Robot-assistant for MRI-guided liver ablation: A pilot study.

Purpose: Percutaneous ablation under MRI-guidance allows treating otherwise inoperable liver tumors locally using a catheter probe. However, manually placing the probe is an error-prone and time consuming task that requires a considerable amount of training. The aim of this paper was to present a pneumatically actuated robotic instrument that can assist clinicians in MRI-guided percutaneous intervention of the liver and to assess its functionality in a clinical setting.

Thermal ablative treatment of uterine fibroids.

In addition to surgical methods of treating uterine fibroids, numerous non-invasive treatments have been developed. Many of these involve the use of hyperthermia, the heating of tissue by a variety of methods. These include the use of lasers, radiofrequency, microwave energy and high intensity focused ultrasound, guided by both ultrasound and magnetic resonance imaging.

Optothermal profile of an ablation catheter with integrated microcoil for MR-thermometry during Nd:YAG laser interstitial thermal therapies of the liver—an in-vitro experimental and theoretical study.

Purpose: Flexible microcoils integrated with ablation catheters can improve the temperature accuracy during local MR-thermometry in Nd:YAG laser interstitial thermal therapies. Here, the authors are concerned with obtaining a preliminary confirmation of the clinical utility of the modified catheter. They investigate whether the thin-film substrate and copper tracks of the printed coil inductor affect the symmetry of the thermal profile, and hence of the lesion produced.

Safety and treatment volumes achieved following new developments of the magnetic resonance-guided focused ultrasound system in the treatment of uterine fibroids: a cohort study.

Background: This research investigates whether modifications to the magnetic resonance-guided focused ultrasound ablation of uterine fibroid (MRgFUS) system used resulted in improved treatment volumes of uterine fibroids, while maintaining safety.

Methods: This study is a prospective cohort analysis of 34 women undergoing the ExAblate 2100 MRgFUS treatment for their uterine fibroids.

Results: The percentage of non-perfused volume (NPV) achieved with the ExAblate 2100 system was 54.

The road to clinical use of high-intensity focused ultrasound for liver cancer: technical and clinical consensus.

Clinical use of high-intensity focused ultrasound (HIFU) under ultrasound or MR guidance as a non-invasive method for treating tumors is rapidly increasing. Tens of thousands of patients have been treated for uterine fibroid, benign prostate hyperplasia, bone metastases, or prostate cancer. Despite the methods' clinical potential, the liver is a particularly challenging organ for HIFU treatment due to the combined effect of respiratory-induced liver motion, partial blocking by the rib cage, and high perfusion/flow.

Quantifying hepatic steatosis - more than meets the eye.

Aims: The non-alcoholic fatty liver disease (NAFLD) activity score (NAS) is the histological tool used to assess disease severity based on steatosis, inflammation and hepatocyte ballooning. As steatosis contributes up to three of a potential eight points to NAS, it is important to quantify steatosis accurately. We sought to determine the optimum histological technique for identifying fat in tissue.

Renal artery stenosis: comparative assessment by unenhanced renal artery MRA versus contrast-enhanced MRA.

Objectives: To evaluate steady-state free precession (SSFP) non-contrast-enhanced MR angiography (Unenhanced-MRA) versus conventional contrast-enhanced MR angiography (CE-MRA) in the detection of renal artery stenosis (RAS).

Methods: Retrospective analysis of 70 consecutive patients referred for suspected RAS, examined by SSFP Unenhanced-MRA and CE-MRA. Image quality, quality of visible renal arterial segments, presence and grade of RAS were evaluated.

Midfoot and hindfoot bone marrow edema identified by magnetic resonance imaging in feet of subjects with diabetes and neuropathic ulceration is common but of unknown clinical significance.

Objective: We conducted a retrospective cohort study assessing the prevalence and clinical and radiological outcome of remote areas of bone marrow edema on magnetic resonance imaging (MRI) in the feet of subjects with diabetes and neuropathic foot ulceration.

