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

摘要

BACKGROUND 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). PURPOSE To evaluate a modified high‐speed T 2 ‐corrected multi‐echo, single voxel spectroscopy sequence (HISTOV) for liver iron concentration (LIC) quantification in patients with hyperferritinemia, with simultaneous fat fraction (FF) estimation. STUDY TYPE Retrospective cohort study. POPULATION Thirty‐eight patients with hyperferritinemia were enrolled. FIELD STRENGTH/SEQUENCE HISTOV, a fat‐saturated multi‐echo gradient echo (GRE) sequence, and a spin echo sequence (FerriScan) were performed at 1.5T. ASSESSMENT R 2 of the water signal and FF were calculated with HISTOV, and R 2 * values were derived from the GRE sequence, with R 2 and LIC from FerriScan serving as the references. STATISTICAL TESTS Linear regression, correlation analyses, receiver operating characteristic analyses, and Bland‐Altman analyses were conducted. RESULTS Abnormal hepatic iron load was detected in 32/38 patients, of whom 10/32 had coexisting steatosis. Strong correlation was found between R 2 * and FerriScan‐LIC ( R 2 = 0.861), and between HISTOV‐R 2_ water and FerriScan‐R 2 ( R 2 ?=?0.889). Furthermore, HISTOV‐R 2_ water was not correlated with HISTOV‐FF. The area under the curve (AUC) for HISTOV‐R 2_ 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‐R 2_ water and R 2 * 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. DATA CONCLUSION 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. Level of Evidence : 3 Technical Efficacy Stage 2 J. Magn. Reson. Imaging 2018.