Combined use of iterative reconstruction and monochromatic imaging in spinal fusion CT images

2016 ◽  
Vol 58 (1) ◽  
pp. 62-69 ◽  
Author(s):  
Fengdan Wang ◽  
Yan Zhang ◽  
Huadan Xue ◽  
Wei Han ◽  
Xianda Yang ◽  
...  
Keyword(s):  
Image Quality ◽  
Spinal Fusion ◽  
Iterative Reconstruction ◽  
Dual Energy ◽  
Image Noise ◽  
Dual Energy Ct ◽  
Spinal Diseases ◽  
Metal Artifacts ◽  
Monochromatic Imaging ◽  
Combined Use

Background Spinal fusion surgery is an important procedure for treating spinal diseases and computed tomography (CT) is a critical tool for postoperative evaluation. However, CT image quality is considerably impaired by metal artifacts and image noise. Purpose To explore whether metal artifacts and image noise can be reduced by combining two technologies, adaptive statistical iterative reconstruction (ASIR) and monochromatic imaging generated by gemstone spectral imaging (GSI) dual-energy CT. Material and Methods A total of 51 patients with 318 spinal pedicle screws were prospectively scanned by dual-energy CT using fast kV-switching GSI between 80 and 140 kVp. Monochromatic GSI images at 110 keV were reconstructed either without or with various levels of ASIR (30%, 50%, 70%, and 100%). The quality of five sets of images was objectively and subjectively assessed. Results With objective image quality assessment, metal artifacts decreased when increasing levels of ASIR were applied ( P < 0.001). Moreover, adding ASIR to GSI also decreased image noise ( P < 0.001) and improved the signal-to-noise ratio ( P < 0.001). The subjective image quality analysis showed good inter-reader concordance, with intra-class correlation coefficients between 0.89 and 0.99. The visualization of peri-implant soft tissue was improved at higher ASIR levels ( P < 0.001). Conclusion Combined use of ASIR and GSI decreased image noise and improved image quality in post-spinal fusion CT scans. Optimal results were achieved with ASIR levels ≥70%.

scholarly journals First experience with combined use of adaptive statistical iterative reconstruction and gemstone spectral imaging in spinal fusion CT images

2015 ◽  
Author(s):  
Fengdan Wang ◽  
Yan Zhang ◽  
Zhengyu Jin ◽  
Richard Zwar
Keyword(s):  
Image Quality ◽  
Iterative Reconstruction ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Metal Artifacts ◽  
Adaptive Statistical Iterative Reconstruction ◽  
Subjective Image Quality ◽  
Gemstone Spectral Imaging ◽  
Statistical Iterative Reconstruction ◽  
Combined Use

Objective. To explore whether the image noises and the metal artifacts could be further managed by the combined use of two technologies, the adaptive statistical iterative reconstruction (ASIR) and the monochromatic imaging generated by gemstone spectral imaging (GSI) dual-energy CT. Materials and Methods. Fifty-one patients with 318 spinal pedicle screws were prospectively scanned with dual energy CT by using fast kV-switching GSI between 80 and 140 kVp. The monochromatic GSI images at 110 keV were reconstructed either without ASIR or with ASIR of various levels (30%, 50%, 70% and 100%). For these five sets of images, both objective and subjective image quality assessments were performed to evaluate the image quality. Results. With objective image quality assessment, the metal artifacts (measured by an artifacts index) significantly decreased when increasing levels of ASIR was utilized (p < 0.001). Moreover, adding ASIR to GSI also decreased the image noise (p < 0.001) and improved the signal-to-noise ratio (SNR, p < 0.001). With subjective image quality analysis, the inter-reader agreements were good, with intra-class correlation coefficients (ICC) of 0.89 to 0.99. Meanwhile, the visualization of the peri-implant soft tissue was improved at higher ASIR levels (p < 0.001). Conclusion. Combined use of ASIR and GSI is shown to decrease the image noise and improve the image quality in post-spinal fusion CT scans. Optimal results were achieved with ASIR levels of over 70%.

scholarly journals First experience with combined use of adaptive statistical iterative reconstruction and gemstone spectral imaging in spinal fusion CT images

2015 ◽  
Author(s):  
Fengdan Wang ◽  
Yan Zhang ◽  
Zhengyu Jin ◽  
Richard Zwar
Keyword(s):  
Image Quality ◽  
Iterative Reconstruction ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Metal Artifacts ◽  
Adaptive Statistical Iterative Reconstruction ◽  
Subjective Image Quality ◽  
Gemstone Spectral Imaging ◽  
Statistical Iterative Reconstruction ◽  
Combined Use

Objective. To explore whether the image noises and the metal artifacts could be further managed by the combined use of two technologies, the adaptive statistical iterative reconstruction (ASIR) and the monochromatic imaging generated by gemstone spectral imaging (GSI) dual-energy CT. Materials and Methods. Fifty-one patients with 318 spinal pedicle screws were prospectively scanned with dual energy CT by using fast kV-switching GSI between 80 and 140 kVp. The monochromatic GSI images at 110 keV were reconstructed either without ASIR or with ASIR of various levels (30%, 50%, 70% and 100%). For these five sets of images, both objective and subjective image quality assessments were performed to evaluate the image quality. Results. With objective image quality assessment, the metal artifacts (measured by an artifacts index) significantly decreased when increasing levels of ASIR was utilized (p < 0.001). Moreover, adding ASIR to GSI also decreased the image noise (p < 0.001) and improved the signal-to-noise ratio (SNR, p < 0.001). With subjective image quality analysis, the inter-reader agreements were good, with intra-class correlation coefficients (ICC) of 0.89 to 0.99. Meanwhile, the visualization of the peri-implant soft tissue was improved at higher ASIR levels (p < 0.001). Conclusion. Combined use of ASIR and GSI is shown to decrease the image noise and improve the image quality in post-spinal fusion CT scans. Optimal results were achieved with ASIR levels of over 70%.

