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.