scholarly journals Evaluation of metal artefacts for two CBCT devices with a new dental arch phantom

2020 ◽  
Vol 49 (5) ◽  
pp. 20190385
Author(s):  
Luciano Augusto Cano Martins ◽  
Polyane Mazucatto Queiroz ◽  
Yuri Nejaim ◽  
Karla de Faria Vasconcelos ◽  
Francisco Carlos Groppo ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
Cone Beam ◽  
Dental Arch ◽  
Adjacent Area ◽  
Significance Level ◽  
Metal Artefacts ◽  
Metal Artefact ◽  
Bone Structures ◽  
The Impact ◽  
Phantom Design

Objectives: To create a new phantom design to evaluate the real impact of artefacts caused by titanium on bone structures in cone beam CT images considering different positions and quantity of metals in the dental arch, with and without metal artefact reduction (MAR). Methods: A three cylindrical polymethyl methacrylate (PMMA) plate phantom was designed containing eight perforations arranged to simulate the lower dental arch in the intermediate plate. Three titanium cylinders were positioned in different locations and quantities to test different clinical conditions and to quantify the impact of the metal artefact around five bone cylinders. Scans were carried out in seven different protocols (Control, A-F) in two cone beam CT devices (OP300 Maxio and Picasso Trio). Eight regions of interest around each cortical and trabecular bone were used to measure the grey value standard deviation corresponding the artefact expression in the Image J software. Both the artefact expression and the MAR effect were assessed using the Wilcoxon, Friedman (Dunn) and Kruskal–Wallis tests (significance level of 5%). Results: For both devices, MAR was statistically efficient only for the protocols E, and F. Protocol F (three metals on the adjacent area of the analysis region) showed higher artefact expression when compared to the others. Conclusion: In conclusion, the new phantom design allowed the quantification of the metal artefact expression caused by titanium. The metal artefact expression is higher when more metal objects are positioned in the adjacent bone structures. MAR may not be effective to reduce artefact expression on the adjacencies of those objects for the devices studied.

SU-FF-I-53: The Impact of Portal Imager Shifts and the Assumption of Rigid Isocentricity On Megavoltage Cone Beam CT Images

2005 ◽  
Vol 32 (6Part3) ◽  
pp. 1916-1916 ◽  
Author(s):  
O Morin ◽  
S Bose ◽  
J Chen ◽  
M Aubin ◽  
J Pouliot
Keyword(s):  
Cone Beam Ct ◽  
Ct Images ◽  
Cone Beam ◽  
Megavoltage Cone Beam Ct ◽  
The Impact

scholarly journals Assessment of metal artefact reduction around dental titanium implants in cone beam CT

2014 ◽  
Vol 43 (7) ◽  
pp. 20140019 ◽  
Author(s):  
A Parsa ◽  
N Ibrahim ◽  
B Hassan ◽  
K Syriopoulos ◽  
P van der Stelt
Keyword(s):  
Cone Beam Ct ◽  
Titanium Implants ◽  
Cone Beam ◽  
Metal Artefact Reduction ◽  
Metal Artefact ◽  
Artefact Reduction

scholarly journals Thyroid shielding in cone beam computed tomography: recommendations towards appropriate use

2019 ◽  
Vol 48 (7) ◽  
pp. 20190014 ◽  
Author(s):  
Ruben Pauwels ◽  
Keith Horner ◽  
Jenia Vassileva ◽  
Madan M. Rehani
Keyword(s):  
Cone Beam Ct ◽  
Cone Beam ◽  
Current Evidence ◽  
Appropriate Use ◽  
Risk Models ◽  
Equivalent Thickness ◽  
Metal Artefacts ◽  
Current Trends ◽  
Dosimetric Data ◽  
Tube Current

The objective of this paper is to provide recommendations towards the appropriate use of thyroid shielding in dental cone beam CT (CBCT). Based on current evidence of thyroid radiosensitivity, dosimetric data in the presence and absence of shielding, and a depiction of potential adverse effects of thyroid shielding, a concise set of recommendations was prepared. According to current risk models, thyroid sensitivity is particularly high at a young age, and much higher for females. In the literature, involving adult male, female and paediatric reference phantoms, the use of a tightly fitted thyroid collar with a lead-equivalent thickness of at least 0.25 mm has consistently shown a significant reduction (average: 45.9%) of the equivalent dose to the thyroid. It can therefore be recommended that thyroid shielding should be routinely used for children undergoing CBCT scanning and is recommended for adults up to the age of 50. The increase of the X-ray tube current from automatic exposure control systems due to thyroid shielding can be avoided by placing the shielding collar after acquiring the scout images. Should real-time tube current modulation be implemented in dental CBCT imaging in the future, perspectives regarding the appropriate use of shielding may change according to current trends in CT. In view of the manifestation of metal artefacts, shielding is best avoided if radiological evaluation of tissues below the lower border of the mandible is needed.

