scholarly journals Complex confounder-corrected R2* mapping for liver iron quantification with MRI

2020 ◽  
Vol 31 (1) ◽  
pp. 264-275
Author(s):  
Diego Hernando ◽  
Rachel J. Cook ◽  
Naila Qazi ◽  
Colin A. Longhurst ◽  
Carol A. Diamond ◽  
...  
Keyword(s):  
Liver Iron ◽  
Iron Quantification

scholarly journals Liver Iron Quantification with MR Imaging: A Primer for Radiologists

Radiographics ◽  
2018 ◽  
Vol 38 (2) ◽  
pp. 392-412 ◽  
Author(s):  
Roxanne Labranche ◽  
Guillaume Gilbert ◽  
Milena Cerny ◽  
Kim-Nhien Vu ◽  
Denis Soulières ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Liver Iron ◽  
Iron Quantification

Agreement of liver iron quantification measurements with low Tc-SQUID biosusceptometers in Oakland, Torino and Hamburg

2007 ◽  
Vol 1300 ◽  
pp. 279-282
Author(s):  
Rainer Engelhardt ◽  
Ellen B. Fung ◽  
Filomena Longo ◽  
Marco Borri ◽  
Zahra Pakbaz ◽  
...  
Keyword(s):  
Liver Iron ◽  
Iron Quantification

scholarly journals Hepatic Iron Quantification on 3 Tesla (3 T) Magnetic Resonance (MR): Technical Challenges and Solutions

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Muhammad Anwar ◽  
John Wood ◽  
Deepa Manwani ◽  
Benjamin Taragin ◽  
Suzette O. Oyeku ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Iron Concentration ◽  
Hepatic Iron ◽  
Test Results ◽  
Cell Disease ◽  
Liver Iron ◽  
Iron Quantification ◽  
Fast Gradient ◽  
Technical Challenges ◽  
Hepatic Iron Concentration

MR has become a reliable and noninvasive method of hepatic iron quantification. Currently, most of the hepatic iron quantification is performed on 1.5 T MR, and the biopsy measurements have been paired withR2andR2*values for 1.5 T MR. As the use of 3 T MR scanners is steadily increasing in clinical practice, it has become important to evaluate the practicality of calculating iron burden at 3 T MR. Hepatic iron quantification on 3 T MR requires a better understanding of the process and more stringent technical considerations. The purpose of this work is to focus on the technical challenges in establishing a relationship betweenT2*values at 1.5 T MR and 3 T MR for hepatic iron concentration (HIC) and to develop an appropriately optimized MR protocol for the evaluation ofT2*values in the liver at 3 T magnetic field strength. We studied 22 sickle cell patients using multiecho fast gradient-echo sequence (MFGRE) 3 T MR and compared the results with serum ferritin and liver biopsy results. Our study showed that the quantification of hepatic iron on 3 T MRI in sickle cell disease patients correlates well with clinical blood test results and biopsy results. 3 T MR liver iron quantification based on MFGRE can be used for hepatic iron quantification in transfused patients.

scholarly journals Liver iron quantification by 3 tesla MRI: Calibration on a rabbit model

2013 ◽  
Vol 38 (6) ◽  
pp. 1585-1590 ◽  
Author(s):  
Peng Peng ◽  
Zhongkui Huang ◽  
Liling Long ◽  
Fanyu Zhao ◽  
Chunyan Li ◽  
...  
Keyword(s):  
Rabbit Model ◽  
3 Tesla ◽  
Liver Iron ◽  
Iron Quantification ◽  
3 Tesla Mri

scholarly journals Ferrozine-Based Iron Quantification of Iron Overloaded Mice: a Simple, Robust Method for the Assessment of Iron Chelation Therapies

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2054-2054
Author(s):  
David T Tran ◽  
Max J Petersen ◽  
Charles O Noble ◽  
Mark E Hayes ◽  
Peter Working ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Iron Chelation ◽  
Iron Removal ◽  
Iron Dextran ◽  
Employment Equity ◽  
Liver Iron ◽  
Iron Quantification ◽  
Tissue Iron ◽  
Nitric Acid Digestion ◽  
Equity Ownership

