The role of diffusion-weighted imaging in prediction liver iron concentration in beta-thalassaemia patients.

OBJECTIVE: The aim of this study was to analyse the value of diffusion-weighted magnetic resonance imaging (DWI) to determine the liver parenchyma iron concentration in β-thalassaemia major patients.

METHODS: Abdominal magnetic resonance (MR) imaging, including gradient echo sequences and DWI sequences, was undertaken of 55 β-thalassaemia major patients. The apparent diffusion coefficient (ADC) values of liver parenchyma were measured in seven regions at the level of the portal bifurcation and compared with liver iron concentration (LIC). Patients with normal and mild liver dry weight (LDW) results were classified as group 1, whereas patients with moderate and severe values were classified as group 2.

RESULTS: There was a dramatic decrease in ADC values as the severity of LIC increased. The median ADC values were 1.6-1.9 × 10-3  mm2 /sec in group 1 and 0.6-0.9 × 10-3  mm2 /sec in group 2. A negative correlation was observed between ADC and the LDW values in both groups. The ADC and LIC correlation in each subgroup was statistically significant with asymptotic 95% confidence intervals of 0.820-0.997.

CONCLUSION: Diffusion-weighted imaging is sensitive to tissue changes as a result of iron accumulation and may be used to predict liver iron overload in β-thalassaemia major patients with a high sensitivity and specificity.