The Experts below are selected from a list of 3660 Experts worldwide ranked by ideXlab platform

Yu-ying Lin - One of the best experts on this subject based on the ideXlab platform.

  • Radiation dose for pediatric scoliosis patients undergoing whole Spine Radiography: Effect of the radiographic length in an auto-stitching digital Radiography system.
    European journal of radiology, 2018
    Co-Authors: Yi-shuan Hwang, H. Y. Tsai, Po-liang Lai, Yung-chuan Kung, Yu-ying Lin
    Abstract:

    Abstract Objective This study investigated the influence of spatial overlap and radiographic length (RL) on the effective dose (ED) and organ dose for pediatric patients undergoing whole Spine Radiography using an auto-stitching digital Radiography (DR) system. Methods First, the system parameters were tested on a 10-year-old pediatric anthropomorphic phantom with a Shimadzu DR system, and the effects of the spatial overlap and RL on radiation doses were validated. The ED and organ dose were calculated on the basis of a Monte Carlo simulation program. Subsequently, 82 patients with adolescent idiopathic scoliosis were recruited. The spatial overlap and RL for each patient were modified to further investigate the dose reduction feasibility. Results RL and ED were appropriately correlated on the basis of patients’ height. For a patient measuring 158 cm, the Shimadzu DR system was equipped with a 17-inch detector with a cut-off RL of 75 cm. The phantom simulations indicated that ED was reduced to a minimum value of 0.188 ± 0.001 mSv with a high RL for RL  Conclusion A decrease in the spatial overlap and number of radiographic acquisitions by adjusting RLs when possible could reduce ED and almost all organ doses. This study emphasized the effects of RL on the radiation dose and provided useful guidance for modifying the RL for patients to reduce the whole Spine Radiography dose using a modern auto-stitching DR system.

  • SU-E-I-54: Effective Dose and Radiation Cancer Risks for Scoliosis Patients Undergoing Full Spine Radiography
    Medical Physics, 2015
    Co-Authors: Yu-ying Lin, Yi-shuan Hwang, H. Y. Tsai
    Abstract:

    Purpose: Scoliotic patients underwent a lot of radiologic examinations during the control and treatment periods. This study used the PCXMC program to calculate the effective dose of the patients and assess the radiation cancer risks. Methods: Seventy five scoliotic patients were examined using CR or DR systems during the control and treatment periods in Chang Gung Memorial Hospital. The technical factors were recorded for each patient during his/her control and treatment period. The entrance surface dose was measured using thermoluminence dosimeters and derived from technical factors and irradiated geometry. The effective dose of patients and relative radiation cancer risks were calculated by the PCXMC program. All required information regarding patient age and sex, the x-ray spectra, and the tube voltage and current were registered. The radiation risk were estimated using the model developed by the BEIR VII committee (2006). Results: The effective doses of full Spine Radiography with anteroposterior and lateral projections were 0.626 mSv for patients using DR systems, and 0.483mSv for patients using CR systems, respectively. The dose using DR system was 29.6% higher than those using CR system. The maximum organ dose was observed in the breast for both projections in all the systems. The risk ofmore » exposure—induced cancer death (REID) of patients for DR and CR systems were 0.009% and 0.007%, respectively. Conclusion: The risk estimates were regarded with healthy skepticism, placed more emphasis on the magnitude of the risk. The effective doses estimated in this study could be served as a reference for radiologists and technologists and demonstrate the necessity to optimize patient protection for full Spine Radiography though the effective doses are not at the level to induce deterministic effects and not significant in the stochastic effect. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1D0421)« less

H. Y. Tsai - One of the best experts on this subject based on the ideXlab platform.

  • Radiation dose for pediatric scoliosis patients undergoing whole Spine Radiography: Effect of the radiographic length in an auto-stitching digital Radiography system.
    European journal of radiology, 2018
    Co-Authors: Yi-shuan Hwang, H. Y. Tsai, Po-liang Lai, Yung-chuan Kung, Yu-ying Lin
    Abstract:

