Hospital, Division of Pediatric Hematology and Oncology, İzmir, Turkey
| | - Neryal Tahta
- Dr. Behcet Uz Child Disease and Pediatric Surgery Training and Research Hospital, Division of Pediatric Hematology and Oncology, İzmir, Turkey
| | - Yeşim Aydınok
- Ege University Faculty of Medicine, Division of Pediatric Hematology and Oncology, İzmir, Turkey
| | - Raziye C. Vergin
- Dr. Behcet Uz Child Disease and Pediatric Surgery Training and Research Hospital, Division of Pediatric Hematology and Oncology, İzmir, Turkey
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Wurschi GW, Mentzel HJ, Herrmann KH, Krumbein I, Beck JF, Reichenbach JR, Kentouche K. MRI as an alternative to serum ferritin for diagnosis of iron overload in children in the context of immune response after stem cell transplantation. Pediatr Transplant 2019; 23:e13583. [PMID: 31535426 DOI: 10.1111/petr.13583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 06/18/2019] [Accepted: 08/07/2019] [Indexed: 12/30/2022]
Abstract
Multiple blood cell transfusions may cause iron overload or even liver fibrosis, requiring early diagnosis and intervention. SF is the standard for estimating iron levels in the body, but it also increases with inflammation. We hypothesized that T2 * magnetic resonance (MR) relaxometry is a more accurate alternative for follow-up in pediatric patients before and after allogenic SCT. Twenty-three children (mean age 10.2 years, 10 female, 13 male) were evaluated prospectively before SCT as well as at least 1 year after SCT with T2 * relaxometry on a 1.5 T MR-scanner to estimate liver iron concentrations from the T2 * values ("MR-Fe"). The results were compared with SF, while also considering CRP, and correlated with the number of transfusions. Overall, 24.3 transfusions were administered in average, mainly within 100 days of SCT (mean 10.5 units). Both MR-Fe and SF increased after SCT and decreased in the absence of new transfusions 1 year later without chelate therapy. This suggests regeneration of LP and iron loss, although the original states were not reached. Additionally, simultaneous peaks of CRP and SF were observed directly after SCT. MR-Fe did neither reveal these peaks nor was it associated with CRP (P = .39). We postulate that these early CRP and SF peaks after SCT are probably related to inflammatory reactions and not to iron overload. Thus, SF is not reliable for iron overload diagnosis after SCT in every condition. Beside this interaction, SF and MR-Fe revealed similar accuracy. MRI, however, has practical and economical disadvantages in routine estimation of iron.
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Affiliation(s)
- Georg W Wurschi
- Section of Pediatric Radiology, Institute of Diagnostic and Interventional Radiology, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - Hans-Joachim Mentzel
- Section of Pediatric Radiology, Institute of Diagnostic and Interventional Radiology, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - Karl-Heinz Herrmann
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - Ines Krumbein
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - James F Beck
- Section of Pediatric Hematology and Oncology, Department of Pediatrics, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - Juergen R Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - Karim Kentouche
- Section of Pediatric Hematology and Oncology, Department of Pediatrics, University Hospital Jena, Friedrich Schiller University, Jena, Germany
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Calle-Toro JS, Barrera CA, Khrichenko D, Otero HJ, Serai SD. R2 relaxometry based MR imaging for estimation of liver iron content: A comparison between two methods. Abdom Radiol (NY) 2019; 44:3058-3068. [PMID: 31161282 DOI: 10.1007/s00261-019-02074-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE To compare the reproducibility and accuracy of R2-relaxometry MRI for estimation of liver iron concentration (LIC) between in-house analysis and FDA-approved commercially available third party results. METHODS All MR studies were performed on a 1.5T scanner. Multi-echo spin-echo scans with a fixed TR and increasing TE values of 6 ms, 9 ms, 12 ms, 15 ms, and 18 ms (spaced at 3 ms intervals) were used. Post-processing of the images to calculate mean relaxivity, R2, included drawing of regions of interest to include the whole liver on mid-slice. The relationship between liver R2 values and estimated LIC calculated with in-house analysis and values reported by an external company (FerriScan®, Resonance Health, Australia) were assessed with correlation coefficients and Bland-Altman difference plots. Continuous variables are presented as mean ± standard deviation. Significance was set at p value < 0.05. RESULTS 474 studies from 175 patients were included in the study (mean age 10.4 ± 4.2 years (range 1-18 years); 254 studies from girls, 220 studies from boys). LIC ranged from 0.6 to 43 mg/g dry tissue, covering a broad range from normal levels to extremely high iron levels. Linearity between proprietary and in-house methods was excellent across the observed range for R2 (31.5 to 334.8 s-1); showing a correlation coefficient of r = 0.87, p < 0.001. Bland-Altman R2 difference plot between the two methods shows a mean bias of + 21.5 s-1 (range - 47.0 to + 90.0 s-1 between two standard deviations). LIC reported by FerriScan® compared with LIC estimated in-house with R2 as reported by FerriScan® agreed strongly, (r = 1.0, p < 0.001). CONCLUSION R2 relaxometry MR imaging for liver iron concentration estimation is reproducible between proprietary FDA-approved commercial software and in-house analysis methods.
