Sterartefacten in cone beam CT van zes verschillende wortelkanaalvulmaterialen; een in-vitro-onderzoek

2015 ◽  
pp. 225-238
Author(s):  
N. D’hondt ◽  
J. K. M. Aps
Keyword(s):  
Cone Beam Ct ◽  
Cone Beam

Distortion or magnification? An in vitro cone-beam CT study of dimensional changes of objects with different compositions

2021 ◽  
pp. 20210063
Author(s):  
Fernanda Coelho-Silva ◽  
Hugo Gaêta-Araujo ◽  
Lucas P Lopes Rosado ◽  
Deborah Queiroz Freitas ◽  
Francisco Haiter-Neto ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Cone Beam Ct ◽  
Posterior Region ◽  
Anterior Region ◽  
Cone Beam ◽  
Cobalt Chromium ◽  
Shape Distortion ◽  
Dimensional Changes ◽  
Post Hoc

Objectives: To assess whether dimensional changes occur as shape distortion (unevenly), contraction or magnification (evenly) in cone beam computed tomography (CBCT) considering materials, anatomical regions, and metal artefact reduction algorithms (MAR). Methods: Four cylinders of amalgam (Am), cobalt-chromium (Co-Cr), gutta-percha (Gu), titanium (Ti) and zirconium (Zi) were inserted inside a polymethylmethacrylate phantom in anterior and posterior regions for acquisitions in Picasso Trio and OP300 with MAR enabled and disabled. Two observers measured the dimensions of each cylinder in three axes: Y (height), Z (antero posterior diameter), and X (latero-lateral diameter). Repeated measures ANOVA with Tukey post-hoc test compared the data (α = 5%). Results: Shape distortion occurred for all materials in anterior region of Picasso Trio without MAR (p < 0.05). With MAR enabled, Gu and Ti contracted, while the others showed distortion (p ≥ 0.05). In posterior region, all materials distorted in both MAR conditions (p < 0.05), except Gu, which magnified without MAR (p ≥ 0.05) and contracted unevenly with MAR (p < 0.05). In anterior region of OP300, all materials magnified without MAR, (p ≥ 0.05), and had shape distortion with MAR (p < 0.05). In posterior region, only Am showed magnification without MAR (p ≥ 0.05), while all materials presented shape distortion with MAR (p < 0.05). Conclusion: Dimensional changes of high-density materials in CBCT can be either a magnification, a contraction or a distortion; the last condition is the most prevalent. Furthermore, changes differ considering material, anatomical region and MAR condition.

Comparison of linear and volumetric measurements obtained from periodontal defects by using cone beam-CT and micro-CT: an in vitro study

2018 ◽  
Vol 23 (5) ◽  
pp. 2235-2244 ◽  
Author(s):  
M. Ayşe Tayman ◽  
Kıvanç Kamburoğlu ◽  
Özlem Küçük ◽  
Funda S. Ö. Ateş ◽  
Meral Günhan
Keyword(s):  
Cone Beam Ct ◽  
In Vitro Study ◽  
Vitro Study ◽  
Cone Beam ◽  
Micro Ct ◽  
Volumetric Measurements

scholarly journals Accuracy of cone-beam CT in detecting vertical root fractures in teeth with post-endodontic restorations: an in vitro study

2021 ◽  
Vol 43 ◽  
pp. e55832
Author(s):  
Fernanda Chiguti Yamashita ◽  
Amanda Lury Yamashita ◽  
Irma Milena Menck Romanichen ◽  
Elen de Souza Tolentino ◽  
Sérgio Sábio ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
In Vitro Study ◽  
Cone Beam ◽  
Control Group ◽  
Endodontically Treated Teeth ◽  
Kappa Value ◽  
Diagnostic Capacity ◽  
Root Fractures ◽  
Sensitivity Specificity

The aim of this study was to evaluate the accuracy of cone-beam CT (CBCT) for the detection of artificially created vertical root fractures (VRF) in extracted teeth restored with metallic (MP) and fiberglass (FGP) posts. After root canal obturation, 60 extracted human premolars were scanned by using the highest-resolution settings of a CBCT unit. The prepared roots were randomly divided into three groups: group C (control group): non-restored and non- endodontically treated teeth (n = 20); group MP (n = 20); group FGP (n = 20). In all groups, 10 teeth were artificially fractured. Two external and independent observers blindly recorded the presence or absence of VRF. Sensitivity, specificity, accuracy, intra- and interobserver agreement were calculated. Kappa value for inter- and intraobserver agreement was 0.82 and 0.84 respectively, demonstrating good agreement. The highest values for sensitivity (0.80 - 0.90), specificity (1.00) and accuracy (0.90 - 0.95) were found in the control group. The teeth with FGP restoration presented the lowest sensitivity (0.30 - 0.50) and accuracy (0.60 - 0.65) values. Both examiners had a good performance in the diagnosis of fractures in teeth with MP, with accuracy ranging between 0.85 - 0.90. The presence of MP did not influence accuracy; however, the presence of FGP reduced the diagnostic capacity of CBCT.