S192 – 3D Diagnosis of Vocalizing Larynx Using Cone Beam CT

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P140-P140
Author(s):  
Koji Inagaki ◽  
Koichiro Saito ◽  
Hideki Naganishi ◽  
Takaoka Takuj ◽  
Momoshima Suketaka ◽  
...  
Keyword(s):  
Vocal Fold ◽  
3D Visualization ◽  
Cone Beam Ct ◽  
Vocal Folds ◽  
Cone Beam ◽  
3 Dimensional ◽  
Scanning Time ◽  
Informative Role ◽  
Glottal Insufficiency ◽  
The Impact

Objectives Cone beam computed tomography (CBCT) was developed for the office-based quick and precise 3D visualization of maxillofacial region. CBCT requires scanning time of less than 10 seconds and provides isotropic 3D image with high resolution. In this study, we examined the potential role of CBCT as a tool for 3-dimensional evaluation of the glottal insufficiency. Methods CBCT was performed in 2 normal controls and in 14 patients with unilateral vocal fold paralysis (13 cases) or paresis (1 case). Laryngeal CBCT images were taken in the resting state and during phonation. Furthermore, preoperative and postoperative images were evaluated to assess the impact of phonosurgeries in 5 cases. Results CBCT of the vocalizing vocal fold was successfully performed in all the cases, producing clear coronal images. During phonation, no remarkable differences in levels between the paralyzed and normal vocal folds were observed in 10 cases, proving the 2-dimensional glottal gap (2D cases). On the other hand, the levels of paralyzed vocal folds stayed higher during phonation compared to the normal side in 4 cases, proving the 3-dimensional glottal gap (3D cases). 4 of the 2D cases had injection laryngoplasty and 1 of the 3D cases had arytenoid adduction procedure to correct their glottal gaps. Postoperative CBCT images verified the successful correction of these gaps. Conclusions Our study proved the feasibility of CBCT for 3D evaluation of vocalizing larynx. This quick and easy system may have an informative role to suggest the proper phonosurgical procedure for glottic insufficiency.

Comparison of rotary NiTi reciprocating file systems using Cone Beam CT in root canal transportation

2021 ◽  
Vol 15 (6) ◽  
pp. 1206-1209
Author(s):  
N. Zahid ◽  
S. A. Khan ◽  
A. Saqib ◽  
A. Tariq
Keyword(s):  
Computed Tomography ◽  
Root Canal ◽  
Cone Beam Ct ◽  
File Systems ◽  
Cone Beam ◽  
Niti Wire ◽  
Significance Level ◽  
Single File ◽  
Canal Transportation ◽  
Tomography Method

Aim: T assess the root canal transportation caused by these rotary NiTi reciprocating file systems using 3D cone beam computed tomography Method: This experimental study was conducted on 60 samples of rotary NiTi reciprocating file systems using CBCT. The extent of canal transportation and the centering ratio was analyzed using independent sample t test. The significance level was set at 95%. Results: Mean apical canal transportation was lower in wave one Gold groups as compare to Reciproc (0.8724±0.04SD vs 0.9463±0.02SD, p=0.000). Mean apical canal transportation at 5 mm was lower in wave one gold group as compare to reciproc blue group (0.5610±0.02SD vs 0.7253±0.06SD, p=0.000). Mean apical canal transportation at 8mm was lower in wave one group as compare to reciproc blue (0.358±0.03SD vs 0.5766±0.10SD, p=0.000). Conclusion: Wave one Gold had high centering ability and lower canal transportation as compare to Reciproc Blue single file system. CBCT is an efficient method of understanding Canal transportation Keywords: CBCT, NiTi wire, Root canal transportation, Reciproc blue

scholarly journals A comparative evaluation of cone beam CT and micro-CT on trabecular bone structures in the human mandible

2013 ◽  
Vol 42 (8) ◽  
pp. 20130145 ◽  
Author(s):  
J Van Dessel ◽  
Y Huang ◽  
M Depypere ◽  
I Rubira-Bullen ◽  
F Maes ◽  
...  
Keyword(s):  
Trabecular Bone ◽  
Comparative Evaluation ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Micro Ct ◽  
Bone Structures

scholarly journals The impact of Cone Beam CT on financial costs and orthodontists’ treatment decisions in the management of maxillary canines with eruption disturbance

2017 ◽  
Vol 40 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Helena Christell ◽  
Stephen Birch ◽  
Lars Bondemark ◽  
Keith Horner ◽  
Christina Lindh ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
Treatment Decisions ◽  
Cone Beam ◽  
Financial Costs ◽  
The Impact
Sign in / Sign up

Export Citation Format

Share Document