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Image Registration-Based Method for Reconstructing Transcatheter Heart Valve Geometry from Patient-Specific CT Scans. Ann Biomed Eng 2022; 50:805-815. [DOI: 10.1007/s10439-022-02962-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 03/30/2022] [Indexed: 01/18/2023]
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Chisena RS, Sengenberger J, Shih AJ, Gurm H. Novel preclinical method for evaluating the efficacy of a percutaneous treatment in human ex vivo calcified plaque. Med Biol Eng Comput 2021; 59:799-811. [PMID: 33710527 DOI: 10.1007/s11517-021-02334-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 02/03/2021] [Indexed: 11/28/2022]
Abstract
The lack of suitable atherosclerotic calcification models and testing strategies inhibits preclinical efficacy testing of existing and novel percutaneous devices. The goal of this study is to develop a preclinical testing method for quantitatively and qualitatively evaluating the efficacy of noncompliant balloon angioplasty (NC BA) treatment in human ex vivo calcified plaque (CP). NC BA using a 3- and 4-mm diameter balloon was performed on an ex vivo tibial calcified vessel obtained from an amputation. Three-dimensional microcomputed tomography (μ-CT) imaging was performed pre- and post-BA to compare crack density in the CP. Comparing the pre- and posttreatment three-dimensional μ-CT images showed a glass-like cracking that occurred in the CP due to the BA procedure. Expansion of the 3-mm balloon showed little tissue deformation and no CP cracking. Although expansion of the 4-mm balloon occurred nonuniformly along balloon length and across the perpendicular projections, the balloon generated cracking throughout the CP, which allowed the surrounding elastic tissue to be dilated. This combined X-ray microscopy and μ-CT technique is a useful preclinical tool for quantifying the efficacy of percutaneous treatments for CP. Because of its nondestructive nature, the CP structure can be visualized pre- and posttreatment to determine the treatment effect.
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Affiliation(s)
- Robert S Chisena
- Department of Mechanical Engineering, University of Michigan at Ann Arbor, 2350 Hayward St, Ann Arbor, MI, 48109, USA.
| | - Jordan Sengenberger
- Department of Biomedical Engineering, University of Michigan at Ann Arbor, 2200 Bonisteel Blvd, Ann Arbor, MI, 48109, USA
| | - Albert J Shih
- Department of Mechanical Engineering, University of Michigan at Ann Arbor, 2350 Hayward St, Ann Arbor, MI, 48109, USA
| | - Hitinder Gurm
- Department of Internal Medicine, University of Michigan Health System at Ann Arbor, 1500 E Medical Center Dr, Ann Arbor, MI, 48109, USA
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Duckworth EA, Chintalapani G, Camstra KM, Kan P. Optimizing contrast-enhanced cone-beam CT protocol to facilitate simultaneous visualization of neurovascular pathologies and surrounding structures of interest. Interv Neuroradiol 2018; 25:102-110. [PMID: 30231798 DOI: 10.1177/1591019918800216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE Contrast-enhanced cone-beam computed tomography (CBCT) imaging is commonly used for evaluating neurovascular stents and their relationship to the parent artery or vascular pathologies such as arteriovenous malformations (AVMs) and dural arteriovenous fistulas (dAVFs) in the context of surrounding anatomical structures. The purpose of this study was to understand the effects of varying concentrations of contrast medium used in CBCT imaging for optimal visualization of various endovascular devices and anatomical pathologies. METHODS Thirty-five patients with various neurovascular pathologies were included in the study. Contrast-enhanced CBCT images (20 s DR, Siemens syngo DynaCT, Siemens AG, Forchheim, Germany) were acquired in all cases, with varying dilutions of contrast medium, from 1% to 30%. The injection rate was kept constant at 3 cc/sec with an X-ray delay of two sec, and a total volume of 66 cc of diluted contrast was administered. Results from visual and quantitative analysis were reported. RESULTS Ten percent dilution of contrast medium resulted in the best image differentiation between flow-diverter devices and the parent artery. Concentrations as low as 2.5% contrast medium also resulted in identifying AVMs in the context of the surrounding brain parenchyma, whereas 20% to 30% dilution provided the best visualization of residual AVMs with prior Onyx embolization and dAVFs in the presence of bony structures. CONCLUSIONS Simultaneous visualization of brain parenchyma, bony structures, devices, and pathological anatomy using contrast-enhanced CBCT imaging is feasible with appropriate doses of iodinated contrast, and should be tailored to the individual case based on the goals of CBCT.
