The Experts below are selected from a list of 86661 Experts worldwide ranked by ideXlab platform

Samta Thacker - One of the best experts on this subject based on the ideXlab platform.

  • a Computer Simulation Study comparing lesion detection accuracy with digital mammography breast tomosynthesis and cone beam ct breast imaging
    Medical Physics, 2006
    Co-Authors: Xing Gong, Stephen J Glick, Bob Liu, Aruna A Vedula, Samta Thacker
    Abstract:

    Although conventional mammography is currently the best modality to detect early breast cancer, it is limited in that the recorded image represents the superposition of a three-dimensional (3D) object onto a 2D plane. Recently, two promising approaches for 3D volumetric breast imaging have been proposed, breast tomosynthesis (BT) and CT breast imaging (CTBI). To investigate possible improvements in lesion detection accuracy with either breast tomosynthesis or CT breast imaging as compared to digital mammography (DM), a Computer Simulation Study was conducted using simulated lesions embedded into a structured 3D breast model. The Computer Simulation realistically modeled x-ray transport through a breast model, as well as the signal and noise propagation through a CsI based flat-panel imager. Polyenergetic x-ray spectra of Mo/Mo 28 kVp for digital mammography, Mo/Rh 28 kVp for BT, and W/Ce 50 kVp for CTBI were modeled. For the CTBI Simulation, the intensity of the x-ray spectra for each projection view was determined so as to provide a total average glandular dose of 4 mGy, which is approximately equivalent to that given in conventional two-view screening mammography. The same total dose was modeled for both the DM and BT Simulations. Irregular lesions were simulated by using a stochastic growth algorithm providing lesions with an effective diameter of 5 mm. Breast tissue was simulated by generating an ensemble of backgrounds with a power law spectrum, with the composition of 50% fibroglandular and 50% adipose tissue. To evaluate lesion detection accuracy, a receiver operating characteristic (ROC) Study was performed with five observers reading an ensemble of images for each case. The average area under the ROC curves (Az) was 0.76 for DM, 0.93 for BT, and 0.94 for CTBI. Results indicated that for the same dose, a 5 mm lesion embedded in a structured breast phantom was detected by the two volumetric breast imaging systems, BT and CTBI, with statistically significant higher confidence than with planar digital mammography, while the difference in lesion detection between BT and CTBI was not statistically significant.

  • a Computer Simulation Study comparing lesion detection accuracy with digital mammography breast tomosynthesis and cone beam ct breast imaging
    Medical Physics, 2006
    Co-Authors: Xing Gong, Stephen J Glick, Bob Liu, Aruna A Vedula, Samta Thacker
    Abstract:

    Although conventional mammography is currently the best modality to detect early breast cancer, it is limited in that the recorded image represents the superposition of a three-dimensional (3D) object onto a 2D plane. Recently, two promising approaches for 3D volumetric breast imaging have been proposed, breast tomosynthesis (BT) and CT breast imaging (CTBI). To investigate possible improvements in lesion detection accuracy with either breast tomosynthesis or CT breast imaging as compared to digital mammography (DM), a Computer Simulation Study was conducted using simulated lesions embedded into a structured 3D breast model. The Computer Simulation realistically modeled x-ray transport through a breast model, as well as the signal and noise propagation through a CsI based flat-panel imager. Polyenergetic x-ray spectra of Mo/Mo 28 kVp for digital mammography, Mo/Rh 28 kVp for BT, and W/Ce 50 kVp for CTBI were modeled. For the CTBI Simulation, the intensity of the x-ray spectra for each projection view was determined so as to provide a total average glandular dose of 4 mGy, which is approximately equivalent to that given in conventional two-view screening mammography. The same total dose was modeled for both the DM and BT Simulations. Irregular lesions were simulated by using a stochasticmore » growth algorithm providing lesions with an effective diameter of 5 mm. Breast tissue was simulated by generating an ensemble of backgrounds with a power law spectrum, with the composition of 50% fibroglandular and 50% adipose tissue. To evaluate lesion detection accuracy, a receiver operating characteristic (ROC) Study was performed with five observers reading an ensemble of images for each case. The average area under the ROC curves (A{sub z}) was 0.76 for DM, 0.93 for BT, and 0.94 for CTBI. Results indicated that for the same dose, a 5 mm lesion embedded in a structured breast phantom was detected by the two volumetric breast imaging systems, BT and CTBI, with statistically significant higher confidence than with planar digital mammography, while the difference in lesion detection between BT and CTBI was not statistically significant.« less

Guobao Wang - One of the best experts on this subject based on the ideXlab platform.

