In this paper, a new image reconstruction algorithm employing dynamic grids technique is proposed for tomographic gamma scanning. The key feature of the algorithm is the use of adaptive grid refinement in areas that i...In this paper, a new image reconstruction algorithm employing dynamic grids technique is proposed for tomographic gamma scanning. The key feature of the algorithm is the use of adaptive grid refinement in areas that indicate large values. Simulation results show that the application of dynamic grids has a good performance in emission reconstruction with a distinct advantage in the accurate positioning of the 'hot spots' and reducing the number of grids, but doesn't achieve a tangible improvement in transmission reconstruction.展开更多
Pediatric head injury is one of the major health problems. That can be easily evaluated by computed tomographic scanning. This study describes the various findings of pediatric head trauma seen on CT scan, the timely ...Pediatric head injury is one of the major health problems. That can be easily evaluated by computed tomographic scanning. This study describes the various findings of pediatric head trauma seen on CT scan, the timely diagnosis of which plays a vital role in prognosis, especially in semiurban and remote location where the decision for tertiary referral is important. Timely intervention in traumatic brain injury cases reduces morbidity and mortality. Cerebral edema, which is the most common intracranial lesion, can be promptly managed by medicosurgical support with ICP monitoring, thereby improving the overall prognosis. Other lesions commonly seen are subdural hematomas and skull fractures. Limitations of radiographs, ultrasound and MRI in these acute cases, highlight the benefit of CT scans.展开更多
It is difficult to develop image reconstruction algorithms for tomographic gamma scanning based on drummed radioactive residues or wastes.In this paper,a novel reconstruction algorithm of transmission image for tomogr...It is difficult to develop image reconstruction algorithms for tomographic gamma scanning based on drummed radioactive residues or wastes.In this paper,a novel reconstruction algorithm of transmission image for tomographic gamma scanning is proposed.It is based on the conventional transmission equation and equivalent gamma-ray track length modified by a Monte Carlo method.The algorithm is implemented by simulating the samples on the established platform.For the verification experiments of the algorithm,several cubic voxel samples were designed and manufactured.Experimental tests were conducted.The tomographic gamma scanning of transmission images is compared with the linear attenuation coefficients by the simulated values and experimental data with the algorithm and the reference values.The results show that the absolute relative errors of the reconstructed images are less than 5%.展开更多
Evaluation of Renal vascular anatomical variations Using Multi-Detector Computerized Tomographic scan in Sudan, the total number of patients studied is 400, 202 (50.5%) male and 98 (49.5%) females, and their ages rang...Evaluation of Renal vascular anatomical variations Using Multi-Detector Computerized Tomographic scan in Sudan, the total number of patients studied is 400, 202 (50.5%) male and 98 (49.5%) females, and their ages ranged between (3 - 94) years. The types of Accessory renal arteries were 1.8% (7/24) upper pole, 1.8% (7/24) lower pole and 2.5% (10/24) hilus. In males, 4 upper pole, 4 lower pole and 7 hilus. In females, 3 upper pole, 3 lower pole and 3 hilus. The percentage of right accessory renal arteries is almost twice that of the left and more than twice the bilateral accessory arteries. Accessory renal artery is a common but a significant anatomical variant of the renal vascular system, due to their clinical importance. In our sample, the accessory renal artery presence was detected in 6% and displayed a greater variation on the right than the left side. Because this abnormality plays an important role in kidney transplantations, in radiological, vascular and urological interventions, a detailed presentation of accessory renal artery incidence was conducted, gathering from the literature a large number of relevant studies in order to create a classification according to population, gender, side and specimen. The study concluded that the renal arteries present a broad spectrum of variability in their morphological expression regarding their length, diameter and entrance to the kidney parenchyma, additional arteries’ morphological expression was higher in men than women. This is statistically not significant and variation in the right side was found greater frequency than the left side.展开更多
Anatomical Variations of Renal Vascular in Patients Undergoing Computerized Tomographic scan in Sudan, the total number of patients studied is 400, 202 (50.5%) males and 198 (49.5%) females, and their ages ranged betw...Anatomical Variations of Renal Vascular in Patients Undergoing Computerized Tomographic scan in Sudan, the total number of patients studied is 400, 202 (50.5%) males and 198 (49.5%) females, and their ages ranged between (3 - 94) years. The study showed mean of total samples of the width and length of right and left kidneys respectively measurements were 5.354 ± 0.948 and 5.571 ± 0.966 for width and 10.028 ± 1.3684 and 10.060 ± 1.5203 for length, the width and length for right renal artery 5.746 ± 1.2814 and 5.881 ± 1.1444 respectively and for left renal artery 5.894 ± 1.3175 and 4.961 ± 1.3175 respectively. Accessory renal artery is a common but a significant anatomical variant of the renal vascular system, due to its clinical importance. In our sample, the accessory renal artery presence was detected