MR Quantification of Hepatic Iron Concentration

Alústiza, J.M.; Artetxe, Jose; Castiella, Agustín; Agirre, Cristina; Emparanza, José Ignacio; Otazua, Pedro; García-Bengoechea, M; Barrio, Jesús; Mujica, Fernando; Recondo, José Antonio

doi:10.1148/radiol.2302020820

Cited by 203 publications

(142 citation statements)

References 21 publications

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“…The parameters utilized for the sequences acquisition were based on the protocol proposed by Alústiza et al (8) . The technique comprised five breath-hold GRE sequences (20 sections each), and one TSE trigger sequence (with respiratory synchronization and 35 sections), whose details are described on Table 1.…”

Section: Methodsmentioning

confidence: 99%

“…Several studies have described the utilization of MRI in the quantification of hepatic iron content, with variable results among them (5)(6)(7)(8)(9) . Iron overload causes a decrease in the signal intensity of the hepatic parenchyma and the measurement of such an overload is possible since there is a correlation between the magnitude of signal reduction and the degree of iron excess (8) .…”

Section: Introductionmentioning

confidence: 99%

“…Iron overload causes a decrease in the signal intensity of the hepatic parenchyma and the measurement of such an overload is possible since there is a correlation between the magnitude of signal reduction and the degree of iron excess (8) .…”

Section: Introductionmentioning

confidence: 99%

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Sobrecarga de ferro transfusional em portadores de anemia falciforme: comparação entre ressonância magnética e ferritina sérica

Filho¹,

Ferrão

França

et al. 2011

Radiol Bras

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Objective: To identify predictive variables of iron overload in patients with sickle cell anemia, correlating biochemical and imaging markers. Materials and Methods: The authors developed a cross-sectional study involving 32 patients with sickle cell anemia who were evaluated for ferritin and iron serum levels and submitted to liver magnetic resonance imaging with one spin-echo and five gradient-echo sequences. The signal intensity was obtained at each sequence, corresponding to the arithmetical mean of the measurements on regions of interest in the liver and paraspinal muscles to obtain the liver/muscle signal intensity ratio (SIR). Based on such SIR, the liver iron concentration (LIC) was estimated by means of the following formula: e [5.808 -(0.877 × T2*) -(1.518 × IW)] , where T2* is the SIR on the sequence with echo time = 13 ms and IW is the SIR on the intermediate-weighted sequence. Patients were grouped according to their blood transfusion regimen (regular monthly versus sporadic transfusions). Results: The comparison between the transfusion groups was based on clinical-laboratory variables, with significant differences in SIR, LIC and serum ferritin levels: the group with regular transfusions demonstrated greater hepatic iron overload. Conclusion: Magnetic resonance imaging is an efficient tool for evaluating liver iron overload in patients with sickle cell anemia. Keywords: Sickle cell anemia; Magnetic resonance imaging; Ferritin.Objetivo: Identificar variáveis preditoras de sobrecarga de ferro em portadores de anemia falciforme e correlacionar indicadores bioquímicos e imaginológicos. Materiais e Métodos: Foi realizado estudo transversal envolvendo 32 portadores de anemia falciforme, que foram submetidos a dosagem sérica de ferro, ferritina e a ressonância magné-tica do fígado. Foram realizadas cinco sequências gradiente-eco e uma spin-eco. A intensidade de sinal foi obtida em cada sequência pelas médias das regiões de interesse no fígado e musculatura paravertebral para obter a razão da intensidade de sinal (RIS) fígado/músculo. A partir da RIS foi obtida a concentração hepática estimada de ferro (CHEF) pela fórmula: e [5,808 -(0,877 × T2*) -(1,518 × PI)] , onde T2* é a RIS na sequência com TE de 13 ms e PI é a RIS da sequência com ponderação intermediária. Os pacientes foram agrupados segundo o regime de transfusão de hemácias (regulares mensais versus esporádicas). Resultados: Os grupos transfusionais foram comparados pelas variáveis clínico-laboratoriais, sendo significativas as diferenças entre RIS, CHEF e ferritina sérica: o grupo que recebeu transfusões regulares apresentou sobrecarga de ferro hepático mais intensa. Conclusão: A ressonância magnética foi ferramenta eficiente para avaliação de sobrecarga hepática de ferro em portadores de anemia falciforme. Unitermos: Anemia falciforme; Imagem por ressonância magnética; Ferritina. AbstractResumo