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Affiliation(s)
| | | | - Kevin M Camstra
- 1 Department of Neurosurgery, Baylor College of Medicine, Houston, USA
| | - Peter Kan
- 1 Department of Neurosurgery, Baylor College of Medicine, Houston, USA
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Gastropod shell size and architecture influence the applicability of methods used to estimate internal volume. Sci Rep 2018; 8:440. [PMID: 29323195 PMCID: PMC5765162 DOI: 10.1038/s41598-017-18906-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 12/19/2017] [Indexed: 11/19/2022] Open
Abstract
Obtaining accurate and reproducible estimates of internal shell volume is a vital requirement for studies into the ecology of a range of shell-occupying organisms, including hermit crabs. Shell internal volume is usually estimated by filling the shell cavity with water or sand, however, there has been no systematic assessment of the reliability of these methods and moreover no comparison with modern alternatives, e.g., computed tomography (CT). This study undertakes the first assessment of the measurement reproducibility of three contrasting approaches across a spectrum of shell architectures and sizes. While our results suggested a certain level of variability inherent for all methods, we conclude that a single measure using sand/water is likely to be sufficient for the majority of studies. However, care must be taken as precision may decline with increasing shell size and structural complexity. CT provided less variation between repeat measures but volume estimates were consistently lower compared to sand/water and will need methodological improvements before it can be used as an alternative. CT indicated volume may be also underestimated using sand/water due to the presence of air spaces visible in filled shells scanned by CT. Lastly, we encourage authors to clearly describe how volume estimates were obtained.
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Zwarzany Ł, Poncyljusz W, Burke TH. Flat detector CT and its applications in the endovascular treatment of wide-necked intracranial aneurysms-A literature review. Eur J Radiol 2017; 88:26-31. [PMID: 28189205 DOI: 10.1016/j.ejrad.2016.12.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 12/21/2016] [Accepted: 12/24/2016] [Indexed: 10/20/2022]
Abstract
Flat detector CT (FDCT) provides cross sectional imaging within an angiographic suite and is increasingly gaining popularity in various areas of interventional radiology, as an alternative imaging modality. Its relatively high spatial resolution improves visualization of intraluminal devices such as intracranial stents or flow-diverters. Device deployment and positioning, in relation to the parent vessel and surrounding structures, are easily assessible with FDCT. Furthermore, with contrast agent administration, it expands the diagnostic capabilities of this new imaging tool. However, beam-hardening artifacts is a major limitation in some cases. The examination can be performed both during the endovascular procedure and for pre- and post-treatment imaging. Intravenous contrast agent injection reduces the risk of complications, making it possible to perform this examination in the outpatient settings. The aim of this paper is to present an overview of published studies reporting experience with FDCT in the field of endovascular neurosurgery and in particular, FDCT's contribution in treatment of wide-necked intracranial aneurysms. The authors have focused specifically on stent-assisted coiling and flow-diverter implantation, since obtaining proper parent vessel wall apposition of these devices is essential for short- and long-term procedural outcomes.
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Affiliation(s)
- Łukasz Zwarzany
- Department of Radiology and Diagnostic Imaging, M. Curie Hospital, Arkońska 4, 71-455 Szczecin, Poland.
| | - Wojciech Poncyljusz
- Departament of Interventional Radiology, Pomeranian Medical University, Neurointerventional Cath Lab MSW Hospital, Al. Powst. Wielkopolskich 72, 70-111 Szczecin, Poland.
