Concerning x-ray scatter reduction for CT scanners

1981 ◽  
Vol 8 (2) ◽  
pp. 249-249 ◽  
Author(s):  
Robert K. Cacak
Keyword(s):  
X Ray ◽  
Ct Scanners ◽  
Scatter Reduction

A feasibility study of time of flight cone beam computed tomography imaging

2021 ◽  
pp. 1-14
Author(s):  
Ignacio O. Romero ◽  
Changqing Li
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Time Of Flight ◽  
Cone Beam ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Effects ◽  
Breast Phantom ◽  
Scatter Reduction ◽  
Strong Scattering

BACKGROUND: The time of flight (TOF) cone beam computed tomography (CBCT) was recently shown to reduce the X-ray scattering effects by 95%and improve the image CNR by 110%for large volume objects. The advancements in X-ray sources like in compact Free Electron Lasers (FEL) and advancements in detector technology show potential for the TOF method to be feasible in CBCT when imaging large objects. OBJECTIVE: To investigate feasibility and efficacy of TOF CBCT in imaging smaller objects with different targets such as bones and tumors embedded inside the background. METHODS: The TOF method used in this work was verified using a 24cm phantom. Then, the GATE software was used to simulate the CBCT imaging of an 8 cm diameter cylindrical water phantom with two bone targets using a modeled 20 keV quasi-energetic FEL source and various TOF resolutions ranging from 1 to 1000 ps. An inhomogeneous breast phantom of similar size with tumor targets was also imaged using the same system setup. RESULTS: The same results were obtained in the 24cm phantom, which validated the applied CBCT simulation approach. For the case of 8cm cylindrical phantom and bone target, a TOF resolution of 10 ps improved the image contrast-to-noise ratio (CNR) by 57%and reduced the scatter-to-primary ratio (SPR) by 8.63. For the case of breast phantom and tumor target, image CNR was enhanced by 12%and SPR was reduced by 1.35 at 5 ps temporal resolution. CONCLUSIONS: This study indicates that a TOF resolution below 10 ps is required to observe notable enhancements in the image quality and scatter reduction for small objects around 8cm in diameter. The strong scattering targets such as bone can result in substantial improvements by using TOF CBCT.

scholarly journals 371 Half Value Layer and X-ray Spectra of CT : Comparison of Three CT-scanners

1997 ◽  
Vol 53 (8) ◽  
pp. 1243
Author(s):  
H Okamoto ◽  
T Kumatani ◽  
K Ueda ◽  
O Hiruma ◽  
Y Kumatani ◽  
...  
Keyword(s):  
X Ray ◽  
Ct Scanners

scholarly journals A Deep Learning-Based Scatter Correction of Simulated X-ray Images

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 944 ◽  
Author(s):  
Heesin Lee ◽  
Joonwhoan Lee
Keyword(s):  
Deep Learning ◽  
Image Quality ◽  
Imaging System ◽  
Scatter Correction ◽  
Similarity Index ◽  
Real Data ◽  
Correction Method ◽  
Training Data ◽  
X Ray ◽  
Scatter Reduction

X-ray scattering significantly limits image quality. Conventional strategies for scatter reduction based on physical equipment or measurements inevitably increase the dose to improve the image quality. In addition, scatter reduction based on a computational algorithm could take a large amount of time. We propose a deep learning-based scatter correction method, which adopts a convolutional neural network (CNN) for restoration of degraded images. Because it is hard to obtain real data from an X-ray imaging system for training the network, Monte Carlo (MC) simulation was performed to generate the training data. For simulating X-ray images of a human chest, a cone beam CT (CBCT) was designed and modeled as an example. Then, pairs of simulated images, which correspond to scattered and scatter-free images, respectively, were obtained from the model with different doses. The scatter components, calculated by taking the differences of the pairs, were used as targets to train the weight parameters of the CNN. Compared with the MC-based iterative method, the proposed one shows better results in projected images, with as much as 58.5% reduction in root-mean-square error (RMSE), and 18.1% and 3.4% increases in peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM), on average, respectively.