    Abstract Objective This study investigated the influence of spatial overlap and radiographic length (RL) on the effective dose (ED) and organ dose for pediatric patients undergoing whole Spine Radiography using an auto-stitching digital Radiography (DR) system. Methods First, the system parameters were tested on a 10-year-old pediatric anthropomorphic phantom with a Shimadzu DR system, and the effects of the spatial overlap and RL on radiation doses were validated. The ED and organ dose were calculated on the basis of a Monte Carlo simulation program. Subsequently, 82 patients with adolescent idiopathic scoliosis were recruited. The spatial overlap and RL for each patient were modified to further investigate the dose reduction feasibility. Results RL and ED were appropriately correlated on the basis of patients’ height. For a patient measuring 158 cm, the Shimadzu DR system was equipped with a 17-inch detector with a cut-off RL of 75 cm. The phantom simulations indicated that ED was reduced to a minimum value of 0.188 ± 0.001 mSv with a high RL for RL  Conclusion A decrease in the spatial overlap and number of radiographic acquisitions by adjusting RLs when possible could reduce ED and almost all organ doses. This study emphasized the effects of RL on the radiation dose and provided useful guidance for modifying the RL for patients to reduce the whole Spine Radiography dose using a modern auto-stitching DR system.

  • SU-E-I-54: Effective Dose and Radiation Cancer Risks for Scoliosis Patients Undergoing Full Spine Radiography
    Medical Physics, 2015
    Co-Authors: Yu-ying Lin, Yi-shuan Hwang, H. Y. Tsai
    Abstract:

    Purpose: Scoliotic patients underwent a lot of radiologic examinations during the control and treatment periods. This study used the PCXMC program to calculate the effective dose of the patients and assess the radiation cancer risks. Methods: Seventy five scoliotic patients were examined using CR or DR systems during the control and treatment periods in Chang Gung Memorial Hospital. The technical factors were recorded for each patient during his/her control and treatment period. The entrance surface dose was measured using thermoluminence dosimeters and derived from technical factors and irradiated geometry. The effective dose of patients and relative radiation cancer risks were calculated by the PCXMC program. All required information regarding patient age and sex, the x-ray spectra, and the tube voltage and current were registered. The radiation risk were estimated using the model developed by the BEIR VII committee (2006). Results: The effective doses of full Spine Radiography with anteroposterior and lateral projections were 0.626 mSv for patients using DR systems, and 0.483mSv for patients using CR systems, respectively. The dose using DR system was 29.6% higher than those using CR system. The maximum organ dose was observed in the breast for both projections in all the systems. The risk ofmore » exposure—induced cancer death (REID) of patients for DR and CR systems were 0.009% and 0.007%, respectively. Conclusion: The risk estimates were regarded with healthy skepticism, placed more emphasis on the magnitude of the risk. The effective doses estimated in this study could be served as a reference for radiologists and technologists and demonstrate the necessity to optimize patient protection for full Spine Radiography though the effective doses are not at the level to induce deterministic effects and not significant in the stochastic effect. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1D0421)« less

Nejc Mekis - One of the best experts on this subject based on the ideXlab platform.

  • OPTIMAL COLLIMATION SIGNIFICANTLY IMPROVES LUMBAR Spine Radiography
    Radiation protection dosimetry, 2020
    Co-Authors: Anamaria Pazanin, Damijan Skrk, Jessica C O'driscoll, Mark F. Mcentee, Nejc Mekis
    Abstract:

    PURPOSE To determine the influence of optimal collimation during lumbar Spine Radiography on radiation dose and image quality. MATERIAL AND METHODS 110 lumbar Spine patients were split into two groups-the first imaged with standard collimation and the second with optimal collimation. Body mass index, image field size, exposure conditions and dose area product were measured. Effective and absorbed organ doses were calculated. Image quality was assessed. RESULTS Optimal collimation reduced the primary field by up to 40%. The effective dose was reduced by 48% for the AP projection, while no differences were found for the LAT projection due to incorrect positioning of the central beam with standard collimation. The absorbed dose to selected radiosensitive organs decreased by 41 and 10% in the AP and LAT projections, respectively. Image quality for the LAT projection improved by 24% and maintained for the AP projection. CONCLUSION Optimal collimation in lumbar Spine imaging significantly influences patient exposure to radiation.

  • Proper collimation effect on radiation dose and image quality in thoracic Spine Radiography
    Nuclear Technology and Radiation Protection, 2020
    Co-Authors: Anamaria Pazanin, Damijan Skrk, Nika Zalokar, Nejc Mekis
    Abstract:

    The purpose of this research was to determine the impact of collimation in thoracic Spine Radiography on patient exposure and image quality. The study was performed on 84 patients referred to thoracic Spine Radiography. Patients were randomly divided into two equal groups of 42. The first group was imaged according to the standard collimation protocol used in one of the hospitals in Croatia while the second group was imaged by applying ?optimal? collimation, image field size was individually collimated for each patient or according to the greatest image field collimation depicted in professional literature. For each patient body mass index, image field size, exposure conditions and dose area product were noted and absorbed doses by organs were calculated, image quality was assessed. There were no statistically significant differences in BMI between the two groups of patients. With the optimal collimation the size of the imaging field in the anteroposterior projection was reduced by 45 % ( p < 0.001) and in the lateral projection by 41 % (p < 0.001). The study also showed reduced values of DAP for anteroposterior projection by 34 % ( p = 0.007) and for lateral projection by 23 % ( p = 0.040). The mean absorbed dose to the selected organs decreased by 26 % in the anteroposterior projection and by 28 % in the lateral projection. In addition, the optimal collimation protocol improved image quality by 13 % in anteroposterior projection. No differences in image quality were found in lateral projection. By carrying out this research we have demonstrated that optimal collimation in thoracic Spine imaging has a strong influence on patient exposure to radiation and has a positive impact on image quality.

  • LUMBAR Spine Radiography: LOWER ORGAN DOSE WITH THE USE OF PA PROJECTION.
    Radiation protection dosimetry, 2019
    Co-Authors: Erna Alukić, Nejc Mekis
    Abstract:

    The purpose of the research was to determine the effect of the posteroanterior (PA) patient position in lumbar Spine imaging on effective dose and the absorbed organ dose. The study was performed on 100 patients that were referred to the lumbar Spine Radiography that were divided into two equal groups of 50. Body Mass Index, Dose Area Product (DAP), exposure index (EXI), tube time-current (mAs), image field size and the source-patient distance were acquired for each patient. The entrance surface dose (ESD), the effective dose and the absorbed organ doses were calculated. There was no statistically significant difference in the BMI and EXI between the AP and PA projection. The results showed a significant reduction of ESD by 33% and the effective dose by 53% when the PA projection was used. Furthermore, there was a 64% average reduction of the absorbed organ doses to the selected organs.

  • COMPARISON OF ANTEROPOSTERIOR AND POSTEROANTERIOR PROJECTION IN LUMBAR Spine Radiography
    Radiology and oncology, 2018
    Co-Authors: Erna Alukić, Damijan Skrk, Nejc Mekis
    Abstract:

    Background The aim of the study was to compare patient radiation dose and image quality in planar lumbar Spine Radiography using the PA and AP projection in a large variety of patients of both sexes and different sizes. Patients and methods In the first phase data of image field size, DAP, effective dose and image quality were gathered for AP and PA projection in lumbar Spine imaging of anthropomorphic phantom. In the second phase, data of BMI, image field size, diameter of the patient's abdomen, DAP, effective dose and image quality were gathered for 100 patients of both sexes who were referred to lumbar Spine Radiography. The patients were divided into two groups of 50 patients, one of which was imaged using the AP projection while the other the PA projection. Results The study on the phantom showed no statistically significant difference in image field size, DAP and image quality. However, the calculated effective dose in the PA projection was 25% lower compared to AP projection (p =0.008). Measurements on the patients showed no statistically significant difference between the BMI and the image field size. In the PA projection, the thickness of abdomen was 10% (p < 10-3) lower, DAP 27% lower (p = 0.009) and the effective dose 53% (p < 10-3) lower than in AP projection. There was no statistically significant difference in image quality between the AP and the PA projection. Conclusions The study results support the use of the PA projection as the preferred method of choice in planar lumbar Spine Radiography.

  • Breast shielding significantly reduces breast dose during thoracic Spine Radiography
    2015
    Co-Authors: David Jecl, Nejc Mekis
    Abstract:

    Poster: "ECR 2015 / C-0798 / Breast shielding significantly reduces breast dose during thoracic Spine Radiography" by: "D. Jecl, N. Mekis; Ljubljana/SI"

William R Mower - One of the best experts on this subject based on the ideXlab platform.

  • Epidemiology of cervical Spine injury victims
    Annals of Emergency Medicine, 2001
    Co-Authors: Douglas W. Lowery, Marlena M. Wald, Brian J. Browne, Stefan Tigges, Jerome R. Hoffman, William R Mower
    Abstract:

