Magnetic resonance-guided focused ultrasound surgery for uterine fibroids: relationship between the therapeutic effects and signal intensity of preexisting T2-weighted magnetic resonance images.

OBJECTIVE: This study was undertaken to clarify the relationship between the signal intensity of T2-weighted magnetic resonance images and the therapeutic effect of magnetic resonance-guided focused ultrasound surgery (MRgFUS) on uterine fibroids. STUDY DESIGN: Ninety-five fibroids in 63 patients were classified into 3 types based on the signal intensity of T2-weighted magnetic resonance images as follows: type 1, low intensity; type 2, intermediate intensity; type 3, high intensity. The treated area ratio of MRgFUS and the volume reduction ratio 6 months after treatment were used as the indices of therapeutic effect. RESULTS: The treated area ratio of type 3 fibroids was the lowest among the 3 types (P < .01). The volume reduction ratio correlated with the treated area ratio (r = 0.64; P < .01). CONCLUSION: The efficacy of MRgFUS correlates with the signal intensity of T2-weighted magnetic resonance images. Type 1 and type 2 fibroids are suitable candidates for MRgFUS, whereas type 3 fibroids are not.

Giant cystic leiomyoma of the uterus occupying the retroperitoneal space.

A 31-year-old nulliparous woman visited our hospital complaining of abdominal distension. Abdominal ultrasonography and computed tomography revealed a 40 × 40 × 30-cm, multilocular cystic mass extending from the upper abdomen to the pelvis. Magnetic resonance imaging (MRI) revealed a cystic tumor that was hypointense on T1-weighted images and was heterogeneously hyperintense on T2-weighted images. The final diagnosis was an 8 kg leiomyoma with cystic degeneration. Uterine leiomyomas are common benign tumors in females of reproductive age. However, subserosal leiomyomas with complete cystic degeneration of the retroperitoneal space are rare, and they are difficult to accurately diagnosis without pathological examination.

Adenomyosis with extensive glandular proliferation simulating infiltrating malignancy on magnetic resonance imaging.

We report a case of multicystic adenomyosis, which is an exceedingly rare benign tumor. The patient complained of an irregular menstrual cycle and abnormal genital bleeding that gradually increased in amount and frequency. The patient finally became severely anemic, and a hysterectomy was therefore performed. T2-weighted magnetic resonance imaging (MRI) indicated hyperplasia of the endometrium, with a myometrial lesion, where a high signal intensity multicystic mass was observed. The preoperative diagnosis was complicated by confusing MRI results. Postoperative macroscopic examination revealed a villous endometrium and a myometrium thickened with multiple small cysts containing serous transparent fluid. The final diagnosis, based on the hysterectomy specimen, was adenomyosis coexisting with simple endometrial hyperplasia. The MRI and positron emission tomography images are presented.

Pregnancy outcome after magnetic resonance-guided focused ultrasound surgery (MRgFUS) for conservative treatment of uterine fibroids.

OBJECTIVE: To report all pregnancies to date after magnetic resonance-guided focused ultrasound surgery (MRgFUS) for the conservative treatment of clinically significant uterine fibroids. DESIGN: Prospective registry of all known pregnancies occurring after MRgFUS maintained by the device manufacturer and reported to the Food and Drug Administration. SETTING: World experience of pregnancies after treatment with reports from 13 sites in seven countries. PATIENT(S): Fifty-one reproductive-age women with uterine leiomyomas. INTERVENTION(S): Women underwent MRgFUS treatment for symptomatic uterine leiomyomas before this report. MAIN OUTCOME MEASURE(S): Pregnancy outcomes and complications. RESULT(S): Fifty-four pregnancies in 51 women have occurred after MRgFUS treatment of uterine leiomyomas. The mean time to conception was 8 months after treatment. Live births occurred in 41% of pregnancies, with a 28% spontaneous abortion rate, an 11% rate of elective pregnancy termination, and 11 (20%) ongoing pregnancies beyond 20 gestational weeks. The mean birth weight was 3.3 kg, and the vaginal delivery rate was 64%. CONCLUSION(S): Preliminary pregnancy experience after MRgFUS is encouraging, with a high rate of delivered and ongoing pregnancies.

Early results of magnetic resonance-guided focused ultrasound surgery of adenomyosis: analysis of 20 cases.

STUDY OBJECTIVE: To evaluate the thermal ablative effects of magnetic resonance-(MR) guided focused ultrasound surgery (MRgFUS) on adenomyosis and to assess improvement in clinical parameters. DESIGN: Twenty patients with adenomyosis were treated with MRgFUS. Extensive adenomyosis (6 cases) was treated with 2 applications. Uterine volume was evaluated by MR imaging before and immediately after MRgFUS. Ablation of adenomyosis and the architecture of nonperfused areas were evaluated immediately after MRgFUS. Improvement in patient symptoms was assessed through the symptom severity score questionnaire (Canadian Task Force classification II-3). SETTING: Department of gynecology at a Japanese general hospital. PATIENTS: Premenopausal women at least 18 years of age with symptomatic adenomyosis. INTERVENTIONS: Thermal ablation by MRgFUS. MEASUREMENTS AND MAIN RESULTS: We classified the nonperfused lesions on contrast-enhanced MR images immediately after MRgFUS into 3 types: lesions with round margins (type R), serrated margins (type S), and honeycomb architecture (type H). Type R was the most common (16/20 patients). Most adenomyosis lesions could be sufficiently ablated close to the serosal surface or to the endometrium by MRgFUS. The mean uterine volume 6 months after therapy was decreased by 12.7%. Symptom severity score improved significantly during 6 months of follow-up. No serious complications were observed. CONCLUSION: These early results indicate the safe and effective ablation of adenomyosis tissue by MRgFUS. The procedure also resulted in the improvement in clinical symptoms during the 6 months of follow-up.

Mid-term outcome of magnetic resonance-guided focused ultrasound surgery for uterine myomas: from six to twelve months after volume reduction.

STUDY OBJECTIVE: To clarify the volume change ratio of uterine myomas treated with magnetic resonance-guided focused ultrasound surgery (MRgFUS), in relation to the signal intensity of T(2)-weighted magnetic resonance (MR) images. DESIGN: Prospective study (Canadian Task Force classification II-3). SETTING: Department of Gynecology, Shinsuma General Hospital, Kobe, Japan. PATIENTS: Forty-eight myomas in 35 patients were followed up with MR images 6 months after MRgFUS, and 23 myomas in 17 patients were followed up 12 months after MRgFUS. Before treatment, the myomas were classified into 3 types on the basis of the signal intensity of T(2)-weighted MR images as follows: Type 1, low intensity; type 2, intermediate intensity; type 3, high intensity. INTERVENTIONS: Thermal ablation therapy was performed with an MRgFUS system (ExAblate 2000). MEASUREMENTS AND MAIN RESULTS: MRgFUS produced a greater volume reduction in type 1 and type 2 myomas than in type 3 myomas. Nonperfused areas always diminished in the period after MRgFUS; however, the volume change was affected by the volume change ratio of perfused areas inside the treated myomas. CONCLUSION: At present, type 3 myomas should be exempted from the application of MRgFUS, because the nonperfused ratio immediately after the procedure was small compared with that in type 1 and type 2 myomas, and the subsequent volume change was unfavorable.