The value of apparent diffusion coefficient map with low b-value to monitor the therapy of high-intensity focused ultrasonic for uterine fibroids / 实用放射学杂志

ABSTRACT

Objective To assess the value of apparent diffusion coefficient (ADC)map with low b-value to monitor the ablated tissue after high-intensity focused ultrasonic (HIFU)treatment for uterine fibroids.Methods 25 patients with 34 uterine fibroids were treated with HIFU.All patients underwent the routine MRI scans (including pre-and post-contrast scanning)and monoexponential model DWI with b values of 150,600 and 1 000 s/mm2 before the surgery and within 24 hours after the surgery.The mean ADC values with different b-values of the ablated and non-ablated tissues between pre-and post-treatment were analyzed by one-way ANOVA test.The consistency of the ablation area between ADC maps with different b-values and contrast enhancement MRI were evaluated. Results With the b-value of 150 s/mm2 ,the mean ADC value of the ablated tissue was (1.48±0.27)×10-3 mm2/s,which was less significantly than that of pre-treatment (2.06±0.21)×10-3 mm2/s and non-ablated tissue (1.98±0.23)×10-3 mm2/s (P0.05).A fine consistency of the ADC map with the low b-value (150 s/mm2 )was found with non-perfusion volume on contrast-enhanced T1 WI,which was superior to that with high b-values (600 s/mm2 and 1 000 s/mm2 )(P<0.05).Conclusion ADC map with low b-value (150 s/mm2 )can be used to evaluate the blood-supply changes and ablated volume of uterine fibroids indirectly,which helps to assess the treatment effect of HIFU.