Computer Automated Tomography has been shown to be a valuable tool in production research because it provides a non-destructive method to identify and evaluate the internal structural characteristics of reservoir rock...Computer Automated Tomography has been shown to be a valuable tool in production research because it provides a non-destructive method to identify and evaluate the internal structural characteristics of reservoir rock. In CT scan, Hounsfield Unit (HU) is proportional to the degree of X-ray attenuation by the tissue. The aim of the present study was to introduce the method to estimate porosity which is one of physical parameters of reservoir rock though HU data. In this study, an Image J software was used to extract Hounsfield Unit data and calibrate by standard material’s density. This method provides the ability of using CT Scanner in advanced reservoir characterization and flow test experiments.展开更多
Eclampsia is a common complication of hypertensive disorders of pregnancy and in the puerperium with the attendant risk to both the mother and baby. Although it is a multi-systemic disorder, its manifestation that aff...Eclampsia is a common complication of hypertensive disorders of pregnancy and in the puerperium with the attendant risk to both the mother and baby. Although it is a multi-systemic disorder, its manifestation that affects the brain and resulting in altered sensorium demands brain imaging to define the possible brain lesions and the implications for critical care management and outcome. We evaluated the CT brain lesions in the patients with eclampsia who were admitted in the intensive care unit, University of Port Harcourt, Port Harcourt Nigeria. Objective: To analyse the CT brain images of eclamptic parturients and the outcome following their admission in the intensive care unit. Methods: We undertook this observational study after obtaining ethical exemption from the University of Portharcourt Teaching Hospital ethical review board, and commenced the review between March 2021 to February 2023. We included all parturients that were admitted into the intensive care unit of the University of Portharcourt Teaching Hospital, a nine-bedded open intensive care unit with the clinical diagnosis of eclampsia. Every admitted parturient was required to obtain a brain computed tomography (CT) by local protocol. The brain CT images were retrieved for review from the parturients’ relatives, radiology department and the ICU. Parturients included were aged ≥ 18 years. The radiological reports of these brain images which were also reviewed by a neurosurgeon in case of any need for secondary opinion were subjected to statistical analysis. Result: Thirty-one parturients were admitted with eclampsia with a mean age of 30 years ± 5.29. Sixteen (16) parturients died representing 52%. Only twenty-four (24) CT brain images were retrieved for review (77%). The following brain lesions were identified from the brain CT and they comprised the following: intracerebral haemorrhage, including extensions into the ventricles 7 (29.17%), cerebral oedema 12 (50%), subdural hematoma 1 (4.17%) and normal imaging 4 (16.66%). The subdural haematoma was promptly evacuated with a good outcome. Conclusion: Neuro imaging comprising computed tomography and magnetic resonance imaging of the brain are basic ancillary investigations for patients with eclampsia presenting with neurologic deficits and low GCS. Early presentation and access to brain CT could influence outcome as it was demonstrated in the prompt intervention in the patient with subdural haematoma which was evacuated with a satisfactory outcome.展开更多
