scholarly journals Dual-rotation C-arm cone-beam computed tomography to increase low-contrast detection

2017 ◽  
Vol 44 (9) ◽  
pp. e164-e173
Author(s):  
Aymeric Reshef ◽  
Cyril Riddell ◽  
Yves Trousset ◽  
Saïd Ladjal ◽  
Isabelle Bloch
Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6416
Author(s):  
Sunghoon Choi ◽  
Chang-Woo Seo ◽  
Bo Kyung Cha

In this study, the effect of filter schemes on several low-contrast materials was compared using standard and ultra-high-resolution (UHR) cone-beam computed tomography (CBCT) imaging. The performance of the UHR-CBCT was quantified by measuring the modulation transfer function (MTF) and the noise power spectrum (NPS). The MTF was measured at the radial location around the cylindrical phantom, whereas the NPS was measured in the eight different homogeneous regions of interest. Six different filter schemes were designed and implemented in the CT sinogram from each imaging configuration. The experimental results indicated that the filter with smaller smoothing window preserved the MTF up to the highest spatial frequency, but larger NPS. In addition, the UHR imaging protocol provided 1.77 times better spatial resolution than the standard acquisition by comparing the specific spatial frequency (f50) under the same conditions. The f50s with the flat-top window in UHR mode was 1.86, 0.94, 2.52, 2.05, and 1.86 lp/mm for Polyethylene (Material 1, M1), Polystyrene (M2), Nylon (M3), Acrylic (M4), and Polycarbonate (M5), respectively. The smoothing window in the UHR protocol showed a clearer performance in the MTF according to the low-contrast objects, showing agreement with the relative contrast of materials in order of M3, M4, M1, M5, and M2. In conclusion, although the UHR-CBCT showed the disadvantages of acquisition time and radiation dose, it could provide greater spatial resolution with smaller noise property compared to standard imaging; moreover, the optimal window function should be considered in advance for the best UHR performance.


2019 ◽  
Vol 100 (2) ◽  
pp. 89-94
Author(s):  
V. V. Petrovskaya ◽  
N. N. Potrakhov ◽  
A. Yu. Vasil’ev

Objective. To determine peculiarities when using microfocus cone beam computed tomography (micro-CBCT) and cone beam computed tomography (CBCT) to analyze the anatomy of the teeth and the quality of endodontic treatment.Material and methods. Micro-CBCT and CBCT were experimentally used to examine 8 extracted tooth preparations before and after endodontic root canal treatment using different types of filling material.Results. Micro-CBCT showed the high informative value of determining the type, nature, and quality of canal filling and diagnosed many cracks and accessory canals. According to the micro-CBCT findings, the tooth apexes were not filled; the lumen of the canals was unevenly and loosely filled with endodontic material; the passages of guttapercha points were well traced; the nature of the endodontic material was differentiated.Conclusion. Micro-CBCT opens up new opportunities in dentistry with tooth volume visualization, allowing the minor and low-contrast details of the anatomical structure of the teeth to be seen on the X-ray image.


2019 ◽  
Vol 1 (1) ◽  
pp. 16-18 ◽  
Author(s):  
Norafida Bahari ◽  
Nik Azuan Nik Ismail ◽  
Jegan Thanabalan ◽  
Ahmad Sobri Muda

In this article, we evaluate the effectiveness of Cone Beam Computed Tomography, through a case study, in assessing the complication of intracranial bleeding during an endovascular treatment of brain arteriovenous malformation when compared to Multislice-Detector Computed Tomography performed immediately after the procedure. The image quality of Cone Beam Computed Tomography has enough diagnostic value in differentiating between haemorrhage, embolic materials and the arteriovenous malformation nidus to facilitate physicians to decide for further management of the patient.


Author(s):  
Norafida Bahari ◽  
NikAzuan Nik Ismail ◽  
Jegan Thanabalan ◽  
Ahmad Sobri Muda

In this article, we evaluate the effectiveness of Cone Beam Computed Tomography, through a case study, in assessing the complication of intracranial bleeding during an endovascular treatment of brain arteriovenous malformation when compared to Multislice-Detector Computed Tomography performed immediately after the procedure. The image quality of Cone Beam Computed Tomography has enough diagnostic value in differentiating between haemorrhage, embolic materials and the arteriovenous malformation nidus to facilitate physicians to decide for further management of the patient.


2020 ◽  
Vol 69 (1) ◽  
Author(s):  
Andrea Pilloni ◽  
Lorenza Montanaro ◽  
Fabiola Dell'olmo ◽  
Alberto Fonzar ◽  
Francesco Cairo ◽  
...  

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