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MR fluoroscopy in vascular and cardiac interventions (review).

Saeed M, Hetts SW, English J, Wilson M - Int J Cardiovasc Imaging (2011)

Bottom Line: Development of more MR compatible equipment and devices will widen the applications of MR-guided procedures.At post-intervention, MR imaging aids in assessing the efficacy of therapies, success of interventions.MR fluoroscopy has the potential to form the basis for minimally invasive image-guided surgeries that offer improved patient management and cost effectiveness.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94107-1701, USA. Maythem.Saeed@radiology.UCSF.edu

ABSTRACT
Vascular and cardiac disease remains a leading cause of morbidity and mortality in developed and emerging countries. Vascular and cardiac interventions require extensive fluoroscopic guidance to navigate endovascular catheters. X-ray fluoroscopy is considered the current modality for real time imaging. It provides excellent spatial and temporal resolution, but is limited by exposure of patients and staff to ionizing radiation, poor soft tissue characterization and lack of quantitative physiologic information. MR fluoroscopy has been introduced with substantial progress during the last decade. Clinical and experimental studies performed under MR fluoroscopy have indicated the suitability of this modality for: delivery of ASD closure, aortic valves, and endovascular stents (aortic, carotid, iliac, renal arteries, inferior vena cava). It aids in performing ablation, creation of hepatic shunts and local delivery of therapies. Development of more MR compatible equipment and devices will widen the applications of MR-guided procedures. At post-intervention, MR imaging aids in assessing the efficacy of therapies, success of interventions. It also provides information on vascular flow and cardiac morphology, function, perfusion and viability. MR fluoroscopy has the potential to form the basis for minimally invasive image-guided surgeries that offer improved patient management and cost effectiveness.

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Related in: MedlinePlus

Simulation of deployment of the septal occluder device in vitro (a, b), and corresponding selected real-time MR images in vivo (c, d). The device was easily detected as a signal void on real time MR images. The closure device was advanced inside the delivery sheath until the folded first disk appeared (c) followed by the release of the second disk in the right atrium (d)
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Fig6: Simulation of deployment of the septal occluder device in vitro (a, b), and corresponding selected real-time MR images in vivo (c, d). The device was easily detected as a signal void on real time MR images. The closure device was advanced inside the delivery sheath until the folded first disk appeared (c) followed by the release of the second disk in the right atrium (d)

Mentions: Atrial septal defect (ASD) is another congenital defect common in children, leading to heart failure and pulmonary hypertension. Percutaneous transcatheter delivery of an ASD occluder has been performed on X-ray fluoroscopy [162]. A recent study showed that MR imaging provides reliable diagnosis of ASD [163]. Substantial experience has been obtained in animal models where MR fluoroscopy was used for delivery of ASD closure [164, 165] and sizing of the ASD (Fig. 6) [166]. The ASD occluders, delivered on MR fluoroscopy, are made of a nitenol mesh to reduce the artifacts [161]. Others used a commercial nitinol snare coaxial catheter system for delivering septal occluders [166]. Schalla et al. [161] simulated clinical-grade pediatric diagnostic catheterization in an animal model of ASD. The advancement of the delivery system through the IVC to the right atrium was monitored under MR fluoroscopy (Fig. 7). In another study, they advanced an active catheter, under MR fluoroscopy, to right and left sides of the heart and invasively measured pressure and oxygen in both right and left sides of the heart [70, 161] (Figs. 7, 8). Measurements of flow from velocity encoded MR imaging and blood pressure from the catheter were used to calculate pulmonary resistance. The flow and resistance data obtained from Fick and MR cardiac catheterization methods were in agreement [70, 161], suggesting accurate physiologic data can be obtained on MR imaging.Fig. 6


MR fluoroscopy in vascular and cardiac interventions (review).

Saeed M, Hetts SW, English J, Wilson M - Int J Cardiovasc Imaging (2011)

Simulation of deployment of the septal occluder device in vitro (a, b), and corresponding selected real-time MR images in vivo (c, d). The device was easily detected as a signal void on real time MR images. The closure device was advanced inside the delivery sheath until the folded first disk appeared (c) followed by the release of the second disk in the right atrium (d)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3275732&req=5

Fig6: Simulation of deployment of the septal occluder device in vitro (a, b), and corresponding selected real-time MR images in vivo (c, d). The device was easily detected as a signal void on real time MR images. The closure device was advanced inside the delivery sheath until the folded first disk appeared (c) followed by the release of the second disk in the right atrium (d)
Mentions: Atrial septal defect (ASD) is another congenital defect common in children, leading to heart failure and pulmonary hypertension. Percutaneous transcatheter delivery of an ASD occluder has been performed on X-ray fluoroscopy [162]. A recent study showed that MR imaging provides reliable diagnosis of ASD [163]. Substantial experience has been obtained in animal models where MR fluoroscopy was used for delivery of ASD closure [164, 165] and sizing of the ASD (Fig. 6) [166]. The ASD occluders, delivered on MR fluoroscopy, are made of a nitenol mesh to reduce the artifacts [161]. Others used a commercial nitinol snare coaxial catheter system for delivering septal occluders [166]. Schalla et al. [161] simulated clinical-grade pediatric diagnostic catheterization in an animal model of ASD. The advancement of the delivery system through the IVC to the right atrium was monitored under MR fluoroscopy (Fig. 7). In another study, they advanced an active catheter, under MR fluoroscopy, to right and left sides of the heart and invasively measured pressure and oxygen in both right and left sides of the heart [70, 161] (Figs. 7, 8). Measurements of flow from velocity encoded MR imaging and blood pressure from the catheter were used to calculate pulmonary resistance. The flow and resistance data obtained from Fick and MR cardiac catheterization methods were in agreement [70, 161], suggesting accurate physiologic data can be obtained on MR imaging.Fig. 6

Bottom Line: Development of more MR compatible equipment and devices will widen the applications of MR-guided procedures.At post-intervention, MR imaging aids in assessing the efficacy of therapies, success of interventions.MR fluoroscopy has the potential to form the basis for minimally invasive image-guided surgeries that offer improved patient management and cost effectiveness.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94107-1701, USA. Maythem.Saeed@radiology.UCSF.edu

ABSTRACT
Vascular and cardiac disease remains a leading cause of morbidity and mortality in developed and emerging countries. Vascular and cardiac interventions require extensive fluoroscopic guidance to navigate endovascular catheters. X-ray fluoroscopy is considered the current modality for real time imaging. It provides excellent spatial and temporal resolution, but is limited by exposure of patients and staff to ionizing radiation, poor soft tissue characterization and lack of quantitative physiologic information. MR fluoroscopy has been introduced with substantial progress during the last decade. Clinical and experimental studies performed under MR fluoroscopy have indicated the suitability of this modality for: delivery of ASD closure, aortic valves, and endovascular stents (aortic, carotid, iliac, renal arteries, inferior vena cava). It aids in performing ablation, creation of hepatic shunts and local delivery of therapies. Development of more MR compatible equipment and devices will widen the applications of MR-guided procedures. At post-intervention, MR imaging aids in assessing the efficacy of therapies, success of interventions. It also provides information on vascular flow and cardiac morphology, function, perfusion and viability. MR fluoroscopy has the potential to form the basis for minimally invasive image-guided surgeries that offer improved patient management and cost effectiveness.

Show MeSH
Related in: MedlinePlus