scholarly journals The impact of software-based metal artifact reduction on the liquid embolic agent Onyx in cone-beam CT: a systematic in vitro and in vivo study

2021 ◽  
pp. neurintsurg-2021-018018
Author(s):  
Niclas Schmitt ◽  
Charlotte S Weyland ◽  
Lena Wucherpfennig ◽  
Christof M Sommer ◽  
Martin Bendszus ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
Brain Parenchyma ◽  
Cone Beam ◽  
Embolic Agent ◽  
Artifact Reduction ◽  
Metal Artifact ◽  
Metal Artifact Reduction ◽  
The Impact

BackgroundOnyx is frequently used for endovascular embolization of intracranial arteriovenous malformations (AVMs) and dural arteriovenous fistulas (dAVFs). One drawback of using Onyx is the generation of artifacts in cone-beam CT (CBCT). These artifacts can represent an obstacle for the detection of periprocedural hemorrhage or planning of subsequent radiosurgery. This study investigates the effect of artifact reduction by the syngo DynaCT SMART Metal Artifact Reduction (MAR) software.MethodsA standardized in vitro tube model (n=10) was filled with Onyx 18 and CBCT image acquisition was conducted in a brain imaging phantom. Furthermore, post-interventional CBCT images of 20 patients with AVM (n=13) or dAVF (n=7), each treated with Onyx, were investigated. The MAR software was applied for artifact reduction. Artifacts of the original and the post-processed images were analyzed quantitatively (standard deviation in a region of interest on the layer providing the most artifacts) and qualitatively. For the patient images, the effect of the MAR software on brain parenchyma on artifact-free images was further investigated.ResultsQuantitative and qualitative analyses of both datasets demonstrated a lower degree of artifacts in the post-processed images (eg, patient images: 38.30±22.03 density units (no MAR; mean SD±SD) vs 19.83±12.31 density units (with MAR; p<0.001). The MAR software had no influence on the brain parenchyma in artifact-free images.ConclusionThe MAR software significantly reduced the artifacts evoked by Onyx in CBCT without affecting the visualization of brain parenchyma on artifact-free images. Applying this software could thus improve the quality of periprocedural CBCT images after embolization with Onyx.

Abstract TP261: Clot Integration Factor for in-vitro Quantification of Stent-retriever Configuration Using Cone-beam CT

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Kajo van der Marel ◽  
Olivia W Brooks ◽  
Robert M King ◽  
Ju-Yu Chueh ◽  
Miklos Marosfoi ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Cone Beam Ct ◽  
Treatment Strategies ◽  
Stent Retriever ◽  
Cone Beam ◽  
Vessel Occlusion ◽  
Device Integration ◽  
Vitro Model ◽  
Phantom Experiments

Objective: Mechanical thrombectomy using stent-retriever technology provides acute ischemic stroke patients with beneficial treatment of emergent large vessel occlusion. Still, the disparity between recanalization rates and clinical outcomes calls for enhanced device designs and treatment strategies with better reperfusion efficiency. Intuitively, sufficient device integration with the embolus is pursued to maximize chances of first-pass success, thereby limiting clot fragmentation and intimal trauma during extensive clot manipulation. Our aim was to develop an imaging-based measure of device integration in reproducible phantom experiments that could help identifying differences in aspects of thrombectomy procedures that may be related to angiographic and clinical outcomes. Methods: Deployment variations of the Trevo(TM) ProVue/XP retriever were tested in an in-vitro model system that mimicked a MCA-occlusion with a silicone vascular replica and two visible clot models (soft elastic, and hard inelastic) with 8 trials/group. High-resolution cone-beam CT imaging was performed prior to retriever retraction. An image processing pipeline was devised that used level-set segmentation, path-tracing, and Steiner circumellipse fitting to extract and determine the interior volumes of the clot and the three visible wires. Clot Integration Factor (CIF) was calculated as the ratio of the volume of clot-device intersection to the clot volume. Results: Example of the device, its wires, and the clot: Average clot volumes were 90.4±12.2mm3. CIF was significantly different for two deployment variations when the device engaged a hard clot (difference between means, 95%CI=[0.003,0.187], p=0.043), but not a soft clot model (95%CI=[-0.152,0.263], p=0.567). Conclusion: In-vitro imaging-based quantification of clot integration can detect differences in deployment configuration relative to a clot, which may support procedural and design improvements.

scholarly journals Predicting Trabecular Bone Stiffness from Clinical Cone-Beam CT and HR-pQCT Data; an In Vitro Study Using Finite Element Analysis

