Liver Diffusion Weighted MRI: Effect of Iron Overload on Apparent Diffusion Coefficient.

Area of Science:

• Radiology
• Medical Imaging
• Biophysics

Background:

• Beta-thalassemia patients often develop liver iron overload due to frequent blood transfusions.
• Hepatic iron concentration (LIC) can lead to liver dysfunction and fibrosis.
• Accurate, non-invasive assessment of LIC is critical for managing beta-thalassemia.

Purpose of the Study:

• To evaluate the impact of hepatic iron levels on liver apparent diffusion coefficient (ADC) values measured by MRI.
• To determine how different b-values influence the association between LIC and liver ADC.
• To assess the clinical implications of liver iron overload on quantitative diffusion-weighted imaging (DWI).

Main Methods:

• Prospective enrollment of 110 beta-thalassemia patients.
• Acquisition of diffusion-weighted imaging (DWI) with varying b-values (200, 600, 1000 s/mm²).
• Calculation of ADC values (ADC_200, ADC_600, ADC_1000) and measurement of liver T2* to estimate LIC.

Main Results:

• A significant inverse correlation was observed between LIC and all measured ADC values (ADC_200, ADC_600, ADC_1000).
• The correlation was strongest at higher b-values (ADC_600 and ADC_1000) compared to ADC_200.
• Patients with liver iron overload showed significantly lower ADC_600 and ADC_1000 values.

Conclusions:

• Liver iron overload is a significant confounding factor in quantitative liver DWI.
• Higher b-values (ADC_600, ADC_1000) are more sensitive to the effects of hepatic iron.
• Accounting for LIC is essential to prevent misinterpretation of liver ADC measurements in clinical practice.