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Simgen A, Ley D, Roth C, Cattaneo GFM, Mühl-Benninghaus R, Müller A, Körner H, Kim YJ, Scheller B, Reith W, Yilmaz U. Evaluation of occurring complications after flow diverter treatment of elastase-induced aneurysm in rabbits using micro-CT and MRI at 9.4 T. Neuroradiology 2016; 58:987-996. [DOI: 10.1007/s00234-016-1730-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 07/12/2016] [Indexed: 12/22/2022]
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Pakdel A, Fialkov J, Whyne CM. High resolution bone material property assignment yields robust subject specific finite element models of complex thin bone structures. J Biomech 2016; 49:1454-1460. [DOI: 10.1016/j.jbiomech.2016.03.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/07/2016] [Accepted: 03/10/2016] [Indexed: 10/22/2022]
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Kuriyama T, Sakai N, Niida N, Sueoka M, Beppu M, Dahmani C, Kojima I, Sakai C, Imamura H, Masago K, Katakami N. Dose reduction in cone-beam CT scanning for intracranial stent deployment before coil embolization of intracranial wide-neck aneurysms. Interv Neuroradiol 2016; 22:420-5. [PMID: 26916658 DOI: 10.1177/1591019916632489] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 01/23/2016] [Indexed: 11/16/2022] Open
Abstract
PURPOSE Flat panel detector (FD)-equipped angiography machines are increasingly used for neuro-angiographic imaging. During intracranial stent-assisted coil embolization procedures, it is very important to clearly and quickly visualize stent shape after deployment in the vessel. It is necessary to quickly visualize stents by cone-beam computed tomography (CBCT). The aim of this study was to compare CBCTs at 10 and 20 s, and to confirm that this method is useful for neuro-endovascular treatment procedures. MATERIALS AND METHODS We treated 30 patients with wide-necked intracranial aneurysms with a flexible, self-expanding neurovascular stent and subsequent aneurysm embolization with platinum micro-coils. We performed the CBCT after stent deployment. We compared the 10 s and 20 s CBCTs, using the full width one-half maximum (FWHM) visualization. RESULTS Accurate stent placement with subsequent coil occlusion of the aneurysms was feasible in all patients. Stent struts were clearly visualized on both 10 s and 20 s CBCTs. Importantly, 10 s CBCT can reduce the radiation dose by about 42%, compared with 20 s CBCT. Performing 10 s CBCT with a 14% dilution of the contrast medium may significantly improve image acquisition during stent-assisted coil embolization. CONCLUSIONS Reduced-dose, 10 s CBCT can visualize stents in clinical cases, while significantly reducing radiation exposure.
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Affiliation(s)
- Takumi Kuriyama
- Division of Radiological Technology, Institute of Biomedical Research and Innovation, Kobe, Japan
| | - Nobuyuki Sakai
- Division of Neuroendovascular Therapy, Institute of Biomedical Research and Innovation, Kobe, Japan Division of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Norimitsu Niida
- CA/IR Department, Division of Advanced Therapies, Siemens Japan, Tokyo, Japan
| | - Masaki Sueoka
- Division of Radiological Technology, Institute of Biomedical Research and Innovation, Kobe, Japan
| | - Mikiya Beppu
- Division of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | | | - Iwao Kojima
- Research and Collaboration Department, Siemens Japan, Tokyo, Japan
| | - Chiaki Sakai
- Division of Neuroendovascular Therapy, Institute of Biomedical Research and Innovation, Kobe, Japan
| | - Hirotoshi Imamura
- Division of Neurosurgery, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Katsuhiro Masago
- Division of Integrated Oncology, Institute of Biomedical Research and Innovation, Kobe, Japan
| | - Nobuyuki Katakami
- Division of Integrated Oncology, Institute of Biomedical Research and Innovation, Kobe, Japan
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Ott S, Struffert T, Saake M, Gölitz P, Adamek E, Doerfler A. Influence of different reconstruction parameters in the visualization of intracranial stents using C-arm flat panel CT angiography: experience in an animal model. Acta Radiol 2016; 57:233-40. [PMID: 25711233 DOI: 10.1177/0284185115571988] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 01/18/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND C-arm flat panel computed tomography angiography (CA-CTA) is a relatively new imaging modality. Consequently, knowledge about postprocessing parameters and their influence on image quality is still limited, especially for the visualization of implanted microstents. PURPOSE To optimize reconstruction parameters by evaluating