PLoS ONE ◽  
2016 ◽  
Vol 11 (8) ◽  
pp. e0161101 ◽  
Author(s):  
Eva Klintström ◽  
Benjamin Klintström ◽  
Rodrigo Moreno ◽  
Torkel B. Brismar ◽  
Dieter H. Pahr ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Trabecular Bone ◽  
Cone Beam Ct ◽  
In Vitro Study ◽  
Vitro Study ◽  
Cone Beam ◽  
Element Analysis ◽  
Bone Stiffness

scholarly journals The detection of vertical root fractures in post-core restored teeth with cone-beam CT: in vivo and ex vivo

2019 ◽  
Vol 48 (6) ◽  
pp. 20180327 ◽  
Author(s):  
Svetlana F. Byakova ◽  
Nina E. Novozhilova ◽  
Irina M. Makeeva ◽  
Vasiliy I. Grachev ◽  
Inna V. Kasatkina
Keyword(s):  
Image Quality ◽  
Ex Vivo ◽  
Cone Beam Ct ◽  
Ct Scanning ◽  
Cone Beam ◽  
Human Teeth ◽  
Fracture Width ◽  
Root Fractures

Objectives: To compare the accuracy of cone-beam CT ex vivo and in vivo for the detection of artificially created large and small vertical root fractures in extracted teeth restored with post-core. Methods: Individual metal cast post-cores were fixed in the root canals of 50 extracted single-rooted human teeth. In 30 teeth fractures were created by tapping posts with a hammer. The teeth were sterilised in autoclave and embedded into bite-plates made of silicon impression material. Cone-beam CT scanning was performed ex vivo and in vivo . For the in vivo scanning, teeth in sterile plastic bags were inserted into the mouths of volunteers. Then the teeth were sectioned with low-speed saw and the widths of the VRFs were measured microscopically. The teeth were distributed into 2 groups in accordance with the measured fractures’ widths: large (wider than 180–250 µm) and small (80–150 µm). Five observers assessed the presence of vertical root fractures on axial CBCT slices. Sensitivity, specificity, accuracy and inter examiner agreement were calculated. Results: The accuracy of cone-beam CT in vitro for large and small vertical root fractures detection was 0.56 and 0.40 respectively (p = 0.043). The sensitivity values were 0.53 and 0.27 for large and small vertical root fractures, respectively (p = 0.043). The visualisation of fracture lines in vivo was impossible in 90 % of cases, because of low image quality. Inter examiner reliability analysis showed κ values ranging from 0.02 to 0.54. Conclusions: Fracture width affected the in vitro detectability of vertical root fractures by cone-beam CT in teeth with metal cast post-cores. The detectability of root fractures in vivo was decreased because of low image quality, making the assessment of sound tooth tissue impossible.

scholarly journals Imaging Artifacts of Nonadhesive Liquid Embolic Agents in Conventional and Cone-beam CT in a Novel in Vitro AVM Model

2021 ◽  
Author(s):  
Niclas Schmitt ◽  
Ralf O Floca ◽  
Daniel Paech ◽  
Rami A El Shafie ◽  
Ulf Neuberger ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Cone Beam ◽  
Major Drawback ◽  
Embolic Agents ◽  
Liquid Embolic ◽  
Imaging Artifacts ◽  
Different Diameters

Abstract Background A major drawback of liquid embolic agents (LEAs) is the generation of imaging artifacts (IA), which may represent a crucial obstacle for the detection of periprocedural hemorrhage or subsequent radiosurgery of cerebral arteriovenous malformations (AVMs). This study aimed to compare the IAs of Onyx, Squid and PHIL in a novel three-dimensional in vitro AVM model in conventional computed tomography (CT) and cone-beam CT (CBCT). Methods Tubes with different diameters were configured in a container resembling an AVM with an artificial nidus at its center. Subsequently, the AVM models were filled with Onyx 18, Squid 18, PHIL 25% or saline and inserted into an imaging phantom (n = 10/LEA). Afterwards CT and CBCT scans were acquired. The degree of IAs was graded quantitatively (Hounsfield units in a defined region of interest) and qualitatively (feasibility of defining the nidus)—Onyx vs. Squid vs. PHIL vs. saline, respectively. Results Quantitative density evaluation demonstrated more artifacts for Onyx compared to Squid and PHIL, e.g. 48.15 ± 14.32 HU for Onyx vs. 7.56 ± 1.34 HU for PHIL in CT (p < 0.001) and 41.88 ± 7.22 density units (DU) for Squid vs. 35.22 ± 5.84 DU for PHIL in CBCT (p = 0.044). Qualitative analysis showed less artifacts for PHIL compared to Onyx and Squid in both imaging modalities while there was no difference between Onyx and Squid regarding the definition of the nidus (p > 0.999). Conclusion In this novel three-dimensional in vitro AVM model, IAs were higher for the EVOH/tantalum-based LEAs Onyx and Squid compared to iodine-based PHIL. Onyx induced the highest degree of IAs with only minor differences to Squid.

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