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Measurement of liver iron concentration by MRI is reproducible.

Alústiza JM, Emparanza JI, Castiella A, Casado A, Garrido A, Aldazábal P, San Vicente M, Garcia N, Asensio AB, Banales J, Salvador E, Moyua A, Arozena X, Zarco M, Jauregui L, Vicente O - Biomed Res Int (2015)

Bottom Line: The phantom was analysed in the same equipment and 14 times in the reference machine.FeCl3 solutions containing 0.3, 0.5, 0.6, and 1.2 mg Fe/mL were chosen to generate the phantom.The average of the intramachine variability for patients was 10% and for the intermachines 8%.

View Article: PubMed Central - PubMed

Affiliation: Osatek, Donostia Universitary Hospital, P. Dr. Beguiristain 109, 20014 Donostia/San Sebastián, Spain.

ABSTRACT

Purpose: The objectives were (i) construction of a phantom to reproduce the behavior of iron overload in the liver by MRI and (ii) assessment of the variability of a previously validated method to quantify liver iron concentration between different MRI devices using the phantom and patients.

Materials and methods: A phantom reproducing the liver/muscle ratios of two patients with intermediate and high iron overload. Nine patients with different levels of iron overload were studied in 4 multivendor devices and 8 of them were studied twice in the machine where the model was developed. The phantom was analysed in the same equipment and 14 times in the reference machine.

Results: FeCl3 solutions containing 0.3, 0.5, 0.6, and 1.2 mg Fe/mL were chosen to generate the phantom. The average of the intramachine variability for patients was 10% and for the intermachines 8%. For the phantom the intramachine coefficient of variation was always below 0.1 and the average of intermachine variability was 10% for moderate and 5% for high iron overload.

Conclusion: The phantom reproduces the behavior of patients with moderate or high iron overload. The proposed method of calculating liver iron concentration is reproducible in several different 1.5 T systems.

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Related in: MedlinePlus

Relationship between liver-to-muscle signal intensity ratio (SIR) and liver iron concentration (LIC) for 112 patients. SIRs of the phantom for moderate (A1-B1) and for high iron overload (A2-B2) in the two sequences of the method have also been included in the graph. (a) IW sequence (TR/TE/Flip 120/4/20°); (b) T2 sequence (TR/TE/Flip 120/14/20°). The values A1 and B1 correspond to the same LIC value in each of the two sequences: 62 μmol Fe/g and they maintain the same correlation SIR/LIC as patients in the two sequences. The same applies to A2 and B2 values for high iron overload, with a value of LIC of μmol Fe/g in both sequences.
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fig3: Relationship between liver-to-muscle signal intensity ratio (SIR) and liver iron concentration (LIC) for 112 patients. SIRs of the phantom for moderate (A1-B1) and for high iron overload (A2-B2) in the two sequences of the method have also been included in the graph. (a) IW sequence (TR/TE/Flip 120/4/20°); (b) T2 sequence (TR/TE/Flip 120/14/20°). The values A1 and B1 correspond to the same LIC value in each of the two sequences: 62 μmol Fe/g and they maintain the same correlation SIR/LIC as patients in the two sequences. The same applies to A2 and B2 values for high iron overload, with a value of LIC of μmol Fe/g in both sequences.

Mentions: A subject with IW and T2 ratios corresponding to intermediate iron overload would be predicted to have an LIC of 62 μmol Fe/g by our equation. On the other hand, a person with high iron overload ratios would be estimated to have an LIC of 180 μmol Fe/g. These values are very similar to those obtained in our groups of real patients with moderate (51 μmol Fe/g) and high (187 μmol Fe/g) iron overload (Figure 3).


Measurement of liver iron concentration by MRI is reproducible.

Alústiza JM, Emparanza JI, Castiella A, Casado A, Garrido A, Aldazábal P, San Vicente M, Garcia N, Asensio AB, Banales J, Salvador E, Moyua A, Arozena X, Zarco M, Jauregui L, Vicente O - Biomed Res Int (2015)

Relationship between liver-to-muscle signal intensity ratio (SIR) and liver iron concentration (LIC) for 112 patients. SIRs of the phantom for moderate (A1-B1) and for high iron overload (A2-B2) in the two sequences of the method have also been included in the graph. (a) IW sequence (TR/TE/Flip 120/4/20°); (b) T2 sequence (TR/TE/Flip 120/14/20°). The values A1 and B1 correspond to the same LIC value in each of the two sequences: 62 μmol Fe/g and they maintain the same correlation SIR/LIC as patients in the two sequences. The same applies to A2 and B2 values for high iron overload, with a value of LIC of μmol Fe/g in both sequences.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385637&req=5

fig3: Relationship between liver-to-muscle signal intensity ratio (SIR) and liver iron concentration (LIC) for 112 patients. SIRs of the phantom for moderate (A1-B1) and for high iron overload (A2-B2) in the two sequences of the method have also been included in the graph. (a) IW sequence (TR/TE/Flip 120/4/20°); (b) T2 sequence (TR/TE/Flip 120/14/20°). The values A1 and B1 correspond to the same LIC value in each of the two sequences: 62 μmol Fe/g and they maintain the same correlation SIR/LIC as patients in the two sequences. The same applies to A2 and B2 values for high iron overload, with a value of LIC of μmol Fe/g in both sequences.
Mentions: A subject with IW and T2 ratios corresponding to intermediate iron overload would be predicted to have an LIC of 62 μmol Fe/g by our equation. On the other hand, a person with high iron overload ratios would be estimated to have an LIC of 180 μmol Fe/g. These values are very similar to those obtained in our groups of real patients with moderate (51 μmol Fe/g) and high (187 μmol Fe/g) iron overload (Figure 3).

Bottom Line: The phantom was analysed in the same equipment and 14 times in the reference machine.FeCl3 solutions containing 0.3, 0.5, 0.6, and 1.2 mg Fe/mL were chosen to generate the phantom.The average of the intramachine variability for patients was 10% and for the intermachines 8%.

View Article: PubMed Central - PubMed

Affiliation: Osatek, Donostia Universitary Hospital, P. Dr. Beguiristain 109, 20014 Donostia/San Sebastián, Spain.

ABSTRACT

Purpose: The objectives were (i) construction of a phantom to reproduce the behavior of iron overload in the liver by MRI and (ii) assessment of the variability of a previously validated method to quantify liver iron concentration between different MRI devices using the phantom and patients.

Materials and methods: A phantom reproducing the liver/muscle ratios of two patients with intermediate and high iron overload. Nine patients with different levels of iron overload were studied in 4 multivendor devices and 8 of them were studied twice in the machine where the model was developed. The phantom was analysed in the same equipment and 14 times in the reference machine.

Results: FeCl3 solutions containing 0.3, 0.5, 0.6, and 1.2 mg Fe/mL were chosen to generate the phantom. The average of the intramachine variability for patients was 10% and for the intermachines 8%. For the phantom the intramachine coefficient of variation was always below 0.1 and the average of intermachine variability was 10% for moderate and 5% for high iron overload.

Conclusion: The phantom reproduces the behavior of patients with moderate or high iron overload. The proposed method of calculating liver iron concentration is reproducible in several different 1.5 T systems.

Show MeSH
Related in: MedlinePlus