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Affiliation(s)
- Juan S Calle-Toro
- Division of Body Imaging, Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA, 19104, USA
| | - Christian A Barrera
- Division of Body Imaging, Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA, 19104, USA
| | - Dmitry Khrichenko
- Division of Body Imaging, Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA, 19104, USA
| | - Hansel J Otero
- Division of Body Imaging, Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA, 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Suraj D Serai
- Division of Body Imaging, Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA, 19104, USA.
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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15
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Henninger B, Alustiza J, Garbowski M, Gandon Y. Practical guide to quantification of hepatic iron with MRI. Eur Radiol 2019; 30:383-393. [PMID: 31392478 PMCID: PMC6890593 DOI: 10.1007/s00330-019-06380-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 07/03/2019] [Accepted: 07/19/2019] [Indexed: 01/19/2023]
Abstract
Abstract Our intention is to demystify the MR quantification of hepatic iron (i.e., the liver iron concentration) and give you a step-by-step approach by answering the most pertinent questions. The following article should be more of a manual or guide for every radiologist than a classic review article, which just summarizes the literature. Furthermore, we provide important background information for professional communication with clinicians. The information regarding the physical background is reduced to a minimum. After reading this article, you should be able to perform adequate MR measurements of the LIC with 1.5-T or 3.0-T scanners. Key Points • MRI is widely accepted as the primary approach to non-invasively determine liver iron concentration (LIC). • This article is a guide for every radiologist to perform adequate MR measurements of the LIC. • When using R2* relaxometry, some points have to be considered to obtain correct measurements—all explained in this article.
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Affiliation(s)
- Benjamin Henninger
- Department of Radiology, Medical University of Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria.
| | - Jose Alustiza
- Osatek, Donostia Universitary Hospital, P. Dr. Beguiristain 109, 20014, Donostia/San Sebastian, Spain
| | - Maciej Garbowski
- Department of Haematology, Cancer Institute, University College London, Paul O'Gorman Bld, 72 Huntley St, London, WC1E 6BT, UK
| | - Yves Gandon
- CHU Rennes, Inserm, LTSI - UMR_S 1099, University of Rennes, F-35000, Rennes, France
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16
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Comparison of navigator-gated and breath-held image acquisition techniques for multi-echo quantitative dixon imaging of the liver in children and young adults. Abdom Radiol (NY) 2019; 44:2172-2181. [PMID: 30815713 DOI: 10.1007/s00261-019-01960-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
PURPOSE Acquired over a breath hold, multi-echo Dixon (mDixon) magnetic resonance imaging (MRI) of the liver can be used to quantify proton density fat fraction (PDFF) and iron-related signal decay. However, young, obese, and co-morbid patients may have limited breath holding capacity and could benefit from a motion-robust mDixon acquisition. The purpose of this study was to compare hepatic PDFF and R2* values between navigator-gated and breath-held mDixon MRI acquisition techniques in children and young adults with suspected liver disease. MATERIALS AND METHODS This retrospective study was institutional review board-approved with a waiver of informed consent. Patients who underwent liver MRI with breath-held and navigator-gated mDixon sequences between January 2017 and July 2018 were included. One reviewer, blinded to sequence, measured PDFF and R2* on four images from each sequence. Another blinded reviewer graded respiratory motion (5-point Likert scale). Pearson correlation (r), Lin's concordance coefficients (rc), and Bland-Altman analyses were used to assess agreement between techniques. Frequency of clinically limiting motion (score ≥ 3) was compared with Fisher's exact test. RESULTS Forty-two patients were included (15 female, 27 male; mean age: 15.7 ± 4.6 years). Mean PDFF and R2* were 16.6 ± 13.1% and 29.3 ± 4.7 s-1 (breath-held) versus 17.0 ± 13.2% and 29.6 ± 5.2 s-1 (navigator-gated). PDFF agreed almost perfectly between sequences (rc = 0.997, 95% CI 0.994-0.998; mean bias: 0.3%; 95% limits of agreement: - 2.4 to +1.7%), while R2* values correlated very strongly but with poor agreement (r = 0.837, rc = 0.832, 95% CI 0.716-0.910). Navigator-gated images exhibited significantly higher frequency of clinically limiting respiratory motion (88% vs. 48%, p = 0.0001). CONCLUSION Despite greater respiratory motion artifact, a free-breathing navigator-gated mDixon sequence produces PDFF values with almost perfect agreement to a breath-held sequence.