Current minimally invasive interventions for ureteric stones involve either ESWL or Ureteroscopy and stone localization is mandatory for successful treatment in both. Objectives: To avoid doing KUB radiograph before E...Current minimally invasive interventions for ureteric stones involve either ESWL or Ureteroscopy and stone localization is mandatory for successful treatment in both. Objectives: To avoid doing KUB radiograph before ESWL routinely by correlating the stone attenuation value on CT KUB with stone visualization at fluoroscopy. Methods: This is a prospective cross sectional hospital based, Multicentric study carried out on 1010 patients with ureteric stones in Sudan from August 2014 to March 2016. Results: Mean stone density in HU was 704.45 ± 300 (SD) ranging (81 - 1873) HU. All of the stones were localized using fluoroscopy and only 26.5% of them were not seen under fluoroscopy. I.V contrast was used mostly, and also mainly in the upper ureter. More than 80% of the application of contrast through the ureteric catheter was in the lower ureteric stones. 91.2% of patients with stone density ≤ 400 HU failed to appear at fluoroscopy and therefore 400 HU attenuation value can be used as a cut-off level to request doing KUB before ESWL and Ureteroscopy. Conclusion: the ureteric stones with density ≤400 HU the likelihood of being non-visualized at fluoroscopy is 91.2% therefore if the stone has ≤400 HU at CT KUB it is mandatory to do KUB before treatment above that it is most likely to be seen at fluoroscopy and no need to request KUB for them before ESWL or URS. 1) Inclusion Criteria: All patients diagnosed by CT scan to have ureteric stones for ESWL or Ureteroscopy. 2) Exclusion Criteria: Patients for whom treatment of ureteric stone by ESWL or ureteroscopy is not indicated like severe infection or poor kidney function where nephrectomy is needed.展开更多
本文描述了飞利浦16排Brilliance CT Big Bore的常见维修故障3例,探寻故障排除方法及解决途径。文章首先分析了CT的组成部件及工作原理,然后根据故障现象逐步分析、探究故障原因,最终找到了CT故障原因,并给予修复。CT在临床使用中常见...本文描述了飞利浦16排Brilliance CT Big Bore的常见维修故障3例,探寻故障排除方法及解决途径。文章首先分析了CT的组成部件及工作原理,然后根据故障现象逐步分析、探究故障原因,最终找到了CT故障原因,并给予修复。CT在临床使用中常见的故障有一定的普遍性,探讨最优的维修策略可以节约维修工时以及降低设备的维护成本,从而更好地保障临床工作。展开更多
三维锥束CT图像重建运算量大,纯软件(仅使用CPU)计算时间较长。为了充分利用计算机图形处理器(Graphic Process Unit,GPU)的并行处理能力以及提高数据传输效率,研究了一种结合使用GPU多重纹理(multitexture)加速三维锥束CT的FDK图像重...三维锥束CT图像重建运算量大,纯软件(仅使用CPU)计算时间较长。为了充分利用计算机图形处理器(Graphic Process Unit,GPU)的并行处理能力以及提高数据传输效率,研究了一种结合使用GPU多重纹理(multitexture)加速三维锥束CT的FDK图像重建过程的方法。该方法采用多重纹理映射来提高反投影速度、减少中间数据存储量、减少浮点累加次数,使用顶点颜色通道来实现距离加权运算,采用扩展方法来增加并行反投影的纹理单元,从而提高重建速度。计算机实验结果表明,使用普通PC机重建尺寸为2563的图像,在保证数据精度为16bit浮点数的要求下,GPU反投影计算可以在10s以内完成。与仅使用CPU的重建方法相比,GPU重建图像加速方法达到了较高的时间加速比。展开更多
文摘Computer Automated Tomography has been shown to be a valuable tool in production research because it provides a non-destructive method to identify and evaluate the internal structural characteristics of reservoir rock. In CT scan, Hounsfield Unit (HU) is proportional to the degree of X-ray attenuation by the tissue. The aim of the present study was to introduce the method to estimate porosity which is one of physical parameters of reservoir rock though HU data. In this study, an Image J software was used to extract Hounsfield Unit data and calibrate by standard material’s density. This method provides the ability of using CT Scanner in advanced reservoir characterization and flow test experiments.
