scholarly journals Dose reduction potential in cone-beam CT imaging of upper extremity joints with a twin robotic x-ray system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karsten Sebastian Luetkens ◽  
Süleyman Ergün ◽  
Henner Huflage ◽  
Andreas Steven Kunz ◽  
Carsten Herbert Gietzen ◽  
...  
Keyword(s):  
Image Quality ◽  
Dose Reduction ◽  
Cancellous Bone ◽  
Low Dose ◽  
Bone Microarchitecture ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
X Ray ◽  
Convolution Kernels

AbstractCone-beam computed tomography is a powerful tool for 3D imaging of the appendicular skeleton, facilitating detailed visualization of bone microarchitecture. This study evaluated various combinations of acquisition and reconstruction parameters for the cone-beam CT mode of a twin robotic x-ray system in cadaveric wrist and elbow scans, aiming to define the best possible trade-off between image quality and radiation dose. Images were acquired with different combinations of tube voltage and tube current–time product, resulting in five scan protocols with varying volume CT dose indices: full-dose (FD; 17.4 mGy), low-dose (LD; 4.5 mGy), ultra-low-dose (ULD; 1.15 mGy), modulated low-dose (mLD; 0.6 mGy) and modulated ultra-low-dose (mULD; 0.29 mGy). Each set of projection data was reconstructed with three convolution kernels (very sharp [Ur77], sharp [Br69], intermediate [Br62]). Five radiologists subjectively assessed the image quality of cortical bone, cancellous bone and soft tissue using seven-point scales. Irrespective of the reconstruction kernel, overall image quality of every FD, LD and ULD scan was deemed suitable for diagnostic use in contrast to mLD (very sharp/sharp/intermediate: 60/55/70%) and mULD (0/3/5%). Superior depiction of cortical and cancellous bone was achieved in FDUr77 and LDUr77 examinations (p < 0.001) with LDUr77 scans also providing favorable bone visualization compared to FDBr69 and FDBr62 (p < 0.001). Fleiss’ kappa was 0.618 (0.594–0.641; p < 0.001), indicating substantial interrater reliability. In this study, we demonstrate that considerable dose reduction can be realized while maintaining diagnostic image quality in upper extremity joint scans with the cone-beam CT mode of a twin robotic x-ray system. Application of sharper convolution kernels for image reconstruction facilitates superior display of bone microarchitecture.

Dental cone-beam CT reconstruction from limited-angle view data based on compressed-sensing (CS) theory for fast, low-dose X-ray imaging

2014 ◽  
Vol 64 (12) ◽  
pp. 1907-1911
Author(s):  
Uikyu Je ◽  
Hyosung Cho ◽  
Minsik Lee ◽  
Jieun Oh ◽  
Yeonok Park ◽  
...  
Keyword(s):  
Compressed Sensing ◽  
Low Dose ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Ct Reconstruction ◽  
X Ray ◽  
X Ray Imaging ◽  
Limited Angle

Improved image quality of cone beam CT scans for radiotherapy image guidance using fiber-interspaced antiscatter grid

2014 ◽  
Vol 41 (6Part1) ◽  
pp. 061910 ◽  
Author(s):  
Uros Stankovic ◽  
Marcel van Herk ◽  
Lennert S. Ploeger ◽  
Jan-Jakob Sonke
Keyword(s):  
Image Quality ◽  
Image Guidance ◽  
Cone Beam Ct ◽  
Ct Scans ◽  
Cone Beam ◽  
Antiscatter Grid

Image quality of flat-panel cone beam CT

2003 ◽  
Author(s):  
Georg Rose ◽  
Jens Wiegert ◽  
Dirk Schaefer ◽  
Klaus Fiedler ◽  
Norbert Conrads ◽  
...  
Keyword(s):  
Image Quality ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Flat Panel

scholarly journals Evaluation of a low-dose protocol for cone beam computed tomography of the temporomandibular joint

