A FDK-Based Reconstruction Method for Off-Centered Circular Trajectory Cone Beam Tomography

2006 ◽  
Vol 53 (5) ◽  
pp. 2736-2745 ◽  
Author(s):  
S. Valton ◽  
F. Peyrin ◽  
D. Sappey-Marinier
1990 ◽  
Vol 217 ◽  
Author(s):  
Ph. Rizo ◽  
P. Grangeat ◽  
P. Sire ◽  
P. Lemasson ◽  
S. Delageniere

ABSTRACTIn X-ray cone-beam tomography, the only planar source trajectory that does not produce incomplete data is the infinite line. Such a source trajectory is not experimentally possible. To ensure complete data acquisition with cone-beam radiographs, a set of nonplanar trajectories has been studied. Among the trajectories proposed in the literature, a simple one is a set of two circular trajectories with intersection of the two trajectory axes. The angle between the two axes is related to the maximum aperture of the cone beam. We propose here an exact method for performing this reconstruction using the 3-D Radon transform of the object. The modulation transfer function of this algorithm remains identical to that for the central slice of reconstruction in a single circular trajectory. The relative mean square error for density stays within 2% for an aperture of ±30°. With a single circular trajectory, the relative mean square error may reach 20% at the same aperture. With a double circular trajectory, horizontal artifacts are nearly suppressed.


Skull Base ◽  
2011 ◽  
Vol 21 (S 01) ◽  
Author(s):  
Christian Gueldner ◽  
Isabell Diogo ◽  
Siegfried Bien ◽  
Afshin Teymoortash ◽  
Jochen Werner

2019 ◽  
pp. 84-92
Author(s):  
Anh Chi Phan ◽  
Xuan Anh Ngoc Ho

Background: The condylar position discrepancy between centric relation and maximal intercuspation has been still a controversial issue. Aims: To compare the condylar position between centric relation and maximal intercuspation using cone-beam tomography in patients without temporomandibular joints disorder. Materials and methods: To assess the condylar position in centric relation and maximal intercuspation using cone-beam tomography on 40 fifth-year and sixth-year dental students of Hue University of Medicine and Pharmacy without temporomandibular joints disorder. The condylar positions are assessed following Sener classification (2009) and are compared between centric relation and maximal intercuspation using pairedsamples t-test and Mann-Whitney U-test. Results: Among 480 condye-to-fossa measurement pairs, there are 91.2% pairs having difference between two reference position but there is no significant difference. The condylar position at the superior of mandibular fossa has the greatest percentage in both centric relation and maximal intercuspation (43.8% in centric relation and 51.2% in maximal intercuspation). This greatest percentage is followed by the condylar position at posterior of mandibular fossa (32.5% in centric relation and 36.3% in maximal intercuspation). Lastly, the condylar position at the anterior of mandibular fossa has the fewest percentage (23.7% in centric relation and 12.5% in maximal intercuspation). Conclusion: There is no significant difference of condylar position between centric relation and maximal intercuspation in patients without temporomandibular joints disorder. Key words: Condylar position, centric relation, maximal intercuspation, cone-beam tomography


2001 ◽  
Vol 40 (11) ◽  
pp. 1795 ◽  
Author(s):  
Daniel L. Marks ◽  
Ronald Stack ◽  
Andrew J. Johnson ◽  
David J. Brady ◽  
David C. Munson

2010 ◽  
Author(s):  
I. Jerjen ◽  
V. Revol ◽  
C. Kottler ◽  
Th. Luethi ◽  
U. Sennhauser ◽  
...  

2002 ◽  
Author(s):  
Zhongyuan Qin ◽  
Xuan-qin Mu ◽  
Ping Wang ◽  
Yuanlong Cai
Keyword(s):  
X Ray ◽  

2021 ◽  
pp. 51-61
Author(s):  
A. Yu. Vasil'ev ◽  
V. V. Petrovskaya ◽  
E. A. Nichipor ◽  
V. G. Alpatova ◽  
N. N. Potrakhov ◽  
...  

During the course of this experimental study tomograms of extracted teeth were analyzed before and after filling the root canals with an endodontic material and fragments of broken metal instruments for root canal treatment. During the first stage of the experiment, untreated extracted teeth were scanned using conebeam computed tomography and microfocus cone-beam computed tomography. A comparative assessment of capabilities of the two methods of cone-beam computed tomography based on examination of untreated root canals was carried out. The second part of the study is dedicated to visualization of root canals that contain foreign high-density materials.


2004 ◽  
Vol 270-273 ◽  
pp. 1135-1142 ◽  
Author(s):  
Masaki Misawa ◽  
Ion Tiseanu ◽  
Ryusuke Hirashima ◽  
Kazuto Koizumi ◽  
Yasushi Ikeda

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