the influence of these different parameters for CA-CTA visualization of microstents in an animal model. MATERIAL AND METHODS Eleven microstents were implanted within the left common carotid artery of 11 New Zealand white rabbits. Both CA-CTA, using intra-venous delivery of contrast material, and conventional digital subtraction angiography (DSA) was performed. CA-CTA datasets were reconstructed using three different image characteristics (normal, sharp, smooth). Two experienced neuroradiologists evaluated the image quality and performed measurements of inner and outer stent diameters as well as measurements of the lumen area. RESULTS Stent deployment was performed successfully in all animals. Inter-observer correlation coefficient for all measurements was high (r = 0.87-0.92). Lumen area and inner stent diameter were significantly smaller in image characteristic "smooth" (P < 0.01) than in "sharp" and "normal". Outer stent diameter was larger in "smooth" than in "sharp" and "normal" (P < 0.01). Stent strut size was significantly wider using image characteristic "smooth". "Sharp" and "normal" compared best to DSA, with "sharp" providing the closest match to DSA measurements, with the trade-off of significantly more noise than in the "normal" reconstructions. CONCLUSION The use of different image characteristics in the postprocessing of CA-CTA datasets has an influence on the visualization of implanted stents. Image characteristic "sharp" and "normal" compared best to DSA.
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Affiliation(s)
- Sabine Ott
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Tobias Struffert
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Marc Saake
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Philipp Gölitz
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Edyta Adamek
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Arnd Doerfler
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
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Pierce EL, Bloodworth CH, Naran A, Easley TF, Jensen MO, Yoganathan AP. Novel Method to Track Soft Tissue Deformation by Micro-Computed Tomography: Application to the Mitral Valve. Ann Biomed Eng 2015; 44:2273-81. [PMID: 26553575 DOI: 10.1007/s10439-015-1499-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 10/31/2015] [Indexed: 11/29/2022]
Abstract
Increasing availability of micro-computed tomography (µCT) as a structural imaging gold-standard is bringing unprecedented geometric detail to soft tissue modeling. However, the utility of these advances is severely hindered without analogous enhancement to the associated kinematic detail. To this end, labeling and following discrete points on a tissue across various deformation states is a well-established approach. Still, existing techniques suffer limitations when applied to complex geometries and large deformations and strains. Therefore, we herein developed a non-destructive system for applying fiducial markers (minimum diameter: 500 µm) to soft tissue and tracking them through multiple loading conditions by µCT. Using a novel applicator to minimize adhesive usage, four distinct marker materials were resolvable from both tissue and one another, without image artifacts. No impact on tissue stiffness was observed. µCT addressed accuracy limitations of stereophotogrammetry (inter-method positional error 1.2 ± 0.3 mm, given marker diameter 1.9 ± 0.1 mm). Marker application to ovine mitral valves revealed leaflet Almansi areal strains (45 ± 4%) closely matching literature values, and provided radiographic access to previously inaccessible regions, such as the leaflet coaptation zone. This system may meaningfully support mechanical characterization of numerous tissues or biomaterials, as well as tissue-device interaction studies for regulatory standards purposes.
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Affiliation(s)
- Eric L Pierce
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 387 Technology Circle NW, Suite 200, Atlanta, GA, 30313, USA
| | - Charles H Bloodworth
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 387 Technology Circle NW, Suite 200, Atlanta, GA, 30313, USA
| | - Ajay Naran
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 387 Technology Circle NW, Suite 200, Atlanta, GA, 30313, USA
| | - Thomas F Easley
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 387 Technology Circle NW, Suite 200, Atlanta, GA, 30313, USA
| | - Morten O Jensen
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 387 Technology Circle NW, Suite 200, Atlanta, GA, 30313, USA
| | - Ajit P Yoganathan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 387 Technology Circle NW, Suite 200, Atlanta, GA, 30313, USA.