scholarly journals Evaluation and Comparison of Dose Profiles and Patient Doses among X-ray CT Scanners

2005 ◽  
Vol 61 (5) ◽  
pp. 683-690 ◽  
Author(s):  
KOSUKE MATSUBARA ◽  
KICHIRO KOSHIDA ◽  
MASAYUKI SUZUKI ◽  
ATSUSHI FUKUDA ◽  
CHIKAKO KAWABATA ◽  
...  
Keyword(s):  
X Ray ◽  
Patient Doses ◽  
Ct Scanners

scholarly journals Contrast enhancement in abdominal computed tomography: influence of photon energy of different scanners

2018 ◽  
Vol 91 (1081) ◽  
pp. 20170285 ◽  
Author(s):  
Narumi Taguchi ◽  
Seitaro Oda ◽  
Takeshi Nakaura ◽  
Daisuke Utsunomiya ◽  
Yoshinori Funama ◽  
...  
Keyword(s):  
Clinical Study ◽  
Contrast Enhancement ◽  
Contrast Material ◽  
Vena Cava ◽  
Phantom Study ◽  
Absolute Difference ◽  
X Ray ◽  
Abdominal Organs ◽  
Ct Scanners ◽  
The Impact

Objective: Different CT scanners have different X-ray spectra and photon energies indicating that contrast enhancement vary among scanners. However, this issue has not been fully validated; therefore, we performed phantom and clinical studies to assess this difference. Methods: Two scanners were used: scanner-A and scanner-B. In the phantom study, we compared the contrast enhancement between the scanners at tube voltage peaks of 80, 100 and 120 kVp. Then, we calculated the effective energies of the two CT scanners. In the clinical study, 40 patients underwent abdominal scanning with scanner-A and another 40 patients with scanner-B, with each group using the same scanning protocol. The contrast enhancement of abdominal organs was assessed quantitatively (based on the absolute difference between the attenuation of unenhanced scans and contrast-enhanced scans) and qualitatively. A two-tailed independent Student's t-test and or the Mann–Whitney U test were used to compare the discrepancies. Results: In the phantom study, contrast enhancement for scanner-B was 36.9, 32.6 and 30.8% higher than that for scanner-A at 80, 100 and 120 kVp, respectively. The effective energies were higher for scanner-A than for scanner-B. In the quantitative analysis for the clinical study, scanner-B yielded significantly better contrast enhancement of the hepatic parenchyma, pancreas, kidney, portal vein and inferior vena cava compared with that of scanner-A. The mean visual scores for contrast enhancement were also significantly higher on images obtained by scanner-B than those by scanner-A. Conclusion: There were significant differences in contrast enhancement of the abdominal organs between the compared CT scanners from two different vendors even at the same scanning and contrast parameters. Advances in knowledge: Awareness of the impact of different X-ray energies on the resultant attenuation of contrast material is important when interpreting clinical CT images.

SU-E-I-85: Application of Real-Time Dosimetry to Characterize the X-Ray Penetrability of CT Scanners

2011 ◽  
Vol 38 (6Part5) ◽  
pp. 3415-3415
Author(s):  
S McKenney ◽  
G Burkett ◽  
D Gelskey ◽  
J Boone
Keyword(s):  
Real Time ◽  
X Ray ◽  
Ct Scanners

A dose reduction x-ray beam positioning system for high-speed multislice CT scanners

2000 ◽  
Vol 27 (12) ◽  
pp. 2659-2668 ◽  
Author(s):  
Thomas L. Toth ◽  
Neil B. Bromberg ◽  
Tin-Su Pan ◽  
Jerry Rabe ◽  
Steven J. Woloschek ◽  
...  
Keyword(s):  
Dose Reduction ◽  
High Speed ◽  
Multislice Ct ◽  
Positioning System ◽  
X Ray ◽  
Ct Scanners
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