MRI assessment of liver iron content in thalassamic patients with three different protocols: comparisons and correlations

Christoforidis, Athanasios; Perifanis, Vassilios; Σπανός, Γ.; Vlachaki, Efthimia; Economou, Marina; Tsatra, Ioanna; Athanassiou‐Metaxa, Miranda

doi:10.1111/j.1600-0609.2009.01223.x

Cited by 53 publications

(64 citation statements)

References 24 publications

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“…Current limitations of this methodology include lack of standardisation, interference due to external magnetic properties and an inability to quantify iron burden in heavily iron overloaded patients (dry weight >25mg/g) [7].…”

Section: Discussionmentioning

confidence: 99%

“…Validation of Liver T2* measurements against biopsy determined LIC has been documented by several groups [7][8][9][10][11] however there appears to be limited concordance between the studies. It has been hypothesised that inherent limitations of earlier MRI acquisition techniques, lack of methodology standardisation or sampling bias may have contributed to these inconsistencies.…”

Section: Discussionmentioning

confidence: 99%

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T2* MRI Correlates with R2 Liver Iron Concentration in Transfusion Dependent Thalassaemia

Clarke¹,

Kidson‐Gerber²,

Moses³

et al. 2016

Journal of Hematology and Blood Disorders

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Research ArticleOpen Access Regular transfusion in thalassaemia major results in progressive iron overload and its complications. Chelation therapy can prevent these complications and has been pivotal in the improved survival of these patients. With inadequate chelation, cardiac arrhythmias and cardiomyopathy are the predominant causes of death, while endocrinopathies and cirrhosis contribute to both morbidity and mortality [1][2][3]. Each chelating agent has potential risks and benefits. The accurate assessment of iron overload is therefore critical in guiding the appropriate choice of therapy and in managing adherence. AbstractRelaxometry based Magnetic Resonance Imaging (MRI) techniques have increasingly been adopted as a means of non invasive measurement of tissue iron concentration in patients with transfusion dependent thalassaemia. Currently, different MRI techniques are utilised to assess cardiac and hepatic iron concentrations, which correlate poorly. In an attempt to simplify the assessment of tissue iron concentration, we prospectively compared T2* MRI with R2 (FerriScan®) derived liver iron concentration. A strong correlation exists between these two modalities, particularly at lower iron burdens. These findings would enable the concurrent assessment of cardiac and liver iron concentration thus streamlining total body iron assessment. Method: 34 patients with β-thalassemia major underwent MRI assessment. R2 and T2* images were generated concurrently and R2 LIC calculated. Data was analysed with SAS/STAT 9. Conclusion:These results indicate there is a strong correlation between T2* MRI and R2 generated LIC. These findings have the potential to streamline iron assessment by facilitating the concurrent assessment of cardiac and liver iron concentration.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

T2* MRI Correlates with R2 Liver Iron Concentration in Transfusion Dependent Thalassaemia

Clarke¹,

Kidson‐Gerber²,

Moses³

et al. 2016

Journal of Hematology and Blood Disorders

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“…This may be crucial when therapeutic decisions are based on the results from noninvasive hepatic iron quantification. Christoforidis et al compared the data of three different MR protocols (R2* relaxometry with gradient-echo sequences, SIR method and R2) in the assessment of liver iron content [17]. A good correlation between liver R2* and R2 measurement (r = 0.886) and between the R2 and the SIR method (r = 0.927) was found.…”

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confidence: 99%

R2* Relaxometry for the Quantification of Hepatic Iron Overload: Biopsy-Based Calibration and Comparison with the Literature

Henninger

Zoller

Rauch

et al. 2015

Fortschr Röntgenstr

107

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We compared the calibration of hepatic iron based on R2* relaxometry and liver biopsy with similar studies that have already been published to investigate the transferability of published calibration curves. Materials and Methods: 17 patients with clinically suspected hepatic iron overload (HIO) were enrolled. All patients underwent liver biopsy and MRI of the liver using a multi-echo gradient echo sequence (TR = 200 ms; TE-initial 0.99 ms; Delta-TE 1.41 ms; 12 echos; flip-angle: 20°). R2* parameter maps were analyzed using manually placed regions of interest and R2* values were correlated with liver iron concentration (LIC) obtained from liver biopsy. In addition, the results of our study were compared with 6 similar, already published studies. Results: A linear relationship between R2* and LIC was found. Regression analysis yielded a correlation coefficient of 0.926, a slope of 0.024 (s mg/g) [95 % CI 0.013 -0.024] and an intercept of 0.277 (mg/g) [95 % CI -0.328 -2.49]. We found a significant correlation between the calibration curves obtained from our study in comparison to 3/6 similar studies. The other 3 studies used a different reference standard or sequence parameters which lead to a significant difference for slope, intercept or both in comparison to our data. Conclusion: Calibration curves from published studies that are based on a correlation of liver biopsy and R2* can be used for the estimation of liver iron concentration, although different scanning parameters and post-processing protocols were used. Low initial TEs might be a prerequisite for pooling data for liver iron quantification.

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“…The LIC overestimation, particularly in the range around 80 µmol/g (4.5 mg/g) that is important for treatment management, will often result in overtreatment. Deviations of the method publicized by Gandon from R 2 *-based methods were also observed [31,42]. Gandon's method is limited to a maximum liver iron content of 350 µmol/g (20 mg/g) which is often exceeded particularly in patients receiving regular transfusions.…”

Section: Signal-intensity Ratiomentioning

confidence: 99%

“…Unfortunately, an adequate analy-sis method with consideration of the liver fat content has only been insufficiently evaluated to date. 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.…”

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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MRI assessment of liver iron content in thalassamic patients with three different protocols: comparisons and correlations

Cited by 53 publications

References 24 publications

T2* MRI Correlates with R2 Liver Iron Concentration in Transfusion Dependent Thalassaemia

T2* MRI Correlates with R2 Liver Iron Concentration in Transfusion Dependent Thalassaemia

R2* Relaxometry for the Quantification of Hepatic Iron Overload: Biopsy-Based Calibration and Comparison with the Literature

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

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