In vitro comparison of different carotid artery stents: a pixel-by-pixel analysis using CT angiography and contrast-enhanced MR angiography at 1.5 and 3 T

Lettau, M.; Sauer, A.; Heiland, Sabine; Rohde, Stefan; Reinhardt, Julia; Bendszus, Martin; Hähnel, Stefan

doi:10.1007/s00234-009-0625-5

Cited by 16 publications

(10 citation statements)

References 26 publications

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“…Imaging at higher magnetic field strength results in stronger susceptibility artifacts [4,5]. In a study comparing artificial lumen narrowing in stents of stainless steel, nitinol and cobalt alloy with 3D-GRE high-resolution MRA images at 3T and 1.5T, the largest amount of narrowing was found in stainless steel and cobalt alloy stents at 1.5T and the least narrowing was detected in nitinol stents at 3T [6]. …”

Section: Discussionmentioning

confidence: 99%

Pediatric cardiovascular interventional devices: effect on CMR images at 1.5 and 3 Tesla

Khan

Rapacchi

Levi

et al. 2013

Journal of Cardiovascular Magnetic Resonance

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BackgroundTo predict the type and extent of CMR artifacts caused by commonly used pediatric trans-catheter devices at 1.5 T and 3 T as an aid to clinical planning and patient screening.MethodsEleven commonly used interventional, catheter-based devices including stents, septal occluders, vascular plugs and embolization coils made from either stainless steel or nitinol were evaluated ex-vivo at both 1.5T and 3T. Pulse sequences and protocols commonly used for cardiovascular magnetic resonance (CMR) were evaluated, including 3D high-resolution MR angiography (MRA), time-resolved MRA, 2D balanced-SSFP cine and 2D phase-contrast gradient echo imaging (GRE). We defined the signal void amplification factor (F) as the ratio of signal void dimension to true device dimension. F1 and F2 were measured in the long axis and short axes respectively of the device. We defined F3 as the maximum extent of the off-resonance dark band artifact on SSFP measured in the B0direction. The effects of field strength, sequence type, orientation, flip angle and phase encode direction were tested. Clinical CMR images in 3 patients with various indwelling devices were reviewed for correlation with the in-vitro findings.ResultsF1 and F2 were higher (p<0.05) at 3T than at 1.5T for all sequences except 3D-MRA. Stainless steel devices produced greater off-resonance artifact on SSFP compared to nitinol devices (p<0.05). Artifacts were most severe with the stainless steel Flipper detachable embolization coil (Cook Medical, Bloomington, IN), with F1 and F2 10 times greater than with stainless steel stents. The orientation of stents changed the size of off-resonance artifacts by up to two fold. Sequence type did influence the size of signal void or off-resonance artifact (p<0.05). Varying the flip angle and phase encode direction did not affect image artifact.ConclusionStainless steel embolization coils render large zones of anatomy uninterpretable, consistent with predictions based on ex-vivo testing. Most other commonly used devices produce only mild artifact ex-vivo and are compatible with diagnostic quality in-vivo studies. Knowledge of ex-vivo device behavior can help predict the technical success or failure of CMR scans and may preempt the performance of costly, futile studies.

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Section: Discussionmentioning

confidence: 99%

Pediatric cardiovascular interventional devices: effect on CMR images at 1.5 and 3 Tesla

Khan

Rapacchi

Levi

et al. 2013

Journal of Cardiovascular Magnetic Resonance

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“…Hähnel et al 15 found that a lower ALN on CEMRA at larger stent diameters in nitinol stents at 3 T and in stainless steel stents at 1.5 T and 3 T. Lettau et al 4 found a similar trend between ALN and stent diameter—that is, ALN decreased with increasing stent diameter in all of the various stents that they used except one at 1.5 T and 3 T. Lettau postulated that the reason for this correlation was the proportionate nature of the ALN calculation. Therefore, as long as the absolute extent of artifacts remained the same for different stent diameters, the ALN will decrease with increasing stent size 4. In this study, the above trend applied as the smaller Helistent generally showed higher ALN compared with the Enterprise.…”