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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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18
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Barrera CA, Otero HJ, Hartung HD, Biko DM, Serai SD. Protocol optimization for cardiac and liver iron content assessment using MRI: What sequence should I use? Clin Imaging 2019; 56:52-57. [PMID: 30889418 DOI: 10.1016/j.clinimag.2019.02.012] [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: 12/17/2018] [Revised: 01/31/2019] [Accepted: 02/19/2019] [Indexed: 01/19/2023]
Abstract
OBJECTIVE To determine the optimal MRI protocol and sequences for liver and cardiac iron estimation in children. METHODS We evaluated patients ≤18 years with cardiac and liver MRIs for iron content estimation. Liver T2 was determined by a third-party company. Cardiac and Liver T2* values were measured by an observer. Liver T2* values were calculated using the available liver parenchyma in the cardiac MRI. Linear correlations and Bland-Altman plots were run between liver T2 and T2*, cardiac T2* values; and liver T2* on dedicated cardiac and liver MRIs. RESULTS 139 patients were included. Mean liver T2 and T2* values were 8.6 ± 5.4 ms and 4.5 ± 4.1 ms, respectively. A strong correlation between liver T2 and T2* values was observed (r = 0.96, p < 0.001) with a bias (+4.1 ms). Mean cardiac bright- and dark-blood T2* values were 26.5 ± 12.9 ms and 27.2 ± 11.9 ms, respectively. Cardiac T2* values showed a strong correlation (r = 0.81, p < 0.001) with a low bias (-1.0 ms). The mean liver T2* on liver and cardiac MRIs were 4.9 ± 4.7 ms and 4.6 ± 3.9 ms, respectively. A strong correlation between T2* values was observed (r = 0.96, p < 0.001) with a small bias (-0.2 ms). CONCLUSION MRI protocols for iron concentration in the liver and the heart can be simplified to avoid redundant information and reduce scan time. In most patients, a single breath-hold GRE sequence can be used to evaluate the iron concentration in both the liver and heart.
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Affiliation(s)
- Christian A Barrera
- Department of Radiology, The Children's Hospital of Philadelphia, 34th Street & Civic Center Boulevard, Philadelphia, PA 19104, USA.
| | - Hansel J Otero
- Department of Radiology, The Children's Hospital of Philadelphia, 34th Street & Civic Center Boulevard, Philadelphia, PA 19104, USA
| | - Helge D Hartung
- Department of Pediatrics, The Children's Hospital of Philadelphia, 34th Street & Civic Center Boulevard, Philadelphia, PA 19104, USA
| | - David M Biko
- Department of Radiology, The Children's Hospital of Philadelphia, 34th Street & Civic Center Boulevard, Philadelphia, PA 19104, USA
| | - Suraj D Serai
- Department of Radiology, The Children's Hospital of Philadelphia, 34th Street & Civic Center Boulevard, Philadelphia, PA 19104, USA
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Serai SD, Trout AT. Can MR elastography be used to measure liver stiffness in patients with iron overload? Abdom Radiol (NY) 2019; 44:104-109. [PMID: 30066167 DOI: 10.1007/s00261-018-1723-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Untreated hepatic iron overload causes hepatic fibrosis and cirrhosis and can predispose to hepatocellular carcinoma. MR elastography (MRE) provides a non-invasive means to measure liver stiffness, which correlates with liver fibrosis but standard gradient recalled echo (GRE)-based MRE techniques fail in patients with high iron due to very low hepatic signal. Short echo time (TE) 2D spin echo echoplanar imaging (SE-EPI)-based MRE may allow measurement of stiffness in the iron loaded liver. The purpose of this study was to describe the use of such an MRE sequence in patients undergoing liver iron quantification by MRI. In our preliminary study of 43 patients with mean LIC of 9.3 mg/g (range 1.8-21.5 mg/g), liver stiffness measurements could be made in 77% (33/43) of patients with a short TE, SE-EPI based MRE sequence. On average, mean LIC in patients with failed MRE was higher than in those with successful MRE (15.9 mg/g dry weight vs. 7.3 mg/g), but a cut-off value for successful MRE could not be established. Seven patients (21% of those with successful MRE) had liver stiffness values suggestive of the presence of significant fibrosis (> 2.49 kPa). A short TE, SE-EPI based MR elastography sequence allows successful measurement of liver stiffness in a majority of patients with liver iron loading, potentially allowing non-invasive screening for fibrosis.