  • pet enabled dual energy ct image reconstruction and a proof of concept Computer Simulation Study
    Physics in Medicine and Biology, 2020
    Co-Authors: Guobao Wang
    Abstract:

    Standard dual-energy computed tomography (CT) uses two different x-ray energies to obtain energy-dependent tissue attenuation information to allow quantitative material decomposition. The combined use of dual-energy CT and positron emission tomography (PET) may provide a more comprehensive characterization of disease states in cancer and other diseases. However, the integration of dual-energy CT with PET is not trivial, either requiring costly hardware upgrades or increasing radiation exposure. This paper proposes a different dual-energy CT imaging method that is enabled by PET. Instead of using a second x-ray CT scan with a different energy, this method exploits time-of-flight PET image reconstruction via the maximum likelihood attenuation and activity (MLAA) algorithm to obtain a 511 keV gamma-ray attenuation image from PET emission data. The high-energy gamma-ray attenuation image is then combined with the low-energy x-ray CT of PET/CT to provide a pair of dual-energy CT images. A major challenge with the standard MLAA reconstruction is the high noise present in the reconstructed 511 keV attenuation map, which would not compromise the PET activity reconstruction too much but may significantly affect the performance of the gamma-ray attenuation image for material decomposition. To overcome the problem, we further propose a kernel MLAA algorithm to exploit the prior information from the available x-ray CT image. We conducted a Computer Simulation to test the concept and algorithm for the task of material decomposition. The Simulation results demonstrate that this PET-enabled dual-energy CT method is promising for quantitative material decomposition. The proposed method can be readily implemented on time-of-flight PET/CT scanners to enable simultaneous PET and dual-energy CT imaging.

  • pet enabled dual energy ct image reconstruction and a proof of concept Computer Simulation Study
    arXiv: Medical Physics, 2020
    Co-Authors: Guobao Wang
    Abstract:

    Standard dual-energy computed tomography (CT) uses two different X-ray energies to obtain energy-dependent tissue attenuation information to allow quantitative material decomposition. The combined use of dual-energy CT and positron emission tomography (PET) may provide a more comprehensive characterization of disease states in cancer and many other diseases. However, the integration of dual-energy CT with PET is not trivial, either requiring costly hardware upgrade or increasing radiation dose. This paper proposes a novel dual-energy CT imaging method that is enabled by the already-available PET data on PET/CT. Instead of using a second X-ray CT scan with a different energy, this method exploits time-of-flight PET image reconstruction via the maximum likelihood attenuation and activity (MLAA) algorithm to obtain a 511 keV gamma-ray attenuation image from PET emission data. The high-energy gamma-ray CT image is then combined with the low-energy X-ray CT of PET/CT to provide a pair of dual-energy CT images. A major challenge with the standard MLAA reconstruction is the high noise present in the reconstructed 511 keV attenuation map, which does not compromise the PET activity reconstruction too much but significantly affects the performance of the gamma-ray CT for material decomposition. To overcome the problem, we further propose a kernel MLAA algorithm to exploit the prior information from the available X-ray CT image. We conducted a Computer Simulation to test the concept and algorithm for the task of material decomposition. The Simulation results indicate that this PET-enabled dual-energy CT method is promising for quantitative material decomposition. The proposed method can be readily implemented on time-of-flight PET/CT scanners to enable simultaneous PET and dual-energy CT imaging.

Xing Gong - One of the best experts on this subject based on the ideXlab platform.

  • a Computer Simulation Study comparing lesion detection accuracy with digital mammography breast tomosynthesis and cone beam ct breast imaging
    Medical Physics, 2006
    Co-Authors: Xing Gong, Stephen J Glick, Bob Liu, Aruna A Vedula, Samta Thacker
    Abstract:

    Although conventional mammography is currently the best modality to detect early breast cancer, it is limited in that the recorded image represents the superposition of a three-dimensional (3D) object onto a 2D plane. Recently, two promising approaches for 3D volumetric breast imaging have been proposed, breast tomosynthesis (BT) and CT breast imaging (CTBI). To investigate possible improvements in lesion detection accuracy with either breast tomosynthesis or CT breast imaging as compared to digital mammography (DM), a Computer Simulation Study was conducted using simulated lesions embedded into a structured 3D breast model. The Computer Simulation realistically modeled x-ray transport through a breast model, as well as the signal and noise propagation through a CsI based flat-panel imager. Polyenergetic x-ray spectra of Mo/Mo 28 kVp for digital mammography, Mo/Rh 28 kVp for BT, and W/Ce 50 kVp for CTBI were modeled. For the CTBI Simulation, the intensity of the x-ray spectra for each projection view was determined so as to provide a total average glandular dose of 4 mGy, which is approximately equivalent to that given in conventional two-view screening mammography. The same total dose was modeled for both the DM and BT Simulations. Irregular lesions were simulated by using a stochastic growth algorithm providing lesions with an effective diameter of 5 mm. Breast tissue was simulated by generating an ensemble of backgrounds with a power law spectrum, with the composition of 50% fibroglandular and 50% adipose tissue. To evaluate lesion detection accuracy, a receiver operating characteristic (ROC) Study was performed with five observers reading an ensemble of images for each case. The average area under the ROC curves (Az) was 0.76 for DM, 0.93 for BT, and 0.94 for CTBI. Results indicated that for the same dose, a 5 mm lesion embedded in a structured breast phantom was detected by the two volumetric breast imaging systems, BT and CTBI, with statistically significant higher confidence than with planar digital mammography, while the difference in lesion detection between BT and CTBI was not statistically significant.

