Dual-energy imaging method to improve the image quality and the accuracy of dose calculation for cone-beam computed tomography

Abstract Cone-beam computed tomography (CBCT) has promoted changes in approaches in Endodontics, and enhanced decision-making in complex clinical cases. Despite the technological advancements in CBCT hardware, the interpretation of the acquired images is still compromised by viewing software packages that often have limited navigational tools and lack adequate filters to overcome some challenges of the CBCT technology such as artefacts. This study reviews the current limitations of CBCT and the potential of a new CBCT software package (e-Vol DX, CDT- Brazil) to overcome these aspects and support diagnosing, planning and managing of endodontic cases. This imaging method provide high resolution images due to submillimeter voxel sizes, dynamic multi-plane imaging navigation and ability to change the volume parameters such as slice thickness and slice intervals and data correction applying imaging filters and manipulating brightness and contrast. The main differences between e-Vol DX and other software packages are: compatibility with all current CBCT scanners with the capacity to export DICOM Data, a more comprehensive brightness and contrast library, as other applications, in which adjustments are limited, do not usually support all the DICOM dynamic range features; Custom slice thickness adjustment, often limited and pre-defined in other applications; Custom Sharpening adjustment, often limited in other applications; advanced noise reduction algorithm that enhances image quality; preset imaging filters, dedicated endodontic volume rendering filters with the ability to zoom the image over 1000x (3D reconstructions) without loss of resolution and automatic imaging parameters customization for better standardization and opportunities for research; capture screen resolution of 192 dpi, with a 384 dpi option, in contrast to the 96 dpi of most similar applications. This new CBCT software package may support decision-making for the treatment of complex endodontic cases and improve diagnosis and treatment results. Effective improvement of image quality favors the rational prescription and interpretation of CBCT scans.

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Enabling Conventional Cone Beam Computed Tomography With the Capability of Dual Energy Imaging Using a Simple Add-on Beam Modifier

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/j.ijrobp.2016.06.2222 ◽

2016 ◽

Vol 96 (2) ◽

pp. E636

Author(s):

R. Vinke ◽

S. Takao ◽

K. Umegaki ◽

H. Shirato ◽

H. Peng ◽

...

Keyword(s):

Computed Tomography ◽

Cone Beam Computed Tomography ◽

Dual Energy ◽

Cone Beam ◽

Dual Energy Imaging

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A technical note on intra-arterial cone-beam computed tomography for the evaluation of flow-diverter stents: Image quality differences between diluted and non-diluted contrast medium

Interventional Neuroradiology ◽

10.1177/1591019919890929 ◽

2019 ◽

Vol 26 (2) ◽

pp. 164-169

Author(s):

Naci Kocer ◽

Sedat G Kandemirli ◽

Daniel Ruijters ◽

Michalis Mantatzis ◽

Osman Kizilkilic ◽

...

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Contrast Medium ◽

Cone Beam Computed Tomography ◽

Vessel Wall ◽

Flow Diverter ◽

Cone Beam ◽

Gray Scale ◽

Stent Deployment ◽

Contrast Technique

Background Design of flow-diverter stents for flexibility, tractability, and low profile limits their radiopacity on conventional digital subtraction angiography. Cone-beam computed tomography (CBCT) offers higher spatial resolution for the evaluation of flow-diverter stents. However, CBCT requires optimal dilution and timing of contrast medium for simultaneous visualization of the stent, arterial lumen, and vessel wall. There are only limited data on the effects of different contrast dilutions on CBCT image quality in neurointerventional applications. Materials and methods In our institution, intra-arterial CBCTs were acquired during stent deployment and at follow-ups with 10% diluted contrast. We had recently started acquiring intra-arterial CBCTs with non-diluted contrast. Retrospective analysis of our flow-diverter data identified eight cases with different aneurysm locations who had intra-arterial CBCT with 10% diluted contrast immediately after flow-diverter stent deployment and with non-diluted contrast technique during follow-ups. For each case, the image quality between diluted and non-diluted contrast techniques was compared qualitatively by assessing stent visualization and quantitatively by plotting gray-scale intensity values along the vessel lumen. Results In two sets of CBCT images per each case, there was no substantial difference between diluted and non-diluted CBTC techniques for the evaluation of stent architecture and lumen opacification. Gray-scale intensity values perpendicular to the lumen revealed similar intensity values along the neighboring parenchyma, vessel wall, and lumen for the two different contrast techniques. Conclusion Intra-arterial CBCT angiography can be performed without contrast dilution and still achieve adequate image quality in certain cerebral aneurysms treated with flow diverter. The non-diluted contrast technique avoids the time loss during preparation of diluted contrast and installation of diluted contrast to the injector in angiography suites with a single power injector.

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A Method to Improve Electron Density Measurement of Cone-Beam CT Using Dual Energy Technique

BioMed Research International ◽

10.1155/2015/858907 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Kuo Men ◽

Jian-Rong Dai ◽

Ming-Hui Li ◽

Xin-Yuan Chen ◽

Ke Zhang ◽

...

Keyword(s):

Electron Density ◽

Cone Beam Ct ◽

Density Measurement ◽

Dual Energy ◽

Cone Beam ◽

Imaging Method ◽

Basis Material ◽

X Ray ◽

Dual Energy Imaging ◽

Set Up

Purpose. To develop a dual energy imaging method to improve the accuracy of electron density measurement with a cone-beam CT (CBCT) device.Materials and Methods. The imaging system is the XVI CBCT system on Elekta Synergy linac. Projection data were acquired with the high and low energy X-ray, respectively, to set up a basis material decomposition model. Virtual phantom simulation and phantoms experiments were carried out for quantitative evaluation of the method. Phantoms were also scanned twice with the high and low energy X-ray, respectively. The data were decomposed into projections of the two basis material coefficients according to the model set up earlier. The two sets of decomposed projections were used to reconstruct CBCT images of the basis material coefficients. Then, the images of electron densities were calculated with these CBCT images.Results. The difference between the calculated and theoretical values was within 2% and the correlation coefficient of them was about 1.0. The dual energy imaging method obtained more accurate electron density values and reduced the beam hardening artifacts obviously.Conclusion. A novel dual energy CBCT imaging method to calculate the electron densities was developed. It can acquire more accurate values and provide a platform potentially for dose calculation.

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