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20
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Serai SD, Trout AT, Fleck RJ, Quinn CT, Dillman JR. Measuring liver T2* and cardiac T2* in a single acquisition. Abdom Radiol (NY) 2018; 43:2303-2308. [PMID: 29470624 DOI: 10.1007/s00261-018-1477-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE The purpose of this study is determine if both liver T2* and cardiac T2* can be measured on a single breath-hold acquisition. MATERIALS AND METHODS For this IRB-approved retrospective study, 137 patients with dedicated Cardiac MRI and Liver MRI examinations obtained sequentially on 1.5T scanners and on the same day were included for analysis. Both the cardiac and liver MRI examinations utilized GRE sequences for quantification of tissue iron. Specifically, T2* was measured using an 8-echo, multi-echo gradient echo single breath-hold sequence. Liver T2* was measured in a blinded manner on images from each of the cardiac and dedicated liver MRI examinations and were correlated. Bland-Altman difference plot was used to assess mean bias. RESULTS 137 examinations from 93 subjects met inclusion criteria. 10 examination pairs were excluded because the first echo time (TE) on the cardiac MRI was insufficiently short for the very high liver iron content. After exclusion, 127 studies from 89 subjects (67.4% males) were included in the final analysis. The mean subject age (± standard deviation) was 11.5 ± 7.5 years (range 0-29.3 years; median 10.5 years). Mean liver T2* measured on cardiac MRI was 8.3 ± 7.7 ms and mean liver T2* measured on dedicated liver MRI was 7.8 ± 7.4 ms (p < 0.001). There was strong positive correlation between the two liver T2* measurements (r = 0.989, p < 0.0001; 95% CI 0.985-0.992). With the exception of borderline outliers, all values fell within two standard deviations on the Bland-Altman difference plots, with a mean bias of 0.5 ms (range - 1.8 to + 2.7 ms). CONCLUSION In most patients with suspected or known iron overload, a single breath-hold GRE sequence may be sufficient to evaluate the iron concentration (T2*) of both the myocardium and the liver.
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Affiliation(s)
- Suraj D Serai
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA.
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA, 19104, USA.
| | - Andrew T Trout
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
| | - Robert J Fleck
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
| | - Charles T Quinn
- Department of Hematology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
| | - Jonathan R Dillman
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
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Labranche R, Gilbert G, Cerny M, Vu KN, Soulières D, Olivié D, Billiard JS, Yokoo T, Tang A. Liver Iron Quantification with MR Imaging: A Primer for Radiologists. Radiographics 2018. [PMID: 29528818 DOI: 10.1148/rg.2018170079] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Iron overload is a systemic disorder and is either primary (genetic) or secondary (exogenous iron administration). Primary iron overload is most commonly associated with hereditary hemochromatosis and secondary iron overload with ineffective erythropoiesis (predominantly caused by β-thalassemia major and sickle cell disease) that requires long-term transfusion therapy, leading to transfusional hemosiderosis. Iron overload may lead to liver cirrhosis and hepatocellular carcinoma, in addition to cardiac and endocrine complications. The liver is one of the main iron storage organs and the first to show iron overload. Therefore, detection and quantification of liver iron overload are critical to initiate treatment and prevent complications. Liver biopsy was the historical reference standard for detection and quantification of liver iron content. Magnetic resonance (MR) imaging is now commonly used for liver iron quantification, including assessment of distribution, detection, grading, and monitoring of treatment response in iron overload. Several MR imaging techniques have been developed for iron quantification, each with advantages and limitations. The liver-to-muscle signal intensity ratio technique is simple and widely available; however, it assumes that the reference tissue is normal. Transverse magnetization (also known as R2) relaxometry is validated but is prone to respiratory motion artifacts due to a long acquisition time, is presently available only for 1.5-T imaging, and requires additional cost and delay for off-line analysis. The R2* technique has fast acquisition time, demonstrates a wide range of liver iron content, and is available for 1.5-T and 3.0-T imaging but requires additional postprocessing software. Quantitative susceptibility mapping has the highest sensitivity for detecting iron deposition; however, it is still investigational, and the correlation with liver iron content is not yet established. ©RSNA, 2018.
