Objectives: The aim of this work was to initially establish both age and weight driven pediatric diagnostic reference levels (DRLs) for chest computed tomography (CT) examinations performed at tertiary care medical in...Objectives: The aim of this work was to initially establish both age and weight driven pediatric diagnostic reference levels (DRLs) for chest computed tomography (CT) examinations performed at tertiary care medical institution. Another aim was to compare the presented data with internationally published ones. This initial data shall serve as basis for establishing a national DRLs values for pediatric diagnostic CT examinations. Methods: Dosimetric indexes were collected for the chest examination for 93 patients during the past 2 years in a tertiary care medical city. Results: The results are within and below the international reported levels for chest CT in several countries. Conclusion: Continuous monitoring of the radiation doses received by the patients in computed tomography is continuous and ongoing process in order to ensure compliance and to optimize clinical imaging protocols. More extensive data acquisition and analysis are required to allow better understanding of the contributing factors leading to less patient radiation dose while preserving the clinical image quality. .展开更多
Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outsi...Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outside the field of view(FOV)on PET image quality for different reconstruction protocols.Imaging was performed on the Discovery 690 PET/CT scanner,using experimental configurations including the NEMA phantom(a body phantom,with six spheres of different sizes)with a signal background ratio of 4:1.The NEMA phantom(phantom I)was scanned separately in a one-bed position.To simulate the effect of random and scatter coincidences from outside the FOV,six cylindrical phantoms with various diameters were added to the NEMA phantom(phantom II).The 18 emission datasets with mean intervals of 15 min were acquired(3 min/scan).The emission data were reconstructed using different techniques.The image quality parameters were evaluated by both phantoms.Variations in the signal-to-noise ratio(SNR)in a 28-mm(10-mm)sphere of phantom II were 37.9%(86.5%)for ordered-subset expectation maximization(OSEM-only),36.8%(81.5%)for point spread function(PSF),32.7%(80.7%)for time of flight(TOF),and 31.5%(77.8%)for OSEM+PSF+TOF,respectively,indicating that OSEM+PSF+TOF reconstruction had the lowest noise levels and lowest coefficient of variation(COV)values.Random and scatter coincidences from outside the FOV induced lower SNR,lower contrast,and higher COV values,indicating image deterioration and significantly impacting smaller sphere sizes.Amongst reconstruction protocols,OSEM+PSF+TOF and OSEM+PSF showed higher contrast values for sphere sizes of 22,28,and 37 mm and higher contrast recovery coefficient values for smaller sphere sizes of 10 and 13 mm.展开更多
AIM To investigate the hemothorax size for which tube thoracostomy is necessary.METHODS Over a 5-year period, we included all patients who were admitted with blunt chest trauma to our level 1 trauma center. Focus was ...AIM To investigate the hemothorax size for which tube thoracostomy is necessary.METHODS Over a 5-year period, we included all patients who were admitted with blunt chest trauma to our level 1 trauma center. Focus was placed on identifying the hemothorax size requiring tube thoracostomy.RESULTS A total number of 274 hemothoraces were studied. All patients with hemothoraces measuring above 3 cm received a chest tube. The 50% predicted probability of tube thoracostomy was 2 cm. Pneumothorax was associated with odds of receiving tube thoracostomy for hemothoraces below 2 cm(Odds Ratio:4.967, 95%CI: 2.225-11.097, P < 0.0001).CONCLUSION All patients with a hemothorax size greater than 3% underwent tube thoracostomy. Prospective studies are warranted to elucidate the clinical outcome of patients with smaller hemothoraces.展开更多
Background: Epicardial adipose tissue (EAT) may produce several cytokines contributed to coronary atherosclerosis. EAT was measured by transthoracic echocardiography or 3 dimensional cardiac computed tomography (CT) o...Background: Epicardial adipose tissue (EAT) may produce several cytokines contributed to coronary atherosclerosis. EAT was measured by transthoracic echocardiography or 3 dimensional cardiac computed tomography (CT) on previous studies. We aimed to evaluate the correlation between EAT thickness and cardiovascular risk factors in healthy adults. Method: We collected clinical, biochemical information from 469 subjects (371 men and 98 women) who visited our health promotion center. EAT thickness was measured by chest CT on the free wall of the right ventricle. Result: The mean EAT thickness was 2.47 ± 1.64 mm in total of 469 subjects. EAT thickness was significantly correlated to age, weight, body mass index (BMI), total body fat, systolic and diastolic blood pressure, total cholesterol, low density lipoprotein (LDL)-cholesterol, and fasting glucose in men and to age, height, weight, BMI, total body fat, systolic and diastolic blood pressure, triglycerides, C-reactive protein (CRP), and fasting glucose in women. Multivariate analysis showed that age, BMI, systolic blood pressure, fasting glucose were the variables that independently correlated to EAT thickness in men. But there was no significant independent variable in women. Conclusion: In our study, EAT thickness measured with chest CT in healthy individuals correlates with cardiovascular risk factors in men.展开更多
