Non-perfused Volume Ratio Research Articles

A novel method to aid in the visualisation and treatment of uterine fibroids with MRgFUS in patients with abdominal scars

The purpose of this research was to identify a method for performing Magnetic Resonance Imaging Guided Focused Ultrasound Surgery (MRgFUS) of symptomatic uterine fibroids in patients with abdominal scars, by visualisation of these scars on MR images. 25 patients who presented with treatable symptomatic uterine fibroids and having transverse abdominal scars were treated with MRgFUS. A solution containing MRI contrast paramagnetic iron oxide particles was used to demark the skin surface scar tissue on the treatment planning MR images. During treatment, the focused ultrasound energy was steered around the scar based on its enhanced visual location. After the treatment, contrast enhanced MR images were acquired for immediate results evaluation. Adverse events and fibroid related symptoms were captured during the 6-months follow up period. All the women were treated with no complications. No episodes of skin burns, ulceration or skin redness were reported. The post-treatment contrast-enhanced MR images showed an average fibroid non-perfused volume ratio of 64%. At their 6-month follow-up, 92% of the patients reported a clinical improvement. Using paramagnetic iron oxide solution to highlight transverse abdominal scars helps in their identification on MR images, thereby enabling the operator to avoid scars and facilitating the treatment of women who were previously excluded.

Sustained Relief of Leiomyoma Symptoms by Using Focused Ultrasound Surgery

To assess several measures of the long-term outcome of magnetic resonance-guided focused ultrasound surgery for symptomatic uterine leiomyomata. Data on 359 women completing 24-month follow-up in all clinical trials of magnetic resonance-guided focused ultrasound surgery for uterine leiomyomata were analyzed. Quality of life outcomes, measured by the symptom severity score of the Uterine Fibroid Symptoms Quality Of Life Questionnaire were assessed for 24 months after treatment. Clinical endpoints, including uterine shrinkage, the need for additional leiomyoma treatment, and the time to additional leiomyoma treatment, were all assessed. The nonperfused volume ratio after treatment, calculated from the gadolinium-enhanced magnetic resonance imaging after treatment and the best measure of tissue necrosis after treatment, was used to assess outcome based on completeness of leiomyoma ablation. Women undergoing magnetic resonance-guided focused ultrasound surgery for symptomatic uterine leiomyomata have durable symptom relief, as measured by the symptom severity score at 24 months, with significantly greater improvement with more complete ablation (P<.001). Survival analysis demonstrates a significant reduction in the percentage of women undergoing additional leiomyoma treatment (P=.001) in women in the high nonperfused volume group. The mean shrinkage and mean residual nonperfused volume ratio are both significantly above zero at 6 months in the high nonperfused volume group (P<.001). The incidence of adverse events is low. However, for women with minimal treatment, the risk of additional procedures is high. Magnetic resonance-guided focused ultrasound surgery is an effective treatment for uterine leiomyomata and results in sustained symptomatic relief. III.