Section: Discussionmentioning

confidence: 96%

“…The phantom was placed in the center of the coil with the longitudinal axis of the stent parallel to the main magnetic field. The design of contrast enhanced MRA (CEMRA) sequences was based on previous studies and followed these principles3 4 8: (1) the shortest repetition time (TR) possible to maximize the contrast to noise ratio; (2) the shortest echo time (TE) possible to minimize signal loss due to dephasing; (3) a wide bandwidth was chosen as previous studies showed artifact reduction and improved in-stent luminal visualization9–12; (4) a flip angle of 25° was used as a balance between optimal suppression of static tissues and clinically acceptable scanning time; and (5) isotropic voxel of 0.6×0.6×0.6 mm 3 was chosen for its clinical use in three-dimensional reformation. Sequence parameters for 3 T and 1.5 T MR systems are summarized in table 1.…”

Section: Methodsmentioning

confidence: 99%

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In vitro comparison of intracranial stent visibility using various concentrations of gadolinium contrast agent under 1.5 T and 3 T MR angiography

Chiang

Tseng

Chen

et al. 2016

J NeuroIntervent Surg

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“…Vascular signal loss or artificial luminal narrowing (ALN) by carotid stenting on CE-MRA has also been reported (14-17). These reports revealed that a nitinol stent generally creates less artifacts than a stainless steel or cobalt stent (1, 9, 18, 19).…”

Section: Introductionmentioning

confidence: 99%

Artificial Luminal Narrowing on Contrast-Enhanced Magnetic Resonance Angiograms on an Occasion of Stent-Assisted Coiling of Intracranial Aneurysm:In VitroComparison Using Two Different Stents with Variable Imaging Parameters

et al. 2012

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ObjectiveIntracranial stenting for stent-assisted coiling of aneurysms requires adequate follow-up imaging. The aim of this in vitro study was to compare in-stent artificial luminal narrowing on contrast-enhanced MR angiograms (CE-MRA) when applying Neuroform® and Enterprise® stents for stent-assisted coiling.Materials and MethodsTwo intracranial nitinol stents (Enterprise® and Neuroform®) were placed in silicon tubes and then imaged at 3 T and 1.5 T by the use of a T1-weighted three-dimensional spoiled gradient-echo sequence with minimal TR and TE. CE-MRAs were obtained by using different imaging planes, voxel sizes, and bandwidths, and with or without parallel imaging. Artificial lumen narrowing (ALN) was calculated and the results were compared.ResultsLower magnetic field strength, axial plane perpendicular to axis of stent, and wider bandwidth resulted in a lower ALN on CE-MRA for both stents. Larger voxel size resulted in lower ALN for Neuroform® stent. The parallel imaging acceleration factor did not affect ALN. The mean ALN was lower for Neuroform®, but it was not significant by a paired t test.ConclusionCE-MRA of the stented lumen of vascular phantom was partially impaired with ALN. Consequently, image plane orientation, magnetic field strength, bandwidth, and voxel size should be adjusted appropriately to reduce ALN.

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In vitro comparison of different carotid artery stents: a pixel-by-pixel analysis using CT angiography and contrast-enhanced MR angiography at 1.5 and 3 T

Abstract: CTA and CEMRA evaluation of vessel patency after stent placement is possible, but considerably impaired by ALN. Investigators should be informed about the method of choice for every stent.

Cited by 16 publications

References 26 publications

Pediatric cardiovascular interventional devices: effect on CMR images at 1.5 and 3 Tesla

Pediatric cardiovascular interventional devices: effect on CMR images at 1.5 and 3 Tesla

In vitro comparison of intracranial stent visibility using various concentrations of gadolinium contrast agent under 1.5 T and 3 T MR angiography

Artificial Luminal Narrowing on Contrast-Enhanced Magnetic Resonance Angiograms on an Occasion of Stent-Assisted Coiling of Intracranial Aneurysm:In VitroComparison Using Two Different Stents with Variable Imaging Parameters

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