Abstract Introduction: We describe a low heat nitric acid digestion and colorimetric ferrozine-based iron assay that provides a fast, inexpensive and accurate alternative to high temperature animal tissue processing and inductively coupled plasma mass spectrometry (ICP). This technique is useful for the quantification of iron in iron overloaded animal models and diseases such as β-thalassemia, sickle cell anemia, and myelodysplastic syndromes. We applied it to evaluate iron removal by iron chelation therapies such as liposome-encapsulated deferoxamine (LDFO). Methods: CF-1 mouse liver, spleen, heart, plasma, urine and feces were digested in nitric acid (70%) at 65 °C for 1-2 hours. For large tissues such as the liver, tissues were sectioned at 50 mg fractions (n = 4) to also assess iron homogeneousness. Digested samples were bleached with hydrogen peroxide (30%) and diluted with water before iron quantification by ICP or the ferrozine-based assay. For the ferrozine-based assay, nitric acid was neutralized with ammonium acetate and iron was reduced with ascorbic acid before reaction with ferrozine for the colorimetric assessment of the ferrozine-ferrous iron complex at 550 nm. For iron overloaded models, CF-1 mice (n = 4) were loaded I.V. with iron dextran, iron sucrose, liposome encapsulated iron, or horse ferritin for over a week before sacrifice. Iron removal studies of tissues and excreta from iron overloaded CF-1 (n = 4) started 2 weeks after iron dextran overloading. Animals were dosed with either deferoxamine (DFO) and LDFO by I.V. and Exjade by oral gavage. Urine and feces were collected daily at the start of treatment. Animals were sacrificed 7 days post treatment. Tissues and excrements were digested and measured for iron by the ferrozine-based assay. Results: The ferrozine-based tissue iron quantification assay yields high iron recovery from mouse tissue. CF-1 liver spiked with iron dextran or horse ferritin had an iron recovery of 99±2% and 97±2%, respectively. Liver iron measurements of iron dextran overloaded mouse models resulted in identical iron measurements for the ferrozine-based assay and ICP. For CF-1 mice treated with iron dextran I.V. (0, 100, 300, 600 mg/kg, n = 4), liver iron is highly correlative between the two iron quantification techniques with a slope of 1.03 and R2 of 0.999. In addition, there is a linear iron overloading effect in both the liver (R2 = 0.99) and spleen (R2 = 0.98). CF-1 mice were also iron overloaded with iron sucrose, liposome encapsulated iron, and horse ferritin with dose dependent tissue overload. For all iron overloaded models tested, liver iron and spleen iron were homogenous per tissue when multiple sections were analyzed with an average low 6% difference in iron content. Despite high liver and spleen overloading, none of these iron carriers resulted in statistically significant heart iron overload. Iron dextran overloaded CF-1 mice (100 mg/kg) were treated with LDFO, DFO, and Exjade. LDFO at 100 mg/kg I.V. greatly reduces iron levels in the liver (p = 0.019) and spleen (p = 0.014) compared to non-effective no treatment, free DFO (p = 0.3), and empty liposomes (p = 0.1). Exjade at 30 mg/kg by oral gavage did not result in statistically significant iron removal in the liver or spleen (p < 0.2). Over the first four days, urine and feces were collected daily and also analyzed for iron. Results revealed that iron clearance by LDFO is primarily in the urine (p = 0.022 urine; p = 0.8 feces) while Exjade removed iron appeared in the feces (p = 0.06 feces; p = 0.013 urine). During this short period, drug efficiency in iron excretion (5%) from one dose of the novel LDFO at 100 mg/kg was equivalent to four daily doses of the Exjade at 50 mg/kg/dose. Conclusion: The low heat nitric acid digestion and ferrozine-based tissue iron quantification assay is a simple, precise, highly reproducible tool for the assessment of tissue and excretion iron. The assay enabled the rapid, low cost evaluation of novel iron chelation therapies. We gratefully acknowledge support by NIH SBIR Phase 1 Grant 1R43HD075429-01 and NIH SBIR Phase 2 Grant 2R44HD075429-02. Disclosures Tran: Zoneone Pharma, Inc.: Employment. Petersen:Zoneone Pharma, Inc.: Employment. Noble:Zoneone Pharma, Inc.: Employment, Equity Ownership. Hayes:Zoneone Pharma, Inc.: Employment, Equity Ownership. Working:Zoneone Pharma, Inc.: Consultancy, Equity Ownership. Szoka:Zoneone Pharma, Inc.: Consultancy, Equity Ownership.

Dual-energy CT for liver iron quantification in patients with haematological disorders

2018 ◽  
Vol 29 (6) ◽  
pp. 2868-2877 ◽  
Author(s):  
Sebastian Werner ◽  
Bernhard Krauss ◽  
Ulrike Haberland ◽  
Malte Bongers ◽  
Uwe Starke ◽  
...  
Keyword(s):  
Dual Energy ◽  
Dual Energy Ct ◽  
Liver Iron ◽  
Iron Quantification ◽  
Haematological Disorders

Iron Deficiency in Distance Runners A Reinvestigation Using 59Fe-Labelling and Non-Invasive Liver Iron Quantification

1996 ◽  
Vol 17 (07) ◽  
pp. 473-479 ◽  
Author(s):  
D. Nachtigall ◽  
P. Nielsen ◽  
R. Fischer ◽  
R. Engelhardt ◽  
E. Gabbe
Keyword(s):  
Iron Deficiency ◽  
Distance Runners ◽  
Liver Iron ◽  
Non Invasive ◽  
Iron Quantification

scholarly journals Reproducibility of liver R2* quantification for liver iron quantification from cardiac R2* acquisitions

2021 ◽  
Author(s):  
M. R. Muehler ◽  
K. Vigen ◽  
D. Hernando ◽  
A. Zhu ◽  
T. J. Colgan ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Eddy Currents ◽  
Linear Regression Analysis ◽  
Mapping Method ◽  
Breath Hold ◽  
Liver Iron ◽  
Phase Errors ◽  
Iron Quantification ◽  
Clinical Mri

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.

Comparison of Inline R2* MRI versus FerriScan for liver iron quantification in patients on chelation therapy for iron overload: preliminary results

2021 ◽  
Author(s):  
Gerard M. Healy ◽  
Stephan A. R. Kannengiesser ◽  
Osvaldo Espin-Garcia ◽  
Richard Ward ◽  
Kevin H. M. Kuo ◽  
...  
Keyword(s):  
Iron Overload ◽  
Chelation Therapy ◽  
Liver Iron ◽  
Preliminary Results ◽  
Iron Quantification
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