scholarly journals Novel fractionated ultrashort thermal exposures with MRI-guided focused ultrasound for treating tumors with thermosensitive drugs

2020 ◽  
Vol 6 (36) ◽  
pp. eaba5684
Author(s):  
Marc A. Santos ◽  
Sheng-Kai Wu ◽  
Maximilian Regenold ◽  
Christine Allen ◽  
David E. Goertz ◽  
...  
Keyword(s):  
Focused Ultrasound ◽  
Tumor Model ◽  
Current Approach ◽  
Tumor Growth Inhibition ◽  
Two Photon Microscopy ◽  
Control Drug ◽  
Novel Approach ◽  
Thermosensitive Liposome ◽  
Mri Guided ◽  
Magnetic Resonance Imaging Mri

Thermosensitive liposomes represent an important paradigm in oncology, where hyperthermia-mediated release coupled with thermal bioeffects enhance the effectiveness of chemotherapy. Their widespread clinical adoption hinges upon performing controlled targeted hyperthermia, and a leading candidate to achieve this is temperature-based magnetic resonance imaging (MRI)–guided focused ultrasound (MRgFUS). However, the current approach to hyperthermia involves exposures lasting tens of minutes to hours, which is not possible to achieve in many circumstances because of blood vessel cooling and respiratory motion. Here, we investigate a novel approach to overcome these limitations: to use fractionated ultrashort (~30 s) thermal exposures (~41° to 45°C) to release doxorubicin from a thermosensitive liposome. This is first demonstrated in a dorsal chamber tumor model using two-photon microscopy. Thermal exposures were then conducted with a rabbit tumor model using a custom MRgFUS system incorporating temperature feedback control. Drug release was confirmed, and longitudinal experiments demonstrated profoundly enhanced tumor growth inhibition and survival.

scholarly journals The Role of the Anesthesiologist during Magnetic Resonance-Guided Focused Ultrasound Thalamotomy for Tremor: A Single-Center Experience

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Alon Sinai ◽  
Yeshayahu Katz ◽  
Menashe Zaaroor ◽  
Olga Sandler ◽  
Ilana Schlesinger
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Focused Ultrasound ◽  
Anesthetic Management ◽  
Single Center ◽  
Resonance Imaging ◽  
Single Center Experience ◽  
Mri Guided ◽  
Magnetic Resonance Imaging Mri

Ablative incisionless neurosurgery has become possible through advances in focused ultrasound and magnetic resonance imaging (MRI). The great advantage of MRI-guided focused ultrasound (MRgFUS) is that the ablation is performed through an intact skull without surgery. Here, we review the new modality of MRgFUS for treating tremor and enlighten the role of the anesthesiologist in the unique procedural setting of the MRI suite. During the MRgFUS process, the patients should be awake and are required to cooperate with the medical staff to allow assessment of tremor reduction and potential occurrence of adverse effects. In addition, the patient’s head is immobilized inside the MRI tunnel for hours. This combination presents major challenges for the attending anesthesiologist, who is required to try to prevent pain and nausea and when present, to treat these symptoms. Anxiety, vertigo, and vomiting may occur during treatment and require urgent treatment. Here, we review the literature available on anesthetic management during the procedure and our own experience and provide recommendations based on our collected knowledge.

scholarly journals AAPM Task Group 241: A Medical Physicist’s Guide to MRI‐guided Focused Ultrasound Body Systems

2021 ◽  
Author(s):  
Allison Payne ◽  
Rajiv Chopra ◽  
Nicholas Ellens ◽  
Lili Chen ◽  
Pejman Ghanouni ◽  
...  
Keyword(s):  
Focused Ultrasound ◽  
Task Group ◽  
Mri Guided

Invited. On the feasibility of MRI-guided focused ultrasound for local induction of gene expression

1998 ◽  
Vol 8 (1) ◽  
pp. 101-104 ◽  
Author(s):  
David P. Madio ◽  
Peter van Gelderen ◽  
Daryl DesPres ◽  
Alan W. Olson ◽  
Jacco A. de Zwart ◽  
...  
Keyword(s):  
Gene Expression ◽  
Focused Ultrasound ◽  
Mri Guided

Percutaneous selective laser amygdalo-hippocampectomy (SLAH) for treatment of mesial temporal lobe epilepsy within an interventional MRI suite

2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Sherif G. Nour ◽  
Jon T. Willie ◽  
Robert E. Gross
Keyword(s):  
Temporal Lobe ◽  
Laser Energy ◽  
Mesial Temporal Lobe Epilepsy ◽  
Interventional Mri ◽  
Long Term Follow Up ◽  
Institutional Experience ◽  
Mesial Temporal Lobe ◽  
Mri Guided ◽  
Magnetic Resonance Imaging Mri ◽  
Set Up

AbstractPercutaneous selective laser amygdalo-hippocampectomy (SLAH) procedure is a new minimally invasive alternative to surgical amygdalo-hippocampectomy that involves targeted, controlled laser energy deposition under real-time magnetic resonance imaging (MRI) monitoring within a dedicated “interventional MRI” suite. Technical feasibility, safety and initial efficacy results from our program are encouraging and indicate a potential for paradigm shift in future treatment of patients with exclusively or predominantly focal unilateral seizure onsets within the mesial temporal lobe. Several institutions are currently employing this technology and more long-term follow-up results on larger cohorts of patients are expected in the near future. This article reviews the principles of MRI-guided SLAH, procedure set-up and equipment, the detailed phases of intra-procedural MRI guidance and treatment monitoring, and the MRI appearance of the resultant thermal ablation zones. We conclude with a discussion of our institutional experience at Emory University with MRI-guided SLAH as one of the leading sites offering this state-of-the-art technology.

