Department of Surgery, University Hospital Maastricht, The Netherlands, Nephrology, Dialysis and Intensive Care Unit; Lapeyronie University Hospital, Montpellier, France, Department of Diagnostic and Interventional Radiology, Helios Klinikum Wuppertal, University Hospital Witten/Herdecke, Germany, Medical Faculty University of Cologne, Medicine Clinic I, Hospital Merheim, Germany (retired), Department of Medicine, Division of Nephrology, Ege University Medical Faculty, Izmir, Turkey, Departement de Nephrologie JE 2411–Denutrition des Maladies Chroniques, Hopital E Herriot, France, Department of Internal Medicine, Division of Nephrology, University Hospital Maastricht, The Netherlands, Nephrology Department, Reina Sofia University Hospital, Cordoba, Spain, Division of Nephrology and Dialysis, Bolognini Hospital, Seriate, Italy, Nephrology Unit, SM Annunziata Hospital, Florence, Italy, Department of Renal Medicine, St James’s University Hospital, Leeds, UK, Department of Nephrology, Nutrition and Dietetics, Guy’s and St Thomas’ NHS Foundation Trust, London, UK (retired), Department of Medicine, Division of Nephrology, University Hospital, Wurzburg, Germany, Department of Nephrology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands and Nephrology Section, Department of Internal Medicine, University Hospital, Ghent, Belgium

https://www.vascularaccesssociety.com/resources/media/Guidelines/1_patient_referral.pdf

EBPG on Vascular Access

E. Kanal is a consultant for, is a member of the speakers bureau of, and provides research support for Bracco Diagnostics and GE Healthcare; is a member of the speakers bureau of and provides research support for Siemens Medical Solutions; and provides research support for Berlex and Medtronic. T. Gilk is a consultant for Mednovus, Inc. J. R. Gimbel provides research support for St. Jude Medical, Medtronic, and Biotronik. J. Nyenhuis is a consultant for and provides research support to Medtronics. J. Weinreb is a consultant and member of the speakers bureau for GE Healthcare.

/pdf/acr-guidance-document-for-safe-mr-practices-2007-3jidmztvfz.pdf

ACR Guidance Document for Safe MR Practices: 2007

ACR guidance document for safe MR practices: 2007. Commentary

Vascular access for hemodialysis.

Because there are many potential risks in the MR environment and reports of adverse incidents involving patients, equipment and personnel, the need for a guidance document on MR safe practices emerged. Initially published in 2002, the ACR MR Safe Practices Guidelines established de facto industry standards for safe and responsible practices in clinical and research MR environments. As the MR industry changes the document is reviewed, modified and updated. The most recent version will reflect these changes.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmri.24011

ACR guidance document on MR safe practices: 2013.

We examined the unwanted radiofrequency (RF) heating of an endovascular guidewire frequently used in interventional magnetic resonance imaging (MRI). A Terumo guidewire was partly immersed in an oblong saline bath to simulate an endovascular intervention. The temperature rise of the guidewire tip during an FFE sequence [average specific absorption rate (SAR) = 3.9 W/kg] was measured with a Luxtron fluoroscopic fiber. Starting from 26 degrees C, the guidewire tip reached temperatures up to 74 degrees C after 30 seconds of scanning. Touching the guidewire may cause sudden heating at the point of contact, which in one instance caused a skin burn. The excessive heating of a linear conductor like the guidewire can only be explained by resonating RF waves. The capricious dependencies of this resonance phenomenon on environmental factors have severe consequences for predictability and safety guidelines.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/1522-2586%28200007%2912%3A1%3C79%3A%3AAID-JMRI9%3E3.0.CO%3B2-T

Heating Around Intravascular Guidewires by Resonating RF Waves

MR Imaging of Vascular Stents: Effects of Susceptibility, Flow, and Radiofrequency Eddy Currents

The purpose of this study was to demonstrate the potential of MRI for guiding, monitoring, and evaluating endovascular interventions. This was done by investigating the feasibility of MR-guided balloon angioplasty in a stenosed vessel model. Catheters and guidewires were prepared for susceptibility-based MR visualization by incorporating paramagnetic markers into their walls. Near real-time monitoring (up to 1 image/sec) of the interventional procedure was achieved by using a dynamic two-dimensional gradient-echo technique. Devices were localized by on-the-fly subtraction of a baseline image from consecutive dynamic images and by merging the subtraction images with a previously acquired road map. All steps involved in balloon angioplasty, from the introduction and placement of a guidewire to the positioning of a catheter across the stenosis, inflation of the balloon, and dilatation of the stenosis could adequately be monitored with MR fluoroscopy. The beneficial effect of dilatation could be substantiated by a reduction of stenosis-related hypointensities and hyperintensities in the posttreatment MR angiogram as compared to the pretreatment angiogram and by a posttreatment increase of the volumetric flow rate.

MR-guided balloon angioplasty: in vitro demonstration of the potential of MRI for guiding, monitoring, and evaluating endovascular interventions.

Pressure or flow recordings for the surveillance of hemodialysis grafts

In this study the feasibility of intraarterial contrast administration was investigated. Its use for navigation and treatment evaluation during MR-guided intravascular interventions was explored in phantom and animal experiments. An injection protocol was developed, which accounts for sequence parameters and vessel flow rate. Tracking a bolus of contrast agent was useful to verify the catheter tip position and to assess flow conditions. Compared to intravenous contrast-enhanced magnetic resonance angiography (CE-MRA), selective contrast administration permitted a strongly reduced dose. In two-dimensional (2D) acquisitions overlap of vessels was prevented. Injection and acquisition were easily and accurately synchronized in selective 3D CE-MRA, and a high contrast concentration could be maintained during the entire acquisition. Selective injection is useful in the course of an intervention, to facilitate navigation, provide information on flow conditions, and to evaluate treatment progress repeatedly.

Henk F.M. Smits

Papers

Heating Around Intravascular Guidewires by Resonating RF Waves

MR Imaging of Vascular Stents: Effects of Susceptibility, Flow, and Radiofrequency Eddy Currents

MR-guided balloon angioplasty: in vitro demonstration of the potential of MRI for guiding, monitoring, and evaluating endovascular interventions.

Pressure or flow recordings for the surveillance of hemodialysis grafts

Selective contrast-enhanced MR angiography.