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Ott S, Gölitz P, Adamek E, Royalty K, Doerfler A, Struffert T. Flat-detector computed tomography evaluation in an experimental animal aneurysm model after endovascular treatment: A pilot study. Interv Neuroradiol 2015; 21:490-8. [PMID: 26111985 DOI: 10.1177/1591019915590364] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We compared flat-detector computed tomography angiography (FD-CTA) to multislice computed tomography (MS-CTA) and digital subtracted angiography (DSA) for the visualization of experimental aneurysms treated with stents, coils or a combination of both.In 20 rabbits, aneurysms were created using the rabbit elastase aneurysm model. Seven aneurysms were treated with coils, seven with coils and stents, and six with self-expandable stents alone. Imaging was performed by DSA, MS-CTA and FD-CTA immediately after treatment. Multiplanar reconstruction (MPR) was performed and two experienced reviewers compared aneurysm/coil package size, aneurysm occlusion, stent diameters and artifacts for each modality.In aneurysms treated with stents alone, the visualization of the aneurysms was identical in all three imaging modalities. Residual aneurysm perfusion was present in two cases and visible in DSA and FD-CTA but not in MS-CTA. The diameter of coil-packages was overestimated in MS-CT by 56% and only by 16% in FD-CTA compared to DSA (p < 0.05). The diameter of stents was identical for DSA and FD-CTA and was significantly overestimated in MS-CTA (p < 0.05). Beam/metal hardening artifacts impaired image quality more severely in MS-CTA compared to FD-CTA.MS-CTA is impaired by blooming and beam/metal hardening artifacts in the visualization of implanted devices. There was no significant difference between measurements made with noninvasive FD-CTA compared to gold standard of DSA after stenting and after coiling/stent-assisted coiling of aneurysms. FD-CTA may be considered as a non-invasive alternative to the gold standard 2D DSA in selected patients that require follow up imaging after stenting.
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Affiliation(s)
- Sabine Ott
- Department of Neuroradiology, University of Erlangen-Nuremberg, Germany
| | - Philipp Gölitz
- Department of Neuroradiology, University of Erlangen-Nuremberg, Germany
| | - Edyta Adamek
- Department of Neuroradiology, University of Erlangen-Nuremberg, Germany
| | - Kevin Royalty
- Department of Biomedical Engineering and School of Medicine and Public Health, University of Wisconsin, USA
| | - Arnd Doerfler
- Department of Neuroradiology, University of Erlangen-Nuremberg, Germany
| | - Tobias Struffert
- Department of Neuroradiology, University of Erlangen-Nuremberg, Germany
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Stidd DA, Theessen H, Deng Y, Li Y, Scholz B, Rohkohl C, Jhaveri MD, Moftakhar R, Chen M, Lopes DK. Evaluation of a metal artifacts reduction algorithm applied to postinterventional flat panel detector CT imaging. AJNR Am J Neuroradiol 2014; 35:2164-9. [PMID: 25125663 DOI: 10.3174/ajnr.a4079] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Flat panel detector CT images are degraded by streak artifacts caused by radiodense implanted materials such as coils or clips. A new metal artifacts reduction prototype algorithm has been used to minimize these artifacts. The application of this new metal artifacts reduction algorithm was evaluated for flat panel detector CT imaging performed in a routine clinical setting. MATERIALS AND METHODS Flat panel detector CT images were obtained from 59 patients immediately following cerebral endovascular procedures or as surveillance imaging for cerebral endovascular or surgical procedures previously performed. The images were independently evaluated by 7 physicians for metal artifacts reduction on a 3-point scale at 2 locations: immediately adjacent to the metallic implant and 3 cm away from it. The number of visible vessels before and after metal artifacts reduction correction was also evaluated within a 3-cm radius around the metallic implant. RESULTS The metal artifacts reduction algorithm was applied to the 59 flat panel detector CT datasets without complications. The metal artifacts in the reduction-corrected flat panel detector CT images were significantly reduced in the area immediately adjacent to the implanted metal object (P = .05) and in the area 3 cm away from the metal object (P = .03). The average number of visible vessel segments increased from 4.07 to 5.29 (P = .1235) after application of the metal artifacts reduction algorithm to the flat panel detector CT images. CONCLUSIONS Metal artifacts reduction is an effective method to improve flat panel detector CT images degraded by metal artifacts. Metal artifacts are significantly decreased by the metal artifacts reduction algorithm, and there was a trend toward increased vessel-segment visualization.