Background: Radiology in elderly as pediatric radiology poses a number of problems. The normal radiological appearance of the elderly patient’s chest is very varied and the changes are ubiquitous. Purpose: To describ...Background: Radiology in elderly as pediatric radiology poses a number of problems. The normal radiological appearance of the elderly patient’s chest is very varied and the changes are ubiquitous. Purpose: To describe the computed tomography profile of the elderly subject’s chest. Materials and Methods: Descriptive prospective study from January 1st to June 30th, 2018 carried out at the University Campus Hospital of Lomé. Results: We recorded 64 chest CT scans. The average age of the patients was 71.3. Internists (n = 21, 32.8%) and general practitioner (n = 16, 25%) were the major applicants for these tests. In most cases, thoracic CT examinations were requested as part of an extension assessment (n = 21, 32.8%), dyspnea and pneumonitis in 18.8% of cases each. All thoracic CT examinations were performed with contrast injection. CT with the TAP protocol was the most observed, accounted for more than half of the exams (56%). The main pathological lesions observed were diffuse parenchymal lesions (39.5%), pleurisy (11.1%) and PAH (11.1%). Conclusion: Computed tomography occupies an important place in the care of the elderly but the actors involved in their care must be trained to take optimal care.展开更多
文摘Objectives: The aim of this work was to initially establish both age and weight driven pediatric diagnostic reference levels (DRLs) for chest computed tomography (CT) examinations performed at tertiary care medical institution. Another aim was to compare the presented data with internationally published ones. This initial data shall serve as basis for establishing a national DRLs values for pediatric diagnostic CT examinations. Methods: Dosimetric indexes were collected for the chest examination for 93 patients during the past 2 years in a tertiary care medical city. Results: The results are within and below the international reported levels for chest CT in several countries. Conclusion: Continuous monitoring of the radiation doses received by the patients in computed tomography is continuous and ongoing process in order to ensure compliance and to optimize clinical imaging protocols. More extensive data acquisition and analysis are required to allow better understanding of the contributing factors leading to less patient radiation dose while preserving the clinical image quality. .
基金supported by the Tehran University of Medical Sciences under Grant No.36291PET/CT and Cyclotron Center of Masih Daneshvari Hospital at Shahid Beheshti University of Medical Sciences。
文摘Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outside the field of view(FOV)on PET image quality for different reconstruction protocols.Imaging was performed on the Discovery 690 PET/CT scanner,using experimental configurations including the NEMA phantom(a body phantom,with six spheres of different sizes)with a signal background ratio of 4:1.The NEMA phantom(phantom I)was scanned separately in a one-bed position.To simulate the effect of random and scatter coincidences from outside the FOV,six cylindrical phantoms with various diameters were added to the NEMA phantom(phantom II).The 18 emission datasets with mean intervals of 15 min were acquired(3 min/scan).The emission data were reconstructed using different techniques.The image quality parameters were evaluated by both phantoms.Variations in the signal-to-noise ratio(SNR)in a 28-mm(10-mm)sphere of phantom II were 37.9%(86.5%)for ordered-subset expectation maximization(OSEM-only),36.8%(81.5%)for point spread function(PSF),32.7%(80.7%)for time of flight(TOF),and 31.5%(77.8%)for OSEM+PSF+TOF,respectively,indicating that OSEM+PSF+TOF reconstruction had the lowest noise levels and lowest coefficient of variation(COV)values.Random and scatter coincidences from outside the FOV induced lower SNR,lower contrast,and higher COV values,indicating image deterioration and significantly impacting smaller sphere sizes.Amongst reconstruction protocols,OSEM+PSF+TOF and OSEM+PSF showed higher contrast values for sphere sizes of 22,28,and 37 mm and higher contrast recovery coefficient values for smaller sphere sizes of 10 and 13 mm.