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Affiliation(s)
- Roxanne Labranche
- From the Department of Radiology (R.L., G.G., M.C., K.N.V., D.O., J.S.B., A.T.) and Service of Hemato-oncology, Department of Medicine (D.S.), Centre Hospitalier de l'Université de Montréal, 1000 rue Saint-Denis, Montréal, QC, Canada H2X 0C2; MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada (G.G.); Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Tex (T.Y.); and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada (A.T.)
| | - Guillaume Gilbert
- From the Department of Radiology (R.L., G.G., M.C., K.N.V., D.O., J.S.B., A.T.) and Service of Hemato-oncology, Department of Medicine (D.S.), Centre Hospitalier de l'Université de Montréal, 1000 rue Saint-Denis, Montréal, QC, Canada H2X 0C2; MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada (G.G.); Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Tex (T.Y.); and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada (A.T.)
| | - Milena Cerny
- From the Department of Radiology (R.L., G.G., M.C., K.N.V., D.O., J.S.B., A.T.) and Service of Hemato-oncology, Department of Medicine (D.S.), Centre Hospitalier de l'Université de Montréal, 1000 rue Saint-Denis, Montréal, QC, Canada H2X 0C2; MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada (G.G.); Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Tex (T.Y.); and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada (A.T.)
| | - Kim-Nhien Vu
- From the Department of Radiology (R.L., G.G., M.C., K.N.V., D.O., J.S.B., A.T.) and Service of Hemato-oncology, Department of Medicine (D.S.), Centre Hospitalier de l'Université de Montréal, 1000 rue Saint-Denis, Montréal, QC, Canada H2X 0C2; MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada (G.G.); Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Tex (T.Y.); and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada (A.T.)
| | - Denis Soulières
- From the Department of Radiology (R.L., G.G., M.C., K.N.V., D.O., J.S.B., A.T.) and Service of Hemato-oncology, Department of Medicine (D.S.), Centre Hospitalier de l'Université de Montréal, 1000 rue Saint-Denis, Montréal, QC, Canada H2X 0C2; MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada (G.G.); Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Tex (T.Y.); and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada (A.T.)
| | - Damien Olivié
- From the Department of Radiology (R.L., G.G., M.C., K.N.V., D.O., J.S.B., A.T.) and Service of Hemato-oncology, Department of Medicine (D.S.), Centre Hospitalier de l'Université de Montréal, 1000 rue Saint-Denis, Montréal, QC, Canada H2X 0C2; MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada (G.G.); Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Tex (T.Y.); and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada (A.T.)
| | - Jean-Sébastien Billiard
- From the Department of Radiology (R.L., G.G., M.C., K.N.V., D.O., J.S.B., A.T.) and Service of Hemato-oncology, Department of Medicine (D.S.), Centre Hospitalier de l'Université de Montréal, 1000 rue Saint-Denis, Montréal, QC, Canada H2X 0C2; MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada (G.G.); Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Tex (T.Y.); and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada (A.T.)
| | - Takeshi Yokoo
- From the Department of Radiology (R.L., G.G., M.C., K.N.V., D.O., J.S.B., A.T.) and Service of Hemato-oncology, Department of Medicine (D.S.), Centre Hospitalier de l'Université de Montréal, 1000 rue Saint-Denis, Montréal, QC, Canada H2X 0C2; MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada (G.G.); Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Tex (T.Y.); and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada (A.T.)
| | - An Tang
- From the Department of Radiology (R.L., G.G., M.C., K.N.V., D.O., J.S.B., A.T.) and Service of Hemato-oncology, Department of Medicine (D.S.), Centre Hospitalier de l'Université de Montréal, 1000 rue Saint-Denis, Montréal, QC, Canada H2X 0C2; MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada (G.G.); Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Tex (T.Y.); and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada (A.T.)
