scholarly journals Cone-Beam 3-D Reconstruction with Double Circular Trajectory

1990 ◽  
Vol 217 ◽  
Author(s):  
Ph. Rizo ◽  
P. Grangeat ◽  
P. Sire ◽  
P. Lemasson ◽  
S. Delageniere
Keyword(s):  
Mean Square Error ◽  
Incomplete Data ◽  
Cone Beam ◽  
Mean Square ◽  
Modulation Transfer ◽  
Circular Trajectory ◽  
X Ray ◽  
Planar Source ◽  
Infinite Line ◽  
Cone Beam Tomography

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.

scholarly journals Phase Contrast Cone Beam Tomography with an X-Ray Grating Interferometer

2010 ◽  
Author(s):  
I. Jerjen ◽  
V. Revol ◽  
C. Kottler ◽  
Th. Luethi ◽  
U. Sennhauser ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Cone Beam ◽  
X Ray ◽  
Grating Interferometer ◽  
Cone Beam Tomography

Simulation of x-ray projections for 3D cone-beam tomography

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

scholarly journals ANALISIS KOMPARASI METODE PERBAIKAN KONTRAS BERBASIS HISTOGRAM EQUALIZATION PADA CITRA MEDIS

2017 ◽  
Vol 8 (1) ◽  
pp. 383-388
Author(s):  
Aditya Akbar Riadi ◽  
Ahmad Abdul Chamid ◽  
Akh Sokhibi
Keyword(s):  
Mean Square Error ◽  
Histogram Equalization ◽  
Mean Square ◽  
X Ray ◽  
Adaptive Histogram Equalization

Citra merupakan gambaran tentang karakteristik suatu obyek menurut kondisi variabel tertentu. Pengolahan citra bertujuan memperbaiki kualitas citra agar mudah diinterpretasi oleh manusia atau mesin (dalam hal ini komputer). Terdapat beberapa operasi di dalam pengolahan citra, salah satunya adalah perbaikan kontras yang pada dasarnya biasa digunakan untuk memunculkan bagian-bagian yang tidak terlihat (hidden feature) pada citra. Hasil citra dari rontgen yang tidak selalu memiliki kualitas citra yang baik, seperti halnya hasil citra x-ray yang terlalu gelap atau ada bagian tulang yang terlihat samar sehingga gambar tidak terlihat jelas. Pada penelitian ini teknik peningkatan citra dengan perbaikan kontras menggunakan metode berbasis Histrogram Equalization. Pada citra medis tersebut dan juga menunjukkan kinerja hasil pengukuran kontrol eror menggunakan Mean Square Error menjelaskan bahwa metode  Contrast Limited Adaptive Histogram Equalization lebih baik dibandingkan dengan metode Histrogram Equalization dan metode Adaptive Histogram Equalization.

Phleboliths from venous malformations of the head and neck

2013 ◽  
Vol 28 (2) ◽  
pp. 86-92 ◽  
Author(s):  
B Eivazi ◽  
A J Fasunla ◽  
C Güldner ◽  
P Masberg ◽  
J A Werner ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Head And Neck ◽  
Cone Beam ◽  
Venous Malformations ◽  
X Ray Diffraction ◽  
Upper Eyelid ◽  
Submandibular Region ◽  
X Ray ◽  
Intravascular Coagulopathy ◽  
Cone Beam Tomography

Objectives/Hypothesis Phleboliths in venous malformations (VM) of the head and neck are often observed and may cause significant symptoms. Only a few articles refer to the morphology and composition of the phleboliths in VM. The objective of this study was to analyse and to demonstrate their composition and morphology. Methods Patients with VM presenting to a vascular anomalies centre during a three-year period were identified. The incidence of phleboliths was analysed followed by morphological and structural analysis with cone beam tomography and X-ray diffraction. Results Phleboliths were identified in 28/98 patients with VM of the head and neck. Seven patients underwent conventional surgery to reduce the volume of the VM or to remove the phleboliths, which were localized in the cheek (3 cases), submandibular region (2 cases), infrahyoidal neck or upper eyelid (1 case each). The structural analysis showed that more advanced lamination and an increasing radiopacity of the cortex was observed in larger phleboliths. X-ray powder diffraction analysis revealed that the main constituent in the pulverized phleboliths was carbonate-fluorohydroxylapatite. Conclusion This study shows in a vivid way that phleboliths from VM of the head and neck area show a laminar structure and consist of apatite, without any indication of differences in their chemical composition. Treatment of localized intravascular coagulopathy in VM might be able to prevent the formation and the progression of phleboliths. Hypothetically, another option might be lithotripsy.

scholarly journals Optical cone beam tomography of Cherenkov-mediated signals for fast 3D dosimetry of x-ray photon beams in water

2015 ◽  
Vol 42 (7) ◽  
pp. 4127-4136 ◽  
Author(s):  
Adam K. Glaser ◽  
Jacqueline M. Andreozzi ◽  
Rongxiao Zhang ◽  
Brian W. Pogue ◽  
David J. Gladstone
Keyword(s):  
Cone Beam ◽  
Photon Beams ◽  
X Ray ◽  
3D Dosimetry ◽  
Cone Beam Tomography

scholarly journals 51463 X-ray cone beam tomography with two tilted circular trajectories

1994 ◽  
Vol 27 (2) ◽  
pp. 105
Author(s):  
P. Rizo ◽  
P. Grangeat ◽  
P. Sire ◽  
P. Le Masson ◽  
S. Delageniere
Keyword(s):  
Cone Beam ◽  
X Ray ◽  
Cone Beam Tomography

Reconstruction from incomplete data in cone‐beam tomography

1996 ◽  
Vol 35 (9) ◽  
pp. 2748 ◽  
Author(s):  
Harish P. Hiriyannaiah
Keyword(s):  
Incomplete Data ◽  
Cone Beam ◽  
Cone Beam Tomography

scholarly journals Perspectives of the Tooth Restoration Technology Based on the Computed Tomography Data

2018 ◽  
Vol 155 ◽  
pp. 01004
Author(s):  
Maxim Putrik ◽  
Vladimir Ivanov ◽  
Igor Antsygin
Keyword(s):  
Computed Tomography ◽  
Processing System ◽  
Cone Beam ◽  
Tooth Surface ◽  
X Rays ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Tomography Method ◽  
Cone Beam Tomography ◽  
Tomography Data

The aim of the study is to create an image processing system, which allows dentists to create tooth surface automatically. X-rays images of jaws from the cone beam tomography or the spiral computed tomography and images from the micro-computed tomography are the initial data for processing. Example of using the combination of optical and x-ray images in the dentistry is described. Also, it was shown how to use the microcomputed tomography method to plan the placement of orthopedic structures on the lost teeth sites.

51228 X-ray 3D cone beam tomography application to the control of ceramic parts

1994 ◽  
Vol 27 (2) ◽  
pp. 106
Author(s):  
P. Grangeat ◽  
P. Le Masson ◽  
M. Martin ◽  
P. Rizo ◽  
P. Sire
Keyword(s):  
Cone Beam ◽  
X Ray ◽  
Cone Beam Tomography
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