  • a Computer Simulation Study comparing lesion detection accuracy with digital mammography breast tomosynthesis and cone beam ct breast imaging
    Medical Physics, 2006
    Co-Authors: Xing Gong, Stephen J Glick, Bob Liu, Aruna A Vedula, Samta Thacker
    Abstract:

    Although conventional mammography is currently the best modality to detect early breast cancer, it is limited in that the recorded image represents the superposition of a three-dimensional (3D) object onto a 2D plane. Recently, two promising approaches for 3D volumetric breast imaging have been proposed, breast tomosynthesis (BT) and CT breast imaging (CTBI). To investigate possible improvements in lesion detection accuracy with either breast tomosynthesis or CT breast imaging as compared to digital mammography (DM), a Computer Simulation Study was conducted using simulated lesions embedded into a structured 3D breast model. The Computer Simulation realistically modeled x-ray transport through a breast model, as well as the signal and noise propagation through a CsI based flat-panel imager. Polyenergetic x-ray spectra of Mo/Mo 28 kVp for digital mammography, Mo/Rh 28 kVp for BT, and W/Ce 50 kVp for CTBI were modeled. For the CTBI Simulation, the intensity of the x-ray spectra for each projection view was determined so as to provide a total average glandular dose of 4 mGy, which is approximately equivalent to that given in conventional two-view screening mammography. The same total dose was modeled for both the DM and BT Simulations. Irregular lesions were simulated by using a stochasticmore » growth algorithm providing lesions with an effective diameter of 5 mm. Breast tissue was simulated by generating an ensemble of backgrounds with a power law spectrum, with the composition of 50% fibroglandular and 50% adipose tissue. To evaluate lesion detection accuracy, a receiver operating characteristic (ROC) Study was performed with five observers reading an ensemble of images for each case. The average area under the ROC curves (A{sub z}) was 0.76 for DM, 0.93 for BT, and 0.94 for CTBI. Results indicated that for the same dose, a 5 mm lesion embedded in a structured breast phantom was detected by the two volumetric breast imaging systems, BT and CTBI, with statistically significant higher confidence than with planar digital mammography, while the difference in lesion detection between BT and CTBI was not statistically significant.« less

Renyeong Huang - One of the best experts on this subject based on the ideXlab platform.

  • original contributionsdental implantspreoperative assessment of labial bone perforation for virtual immediate implant surgery in the maxillary esthetic zone a Computer Simulation Study
    Journal of the American Dental Association, 2015
    Co-Authors: Chengen Sung, David L Cochran, Wanchien Cheng, Pohsien Huang, Yishing Shieh, Renyeong Huang
    Abstract:

    Background In this Computer Simulation Study, the authors investigated the frequency distribution of labial bone perforation (LBP) between various sagittal root position (SRP) classes with respect to the anterior maxillary osseous housing and evaluated the associated factors correlated with a higher risk of LBP when performing a virtual immediate implant surgery in the esthetic zone.

  • preoperative assessment of labial bone perforation for virtual immediate implant surgery in the maxillary esthetic zone a Computer Simulation Study
    Journal of the American Dental Association, 2015
    Co-Authors: Chengen Sung, David L Cochran, Wanchien Cheng, Pohsien Huang, Yishing Shieh, Renyeong Huang
    Abstract:

    Abstract Background In this Computer Simulation Study, the authors investigated the frequency distribution of labial bone perforation (LBP) between various sagittal root position (SRP) classes with respect to the anterior maxillary osseous housing and evaluated the associated factors correlated with a higher risk of LBP when performing a virtual immediate implant surgery in the esthetic zone. Methods The authors analyzed cone-beam computed tomography (CBCT) images from 285 qualified Study participants (1,449 teeth) to determine the probability of LBP when associated with selected variables, such as tooth type, SRP class, and morphologic parameters. The authors examined associated factors and analyzed the adjusted odds ratios by means of multiple logistic regression analysis. Results The overall probability of LBP was 81.7%, which presented statistically significant differences between each specific tooth type and SRP class (all P Conclusions When a clinician performs an immediate implant in the anterior esthetic zone, he or she should be aware that the specific tooth type, SRP class, and morphologic features of fossa concavities are associated with a risk of experiencing LBP. Practical Implications Presurgical cross-sectional images can be analyzed to identify anatomic features relative to LBP in the maxillary esthetic region, and this can avoid unpleasant complications, specifically when performing immediate implant procedures.

