Feasibility of MR-guided Angioplasty of Femoral Artery Stenoses Using Real-time Imaging and Intraarterial Contrast-enhanced MR Angiography

Paetzel, Christian; Zorger, N.; Bachthaler, Maike; Völk, Markus; Seitz, Johannes; Herold, Thomas; Feuerbach, Stefan; Lenhart, Markus; Nitz, Wolfgang R.

doi:10.1055/s-2004-813365

Cited by 20 publications

(6 citation statements)

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“…Recently, first results of intra-arterial MR angiography in patients have been reported [8,23,24]. However, these studies have applied injection protocols, which were either not aimed to minimize the injected gadolinium dose or not optimized for the aortal flow condition.…”

Section: Discussionmentioning

confidence: 99%

Low-dose intra-arterial contrast-enhanced MR aortography in patients based on a theoretically derived injection protocol

et al. 2005

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Multiple intra-arterial contrast agent injections are necessary during MR-guided endovascular interventions. In respect to the approved limits of maximum daily gadolinium dose, a low-dose injection protocol is mandatory. The objective of this study was to derive and apply a low-dose injection protocol for intra-arterial 3D contrast-enhanced MR aortography in patients. Injection rate (Q inj ), concentration of injected gadolinium [Gd] inj and aortal blood flow rate (Q blood ) were included for the theoretical evaluation of signal intensity (SI) of the arterial lumen. SI simulations were carried out at Q inj =2 versus 4 ml/s in the [Gd] inj range between 0-500 mM. Q inj and [Gd] inj with SI above the 75% threshold of the maximal SI were regarded as optimal injection parameters.[Gd] inj =50 mM and Q inj =4 ml/s were considered as optimal and were administered in five patients for 3D MR aortography. All images revealed clear delineation of the abdominal aorta and its major branches. Mean± SD of contrast-to-noise ratios of the abdominal aorta, common iliac and renal artery were 70.2±15.2, 58.6± 12.3 and 67.4±12.3. Approximately seven intra-aortal injections would be permissible in patients during MRguided interventions without exceeding the maximal dose of gadolinium.

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Section: Discussionmentioning

confidence: 99%

Low-dose intra-arterial contrast-enhanced MR aortography in patients based on a theoretically derived injection protocol

et al. 2005

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“…Investigators in Regensburg have conducted clinical iCMR femoropopliteal angioplasty using passive commercial devices solely under MRI guidance (Manke et al 2001;Paetzel et al 2004). Kee and colleagues, working on a novel integrated X-ray/MRI system, successfully performed TIPS procedures in 13 out of 14 patients with fewer attempted punctures and less fluoroscopy time (Kee et al 2005).…”

Section: Clinical Translationmentioning

confidence: 99%

Interventional Cardiovascular Magnetic Resonance Imaging

Raman

Lederman

2007

Trends in Cardiovascular Medicine

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Magnetic resonance imaging (MRI) provides structural and functional cardiovascular information with excellent soft tissue contrast. Real-time MRI can guide transcatheter cardiovascular interventions in large animal models, and may prove superior to x-ray and adjunct modalities for peripheral vascular, structural heart and cardiac electrophysiology applications. We describe technical considerations, pre-clinical work and early clinical studies in this emerging field.

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“…Razavi and colleagues (25) reported a landmark series of cardiac catheterization performed successfully in children using a combined XMR environment. The Regensburg team conducted high-quality selective intra-arterial MR angiography (74) and reported some preliminary revascularization procedures using passive devices in the iliac (23) and femoral (74) arteries. As described earlier, the Stanford team has conducted rtMRI-assisted TIPS procedures in patients (73).…”

Section: Early Human Experiencementioning

confidence: 99%

Real-time, Interactive MRI for Cardiovascular Interventions1

et al. 2005

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Over the past decade, there has been a small contingent of laboratories developing magnetic resonance imaging (MRI)-guided intravascular techniques and applications. While these efforts have followed in the footsteps of MRI-guided surgical technologies (1,2), intravascular techniques do not carry the requirement for an open access scanner, and hence higher imaging performance during procedures can be achieved. The concept of precise real-time tracking of an active catheter in a standard MRI scanner was fully realized more than 15 years ago by Dumoulin and colleagues (3). Interventional MRI has subsequently developed into the obvious method for delivery of numerous therapies. This review addresses the recent developments and state-of-the-art of a number of aspects of interventional cardiovascular MRI. REAL-TIME IMAGINGOne of the principal enabling technologies for guiding intravascular procedures is real-time imaging. When catheter tracking was first implemented, special pulse sequences were required to obtain the catheter position from a few rapid projections; for some applications, this is now unnecessary due to the ability of modern scanners to provide up to 30 frames per second. There is obviously a tradeoff between spatial resolution and temporal resolution, but this is fully adjustable in an interactive system. One of the significant developments for real-time imaging is the use of multiple receiver systems used in conjunction with specially designed coil arrays to enable parallel imaging techniques. In this next section, some of these techniques are briefly described. PARALLEL IMAGING METHODSParallel imaging is a rapid imaging method that can be applied to real-time imaging. Parallel imaging exploits the difference in sensitivity profiles between individual coil elements in a receive array to reduce the number of gradient encoding steps required for imaging. Parallel imaging uses R-fold k-space undersampling to achieve an acceleration factor of rate R. The alias artifacts (R uniformly spaced ghosts) caused by k-space undersampling are then cancelled by the parallel image reconstruction algorithm. Parallel image reconstruction may be performed in the k-space domain, for example, by using SiMultaneous Acquisition of Spatial Harmonics (SMASH) (4), or in the image domain, for example, by using the sensitivity encoding method (SENSE) (5).

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Feasibility of MR-guided Angioplasty of Femoral Artery Stenoses Using Real-time Imaging and Intraarterial Contrast-enhanced MR Angiography

Abstract: MR-guided balloon dilatation of femoral and popliteal artery stenoses supported by real time imaging and intraarterial MR angiography is feasible with commercially available materials in the above mentioned way.

Cited by 20 publications

References 9 publications

Low-dose intra-arterial contrast-enhanced MR aortography in patients based on a theoretically derived injection protocol

Low-dose intra-arterial contrast-enhanced MR aortography in patients based on a theoretically derived injection protocol

Interventional Cardiovascular Magnetic Resonance Imaging

Real-time, Interactive MRI for Cardiovascular Interventions1

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