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22
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Serai SD, Trout AT, Miethke A, Diaz E, Xanthakos SA, Dillman JR. Putting it all together: established and emerging MRI techniques for detecting and measuring liver fibrosis. Pediatr Radiol 2018; 48:1256-1272. [PMID: 30078038 DOI: 10.1007/s00247-018-4083-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 10/21/2017] [Accepted: 01/16/2018] [Indexed: 12/17/2022]
Abstract
Chronic injury to the liver leads to inflammation and hepatocyte necrosis, which when untreated can lead to myofibroblast activation and fibrogenesis with deposition of fibrous tissue. Over time, liver fibrosis can accumulate and lead to cirrhosis and end-stage liver disease with associated portal hypertension and liver failure. Detection and accurate measurement of the severity of liver fibrosis are important for assessing disease severity and progression, directing patient management, and establishing prognosis. Liver biopsy, generally considered the clinical standard of reference for detecting and measuring liver fibrosis, is invasive and has limitations, including sampling error, relatively high cost, and possible complications. For these reasons, liver biopsy is suboptimal for fibrosis screening, longitudinal monitoring, and assessing therapeutic efficacy. A variety of established and emerging qualitative and quantitative noninvasive MRI methods for detecting and staging liver fibrosis might ultimately serve these purposes. In this article, we review multiple MRI methods for detecting and measuring liver fibrosis and discuss the diagnostic performance and specific strengths and limitations of the various techniques.
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Affiliation(s)
- Suraj D Serai
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA. .,Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
| | - Andrew T Trout
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA
| | - Alexander Miethke
- Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Eric Diaz
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA
| | - Stavra A Xanthakos
- Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Jonathan R Dillman
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA
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23
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Serai SD, Smith EA, Trout AT, Dillman JR. Agreement between manual relaxometry and semi-automated scanner-based multi-echo Dixon technique for measuring liver T2* in a pediatric and young adult population. Pediatr Radiol 2018; 48:94-100. [PMID: 29058039 DOI: 10.1007/s00247-017-3990-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 07/26/2017] [Accepted: 09/12/2017] [Indexed: 12/25/2022]
Abstract
BACKGROUND Commercially available 3D multi-echo Dixon (mDixon) sequences provide parametric maps of liver T2*, obviating manual curve fitting that is often required with conventional gradient recalled echo (GRE)-based multi-echo relaxometry, potentially simplifying clinical work flow. OBJECTIVE The purpose of our study was to compare T2* values generated by a 3D mDixon sequence to values generated by GRE-based T2* relaxometry with manual curve fitting in a pediatric and young adult population. MATERIALS AND METHODS We reviewed clinical MRI exams performed at 1.5T for liver iron content estimation between February 2015 and June 2016 that included both mDixon and multi-echo GRE pulse sequences. We obtained mean T2* measurements based on each sequence by drawing regions of interest on each of four axial slices through the mid-liver. We compared mDixon-based and GRE-based T2* measurements using paired t-tests and assessed agreement using single-measure intra-class correlation coefficients and Bland-Altman difference plots. RESULTS One hundred nine patients met inclusion criteria (site 1=82; site 2=27). Mean age was 12.4±5.8 years, and 42 subjects (39%) were female. There was no statistically significant difference in mean T2* values for the two sequences (pooled means: 11.7±11.0 [GRE] vs. 11.7±10.9 ms [mDixon]; P=0.93). There was excellent absolute agreement between sequences (intraclass correlation coefficient [ICC]=0.98 for patients at both sites, confidence interval [CI]: 0.97-0.98 with mean bias of 0.0 ms [-4.2 ms to +4.2 ms]). CONCLUSION 3D mDixon is accurate for measuring liver T2* and can likely replace 2D GRE-based relaxometry.