in 6% and displayed a greater variation on the right than the left side. Because this abnormality plays an important role in kidney transplantations, in radiological, vascular and urological interventions, a detailed presentation of accessory renal artery incidence was conducted, gathering from the literature a large number of relevant studies in order to create a classification according to population, gender, side and specimen. And the study concluded that the renal arteries present a broad spectrum of variability in their morphological expression regarding their length, diameter and entrance to the kidney parenchyma. The inferior polar renal artery was found same as the superior polar renal artery, additional arteries’ morphological expression was higher in men than women. This is statistically not significant and variation in the right side was found greater frequency than the left side.展开更多
Objective: To compare and analyze the image quality and radiation dose of three scanning modes of dual-source CT coronary artery retrospectively, and to discuss the application value of TurboFlash coarse pitch scannin...Objective: To compare and analyze the image quality and radiation dose of three scanning modes of dual-source CT coronary artery retrospectively, and to discuss the application value of TurboFlash coarse pitch scanning mode. Methods: The imaging data of 100 patients who underwent CT coronary angiography (CCTA) using Siemens force CT retrospective gated triggering spiral scan (RES-SPIRAL), adaptive prospective gated triggering sequence scan (SEQ) and prospective coarse pitch scan (TurboFlash) retrospectively was collected. The image quality was evaluated by objective and subjective methods. The effective radiation dose of patients was compared and analyzed, and the indications of the three scanning modes were analyzed. The application value of dual-source CT TurboFlash coarse pitch scanning in coronary artery imaging was evaluated. Results: The results showed that the left main coronary artery, the right coronary artery and their tertiary branches could be clearly displayed in the three groups of images: the left anterior descending branch, the left circumflex branch, and their three-level branches. There was no statistical difference in subjective image quality among the three groups of pictures (P > 0.05). There was no statistical difference in objective evaluation indexes, such as CT value, SNR, CNR and Noise among the three groups (P > 0.05). The patient radiation dose results showed that the effective radiation dose ED of RES-SPIRA scan was (9.22 ± 1.33) mSv. The dose of SEQ was (2.88 ± 2.47) mSv, and the dose of TurboFlash was (0.51 ± 0.16) mSv. There was significant difference in comparison of the three groups (P 0.05). RES-spiral scanning had the highest radiation dose and TurboFlash coarse pitch scanning (TurboFlash) had the lowest radiation dose. Conclusion: TurboFlash coarse pitch scanning is low in dosage, fast in speed and wide in adaptability. It is especially suitable for the elderly, children, coma and other patients who cannot cooperate with breath-holding examination, as well as for the screening and examination of coronary artery diseases in asymptomatic population. Undoubtedly, it is a worthy method of heart coronary artery examination.展开更多
基金Supported by National Natural Science Foundation of China(No.51106095,11175118)China Postdoctoral Science Foundation(No.20110490717)
文摘In this paper, a new image reconstruction algorithm employing dynamic grids technique is proposed for tomographic gamma scanning. The key feature of the algorithm is the use of adaptive grid refinement in areas that indicate large values. Simulation results show that the application of dynamic grids has a good performance in emission reconstruction with a distinct advantage in the accurate positioning of the 'hot spots' and reducing the number of grids, but doesn't achieve a tangible improvement in transmission reconstruction.
文摘Pediatric head injury is one of the major health problems. That can be easily evaluated by computed tomographic scanning. This study describes the various findings of pediatric head trauma seen on CT scan, the timely diagnosis of which plays a vital role in prognosis, especially in semiurban and remote location where the decision for tertiary referral is important. Timely intervention in traumatic brain injury cases reduces morbidity and mortality. Cerebral edema, which is the most common intracranial lesion, can be promptly managed by medicosurgical support with ICP monitoring, thereby improving the overall prognosis. Other lesions commonly seen are subdural hematomas and skull fractures. Limitations of radiographs, ultrasound and MRI in these acute cases, highlight the benefit of CT scans.
基金Supported by the Foundation for Returned Oversea Chinese Scholars(No.33)
文摘It is difficult to develop image reconstruction algorithms for tomographic gamma scanning based on drummed radioactive residues or wastes.In this paper,a novel reconstruction algorithm of transmission image for tomographic gamma scanning is proposed.It is based on the conventional transmission equation and equivalent gamma-ray track length modified by a Monte Carlo method.The algorithm is implemented by simulating the samples on the established platform.For the verification experiments of the algorithm,several cubic voxel samples were designed and manufactured.Experimental tests were conducted.The tomographic gamma scanning of transmission images is compared with the linear attenuation coefficients by the simulated values and experimental data with the algorithm and the reference values.The results show that the absolute relative errors of the reconstructed images are less than 5%.
