Management of rectal cancer has evolved over the years. In this condition preoperative investigations assist in deciding the optimal treatment. The relation of the tumor edge to the circumferential margin (CRM) is an ...Management of rectal cancer has evolved over the years. In this condition preoperative investigations assist in deciding the optimal treatment. The relation of the tumor edge to the circumferential margin (CRM) is an important factor in deciding the need for neoadjuvant treatment and determines the prognosis. Those with threatened or involved margins are offered long course chemoradiation to enable R0 surgical resection. Endoanal ultrasound (EUS) is useful for tumor (T) staging; hence EUS is a useful imaging modality for early rectal cancer. Magnetic resonance imaging (MRI) is useful for assessing the mesorectum and the mesorectal fascia which has useful prognostic significance and for early identification of local recurrence. Computerized tomography (CT) of the chest, abdomen and pelvis is used to rule out distant metastasis. Identification of the malignant nodes using EUS, CT and MRI is based on the size, morphology and internal characteristics but has drawbacks. Most of the common imaging techniques are suboptimal for imaging following chemoradiation as they struggle to differentiate fibrotic changes and tumor. In this situation, EUS and MRI may provide complementary information to decide further treatment. Functional imaging using positron emission tomography (PET) is useful, particularly PET/CT fusion scans to identify areas of the functionally hot spots. In the current state, imaging has enabled the multidisciplinary team of surgeons, oncologists, radiologists and pathologists to decide on the patient centered management of rectal cancer. In future, functional imaging may play an active role in identifying patients with lymph node metastasis and those with residual and recurrent disease following neoadjuvant chemoradiotherapy.展开更多
Based on the existing component models in the Pspice software package, a combined model for Insulat- ed the Bipolar Transistor (IGBT) is established, in which a non - linear is introduced to represent the parasitic ...Based on the existing component models in the Pspice software package, a combined model for Insulat- ed the Bipolar Transistor (IGBT) is established, in which a non - linear is introduced to represent the parasitic capacitance. Using this model, computerized simulation is conducted for the FB - ZVZCS - PWM soft - ewitching converter,the switching and energy-transferring characteristics of the components are analyzed.The simulation results are testified by experiments.It is proved that by abopting appropriate models,computerized simulation becomes an effective tool for investigation of arc welding inverter power source.展开更多
Background Although transient ischemic attacks （TIA） is a clinical diagnosis, imaging findings are important for its diagnosis and treatment. This study evaluated the value and limitations of conventional CT, CT cer...Background Although transient ischemic attacks （TIA） is a clinical diagnosis, imaging findings are important for its diagnosis and treatment. This study evaluated the value and limitations of conventional CT, CT cerebral perfusion imaging and transcranial Doppler sonography （TCD） in patients with TIA. Methods Conventional CT, CT cerebral perfusion imaging and TCD were performed in 20 patients with TIA. After regular CT examination, d-0-second dynamic scans were performed on selected slice, while 40 ml of nonionic contrast materials was bolus-injected through antecubital vein with power injector. These dynamic images were processed with the perfusion software package on workstation. Cerebral blood flow （CBF） and time to peak （3~FP） were measured in specific regions of the brain. TCD was also performed in 20 patients with TIA. Comparative analysis was made on the basis of the results of conventional CT, CT cerebral perfusion imaging and TCD.Results In the 20 patients with TIA, conventional CT turned out to be normal. However, persisting abnormal perfusion changes corresponding to clinical symptoms were found in 13 cases with the prolonged TFP. The other 7 cases were normal. TFP of the affected side （ 11.6 ± 3.0） s was significantly prolonged （ t =4. 782 ,P 〈0. 01 ） in comparison with the contralateral side （8.8 ± 1.5 ） s. The difference in CBF was not statistically significant （t = 1. 912, P =0. 073） between the affected side [ （223.9 ±19.6） ml ·min^-1 ·L^-1 ] and the contralateral side [ （227.7 ± 19. 8） ml · min^-1· L^-1 ] . TCD revealed severe stenosis or occlusion of the carotid artery in 10 patients, arteriosclerosis in 6 patients, blood speed decrease in 2 patients, vasospasm in 1 patient. Conclusions Conventional CT can exclude intracerebral diseases. Perfusion CT provides valuable hemodynamic information and shows the extent of perfusion disturbances. TCD can demonstrate abnormalities of the involved arteries in patients with TIA. The combination of these thr展开更多