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Sobrecarga de ferro transfusional em portadores de anemia falciforme: comparação entre ressonância magnética e ferritina sérica

Filho¹,

Ferrão

França

et al. 2011

Radiol Bras

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“…Gandon's method is based on the postulated linear relationship between the LIC and signal intensity ratio (SIR) depending on the protocol. It is available free of cost via a web interface, is relatively widely used, and is sometimes called the SIR method although alternatives to the analysis of the SIR values used by Gandon are conceivable [18]. A comparison between Gandon's approach and the Ferriscan ® method showed a discrepancy in the results, namely a significant overestimation of the LIC in the range of 50 -300 µmol/g (3 -17 mg/g) [41].…”

Section: Signal-intensity Ratiomentioning

confidence: 99%

“…The analysis of signal ratios between the liver and reference tissue according to Gandon [19] is apparently problematic [31,41,42]. A further approach introduced by Alustiza that also uses the signal ratio [18] has received little attention. A new analysis method based on SIR allows reliable determination of liver iron content at 3 Tesla [44].…”

mentioning

confidence: 99%

Noninvasive MRI-Based Liver Iron Quantification: Methodic Approaches, Practical Applicability and Significance

Wunderlich

Cario²,

Juchems

et al. 2016

Fortschr Röntgenstr

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Pathophysiology of iron overload ▼Normal iron content plays an important role in the physiological processes of the human body. A disturbance to the precisely regulated iron metabolism system has serious consequences. Therefore, for example, iron overload results in oxidative damage to membrane lipids and proteins and in DNA damage that can cause mitochondrial and lysosomal dysfunction, changes in gene expression, and changes in tumor suppressor genes (p53). Organ damage due to iron overload primarily affects the heart and liver as well as the endocrine organs, i. e., the pituitary gland, pancreas, thyroid, parathyroid, and gonads [1]. Cardiac insufficiency and arrhythmia as a result of myocardial siderosis are the most Abstract ▼Due to the dependence of transverse relaxation times T 2 and T 2 * on tissue iron content, MRI offers different options for the determination of iron concentration. These are the timeconsuming spin-echo sequence as well as the gradient-echo sequence. For the latter, several data analysis approaches have been proposed, with different requirements for acquisition and post-processing: the mathematically challenging R 2 * analysis and the signal-intensity ratio method with its high demand on the signal homogeneity of MR images. Furthermore, special procedures currently under evaluation are presented as future prospects: quantitative susceptibility imaging, as a third approach for analyzing gradient echo data, and multicontrast spin-echo using repeated refocusing pulses. MR theory, as far as needed for understanding the methods, is briefly depicted.

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Inherited Bone Marrow Failure Syndromes

Dror¹

2006

Pediatric Hematology

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MR Quantification of Hepatic Iron Concentration

Abstract: MR imaging is a useful and noninvasive diagnostic tool for quantification of hepatic iron concentration.

Cited by 203 publications

References 21 publications

Sobrecarga de ferro transfusional em portadores de anemia falciforme: comparação entre ressonância magnética e ferritina sérica

Sobrecarga de ferro transfusional em portadores de anemia falciforme: comparação entre ressonância magnética e ferritina sérica

Noninvasive MRI-Based Liver Iron Quantification: Methodic Approaches, Practical Applicability and Significance

Inherited Bone Marrow Failure Syndromes

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