    STUDY OBJECTIVE: We sought to characterize demographics and injury patterns among patients undergoing emergency department cervical Spine Radiography for blunt traumatic injury. METHODS: All patients with blunt trauma undergoing cervical Spine Radiography at 21 centers were enrolled in this prospective, observational study. Patients' date of birth, age, sex, and ethnicity were noted before cervical Spine Radiography. RESULTS: Demographic factors associated with cervical Spine injury, present in 818 of 33,922 patients, included the following: age of 65 years or older (relative risk [RR] 2.09; 95% confidence interval [CI] 1.77 to 2.59); "other" ethnicity (RR 1.79, 95% CI 1.46 to 2.19); male sex (RR 1.72, 95% CI 1.48 to 2.00); and white ethnicity (RR 1.50, 95% CI 1.31 to 1.72). Hispanic ethnicity (RR 0.64, 95% CI 0.51 to 0.79), female sex (RR 0.58, 95% CI 0.50 to 0.67), black ethnicity (RR 0.55, 95% CI 0.45 to 0.66), and age of less than 18 years (RR 0.39, 95% CI 0.27 to 0.55) were associated with reduced risk of cervical Spine injury. CONCLUSION: Among patients undergoing ED cervical Spine Radiography, cervical Spine injury is more common among the elderly, male subjects, and patients of white or "other" ethnicity. Because cervical Spine injury occurs in patients in all demographic categories, however, this information cannot be used to select individual patients who should or should not undergo imaging.

  • Epidemiology of cervical Spine injury victims
    Annals of emergency medicine, 2001
    Co-Authors: Douglas W. Lowery, Marlena M. Wald, Brian J. Browne, Stefan Tigges, Jerome R. Hoffman, William R Mower
    Abstract:

    Abstract Study Objective: We sought to characterize demographics and injury patterns among patients undergoing emergency department cervical Spine Radiography for blunt traumatic injury. Methods: All patients with blunt trauma undergoing cervical Spine Radiography at 21 centers were enrolled in this prospective, observational study. Patients' date of birth, age, sex, and ethnicity were noted before cervical Spine Radiography. Results: Demographic factors associated with cervical Spine injury, present in 818 of 33,922 patients, included the following: age of 65 years or older (relative risk [RR] 2.09; 95% confidence interval [CI] 1.77 to 2.59); "other" ethnicity (RR 1.79, 95% CI 1.46 to 2.19); male sex (RR 1.72, 95% CI 1.48 to 2.00); and white ethnicity (RR 1.50, 95% CI 1.31 to 1.72). Hispanic ethnicity (RR 0.64, 95% CI 0.51 to 0.79), female sex (RR 0.58, 95% CI 0.50 to 0.67), black ethnicity (RR 0.55, 95% CI 0.45 to 0.66), and age of less than 18 years (RR 0.39, 95% CI 0.27 to 0.55) were associated with reduced risk of cervical Spine injury. Conclusion: Among patients undergoing ED cervical Spine Radiography, cervical Spine injury is more common among the elderly, male subjects, and patients of white or "other" ethnicity. Because cervical Spine injury occurs in patients in all demographic categories, however, this information cannot be used to select individual patients who should or should not undergo imaging.[Lowery DW, Wald MM, Browne BJ, Tigges S, Hoffman JR, Mower WR, for the NEXUS Group. Epidemiology of cervical Spine injury victims. Ann Emerg Med. July 2001;38:12-16.]

  • selective cervical Spine Radiography in blunt trauma methodology of the national emergency x Radiography utilization study nexus
    Annals of Emergency Medicine, 1998
    Co-Authors: Jerome R. Hoffman, Allan B Wolfson, Knox H Todd, William R Mower
    Abstract:

    Fear of failure to identify cervical Spine injury has led to extremely liberal use of Radiography in patients with blunt trauma and remotely possible neck injury. A number of previous retrospective and small prospective studies have tried to address the question of whether any clinical criteria can identify patients, from among this group, at sufficiently low risk that cervical Spine Radiography is unnecessary. The National Emergency X-Radiography Utilization Study (NEXUS) is a very large, federally supported, multicenter, prospective study designed to define the sensitivity, for detecting significant cervical Spine injury, of criteria previously shown to have high negative predictive value. Done at 23 different emergency departments across the United States and projected to enroll more than 20 times as many patients with cervical Spine injury than any previous study, NEXUS should be able to answer definitively questions about the validity and reliability of clinical criteria used as a preliminary screen for cervical Spine injury.

  • Low-risk criteria for cervical-Spine Radiography in blunt trauma: a prospective study.
    Annals of emergency medicine, 1992
    Co-Authors: Jerome R. Hoffman, William R Mower, David L. Schriger, John S. Luo, Michael I. Zucker
    Abstract:

    Study hypothesis: Cervical-Spine Radiography does not need to be performed on selected blunt trauma patients who are awake, alert, nonintoxicated, do not complain of midline neck pain, and have no tenderness over the bony cervical Spine. Study population: One thousand consecutive patients seen in the UCLA Emergency Medicine Center with a chief complaint of blunt trauma, for whom cervical-Spine films were ordered and for whom prospective data questionnaires were completed. Methods: Clinicians completed data forms for each patient before radiograph results were known. Data items included mechanism of injury, evidence of intoxication, presence of cervical-Spine pain and/or tenderness, level of alertness, presence of focal neurologic deficits, and presence of other severely painful injuries unrelated to the cervical Spine. Physicians were also asked to estimate likelihood of significant cervical-Spine injury. Results: Twenty-seven patients with cervical-Spine fracture were among the 974 patients for whom data forms were completed. A number of findings were statistically more common in the group of patients with fracture than without, but no single or paired findings identified all patients with fracture. All 27 patients with fracture had at least one of the following four characteristics: midline neck tenderness, evidence of intoxication, altered level of alertness, or a severely painful injury elsewhere. Three hundred fifty-three of 947 (37.3%) patients without cervical-Spine fracture had none of these findings. Conclusion: Cervical-Spine radiology may not be necessary in patients without spinous tenderness in the neck, intoxication, altered level of alertness, or other severely painful injury. A policy to limit films in such patients would have decreased film ordering by more than one third in this series, while identifying all patients with fracture.

Yi-shuan Hwang - One of the best experts on this subject based on the ideXlab platform.

  • Radiation dose for pediatric scoliosis patients undergoing whole Spine Radiography: Effect of the radiographic length in an auto-stitching digital Radiography system.
    European journal of radiology, 2018
    Co-Authors: Yi-shuan Hwang, H. Y. Tsai, Po-liang Lai, Yung-chuan Kung, Yu-ying Lin
    Abstract:

    Abstract Objective This study investigated the influence of spatial overlap and radiographic length (RL) on the effective dose (ED) and organ dose for pediatric patients undergoing whole Spine Radiography using an auto-stitching digital Radiography (DR) system. Methods First, the system parameters were tested on a 10-year-old pediatric anthropomorphic phantom with a Shimadzu DR system, and the effects of the spatial overlap and RL on radiation doses were validated. The ED and organ dose were calculated on the basis of a Monte Carlo simulation program. Subsequently, 82 patients with adolescent idiopathic scoliosis were recruited. The spatial overlap and RL for each patient were modified to further investigate the dose reduction feasibility. Results RL and ED were appropriately correlated on the basis of patients’ height. For a patient measuring 158 cm, the Shimadzu DR system was equipped with a 17-inch detector with a cut-off RL of 75 cm. The phantom simulations indicated that ED was reduced to a minimum value of 0.188 ± 0.001 mSv with a high RL for RL  Conclusion A decrease in the spatial overlap and number of radiographic acquisitions by adjusting RLs when possible could reduce ED and almost all organ doses. This study emphasized the effects of RL on the radiation dose and provided useful guidance for modifying the RL for patients to reduce the whole Spine Radiography dose using a modern auto-stitching DR system.

  • SU-E-I-54: Effective Dose and Radiation Cancer Risks for Scoliosis Patients Undergoing Full Spine Radiography
    Medical Physics, 2015
    Co-Authors: Yu-ying Lin, Yi-shuan Hwang, H. Y. Tsai
    Abstract:

    Purpose: Scoliotic patients underwent a lot of radiologic examinations during the control and treatment periods. This study used the PCXMC program to calculate the effective dose of the patients and assess the radiation cancer risks. Methods: Seventy five scoliotic patients were examined using CR or DR systems during the control and treatment periods in Chang Gung Memorial Hospital. The technical factors were recorded for each patient during his/her control and treatment period. The entrance surface dose was measured using thermoluminence dosimeters and derived from technical factors and irradiated geometry. The effective dose of patients and relative radiation cancer risks were calculated by the PCXMC program. All required information regarding patient age and sex, the x-ray spectra, and the tube voltage and current were registered. The radiation risk were estimated using the model developed by the BEIR VII committee (2006). Results: The effective doses of full Spine Radiography with anteroposterior and lateral projections were 0.626 mSv for patients using DR systems, and 0.483mSv for patients using CR systems, respectively. The dose using DR system was 29.6% higher than those using CR system. The maximum organ dose was observed in the breast for both projections in all the systems. The risk ofmore » exposure—induced cancer death (REID) of patients for DR and CR systems were 0.009% and 0.007%, respectively. Conclusion: The risk estimates were regarded with healthy skepticism, placed more emphasis on the magnitude of the risk. The effective doses estimated in this study could be served as a reference for radiologists and technologists and demonstrate the necessity to optimize patient protection for full Spine Radiography though the effective doses are not at the level to induce deterministic effects and not significant in the stochastic effect. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1D0421)« less