Research Design And Methods: MRIs performed over 6 years looking for osteomyelitis associated with neuropathic lesions were assessed for remote areas of signal change.

Results: Seventy MRI studies were assessed.

Laser ablation of hepatocellular carcinoma--a review.

A wide range of local thermal ablative therapies have been developed in the treatment of non resectable hepatocellular carcinoma (HCC) in the last decade. Laser ablation (LA) and radiofrequency ablation (RFA) are the two most widely used of these. This article provides an up to date overview of the role of laser ablation in the local treatment of HCC.

MR-guided focused ultrasound.

The joining of high-intensity focused ultrasound with high-resolution MR guidance has created a system that can produce tissue destruction deep within solid organs without any invasion. Accurate targeting and thermal mapping are provided by MRI and allow very accurate deposition of energy in tissues that can be altered in response to near real-time thermal imaging produced by MR so that the variation in tissue response that is otherwise observed can be overcome. Current areas of successful application of MR-guided focused ultrasound are described in the treatment of uterine fibroids and other areas of emerging applications in additional solid organs are also discussed.

New clinical applications of magnetic resonance-guided focused ultrasound.

Magnetic resonance-guided ultrasound delivers destructive energy into deep body structures with great accuracy and repeatability with an excellent safety profile. The use of this technology for the treatment of uterine fibroids is already becoming widespread. This article reviews the further areas of magnetic resonance-guided focused ultrasound application that are evolving and how they will be applied to other parts of the body.

Magnetic resonance guidance of thermal ablation.

The aim of this study is to describe all aspects of the process of using MR imaging to control thermal ablation procedures and the strengths and weaknesses of the individual thermal ablation modalities in relation to their use in the MR environment. Magnetic resonance thermal sequences, MR scanner configurations, and the different thermal ablation modalities are discussed in the context of how they are commonly used in MR scanners to provide optimal image guidance of therapy. The outcomes of completed research on some of the applications of thermal tissue ablation using MR guidance are described to indicate how these processes may impact patient treatment.

Clinical outcomes of focused ultrasound surgery for the treatment of uterine fibroids.

Objective: To assess outcomes at 6 and 12 months after magnetic resonance-guided focused ultrasound surgery (MRgFUS) for symptomatic uterine leiomyomas.

Design: Multicenter clinical trial.

Setting: Academic medical centers.

MRI guidance of focused ultrasound therapy of uterine fibroids: early results.

Objective: The purpose of this study was to explore our hypothesis that MRI-guided focused ultrasound therapy for the treatment of uterine fibroids will lead to a significant reduction in symptoms and improvement in quality of life. We describe focused ultrasound therapy applications and the method for monitoring the thermal energy deposited in the fibroids, including the MRI parameters required, in a prospective review of 108 treatments.

Materials And Methods: Patients presenting with symptomatic uterine fibroids who attained a minimal symptom severity score and who would otherwise have been offered a hysterectomy were recruited.

Focused ultrasound treatment of uterine fibroid tumors: safety and feasibility of a noninvasive thermoablative technique.

Objective: The purpose of this study was to determine the safety and efficacy of focused ultrasound surgery with magnetic resonance imaging guidance for the noninvasive treatment of uterine leiomyomas.

Study Design: Fifty-five women with clinically significant uterine leiomyomas were treated. Pain and complications were assessed prospectively, and posttreatment magnetic resonance imaging was used to measure the treatment effects.

Feasibility of abdomino-pelvic T1-weighted real-time thermal mapping of laser ablation.

Purpose: To prove the hypothesis that T1-weighted (T1W) thermal mapping is reliable and achievable in magnetic resonance (MR)-guided laser tumor ablation.

Materials And Methods: Near real-time gray and color-scale T1W thermal maps in 111 MR-guided laser thermal ablations (LTA) of liver, kidney, and uterine tumors were studied. After laser fiber placement, near real-time gray and color-scale thermal maps were produced.