Non-contrast enhanced MRI for efficiency evaluation of high-intensity focused ultrasound in adenomyosis ablation.

Objective: To investigate the value of T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) in evaluating the therapeutic effect of high-intensity focused ultrasound (HIFU) in adenomyosis ablation.

Material and methods: One hundred eighty-nine patients with adenomyosis were treated with HIFU. The ablation areas on T2WI and DWI sequences were classified into different types: type I, relatively ill-defined rim or unrecognizable; subtype IIa, well-defined rim with hyperintensity; subtype IIb, well-defined rim with hypointensity. The volume of ablation areas on T2WI (V_T2WI) and DWI (V_DWI) was measured and compared with the non-perfused volume (NPV), and linear regression was conducted to analyze their correlation with NPV.

Results: The V_T2WI of type I and type II (subtype IIa and subtype IIb) were statistically different from the corresponding NPV (p = 0.004 and 0.024, respectively), while no significant difference was found between the V_DWI of type I and type II with NPV (p = 0.478 and 0.561, respectively). In the linear regression analysis, both V_T2WI and V_DWI were positively correlated with NPV, with R² reaching 0.96 and 0.97, respectively.

Conclusions: Both T2WI and DWI have the potential for efficient evaluation of HIFU treatment in adenomyosis, and DWI can be a replacement for CE-T1WI to some extent.