文摘Evaluation of Renal vascular anatomical variations Using Multi-Detector Computerized Tomographic scan in Sudan, the total number of patients studied is 400, 202 (50.5%) male and 98 (49.5%) females, and their ages ranged between (3 - 94) years. The types of Accessory renal arteries were 1.8% (7/24) upper pole, 1.8% (7/24) lower pole and 2.5% (10/24) hilus. In males, 4 upper pole, 4 lower pole and 7 hilus. In females, 3 upper pole, 3 lower pole and 3 hilus. The percentage of right accessory renal arteries is almost twice that of the left and more than twice the bilateral accessory arteries. Accessory renal artery is a common but a significant anatomical variant of the renal vascular system, due to their clinical importance. In our sample, the accessory renal artery presence was detected in 6% and displayed a greater variation on the right than the left side. Because this abnormality plays an important role in kidney transplantations, in radiological, vascular and urological interventions, a detailed presentation of accessory renal artery incidence was conducted, gathering from the literature a large number of relevant studies in order to create a classification according to population, gender, side and specimen. The study concluded that the renal arteries present a broad spectrum of variability in their morphological expression regarding their length, diameter and entrance to the kidney parenchyma, additional arteries’ morphological expression was higher in men than women. This is statistically not significant and variation in the right side was found greater frequency than the left side.
文摘Anatomical Variations of Renal Vascular in Patients Undergoing Computerized Tomographic scan in Sudan, the total number of patients studied is 400, 202 (50.5%) males and 198 (49.5%) females, and their ages ranged between (3 - 94) years. The study showed mean of total samples of the width and length of right and left kidneys respectively measurements were 5.354 ± 0.948 and 5.571 ± 0.966 for width and 10.028 ± 1.3684 and 10.060 ± 1.5203 for length, the width and length for right renal artery 5.746 ± 1.2814 and 5.881 ± 1.1444 respectively and for left renal artery 5.894 ± 1.3175 and 4.961 ± 1.3175 respectively. Accessory renal artery is a common but a significant anatomical variant of the renal vascular system, due to its clinical importance. In our sample, the accessory renal artery presence was detected in 6% and displayed a greater variation on the right than the left side. Because this abnormality plays an important role in kidney transplantations, in radiological, vascular and urological interventions, a detailed presentation of accessory renal artery incidence was conducted, gathering from the literature a large number of relevant studies in order to create a classification according to population, gender, side and specimen. And the study concluded that the renal arteries present a broad spectrum of variability in their morphological expression regarding their length, diameter and entrance to the kidney parenchyma. The inferior polar renal artery was found same as the superior polar renal artery, additional arteries’ morphological expression was higher in men than women. This is statistically not significant and variation in the right side was found greater frequency than the left side.
文摘Objective: To compare and analyze the image quality and radiation dose of three scanning modes of dual-source CT coronary artery retrospectively, and to discuss the application value of TurboFlash coarse pitch scanning mode. Methods: The imaging data of 100 patients who underwent CT coronary angiography (CCTA) using Siemens force CT retrospective gated triggering spiral scan (RES-SPIRAL), adaptive prospective gated triggering sequence scan (SEQ) and prospective coarse pitch scan (TurboFlash) retrospectively was collected. The image quality was evaluated by objective and subjective methods. The effective radiation dose of patients was compared and analyzed, and the indications of the three scanning modes were analyzed. The application value of dual-source CT TurboFlash coarse pitch scanning in coronary artery imaging was evaluated. Results: The results showed that the left main coronary artery, the right coronary artery and their tertiary branches could be clearly displayed in the three groups of images: the left anterior descending branch, the left circumflex branch, and their three-level branches. There was no statistical difference in subjective image quality among the three groups of pictures (P > 0.05). There was no statistical difference in objective evaluation indexes, such as CT value, SNR, CNR and Noise among the three groups (P > 0.05). The patient radiation dose results showed that the effective radiation dose ED of RES-SPIRA scan was (9.22 ± 1.33) mSv. The dose of SEQ was (2.88 ± 2.47) mSv, and the dose of TurboFlash was (0.51 ± 0.16) mSv. There was significant difference in comparison of the three groups (P 0.05). RES-spiral scanning had the highest radiation dose and TurboFlash coarse pitch scanning (TurboFlash) had the lowest radiation dose. Conclusion: TurboFlash coarse pitch scanning is low in dosage, fast in speed and wide in adaptability. It is especially suitable for the elderly, children, coma and other patients who cannot cooperate with breath-holding examination, as well as for the screening and examination of coronary artery diseases in asymptomatic population. Undoubtedly, it is a worthy method of heart coronary artery examination.
