Liver iron concentration quantification by MRI: are recommended protocols accurate enough for clinical practice?

Castiella, Agustín; Alústiza, J.M.; Emparanza, José Ignacio; Zapata, Eva; Costero, Belén; Díez, Maria I.

doi:10.1007/s00330-010-1899-z

Cited by 43 publications

(28 citation statements)

References 22 publications

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“…Comparing our data with this study, however, we also found a significant difference between the calibration curve given by Virtanen et al and our data. In accordance with other studies, our data indicate that the SIR method apparently overestimates LIC [23]. This may be crucial when therapeutic decisions are based on the results from noninvasive hepatic iron quantification.…”

supporting

confidence: 91%

“…The correlation between both methods was still significant (r = 0.85). Castiella et al recently demonstrated that the SIR method has a tendency to overestimate LIC and that it could measure iron up to 350 μmol/g (19.5 mg/g) [23]. None of our patients had an LIC at that level, although one patient with HFE-associated hemochromatosis had an LIC of 11.64 mg/g which is quite high for that disease.…”

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confidence: 52%

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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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supporting

confidence: 91%

mentioning

confidence: 52%

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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“…Of those, magnetic resonance imaging (MRI) using gradient-echo sequences with long echo times as well as recently introduced multi-echo gradient-echo sequences have proven to be promising methods [3,4]. However, MRI showed limitations including an overestimation of the LIC [5], and an inability to quantify LIC above 300 μmol/g owing to the strong paramagnetic effect of iron resulting in signal loss [6].…”

Section: Introductionmentioning

confidence: 99%

Quantification of liver iron content with CT—added value of dual-energy

et al. 2011

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Virtual iron concentration images generated from DECT provide added value for the quantification of LIC by disregarding the confounding effect of the natural variation of healthy liver attenuation and of co-existing liver fat. AbstractObjective To evaluate the value of dual-energy CT (DECT) with use of an iron-specific, three-material decomposition algorithm for the quantification of liver iron content (LIC). Methods Thirty-one phantoms containing liver tissue, fat and iron were scanned with dual-source CT using singleenergy at 120 kV (SECT) and DECT at 80 kV and 140 kV. Virtual iron concentration (VIC) images derived from an iron-specific, three-material decomposition algorithm and measurements of fat-free and fat-containing phantoms were compared with the LIC and healthy liver tissue. Results In the absence of fat significant linear correlations were found between LIC and HU from SECT and VIC (r= 0.984-0.997, p<0.001) with a detection limit of 145.4 μmol/g LIC for SECT, whereas VIC accurately quantified the lowest LIC of 20 μmol/g dry liver. In the presence of fat, no significant correlation was observed between LIC and SECT, whereas significant correlations were found for VIC. Compared with fat-free phantoms, significant underestimation of LIC was seen for SECT with increasing amounts of fat (all, p≤0.01). On the other hand, similar HU were seen for VIC of fat-containing compared with fat-free phantoms (p>0.632). Conclusions Virtual iron concentration images generated from DECT provide added value for the quantification of LIC by disregarding the confounding effect of the natural variation of healthy liver attenuation and of co-existing liver fat.

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“…A liver biopsy requires a patient to stay in the hospital and is expensive. The MRI tends to overestimate the iron concentration because of its magnetic field [1]. For accurate measurement of the iron concentration, X-ray computed tomography (CT) is a very promising method.…”

Section: Introductionmentioning

confidence: 99%

Energy-resolved computed tomography measurements of iron solution and adipose as a simulation for estimating the iron concentration in the human liver

Yamashita

Shimazaki

Shima

et al. 2013

Journal of Nuclear Science and Technology

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To measure the iron concentration in the human liver, which comprises soft tissue and adipose as well as iron, energy-resolved computed tomography (CT) is applied using a transXend detector. The transXend detector measures X-rays as electric current and gives an energy distribution after analysis. Energy-resolved CT clearly separates iron solution from acrylic, a substitute for soft tissue, whereas conventional currentmeasurement CT cannot. Using CT values obtained in two different energy ranges, a two-dimensional map of iron, adipose and soft tissue is plotted. With this map, the components in the liver can be identified.

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Liver iron concentration quantification by MRI: are recommended protocols accurate enough for clinical practice?

Abstract: The assessment of LIC with the URennes method was useful in 74.3% of the patients to rule out or to diagnose high iron overload. The method has a tendency to overestimate overload, which limits its diagnostic performance.

Cited by 43 publications

References 22 publications

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

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

Quantification of liver iron content with CT—added value of dual-energy

Energy-resolved computed tomography measurements of iron solution and adipose as a simulation for estimating the iron concentration in the human liver

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