文摘Eclampsia is a common complication of hypertensive disorders of pregnancy and in the puerperium with the attendant risk to both the mother and baby. Although it is a multi-systemic disorder, its manifestation that affects the brain and resulting in altered sensorium demands brain imaging to define the possible brain lesions and the implications for critical care management and outcome. We evaluated the CT brain lesions in the patients with eclampsia who were admitted in the intensive care unit, University of Port Harcourt, Port Harcourt Nigeria. Objective: To analyse the CT brain images of eclamptic parturients and the outcome following their admission in the intensive care unit. Methods: We undertook this observational study after obtaining ethical exemption from the University of Portharcourt Teaching Hospital ethical review board, and commenced the review between March 2021 to February 2023. We included all parturients that were admitted into the intensive care unit of the University of Portharcourt Teaching Hospital, a nine-bedded open intensive care unit with the clinical diagnosis of eclampsia. Every admitted parturient was required to obtain a brain computed tomography (CT) by local protocol. The brain CT images were retrieved for review from the parturients’ relatives, radiology department and the ICU. Parturients included were aged ≥ 18 years. The radiological reports of these brain images which were also reviewed by a neurosurgeon in case of any need for secondary opinion were subjected to statistical analysis. Result: Thirty-one parturients were admitted with eclampsia with a mean age of 30 years ± 5.29. Sixteen (16) parturients died representing 52%. Only twenty-four (24) CT brain images were retrieved for review (77%). The following brain lesions were identified from the brain CT and they comprised the following: intracerebral haemorrhage, including extensions into the ventricles 7 (29.17%), cerebral oedema 12 (50%), subdural hematoma 1 (4.17%) and normal imaging 4 (16.66%). The subdural haematoma was promptly evacuated with a good outcome. Conclusion: Neuro imaging comprising computed tomography and magnetic resonance imaging of the brain are basic ancillary investigations for patients with eclampsia presenting with neurologic deficits and low GCS. Early presentation and access to brain CT could influence outcome as it was demonstrated in the prompt intervention in the patient with subdural haematoma which was evacuated with a satisfactory outcome.
文摘Current minimally invasive interventions for ureteric stones involve either ESWL or Ureteroscopy and stone localization is mandatory for successful treatment in both. Objectives: To avoid doing KUB radiograph before ESWL routinely by correlating the stone attenuation value on CT KUB with stone visualization at fluoroscopy. Methods: This is a prospective cross sectional hospital based, Multicentric study carried out on 1010 patients with ureteric stones in Sudan from August 2014 to March 2016. Results: Mean stone density in HU was 704.45 ± 300 (SD) ranging (81 - 1873) HU. All of the stones were localized using fluoroscopy and only 26.5% of them were not seen under fluoroscopy. I.V contrast was used mostly, and also mainly in the upper ureter. More than 80% of the application of contrast through the ureteric catheter was in the lower ureteric stones. 91.2% of patients with stone density ≤ 400 HU failed to appear at fluoroscopy and therefore 400 HU attenuation value can be used as a cut-off level to request doing KUB before ESWL and Ureteroscopy. Conclusion: the ureteric stones with density ≤400 HU the likelihood of being non-visualized at fluoroscopy is 91.2% therefore if the stone has ≤400 HU at CT KUB it is mandatory to do KUB before treatment above that it is most likely to be seen at fluoroscopy and no need to request KUB for them before ESWL or URS. 1) Inclusion Criteria: All patients diagnosed by CT scan to have ureteric stones for ESWL or Ureteroscopy. 2) Exclusion Criteria: Patients for whom treatment of ureteric stone by ESWL or ureteroscopy is not indicated like severe infection or poor kidney function where nephrectomy is needed.
文摘本文描述了飞利浦16排Brilliance CT Big Bore的常见维修故障3例,探寻故障排除方法及解决途径。文章首先分析了CT的组成部件及工作原理,然后根据故障现象逐步分析、探究故障原因,最终找到了CT故障原因,并给予修复。CT在临床使用中常见的故障有一定的普遍性,探讨最优的维修策略可以节约维修工时以及降低设备的维护成本,从而更好地保障临床工作。
基金国家自然科学基金(the National Natural Science Foundation of China under Grant No.600672098)
文摘三维锥束CT图像重建运算量大,纯软件(仅使用CPU)计算时间较长。为了充分利用计算机图形处理器(Graphic Process Unit,GPU)的并行处理能力以及提高数据传输效率,研究了一种结合使用GPU多重纹理(multitexture)加速三维锥束CT的FDK图像重建过程的方法。该方法采用多重纹理映射来提高反投影速度、减少中间数据存储量、减少浮点累加次数,使用顶点颜色通道来实现距离加权运算,采用扩展方法来增加并行反投影的纹理单元,从而提高重建速度。计算机实验结果表明,使用普通PC机重建尺寸为2563的图像,在保证数据精度为16bit浮点数的要求下,GPU反投影计算可以在10s以内完成。与仅使用CPU的重建方法相比,GPU重建图像加速方法达到了较高的时间加速比。