scholarly journals Appropriate Patient Selection at Abdominal Dual-Energy CT Using 80 kV: Relationship between Patient Size, Image Noise, and Image Quality

Radiology ◽  
2010 ◽  
Vol 257 (3) ◽  
pp. 732-742 ◽  
Author(s):  
Luís S. Guimarães ◽  
Joel G. Fletcher ◽  
William S. Harmsen ◽  
Lifeng Yu ◽  
Hassan Siddiki ◽  
...  
Keyword(s):  
Image Quality ◽  
Patient Selection ◽  
Dual Energy ◽  
Image Noise ◽  
Dual Energy Ct ◽  
Patient Size

scholarly journals Virtual monochromatic imaging in dual-source dual-energy CT: Radiation dose and image quality

2011 ◽  
Vol 38 (12) ◽  
pp. 6371-6379 ◽  
Author(s):  
Lifeng Yu ◽  
Jodie A. Christner ◽  
Shuai Leng ◽  
Jia Wang ◽  
Joel G. Fletcher ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Virtual Monochromatic Imaging ◽  
Monochromatic Imaging ◽  
Ct Radiation ◽  
Dual Source

Reduction of metal artifacts from unilateral hip arthroplasty on dual-energy CT with metal artifact reduction software

2017 ◽  
Vol 59 (7) ◽  
pp. 853-860 ◽  
Author(s):  
Dong Yue ◽  
Cheng Fan Rong ◽  
Cai Ning ◽  
Hu Liang ◽  
Liu Ai Lian ◽  
...  
Keyword(s):  
Image Quality ◽  
Hip Arthroplasty ◽  
Dual Energy ◽  
Observer Agreement ◽  
Dual Energy Ct ◽  
Artifact Reduction ◽  
Metal Artifact ◽  
Metal Artifact Reduction ◽  
Metal Artifacts ◽  
Pelvic Organs

Background The evaluation of hip arthroplasty is a challenge in computed tomography (CT). The virtual monochromatic spectral (VMS) images with metal artifact reduction software (MARs) in spectral CT can reduce the artifacts and improve the image quality. Purpose To evaluate the effects of VMS images and MARs for metal artifact reduction in patients with unilateral hip arthroplasty. Material and Methods Thirty-five patients underwent dual-energy CT. Four sets of VMS images without MARs and four sets of VMS images with MARs were obtained. Artifact index (AI), CT number, and SD value were assessed at the periprosthetic region and the pelvic organs. The scores of two observers for different images and the inter-observer agreement were evaluated. Results The AIs in 120 and 140 keV images were significantly lower than those in 80 and 100 keV images. The AIs of the periprosthetic region in VMS images with MARs were significantly lower than those in VMS images without MARs, while the AIs of pelvic organs were not significantly different. VMS images with MARs improved the accuracy of CT numbers for the periprosthetic region. The inter-observer agreements were good for all the images. VMS images with MARs at 120 and 140 keV had higher subjective scores and could improve the image quality, leading to reliable diagnosis of prosthesis-related problems. Conclusion VMS images with MARs at 120 and 140 keV could significantly reduce the artifacts from hip arthroplasty and improve the image quality at the periprosthetic region but had no obvious advantage for pelvic organs.

New Fast kVp Switching Dual-Energy CT: Reduced Severity of Beam Hardening Artifacts and Improved Image Quality in Reduced-Iodine Virtual Monochromatic Imaging

2020 ◽  
Vol 27 (11) ◽  
pp. 1586-1593
Author(s):  
Haruto Sugawara ◽  
Tomoko Takayanagi ◽  
Takuya Ishikawa ◽  
Yoshiaki Katada ◽  
Rika Fukui ◽  
...  
Keyword(s):  
Image Quality ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Beam Hardening ◽  
Virtual Monochromatic Imaging ◽  
Monochromatic Imaging

scholarly journals CT and MRI Techniques for Imaging Around Orthopedic Hardware

2017 ◽  
Vol 190 (01) ◽  
pp. 31-41 ◽  
Author(s):  
Thuy Do ◽  
Reto Sutter ◽  
Stephan Skornitzke ◽  
Marc-André Weber
Keyword(s):  
Image Quality ◽  
Orthopedic Implants ◽  
Surrounding Tissue ◽  
Dual Energy Ct ◽  
Metal Artifacts ◽  
Cross Sectional ◽  
Monochromatic Imaging ◽  
Technological Advances ◽  
Cross Sectional Imaging ◽  
Ct And Mri

Orthopedic hardware impairs image quality in cross-sectional imaging. With an increasing number of orthopedic implants in an aging population, the need to mitigate metal artifacts in computed tomography and magnetic resonance imaging is becoming increasingly relevant. This review provides an overview of the major artifacts in CT and MRI and state-of-the-art solutions to improve image quality. All steps of image acquisition from device selection, scan preparations and parameters to image post-processing influence the magnitude of metal artifacts. Technological advances like dual-energy CT with the possibility of virtual monochromatic imaging (VMI) and new materials offer opportunities to further reduce artifacts in CT and MRI. Dedicated metal artifact reduction sequences contain algorithms to reduce artifacts and improve imaging of surrounding tissue and are essential tools in orthopedic imaging to detect postoperative complications in early stages. Key points  Citation Format

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