Stephen J Glick - One of the best experts on this subject based on the ideXlab platform.

  • a Computer Simulation Study comparing lesion detection accuracy with digital mammography breast tomosynthesis and cone beam ct breast imaging
    Medical Physics, 2006
    Co-Authors: Xing Gong, Stephen J Glick, Bob Liu, Aruna A Vedula, Samta Thacker
    Abstract:

    Although conventional mammography is currently the best modality to detect early breast cancer, it is limited in that the recorded image represents the superposition of a three-dimensional (3D) object onto a 2D plane. Recently, two promising approaches for 3D volumetric breast imaging have been proposed, breast tomosynthesis (BT) and CT breast imaging (CTBI). To investigate possible improvements in lesion detection accuracy with either breast tomosynthesis or CT breast imaging as compared to digital mammography (DM), a Computer Simulation Study was conducted using simulated lesions embedded into a structured 3D breast model. The Computer Simulation realistically modeled x-ray transport through a breast model, as well as the signal and noise propagation through a CsI based flat-panel imager. Polyenergetic x-ray spectra of Mo/Mo 28 kVp for digital mammography, Mo/Rh 28 kVp for BT, and W/Ce 50 kVp for CTBI were modeled. For the CTBI Simulation, the intensity of the x-ray spectra for each projection view was determined so as to provide a total average glandular dose of 4 mGy, which is approximately equivalent to that given in conventional two-view screening mammography. The same total dose was modeled for both the DM and BT Simulations. Irregular lesions were simulated by using a stochastic growth algorithm providing lesions with an effective diameter of 5 mm. Breast tissue was simulated by generating an ensemble of backgrounds with a power law spectrum, with the composition of 50% fibroglandular and 50% adipose tissue. To evaluate lesion detection accuracy, a receiver operating characteristic (ROC) Study was performed with five observers reading an ensemble of images for each case. The average area under the ROC curves (Az) was 0.76 for DM, 0.93 for BT, and 0.94 for CTBI. Results indicated that for the same dose, a 5 mm lesion embedded in a structured breast phantom was detected by the two volumetric breast imaging systems, BT and CTBI, with statistically significant higher confidence than with planar digital mammography, while the difference in lesion detection between BT and CTBI was not statistically significant.

  • a Computer Simulation Study comparing lesion detection accuracy with digital mammography breast tomosynthesis and cone beam ct breast imaging
    Medical Physics, 2006
    Co-Authors: Xing Gong, Stephen J Glick, Bob Liu, Aruna A Vedula, Samta Thacker
    Abstract:

    Although conventional mammography is currently the best modality to detect early breast cancer, it is limited in that the recorded image represents the superposition of a three-dimensional (3D) object onto a 2D plane. Recently, two promising approaches for 3D volumetric breast imaging have been proposed, breast tomosynthesis (BT) and CT breast imaging (CTBI). To investigate possible improvements in lesion detection accuracy with either breast tomosynthesis or CT breast imaging as compared to digital mammography (DM), a Computer Simulation Study was conducted using simulated lesions embedded into a structured 3D breast model. The Computer Simulation realistically modeled x-ray transport through a breast model, as well as the signal and noise propagation through a CsI based flat-panel imager. Polyenergetic x-ray spectra of Mo/Mo 28 kVp for digital mammography, Mo/Rh 28 kVp for BT, and W/Ce 50 kVp for CTBI were modeled. For the CTBI Simulation, the intensity of the x-ray spectra for each projection view was determined so as to provide a total average glandular dose of 4 mGy, which is approximately equivalent to that given in conventional two-view screening mammography. The same total dose was modeled for both the DM and BT Simulations. Irregular lesions were simulated by using a stochasticmore » growth algorithm providing lesions with an effective diameter of 5 mm. Breast tissue was simulated by generating an ensemble of backgrounds with a power law spectrum, with the composition of 50% fibroglandular and 50% adipose tissue. To evaluate lesion detection accuracy, a receiver operating characteristic (ROC) Study was performed with five observers reading an ensemble of images for each case. The average area under the ROC curves (A{sub z}) was 0.76 for DM, 0.93 for BT, and 0.94 for CTBI. Results indicated that for the same dose, a 5 mm lesion embedded in a structured breast phantom was detected by the two volumetric breast imaging systems, BT and CTBI, with statistically significant higher confidence than with planar digital mammography, while the difference in lesion detection between BT and CTBI was not statistically significant.« less