Quantitative analysis of hepatic iron in patients suspected of coexisting iron overload and steatosis using multi-echo single-voxel magnetic resonance spectroscopy: Comparison with fat-saturated multi-echo gradient echo sequence.

<bold>Background: </bold>The coexistence of hepatic iron and fat is common in patients with hyperferritinemia, which plays an interactive and aggressive role in the progression of diseases (fibrosis, cirrhosis, and hepatocellular carcinomas).<bold>Purpose: </bold>To evaluate a modified high-speed T2 -corrected multi-echo, single voxel spectroscopy sequence (HISTOV) for liver iron concentration (LIC) quantification in patients with hyperferritinemia, with simultaneous fat fraction (FF) estimation.<bold>Study Type: </bold>Retrospective cohort study.<bold>Population: </bold>Thirty-eight patients with hyperferritinemia were enrolled.<bold>Field Strength/sequence: </bold>HISTOV, a fat-saturated multi-echo gradient echo (GRE) sequence, and a spin echo sequence (FerriScan) were performed at 1.5T.<bold>Assessment: </bold>R2 of the water signal and FF were calculated with HISTOV, and R2* values were derived from the GRE sequence, with R2 and LIC from FerriScan serving as the references.<bold>Statistical Tests: </bold>Linear regression, correlation analyses, receiver operating characteristic analyses, and Bland-Altman analyses were conducted.<bold>Results: </bold>Abnormal hepatic iron load was detected in 32/38 patients, of whom 10/32 had coexisting steatosis. Strong correlation was found between R2* and FerriScan-LIC (R2 = 0.861), and between HISTOV-R2_ water and FerriScan-R2 (R2  = 0.889). Furthermore, HISTOV-R2_ water was not correlated with HISTOV-FF. The area under the curve (AUC) for HISTOV-R2_ water was 0.974, 0.971, and 1, corresponding to clinical FerriScan-LIC thresholds of 1.8, 3.2, and 7.0 mg/g dw, respectively. No significant difference in the AUC was found between HISTOV-R2_ water and R2* at any of the LIC thresholds, with P-values of 0.42, 0.37, and 1, respectively. HISTOV-LIC showed excellent agreement with FerriScan-LIC, with a mean bias of 0.00 ± 1.18 mg/g dw, whereas the mean bias between GRE-LIC and FerriScan-LIC was 0.53 ± 1.49 mg/g dw.<bold>Data Conclusion: </bold>HISTOV is useful for the quantification and grading of liver iron overload in patients with hyperferritinemia, particularly in cases with coexisting steatosis. HISTOV-LIC showed no systematic bias compared with FerriScan-LIC, making it a promising alternative for iron quantification.<bold>Level Of Evidence: </bold>3 Technical Efficacy Stage 2 J. Magn. Reson. Imaging 2018. [ABSTRACT FROM AUTHOR]