Development of a Master-Slave Robotic System for MRI-Guided Intracardiac Interventions

2013 ◽  
Author(s):  
Amirhossein Salimi ◽  
Amin Ramezanifar ◽  
Javad Mohammadpour ◽  
Karolos M. Grogoriadis
Keyword(s):  
Magnetic Resonance Imaging ◽  
Pid Control ◽  
Control Design ◽  
Robotic System ◽  
Experimental Setup ◽  
Resonance Imaging ◽  
Parallel Platform ◽  
Mri Guided ◽  
Magnetic Resonance Imaging Mri ◽  
Reference Trajectories

Restricted space inside the magnetic resonance imaging (MRI) scanner bore prevents surgeons to directly interact with the patient during MRI-guided procedures. This motivates the development of a robotic system that can act as an interface during those interventions. In this paper, we present a master-slave robotic system as a solution to the aforedescribed issue. The proposed system consists of a commercial PHANTOM device (product of The Sensable Technologies) as the master robot and an MRI-compatible patient-mounted parallel platform (that we name ROBOCATH) designed to serve as the slave mechanism inside the scanner bore. We present in this paper the design principles for the platform, as well as the PID control design for the system. We use our experimental setup to evaluate the performance of the system by examining the effectiveness of the slave platform in tracking the reference trajectories generated by the master robot.

scholarly journals MRI-guided focused ultrasound ablation of lumbar medial branch nerve: Feasibility and safety study in a swine model

2016 ◽  
Vol 32 (7) ◽  
pp. 786-794 ◽  
Author(s):  
Elena A. Kaye ◽  
Sebastien Monette ◽  
Govindarajan Srimathveeravalli ◽  
Majid Maybody ◽  
Stephen B. Solomon ◽  
...  
Keyword(s):  
Focused Ultrasound ◽  
Swine Model ◽  
Medial Branch ◽  
Safety Study ◽  
Ultrasound Ablation ◽  
Mri Guided ◽  
Focused Ultrasound Ablation

Robot-assisted MRI-guided prostatic interventions

Robotica ◽  
2009 ◽  
Vol 28 (2) ◽  
pp. 215-234 ◽  
Author(s):  
Andrew A. Goldenberg ◽  
John Trachtenberg ◽  
Yang Yi ◽  
Robert Weersink ◽  
Marshall S. Sussman ◽  
...  
Keyword(s):  
Thermal Ablation ◽  
Pulse Sequences ◽  
Robot Assisted ◽  
Surgical Ablation ◽  
Image Guided ◽  
Surgical Tool ◽  
Mri Environment ◽  
Focal Ablation ◽  
Mri Guided ◽  
Magnetic Resonance Imaging Mri

SUMMARYThis paper reports on recent progress made toward the development of a new magnetic resonance imaging (MRI)-compatible robot-assisted surgical system for closed-bore image-guided prostatic interventions: thermal ablation, radioactive seed implants (brachytherapy), and biopsy. Each type of intervention will be performed with a different image-guided, robot-based surgical tool mounted on the same MRI-guided robot through a modular trocar. The first stage of this development addresses only laser-based focal ablation. The robot mechanical structure, modular surgical trocar, control architecture, and current stage of performance evaluation in the MRI environment are presented. The robot actuators are ultrasonic motors. A methodology of using such motors in the MRI environment is presented. The robot prototype with surgical ablation tool is undergoing tests on phantoms in the MRI bore. The tests cover MRI compatibility, image visualization, robot accuracy, and thermal mapping. To date, (i) the images are artifact- and noise-free for certain scanning pulse sequences; (ii) the robot tip positioning error is less than 1.2 mm even at positions closer than 0.3 m from the MRI isocenter; (iii) penetration toward the target is image-monitored in near-real time; and (iv) thermal ablation and temperature mapping are achieved using a laser delivered on an optical fiber and MRI, respectively.

A Novel Approach to Nanoscale Materials Synthesis Using Industrial Laser Processing of Organosilazane Liquid Precursors

1990 ◽  
Vol 206 ◽  
Author(s):  
Tongsan D. Xiao ◽  
Peter R. Strutt ◽  
Kenneth E. Gonsalves
Keyword(s):  
Ceramic Powder ◽  
Average Diameter ◽  
Current Approach ◽  
Powder Materials ◽  
Materials Synthesis ◽  
Laser Plume ◽  
New Approach ◽  
Novel Approach ◽  
Liquid Precursors ◽  
Short Time

ABSTRACTA new approach has been developed for the synthesis of nanoscale ceramic powder materials from liquid organosilazane precursors. This technique, by exploiting fast kinetic chemical and physical reactions, makes it possible to synthesize significant quantities of material in a relatively short time. In the current approach aerosols of a silazane monomer, (CH3SiHNH)n, (n = 3 or 4), of mol. wt. 280–320, are injected into the beam of a cw industrial CO2 laser to obtain nanoscale ceramic powders. Injection of the aerosol into the laser-beam results in a high-temperature plume. Rapid condensation of the molecular precursor species emerging from the laser plume results in the formation of preceramic polymer particles, with an average diameter of 62 nm. One attractive feature of this process is that 70 wt.% of the liquid precursor is converted into nanoscale powders. Another feature is that only a further 10 wt.% loss occurs during post thermal treatment to form the end-product.

Sign in / Sign up

Export Citation Format

Share Document