文摘AIM To investigate the hemothorax size for which tube thoracostomy is necessary.METHODS Over a 5-year period, we included all patients who were admitted with blunt chest trauma to our level 1 trauma center. Focus was placed on identifying the hemothorax size requiring tube thoracostomy.RESULTS A total number of 274 hemothoraces were studied. All patients with hemothoraces measuring above 3 cm received a chest tube. The 50% predicted probability of tube thoracostomy was 2 cm. Pneumothorax was associated with odds of receiving tube thoracostomy for hemothoraces below 2 cm(Odds Ratio:4.967, 95%CI: 2.225-11.097, P < 0.0001).CONCLUSION All patients with a hemothorax size greater than 3% underwent tube thoracostomy. Prospective studies are warranted to elucidate the clinical outcome of patients with smaller hemothoraces.
文摘Background: Epicardial adipose tissue (EAT) may produce several cytokines contributed to coronary atherosclerosis. EAT was measured by transthoracic echocardiography or 3 dimensional cardiac computed tomography (CT) on previous studies. We aimed to evaluate the correlation between EAT thickness and cardiovascular risk factors in healthy adults. Method: We collected clinical, biochemical information from 469 subjects (371 men and 98 women) who visited our health promotion center. EAT thickness was measured by chest CT on the free wall of the right ventricle. Result: The mean EAT thickness was 2.47 ± 1.64 mm in total of 469 subjects. EAT thickness was significantly correlated to age, weight, body mass index (BMI), total body fat, systolic and diastolic blood pressure, total cholesterol, low density lipoprotein (LDL)-cholesterol, and fasting glucose in men and to age, height, weight, BMI, total body fat, systolic and diastolic blood pressure, triglycerides, C-reactive protein (CRP), and fasting glucose in women. Multivariate analysis showed that age, BMI, systolic blood pressure, fasting glucose were the variables that independently correlated to EAT thickness in men. But there was no significant independent variable in women. Conclusion: In our study, EAT thickness measured with chest CT in healthy individuals correlates with cardiovascular risk factors in men.
文摘Background: Radiology in elderly as pediatric radiology poses a number of problems. The normal radiological appearance of the elderly patient’s chest is very varied and the changes are ubiquitous. Purpose: To describe the computed tomography profile of the elderly subject’s chest. Materials and Methods: Descriptive prospective study from January 1st to June 30th, 2018 carried out at the University Campus Hospital of Lomé. Results: We recorded 64 chest CT scans. The average age of the patients was 71.3. Internists (n = 21, 32.8%) and general practitioner (n = 16, 25%) were the major applicants for these tests. In most cases, thoracic CT examinations were requested as part of an extension assessment (n = 21, 32.8%), dyspnea and pneumonitis in 18.8% of cases each. All thoracic CT examinations were performed with contrast injection. CT with the TAP protocol was the most observed, accounted for more than half of the exams (56%). The main pathological lesions observed were diffuse parenchymal lesions (39.5%), pleurisy (11.1%) and PAH (11.1%). Conclusion: Computed tomography occupies an important place in the care of the elderly but the actors involved in their care must be trained to take optimal care.
