In the past few years,there have been multiple advances in magnetic resonance (MR) instrumentation,in vivo devices,real-time imaging sequences and interventional procedures with new therapies.More recently,interventi... In the past few years,there have been multiple advances in magnetic resonance (MR) instrumentation,in vivo devices,real-time imaging sequences and interventional procedures with new therapies.More recently,interventionists have started to use minimally invasive image-guided procedures and local therapies,which reduce the pain from conventional surgery and increase drug effectiveness,respectively.Local therapy also reduces the systemic dose and eliminates the toxic side effects of some drugs to other organs.The success of MR-guided procedures depends on visualization of the targets in 3D and precise deployment of ablation catheters,local therapies and devices.MR contrast media provide a wealth of tissue contrast and allows 3D and 4D image acquisitions.After the development of fast imaging sequences,the clinical applications of MR contrast media have been substantially expanded to include pre-during-and post-interventions.Prior to intervention,MR contrast media have the potential to localize and delineate pathologic tissues of vital organs,such as the brain,heart,breast,kidney,prostate,liver and uterus.They also offer other options such as labeling therapeutic agents or cells.During intervention,these agents have the capability to map blood vessels and enhance the contrast between the endovascular guidewire/catheters/devices,blood and tissues as well as direct therapies to the target.Furthermore,labeling therapeutic agents or cells aids in visualizing their delivery sites and tracking their tissue distribution.After intervention,MR contrast media have been used for assessing the efficacy of ablation and therapies.It should be noted that most image-guided procedures are under preclinical research and development.It can be concluded that MR contrast media have great value in preclinical and some clinical interventional procedures.Future applications of MR contrast media in image-guided procedures depend on their safety,tolerability,tissue specificity and effectiveness in demonstrating success of the interventions an展开更多
AIM: To investigate if magnetic resonance(MR)-guided biopsy can improve the performance and safety of such procedures. METHODS: A novel MR-compatible bioptome was evaluated in a series of in-vitro experiments in a 1.5...AIM: To investigate if magnetic resonance(MR)-guided biopsy can improve the performance and safety of such procedures. METHODS: A novel MR-compatible bioptome was evaluated in a series of in-vitro experiments in a 1.5T magnetic resonance imaging(MRI) system. The bioptome was inserted into explanted porcine and bovine hearts under real-time MR-guidance employing a steady state free precession sequence. The artifact produced by the metal element at the tip and the signal voids caused by the bioptome were visually tracked for navigation and allowed its constant and precise localization. RESULTS: Cardiac structural elements and the target regions for the biopsy were clearly visible. Our method allowed a significantly better spatial visualization of the bioptoms tip compared to conventional X-ray guidance. The specific device design of the bioptome avoided inducible currents and therefore subsequent heating. The novel MR-compatible bioptome provided a superior cardiovascular magnetic resonance(imaging) soft-tissue visualization for MR-guided myocardial biopsies. Not at least the use of MRI guidance for endomyocardial biopsies completely avoided radiation exposure for both patients and interventionalists.CONCLUSION: MRI-guided endomyocardial biopsies provide a better than conventional X-ray guided navigation and could therefore improve the specificity and reproducibility of cardiac biopsies in future studies.展开更多
文摘 In the past few years,there have been multiple advances in magnetic resonance (MR) instrumentation,in vivo devices,real-time imaging sequences and interventional procedures with new therapies.More recently,interventionists have started to use minimally invasive image-guided procedures and local therapies,which reduce the pain from conventional surgery and increase drug effectiveness,respectively.Local therapy also reduces the systemic dose and eliminates the toxic side effects of some drugs to other organs.The success of MR-guided procedures depends on visualization of the targets in 3D and precise deployment of ablation catheters,local therapies and devices.MR contrast media provide a wealth of tissue contrast and allows 3D and 4D image acquisitions.After the development of fast imaging sequences,the clinical applications of MR contrast media have been substantially expanded to include pre-during-and post-interventions.Prior to intervention,MR contrast media have the potential to localize and delineate pathologic tissues of vital organs,such as the brain,heart,breast,kidney,prostate,liver and uterus.They also offer other options such as labeling therapeutic agents or cells.During intervention,these agents have the capability to map blood vessels and enhance the contrast between the endovascular guidewire/catheters/devices,blood and tissues as well as direct therapies to the target.Furthermore,labeling therapeutic agents or cells aids in visualizing their delivery sites and tracking their tissue distribution.After intervention,MR contrast media have been used for assessing the efficacy of ablation and therapies.It should be noted that most image-guided procedures are under preclinical research and development.It can be concluded that MR contrast media have great value in preclinical and some clinical interventional procedures.Future applications of MR contrast media in image-guided procedures depend on their safety,tolerability,tissue specificity and effectiveness in demonstrating success of the interventions an
基金Supported by The German Research Foundation(KA493/6_1)
文摘AIM: To investigate if magnetic resonance(MR)-guided biopsy can improve the performance and safety of such procedures. METHODS: A novel MR-compatible bioptome was evaluated in a series of in-vitro experiments in a 1.5T magnetic resonance imaging(MRI) system. The bioptome was inserted into explanted porcine and bovine hearts under real-time MR-guidance employing a steady state free precession sequence. The artifact produced by the metal element at the tip and the signal voids caused by the bioptome were visually tracked for navigation and allowed its constant and precise localization. RESULTS: Cardiac structural elements and the target regions for the biopsy were clearly visible. Our method allowed a significantly better spatial visualization of the bioptoms tip compared to conventional X-ray guidance. The specific device design of the bioptome avoided inducible currents and therefore subsequent heating. The novel MR-compatible bioptome provided a superior cardiovascular magnetic resonance(imaging) soft-tissue visualization for MR-guided myocardial biopsies. Not at least the use of MRI guidance for endomyocardial biopsies completely avoided radiation exposure for both patients and interventionalists.CONCLUSION: MRI-guided endomyocardial biopsies provide a better than conventional X-ray guided navigation and could therefore improve the specificity and reproducibility of cardiac biopsies in future studies.