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Affiliation(s)
- D A Stidd
- From the Departments of Neurosurgery (D.A.S., R.M., M.C., D.K.L.)
| | - H Theessen
- Siemens Healthcare Sector (B.S., C.R., H.T.), Erlangen, Germany
| | - Y Deng
- Internal Medicine (Y.D., Y.L.)
| | - Y Li
- Internal Medicine (Y.D., Y.L.)
| | - B Scholz
- Siemens Healthcare Sector (B.S., C.R., H.T.), Erlangen, Germany
| | - C Rohkohl
- Siemens Healthcare Sector (B.S., C.R., H.T.), Erlangen, Germany
| | - M D Jhaveri
- Radiology (M.D.J.), Rush University Medical Center, Chicago, Illinois
| | - R Moftakhar
- From the Departments of Neurosurgery (D.A.S., R.M., M.C., D.K.L.)
| | - M Chen
- From the Departments of Neurosurgery (D.A.S., R.M., M.C., D.K.L.)
| | - D K Lopes
- From the Departments of Neurosurgery (D.A.S., R.M., M.C., D.K.L.)
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Cosentino D, Zwierzak I, Schievano S, Díaz-Zuccarini V, Fenner JW, Narracott AJ. Uncertainty assessment of imaging techniques for the 3D reconstruction of stent geometry. Med Eng Phys 2014; 36:1062-8. [DOI: 10.1016/j.medengphy.2014.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Revised: 04/16/2014] [Accepted: 04/24/2014] [Indexed: 11/26/2022]
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Pellerin O, Lin M, Bhagat N, Shao W, Geschwind JF. Can C-arm cone-beam CT detect a micro-embolic effect after TheraSphere radioembolization of neuroendocrine and carcinoid liver metastasis? Cancer Biother Radiopharm 2014; 28:459-65. [PMID: 23484809 DOI: 10.1089/cbr.2012.1390] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
RATIONAL AND OBJECTIVE Radioembolization with yttrium-90 microspheres is a therapy that is used for hepatic tumors. 20-30 μm microspheres loaded with Y90 are supposedly occluding tumor vessels at the capillary level. Then, these spheres deliver high-dose radiation to the tumor. However, this theoretical embolic effect has never been appreciated in imaging. Dual-Phase cone-beam computed tomography (DPCBCT) is a multi-phasic intra-procedural scan that uses only one contrast media injection to visualize early (feeding vessel) and delayed (capillary level) tumor enhancement. The purpose of this study was to determine whether there is a micro-embolic effect induced by TheraSpheres® (MDS Nordion, Ottawa, Ontario, Canada) at the capillary level by using DPCBCT imaging. MATERIALS AND METHODS 14 patients with 72 carcinoid or neuroendocrine tumors were treated with radioembolization, and all underwent DPCBCT (Allura Xper, Philips Healthcare) imaging before and immediately after radioembolization with TheraSpheres®. Tumor enhancement was measured in each phase by drawing a region of interest within the tumors. RESULTS 72 tumors were evaluated: average tumor density in the early arterial phase was 241 and 230 Hounsfield units (HU) (p<0.001) before and after radioembolization, respectively; the average density in the delayed arterial phase was 226 and 161 HU (p<0.001) before and after radioembolization, respectively. Average difference in tumor attenuation before and after radioembolization in early arterial and delayed phase was 11 HU and 64 HU (p<0.001), respectively. CONCLUSION The significant decrease in tumor enhancement in the DPCBCT delayed phase after TheraSpheres® injection indicates that there is an appreciable microembolic effect at the tumor capillary bed level.