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Affiliation(s)
- Suraj D Serai
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA.
| | - Ethan A Smith
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA.,Section of Pediatric Radiology, C. S. Mott Children's Hospital, Department of Radiology, University of Michigan Health System, Ann Arbor, MI, USA
| | - Andrew T Trout
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA
| | - Jonathan R Dillman
- Department of Radiology, MLC 5031, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA
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24
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Evaluation of six-point modified dixon and magnetic resonance spectroscopy for fat quantification: a fat–water–iron phantom study. Radiol Phys Technol 2017; 10:349-358. [DOI: 10.1007/s12194-017-0410-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/27/2017] [Accepted: 07/27/2017] [Indexed: 01/11/2023]
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25
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Loeffler RB, McCarville MB, Wagstaff AW, Smeltzer MP, Krafft AJ, Song R, Hankins JS, Hillenbrand CM. Can multi-slice or navigator-gated R2* MRI replace single-slice breath-hold acquisition for hepatic iron quantification? Pediatr Radiol 2017; 47:46-54. [PMID: 27752732 PMCID: PMC5203961 DOI: 10.1007/s00247-016-3700-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 07/21/2016] [Accepted: 08/26/2016] [Indexed: 11/25/2022]
Abstract
BACKGROUND Liver R2* values calculated from multi-gradient echo (mGRE) magnetic resonance images (MRI) are strongly correlated with hepatic iron concentration (HIC) as shown in several independently derived biopsy calibration studies. These calibrations were established for axial single-slice breath-hold imaging at the location of the portal vein. Scanning in multi-slice mode makes the exam more efficient, since whole-liver coverage can be achieved with two breath-holds and the optimal slice can be selected afterward. Navigator echoes remove the need for breath-holds and allow use in sedated patients. OBJECTIVE To evaluate if the existing biopsy calibrations can be applied to multi-slice and navigator-controlled mGRE imaging in children with hepatic iron overload, by testing if there is a bias-free correlation between single-slice R2* and multi-slice or multi-slice navigator controlled R2*. MATERIALS AND METHODS This study included MRI data from 71 patients with transfusional iron overload, who received an MRI exam to estimate HIC using gradient echo sequences. Patient scans contained 2 or 3 of the following imaging methods used for analysis: single-slice images (n = 71), multi-slice images (n = 69) and navigator-controlled images (n = 17). Small and large blood corrected region of interests were selected on axial images of the liver to obtain R2* values for all data sets. Bland-Altman and linear regression analysis were used to compare R2* values from single-slice images to those of multi-slice images and navigator-controlled images. RESULTS Bland-Altman analysis showed that all imaging method comparisons were strongly associated with each other and had high correlation coefficients (0.98 ≤ r ≤ 1.00) with P-values ≤0.0001. Linear regression yielded slopes that were close to 1. CONCLUSION We found that navigator-gated or breath-held multi-slice R2* MRI for HIC determination measures R2* values comparable to the biopsy-validated single-slice, single breath-hold scan. We conclude that these three R2* methods can be interchangeably used in existing R2*-HIC calibrations.
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Affiliation(s)
- Ralf B Loeffler
- Diagnostic Imaging, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-3678, USA
| | - M Beth McCarville
- Diagnostic Imaging, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-3678, USA
| | - Anne W Wagstaff
- Diagnostic Imaging, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-3678, USA
- Rhodes College, Memphis, TN, USA
- University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
| | - Matthew P Smeltzer
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, USA
- Division of Epidemiology, Biostatistics, and Environmental Health, School of Public Health, University of Memphis, Memphis, TN, USA
| | - Axel J Krafft
- Diagnostic Imaging, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-3678, USA
- Department of Radiology, University Hospital Center Freiburg, Freiburg, Germany
| | - Ruitian Song
- Diagnostic Imaging, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-3678, USA
| | - Jane S Hankins
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Claudia M Hillenbrand
- Diagnostic Imaging, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-3678, USA.
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26
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Agostini A, Kircher MF, Do RKG, Borgheresi A, Monti S, Giovagnoni A, Mannelli L. Magnetic Resonanance Imaging of the Liver (Including Biliary Contrast Agents)-Part 2: Protocols for Liver Magnetic Resonanance Imaging and Characterization of Common Focal Liver Lesions. Semin Roentgenol 2016; 51:317-333. [PMID: 27743568 DOI: 10.1053/j.ro.2016.05.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Andrea Agostini
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY; Department of Radiology, School of Radiology, Università Politecnica delle Marche, Ancona, Italy
| | - Moritz F Kircher
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY
| | - Richard K G Do
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY
| | - Alessandra Borgheresi
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY; Department of Radiology, School of Radiology, Università degli Studi di Firenze, Firenze, Italy
| | | | - Andrea Giovagnoni
- Department of Radiology, School of Radiology, Università Politecnica delle Marche, Ancona, Italy
| | - Lorenzo Mannelli
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY.
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