Contrast-Enhanced Angiographic Cone-Beam CT of Cerebrovascular Stents: Experimental Optimization and Clinical Application

Patel, Neil V.; Gounis, Matthew J.; Wakhloo, Ajay K.; Noordhoek, Niels; Blijd, J.; Babić, Draženko; Takhtani, Deepak; Lee, S.-K.; Norbash, Alexander

doi:10.3174/ajnr.a2239

Cited by 77 publications

(77 citation statements)

References 25 publications

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“…The problem of metal artifacts in the reconstruction due to coils and stent delivery wire remains unresolved. 15,16) The stent delivery wire should be out of the field of view before conducting an XperCT study. The part of the stent adjacent to the coil mass might not be visualized after coil insertion due to the artifact caused by platinum coils.…”

Section: Discussionmentioning

confidence: 99%

Analysis of Closed-Cell Intracranial Stent Characteristics Using Cone-Beam Computed Tomography With Contrast Material

Tsuruta

Matsumaru

Hamada

et al. 2013

Neurol. Med. Chir.(Tokyo)

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The intracranial nitinol stent named the Enterprise Vascular Reconstruction Device has poor radiographic visibility. The characteristics of closed-cell intracranial stents were investigated and the efficacy of intraoperative stent visualization examined with the 80 kV high-resolution XperCT protocol, which is a flat detector C-arm volume acquisition functionality system integrated with the angiography equipment. We treated 39 aneurysms with stent-assisted coil embolization. The aneurysms were located on the internal carotid artery in 24 cases, the anterior communicating artery (AcomA) in three, the basilar artery (BA) in 10, and the vertebral artery in two. Intraoperative 80 kV XperCT was performed in all cases after deposition of the stent. We evaluated the coverage of the aneurysm neck, incomplete stent apposition (ISA), and shift of vessels. Accurate stent visualization was achieved in 29 of the 39 cases without coil and delivery wire artifact. Coverage of the aneurysm neck succeeded in 28 cases; there was one case of BA top Y-configuration stenting in which the stent was dislocated into the aneurysm. ISA was detected in nine cases, including seven kinks and one flattening in the carotid siphon and one kink in the BA top. We detected linearization of vessels due to stent deployment in three AcomA cases and three BA top cases. We conclude that intraoperative 80 kV XperCT is an efficient modality for the evaluation of ISA. Stent kinking in the carotid siphon and linearization in distal vessels can be detected with this protocol.

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Section: Discussionmentioning

confidence: 99%

Analysis of Closed-Cell Intracranial Stent Characteristics Using Cone-Beam Computed Tomography With Contrast Material

Tsuruta

Matsumaru

Hamada

et al. 2013

Neurol. Med. Chir.(Tokyo)

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“…24 Intra-arterial CBCTA has been used to image intracranial stents and was found to be useful in simultaneous imaging of the stent and the parent vessel. 25 In the assessment of the degree of in-stent restenosis following a nitinol stent, intra-arterial CBCTA was found to correlate well with histology in an in vivo swine experiment. Intracranial CBCTA also correlated well with DSA in assessing in-stent restenosis following intracranial stents or PEDs in clinical studies.…”

Section: Discussionmentioning

confidence: 99%

“…However, metal artifacts due to beam-hardening, scattered radiation, sampling, and noise artifacts remain a problem in CBCT in the presence of embolization coils. 25 When the ROI is located in proximity to the coils and becomes obscured by metal artifacts, the diagnostic value of CBCT is greatly diminished, though the presence of a coil mass in close proximity to a vascular segment does not necessarily preclude the possibility of good-quality imaging of the vascular segment with IVCBCTA, provided the vascular segment is oriented outside the plane of metal artifacts when CT is performed. The possibility of good quality imaging of the vascular segment despite the presence of metal artifacts was demonstrated in 11 of 14 patients with intracranial coil masses (Fig 2).…”

Section: Figmentioning

confidence: 99%

Intravenous C-Arm Conebeam CT Angiography following Long-Term Flow-Diverter Implantation: Technologic Evaluation and Preliminary Results

Lee

Lau

et al. 2015

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE:A noninvasive investigation with high spatial resolution and without metal artifacts is necessary for long-term imaging follow-up after flow-diverter implantation. We aimed to evaluate the diagnostic value of conebeam CT angiography with intravenous contrast enhancement in the assessment of vascular status following implantation of the Pipeline Embolization Device and to analyze the preliminary results of vascular status following long-term Pipeline Embolization Device implantation.

