Eighty eight patients with 91 uterine leiomyomas who underwent ultrasound-guided percutaneous microwave ablation (PMWA) treatment were prospectively included in the study in order to study the dose-effect relationship parameters (DERP) of PMWA for uterine leiomyomas and its relationship with T2-weighted MR imaging (T2WI). Based on the signal intensity of T2WI, uterine leiomyomas were classified as hypointense, isointense, and hyperintense. During ablation, leiomyomas were treated with quantitative microwave ablation (QMWA) energy of 50â
w Ă 300â
s or 60â
w Ă 300â
s. After QMWA, contrast-enhanced ultrasound (CEUS) was performed to evaluate DERP. No matter under 50â
w Ă 300â
s or 60â
w Ă 300â
s, quantitative microwave ablation volume (QMAV) of hyperintense leiomyoma was smaller than that of hypointense and isointense leiomyoma (P<0.016). For hypointense and isointense leiomyoma, QMAV of 60â
w Ă 300â
s was larger than that of 50â
w Ă 300â
s (P<0.05). DERPs obtained by T2WI can be used to guide the treatment of uterine leiomyoma by PMWA.