2020 ◽  
Vol 49 (6) ◽  
pp. 20190495 ◽  
Author(s):  
Durer Iskanderani ◽  
Mats Nilsson ◽  
Per Alstergren ◽  
Xie-Qi Shi ◽  
Kristina Hellen-halme
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Temporomandibular Joint ◽  
Low Dose ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Sign Test ◽  
Intraobserver Agreement ◽  
Radiographic Findings ◽  
Need To Evaluate

Objective: Evaluation of cone beam CT (CBCT) examination with a low-dose scanning protocol for assessment of the temporomandibular joint (TMJ). Methods: 34 adult patients referred for CBCT imaging of the TMJ underwent two examinations with two scanning protocols, a manufacturer-recommended protocol (default) and a low-dose protocol where the tube current was reduced to 20% of the default protocol. Three image stacks were reconstructed: default protocol, low-dose protocol, and processed (using a noise reduction algorithm) low-dose protocol. Four radiologists evaluated the images. The Sign test was used to evaluate visibility of TMJ anatomic structures and image quality. Receiver operating characteristic analyzes were performed to assess the diagnostic accuracy. κ values were used to evaluate intraobserver agreement. Results: With the low-dose and processed protocols, visibility of the TMJ anatomical structures and overall image quality were comparable to the default protocol. No significant differences in radiographic findings were found for the two low-dose protocols compared to the default protocol. The area under the curves (Az) averaged for the low-dose and processed protocols, according to all observers, were 0.931 and 0.941, respectively. Intraobserver agreement was good to very good. Conclusion: For the CBCT unit used in this study, the low-dose CBCT protocol for TMJ examination was diagnostically comparable to the manufacturer-recommended protocol, but delivered a five times lower radiation dose. There is an urgent need to evaluate protocols for CBCT examinations of TMJ in order to optimize them for a radiation dose as low as diagnostically acceptable (the as low as diagnostically acceptable principle recommended by NCRP).

scholarly journals Patient-based low dose cone beam CT acquisition settings for prostate image-guided radiotherapy treatments on a Varian TrueBeam linear accelerator

2020 ◽  
Vol 93 (1115) ◽  
pp. 20200412
Author(s):  
Maria Antonietta Piliero ◽  
Margherita Casiraghi ◽  
Davide Giovanni Bosetti ◽  
Simona Cima ◽  
Letizia Deantonio ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Image Quality ◽  
Low Dose ◽  
Cone Beam Ct ◽  
Subjective Evaluation ◽  
Cone Beam ◽  
Low Contrast ◽  
Image Guided Radiotherapy ◽  
Image Guided ◽  
Prostate Cancer Radiotherapy

Objective: To evaluate the performance of low dose cone beam CT (CBCT) acquisition protocols for image-guided radiotherapy of prostate cancer. Methods: CBCT images of patients undergoing prostate cancer radiotherapy were acquired with the settings currently used in our department and two low dose settings at 50% and 63% lower exposure. Four experienced radiation oncologists and two radiation therapy technologists graded the images on five image quality characteristics. The scores were analysed through Visual Grading Regression, using the acquisition settings and the patient size as covariates. Results: The low dose acquisition settings have no impact on the image quality for patients with body profile length at hip level below 100 cm. Conclusions: A reduction of about 60% of the dose is feasible for patients with size below 100 cm. The visibility of low contrast features can be compromised if using the low dose acquisition settings for patients with hip size above 100 cm. Advances in knowledge: Low dose CBCT acquisition protocols for the pelvis, based on subjective evaluation of patient images.

TU-FF-A4-05: Physical Performance and Image Quality of Megavoltage Cone-Beam CT

2007 ◽  
Vol 34 (6Part19) ◽  
pp. 2572-2572 ◽  
Author(s):  
O Morin ◽  
M Aubin ◽  
J Aubry ◽  
S Bose ◽  
J Chen ◽  
...  
Keyword(s):  
Image Quality ◽  
Physical Performance ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Megavoltage Cone Beam Ct
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