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Affiliation(s)
- Olivier Pellerin
- Division of Vascular and Interventional Radiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Hospital, Baltimore, Maryland 21287, USA
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Jou LD, Mitchell BD, Shaltoni HM, Mawad ME. Effect of structural remodeling (retraction and recoil) of the pipeline embolization device on aneurysm occlusion rate. AJNR Am J Neuroradiol 2014; 35:1772-8. [PMID: 24722301 DOI: 10.3174/ajnr.a3920] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE During endovascular treatment of unruptured aneurysms with the Pipeline Embolization Device, an oversized device is often selected to achieve better wall apposition; however, this device oversizing could be related to overelongation and possible delayed enlargement of the stented region. The purpose of this study is to investigate the relationship between oversize and treatment outcome. MATERIALS AND METHODS The DynaCT images of 14 aneurysms treated by a single Pipeline Embolization Device were retrospectively analyzed. 3D images of the deployed device were compared with those acquired at the 6-month follow-up for qualitative and quantitative evaluation. The diameter and length of the Pipeline Embolization Device were measured at both time points and compared for determination of the device changes. RESULTS Structural changes of the device have been observed, and it was found that the Pipeline Embolization Device influences the vessel curvature in some cases. On average, it increases its diameter by 0.23 mm and decreases its length by 2.88 mm within 6 months of initial deployment. Excessive elongation beyond its nominal length is correlated with a lower aneurysm occlusion rate at the 6-month follow-up. CONCLUSIONS Not only does a Pipeline Embolization Device reconstruct the aneurysm and parent artery, but its entire structure goes through a gradual remodeling process. The relative deformation between the device and the artery indicates suboptimal wall apposition. Device oversizing does not have a direct effect on shortening or recoil. The aneurysm occlusion rate, however, is lowered by overelongation of the Pipeline Embolization Device.
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Affiliation(s)
- L-D Jou
- From the Departments of Radiology (L.-D.J., H.M.S., M.E.M.)
| | - B D Mitchell
- Neurosurgery (B.D.M.), Baylor College of Medicine, Houston, Texas
| | - H M Shaltoni
- From the Departments of Radiology (L.-D.J., H.M.S., M.E.M.)
| | - M E Mawad
- From the Departments of Radiology (L.-D.J., H.M.S., M.E.M.)
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Keuler A, Taschner C, Brockmann MA, Boll H, Förster K, Lutz L, Herrmann-Frank A, Lelgemann M, Schumacher M. Comparison of high-resolution X-ray and micro-CT for experimental evaluation of intracranial stent prototypes: quality evaluation beyond CE mark. Neuroradiology 2014; 56:315-23. [DOI: 10.1007/s00234-014-1324-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 01/09/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Andreas Keuler
- Department of Neuroradiology, University Medical Center Freiburg, Breisacher Strasse 64, 79106, Freiburg, Germany,
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Lettau M, Bendszus M, Hähnel S. Angiographic CT: In vitro comparison of different carotid artery stents using two different angiography systems. J Neuroradiol 2013; 40:348-54. [DOI: 10.1016/j.neurad.2013.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 03/16/2013] [Accepted: 03/20/2013] [Indexed: 12/24/2022]
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Phan CM, Khalilzadeh O, Dinkel J, Wang IS, Bredella MA, Misra M, Miller KK, Klibanski A, Gupta R. C-arm CT for histomorphometric evaluation of lumbar spine trabecular microarchitecture: a study on anorexia nervosa patients. Br J Radiol 2013; 86:20120451. [PMID: 23640801 DOI: 10.1259/bjr.20120451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Bone histomorphometry measurements require high spatial resolution that may not be feasible using multidetector CT (MDCT). This study evaluated the trabecular microarchitecture of lumbar spine using MDCT and C-arm CT in a series of young adult patients with anorexia nervosa (AN). 11 young females with AN underwent MDCT (anisotropic resolution with a slice thickness of ~626 μm) and C-arm CT (isotropic resolution of ~200 µm). Standard histomorphometric parameters the of L1 vertebral body, namely the apparent trabecular bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular number (TbN) and trabecular separation (TbSp), were analysed using MicroView software (GE Healthcare, Piscataway, NJ). Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Trabecular parameters derived from MDCT and C-arm CT were compared, and their association with BMD parameters was evaluated. Histomorphometric parameters derived from C-arm CT, namely TbTh, TbN and TbSp, were significantly different from the corresponding MDCT parameters. There were no significant correlations between C-arm CT-derived parameters and the corresponding MDCT-derived parameters. C-arm CT-derived parameters were significantly (p<0.001) correlated with anteroposterior L1 spine BMD and Z-scores: TbTh (r=0.723, r=0.744, respectively), TbN (r=-0.720, r=-0.712, respectively) and TbSp (r=0.656, r=0.648, respectively). BV/TV, derived from C-arm CT, was significantly associated with body mass index (r=0.636) and ideal body weight (r=0.730) (p<0.05). These associations were not present in MDCT-derived parameters. This study suggests that the spatial resolution offered by C-arm CT more accurately captures the histomorphometric parameters of trabecular morphology than MDCT in patients with AN.
