This is a phase 3 study to determine the safety of the new features to the FDA approved ExAblate device using a new method to ablate fibroids deemed Enhanced Sonication.

Uterine leiomyoma (fibroids) are the most common neoplasms of the female pelvis. These benign tumors are generally oval in shape, and often highly vascular. On T2 weighted MR imaging exams, or T1 exams with contrast, uterine fibroids are easily identifiable. They occur in 20-25% of women of reproductive age and can cause a variety of problems generally described as either bleeding or mass effects from the fibroid. InSightec has developed an Enhanced Sonication (ES) technique for the ablation of these fibroids. This mode of tissue ablation has been added to the already FDA approved ExAblate system. The goal of this ES technique is to provide an additional treatment tool that will enhance the treatment effect without additional risks while preserving ALL clinical features of the current commercially approved version.

Inclusion Criteria:

1. Women age 18 or older, who present with symptomatic fibroids
2. Women who have given written informed consent
3. Women who are able and willing to attend all study visits.
4. Patient is pre or peri-menopausal (within 12 months of last menstrual period).
5. Able to communicate sensations during the ExAblate procedure.
6. Uterine fibroids, which are device accessible (i.e., positioned in the uterus such that they can be accessed without being shielded by bowel or bone).
7. Fibroids(s) clearly visible on non-contrast MRI.

Exclusion Criteria:

1. Women who are pregnant, as confirmed by serum test at time of screening, or urine pregnancy test on the day of treatment
2. Patient who desire to become pregnant in the future.
3. Patients who are breast-feeding.
4. Patients with an active pelvic inflammatory disease (PID)
5. Active local or systemic infection
6. Metallic implants that are incompatible with MRI
7. Known intolerance to the MRI contrast agent (e.g. Gadolinium or Magnevist)
8. Severe claustrophobia that would prevent completion of procedure in the MR unit.
9. Extensive abdominal scarring in the beam pass or dermoid cyst of the ovary anywhere in the treatment path.
10. Known or suspected pelvic carcinoma or pre-malignant conditions, including sarcoma and adenomatous hyperplasia.
11. Pedunculated fibroids.
12. Intrauterine device (IUD) anywhere in the treatment path
13. Undiagnosed vaginal bleeding.

Out of the 50 treated subjects, 48 received Enhanced Sonications (ITT) and 2 received only normal sonications.