Quantifying Bone Marrow Fat Fraction and Iron by MRI for Distinguishing Aplastic Anemia from Myelodysplastic Syndromes

BACKGROUND: Bone marrow of patients with aplastic anemia (AA) is different from that of patients with myelodysplastic syndrome (MDS) and is difficult to identify by blood examination. IDEAL‐IQ (iterative decomposition of water and fat with echo asymmetry and least‐squares estimation) imaging might be able to quantify fat fraction (FF) and iron content in bone tissues. PURPOSE: To determine if IDEAL‐IQ measurements of bone marrow FF and iron content can distinguish between patients with AA and MDS. STUDY TYPE: Retrospective. POPULATION: Fifty‐seven patients with AA, 21 patients with MDS, and 24 healthy controls. FIELD STRENGTH/SEQUENCE: 3.0 T, IDEAL‐IQ sequence. ASSESSMENT: Three independent observers evaluated the IDEAL‐IQ images and measured FF and R2* in the left posterior superior iliac spine. STATISTICAL TESTS: Kruskal–Wallis test, linear correlations, and Bland–Altman analysis were used. A P‐value of <0.05 was considered statistically significant. RESULTS: The FF in patients with AA (79.46% ± 15.00%) was significantly higher than that in patients with MDS (42.78% ± 30.09%) and control subjects (65.50% ± 14.73%). However, there was no significant difference in FF between control subjects and patients with MDS (P = 0.439). The R2* value of AA, MDS, and controls was 145.38 ± 53.33, (171.13 ± 100.89, and 135.99 ± 32.41/second, respectively, with no significant difference between the three groups (P = 0.553). DATA CONCLUSION: Quantitative IDEAL‐IQ magnetic resonance imaging may facilitate the diagnosis of AA and distinguish it from MDS. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2