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“…40) have been reported. Considering that image-guided interventions require the ability to visualize 67-78 µm wide struts of nitinol stents, 29 there is a need for a high-resolution imaging platform. The investigated detector, in addition to high-resolution imaging, provides for dual-energy imaging that obviates the need for precontrast and postcontrast images during digital subtraction angiography.…”

Section: Discussionmentioning

confidence: 99%

“…For the imaged stent, the strut width is 78 µm and the average strut thickness is 42 µm and contains radiopaque platinum markers at the proximal and distal aspects of the stent to guide treatment since the struts are not visualized with current C-arm systems. 29 Technique factors used for acquisition and the receptor entrance exposure (REE) are provided in the figure caption. For the single frame image [ Fig.…”

Section: C Resampling To Square Pixelsmentioning

confidence: 99%

Photon-counting hexagonal pixel array CdTe detector: Spatial resolution characteristics for image-guided interventional applications

et al. 2016

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Purpose: High-resolution, photon-counting, energy-resolved detector with fast-framing capability can facilitate simultaneous acquisition of precontrast and postcontrast images for subtraction angiography without pixel registration artifacts and can facilitate high-resolution real-time imaging during image-guided interventions. Hence, this study was conducted to determine the spatial resolution characteristics of a hexagonal pixel array photon-counting cadmium telluride (CdTe) detector. Methods: A 650 µm thick CdTe Schottky photon-counting detector capable of concurrently acquiring up to two energy-windowed images was operated in a single energy-window mode to include photons of 10 keV or higher. The detector had hexagonal pixels with apothem of 30 µm resulting in pixel pitch of 60 and 51.96 µm along the two orthogonal directions. The detector was characterized at IEC-RQA5 spectral conditions. Linear response of the detector was determined over the air kerma rate relevant to image-guided interventional procedures ranging from 1.3 nGy/frame to 91.4 µGy/frame. Presampled modulation transfer was determined using a tungsten edge test device. The edge-spread function and the finely sampled line spread function accounted for hexagonal sampling, from which the presampled modulation transfer function (MTF) was determined. Since detectors with hexagonal pixels require resampling to square pixels for distortion-free display, the optimal square pixel size was determined by minimizing the root-mean-squared-error of the aperture functions for the square and hexagonal pixels up to the Nyquist limit. Results: At Nyquist frequencies of 8.33 and 9.62 cycles/mm along the apothem and orthogonal to the apothem directions, the modulation factors were 0.397 and 0.228, respectively. For the corresponding axis, the limiting resolution defined as 10% MTF occurred at 13.3 and 12 cycles/mm, respectively. Evaluation of the aperture functions yielded an optimal square pixel size of 54 µm. After resampling to 54 µm square pixels using trilinear interpolation, the presampled MTF at Nyquist frequency of 9.26 cycles/mm was 0.29 and 0.24 along the orthogonal directions and the limiting resolution (10% MTF) occurred at approximately 12 cycles/mm. Visual analysis of a bar pattern image showed the ability to resolve close to 12 line-pairs/mm and qualitative evaluation of a neurovascular nitinol-stent showed the ability to visualize its struts at clinically relevant conditions. Conclusions: Hexagonal pixel array photon-counting CdTe detector provides high spatial resolution in single-photon counting mode. After resampling to optimal square pixel size for distortion-free display, the spatial resolution is preserved. The dual-energy capabilities of the detector could allow for artifact-free subtraction angiography and basis material decomposition. The proposed high-resolution photon-counting detector with energy-resolving capability can be of importance for several imageguided interventional procedures as well as for pediatric applications. C 2016 Amer...

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Contrast-Enhanced Angiographic Cone-Beam CT of Cerebrovascular Stents: Experimental Optimization and Clinical Application

Abstract: BACKGROUND AND PURPOSE:With modern imaging techniques, visualization of neurovascular stents remains challenging. We present a method for contrast-enhanced C-arm CBCT that provides detailed and simultaneous visualization of neurovascular stents and host arteries.

Cited by 77 publications

References 25 publications

Analysis of Closed-Cell Intracranial Stent Characteristics Using Cone-Beam Computed Tomography With Contrast Material

Analysis of Closed-Cell Intracranial Stent Characteristics Using Cone-Beam Computed Tomography With Contrast Material

Intravenous C-Arm Conebeam CT Angiography following Long-Term Flow-Diverter Implantation: Technologic Evaluation and Preliminary Results

Photon-counting hexagonal pixel array CdTe detector: Spatial resolution characteristics for image-guided interventional applications

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