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Affiliation(s)
- C M Phan
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Lettau M, Bendszus M, Hähnel S. Angiographic CT: in vitro comparison of different carotid artery stents-does stent orientation matter? Neuroradiology 2013; 55:675-82. [PMID: 23411716 DOI: 10.1007/s00234-013-1152-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 01/29/2013] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Our aim was to evaluate the in vitro visualization of different carotid artery stents on angiographic CT (ACT). Of particular interest was the influence of stent orientation to the angiography system by measurement of artificial lumen narrowing (ALN) caused by the stent material within the stented vessel segment to determine whether ACT can be used to detect restenosis within the stent. METHODS ACT appearances of 17 carotid artery stents of different designs and sizes (4.0 to 11.0 mm) were investigated in vitro. Stents were placed in different orientations to the angiography system. Standard algorithm image reconstruction and stent-optimized algorithm image reconstruction was performed. For each stent, ALN was calculated. RESULTS With standard algorithm image reconstruction, ALN ranged from 19.0 to 43.6 %. With stent-optimized algorithm image reconstruction, ALN was significantly lower and ranged from 8.2 to 18.7 %. Stent struts could be visualized in all stents. Differences in ALN between the different stent orientations to the angiography system were not significant. CONCLUSION ACT evaluation of vessel patency after stent placement is possible but is impaired by ALN. Stent orientation of the stents to the angiography system did not significantly influence ALN. Stent-optimized algorithm image reconstruction decreases ALN but further research is required to define the visibility of in-stent stenosis depending on image reconstruction.
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Affiliation(s)
- Michael Lettau
- Division of Neuroradiology, Department of Neurosurgery, University of Freiburg Medical Center, Breisacher Str. 64, 79106 Freiburg, Germany.
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Mahnken AH. CT Imaging of Coronary Stents: Past, Present, and Future. ISRN CARDIOLOGY 2012; 2012:139823. [PMID: 22997590 PMCID: PMC3446716 DOI: 10.5402/2012/139823] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 08/16/2012] [Indexed: 11/23/2022]
Abstract
Coronary stenting became a mainstay in coronary revascularization therapy. Despite tremendous advances in therapy, in-stent restenosis (ISR) remains a key problem after coronary stenting. Coronary CT angiography evolved as a valuable tool in the diagnostic workup of patients after coronary revascularization therapy. It has a negative predictive value in the range of 98% for ruling out significant ISR. As CT imaging of coronary stents depends on patient and stent characteristics, patient selection is crucial for success. Ideal candidates have stents with a diameter of 3 mm and more. Nevertheless, even with most recent CT scanners, about 8% of stents are not accessible mostly due to blooming or motion artifacts. While the diagnosis of ISR is currently based on the visual assessment of the stent lumen, functional information on the hemodynamic significance of in-stent stenosis became available with the most recent generation of dual source CT scanners. This paper provides a comprehensive overview on previous developments, current techniques, and clinical evidence for cardiac CT in patients with coronary artery stents.
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Affiliation(s)
- Andreas H Mahnken
- Department of Diagnostic and Interventional Radiology, University Hospital, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany
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Saake M, Struffert T, Goelitz P, Ott S, Seifert F, Ganslandt O, Doerfler A. Angiographic CT with intravenous contrast agent application for monitoring of intracranial flow diverting stents. Neuroradiology 2011; 54:727-35. [PMID: 21969242 DOI: 10.1007/s00234-011-0965-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Accepted: 09/20/2011] [Indexed: 11/30/2022]
Affiliation(s)
- Marc Saake
- Department of Neuroradiology, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
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