Improved Measurement of Pressure Gradients in Aortic Coarctation by Magnetic Resonance Imaging

Oshinski, John N.; Parks, W. James; Markou, Christos P.; Bergman, Harris L.; Larson, Blake E.; Ku, David N.; Mukundan, Srinivasan; Pettigrew, Roderic I.

doi:10.1016/s0735-1097(96)00395-6

Cited by 89 publications

(58 citation statements)

References 38 publications

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“…A practical advantage of these findings is that both 3D MRA of the thoracic aorta and PVC-MRI flow analysis are established MRI techniques, are commonly used in clinical practice, and require relatively short acquisition and imageprocessing times. 9,[13][14][15][16][23][24][25][26] Moreover, both techniques have been evaluated in patients with CoA and were found to reliably assess aortic morphology and collateral vessels and to accurately quantify flow in the descending aorta. 9,13 Assessment of coarctation severity presents a clinical challenge.…”

Section: Discussionmentioning

confidence: 99%

Magnetic Resonance Imaging Predictors of Coarctation Severity

et al. 2005

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Background-MRI is increasingly used for anatomic assessment of aortic coarctation (CoA), but its ability to predict the transcatheter pressure gradient, considered the reference standard for hemodynamic severity, has not been studied in detail. This study evaluated the ability of MRI to distinguish between mild versus moderate and severe CoA as determined by cardiac catheterization. Methods and Results-The clinical, MRI, and catheterization data of 31 subjects referred for assessment of native or recurrent CoA were reviewed retrospectively. Patients were divided into 2 groups on the basis of peak coarctation gradient by catheterization: Ͻ20 mm Hg (nϭ12) and Ն20 mm Hg (nϭ19). Patients with cardiac index Ͻ2.2 L · min

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Section: Discussionmentioning

confidence: 99%

Magnetic Resonance Imaging Predictors of Coarctation Severity

et al. 2005

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“…MRI also can provide spatially resolved hemodynamic information such as blood velocity during the procedure. 52 Adjunctive color-flow mapping may offer a useful "quick glance" at lesion physiology to guide further procedure conduct. Intraprocedural transesophageal or intravascular ultrasound is unable to resolve aortic adventitia or provide orientation-independent anatomic information.…”

Section: Discussionmentioning

confidence: 99%

Real-Time Magnetic Resonance Imaging–Guided Stenting of Aortic Coarctation With Commercially Available Catheter Devices in Swine

et al. 2005

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Background-Real-time MR imaging (rtMRI) is now technically capable of guiding catheter-based cardiovascular interventions. Compared with x-ray, rtMRI offers superior tissue imaging in any orientation without ionizing radiation. Translation to clinical trials has awaited the availability of clinical-grade catheter devices that are both MRI visible and safe. We report a preclinical safety and feasibility study of rtMRI-guided stenting in a porcine model of aortic coarctation using only commercially available catheter devices. Method and Results-Coarctation stenting was performed wholly under rtMRI guidance in 13 swine. rtMRI permitted procedure planning, device tracking, and accurate stent deployment. "Active" guidewires, incorporating MRI antennas, improved device visualization compared with unmodified "passive" nitinol guidewires and shortened procedure time (26Ϯ11 versus 106Ϯ42 minutes; Pϭ0.008). Follow-up catheterization and necropsy showed accurate stent deployment, durable gradient reduction, and appropriate neointimal formation. MRI immediately identified aortic rupture when oversized devices were tested. Conclusions-This experience demonstrates preclinical safety and feasibility of rtMRI-guided aortic coarctation stenting using commercially available catheter devices. Patients may benefit from rtMRI in the future because of combined device and tissue imaging, freedom from ionizing radiation, and the ability to identify serious complications promptly. Key Words: angioplasty Ⅲ catheterization Ⅲ coarctation Ⅲ heart defects, congenital Ⅲ stents E ndovascular stenting effectively relieves focal native and recurrent aortic coarctation in children and adults. 1-3 X-ray fluoroscopy (XRF) is used in these procedures with intermittent boluses of iodinated radiocontrast to define anatomic targets and to guide devices. This approach is limited because XRF does not visualize soft tissue, lacks depth perspective, and exposes patients to ionizing radiation.MRI displays soft tissue detail in any spatial orientation, requires no ionizing radiation, and can provide hemodynamic information. Real-time MRI (rtMRI) is now technically feasible and has enabled transcatheter treatment of congenital 4 -7 and acquired 8 -20 cardiovascular disease in animal models and humans.Razavi and colleagues 21 demonstrated safety and feasibility of cardiovascular catheterization in children and adults using a combined XRF and MRI suite. MRI-guided therapeutic human procedures will require conspicuous clinical-grade catheter devices. Our aim was to test the safety and feasibility of wholly MRI-guided stenting of aortic coarctation in swine using commercially available clinical devices. Specifically, we hypothesize that rtMRI can (1) provide safe and accurate device navigation, positioning, and deployment; (2) provide immediate preprocedural and postprocedural anatomic and hemodynamic assessment; (3) provide early recognition of significant complications; and (4) be conducted with catheter devices commercially available in the United States. Me...

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“…Phase contrast techniques have also been used as a sensitive means of detecting flow dephasing to locate the presence of atrial and ventricular septal defects, to detect flow restrictive conditions (Fig. 3), and also for quantification of the gradient across a stenosis (Oshinski et al 1996). The Q P :Q S is calculated by phase contrast imaging across the main pulmonary artery and ascending aorta, and provides an important decision-making tool in the presence of an atrial septal defect (ASD), ventricular septal defect (VSD), or anomalous pulmonary veins.…”

Section: Flow Quantificationmentioning

confidence: 99%