In current research, a series of triaxial tests, which were employed to simulate three typical mining lay-outs (i.e., top-coal caving, non-pillar mining and protected coal seam mining), were conducted on coal by using...In current research, a series of triaxial tests, which were employed to simulate three typical mining lay-outs (i.e., top-coal caving, non-pillar mining and protected coal seam mining), were conducted on coal by using MTS815 Flex Test GT rock mechanics test system, and the fracture networks in the broken coal samples were qualitatively and quantitatively investigated by employing CT scanning and 3D reconstruc-tion techniques. This work aimed at providing a detail description on the micro-structure and fracture-connectivity characteristics of rupture coal samples under different mining layouts. The results show that: (i) for protected coal seam mining layout, the coal specimens failure is in a compression-shear manner and oppositely, (ii) the tension-shear failure phenomenon is observed for top-coal caving and non-pillar mining layouts. By investigating the connectivity features of the generated fractures in the direction of r1 under different mining layouts, it is found that the connectivity level of the fractures of the samples corresponding to non-pillar mining layout was the highest.展开更多
Objective： To explore the application of the spiral computerized tomography （CT） image three-dimensional （ 3D ） reconstruction technique associated with the conventional radiography in the diagnosis and treatment...Objective： To explore the application of the spiral computerized tomography （CT） image three-dimensional （ 3D ） reconstruction technique associated with the conventional radiography in the diagnosis and treatment of severe talar neck fracture. Methods： Using the multi-slice spiral CT image 3D reconstruction technique, we analysed Ⅱ cases of talar neck fracture. The fractures were reduced and fixed through a minimal incision and internal fixation with titanium cannulated lag screws. Results. In the Ⅱ cases, the results of CT image 3D reconstruction were in concordance with plain radiograph in 6 case of Hawkins type Ⅱ. And the remaining 5 cases of Hawkins types Ⅲ and Ⅳ could not be classified exactly only by radiographs, one of whom was misdiagnosed. After using the CT image 3D reconstruction, the 5 cases were classified exactly before osteosynthesis. The classifications of these Ⅱ cases were confirmed finally by surgical findings. The duration of operation were 45-Ⅰ40 min, averaging 8Ⅰ min （including the duration of C-arm fluoroscopy）. X-ray exposure time was 6-58 seconds, averaging 22 seconds. The blood loss was less than Ⅰ00 ml. The fracture union was achieved in 3 months. No nonunion, talus avascular necrosis or joint surface collapse occurred. Postoperative follow-up was from Ⅰ to 25 months. According to Hawkins score, excellent result was found in 6 type Ⅱ cases and Ⅰ type Ⅲ case; good result in I type Ⅲ case with both medial and lateral malleolar fracture, Ⅰ type Ⅲ with medial malleolus fractures and Ⅰ open type Ⅲ; fair result in Ⅰ open type Ⅳ with lateral malleolus fracture. Conclusions ： By using the multl-slice spiral CT image 3D reconstruction associated with radiography to diagnose and treat severe talar neck fractures, the accuracy of diagnosis can be improved obviously. Based on this technique, more consummate operational plan can be designed and performed so as to achieve a better therapeutic effect.展开更多
Lung cancer is among the most frequently diagnosed cancers worldwide and the leading cause of cancer death in both males and females. Screening for lung cancer coupled with earlier intervention has long been studied a...Lung cancer is among the most frequently diagnosed cancers worldwide and the leading cause of cancer death in both males and females. Screening for lung cancer coupled with earlier intervention has long been studied as an approach to mortality reduction. However, minimal progress was achieved until recently, when low- dose spiral computed tomography （LDCT） screening demonstrated a 20% reduction in mortality from lung cancer in a randomized controlled trial （RCT）, the National Lung Screening Trial, from the United States. On the basis of this finding, LDCT has been recommended for lung cancer screening in high-risk populations by several clinical guidelines. However, results from the following independent RCTs in Europe failed to show consistent conclusions. In addition, intractable problems gradually emerged with the progress of LDCT screening. This paper summarizes and discusses the main observations and challenges of LDCT screening for lung cancer. Before spreading implementation of LDCT screening, challenges, including high false-positive rates, overdiagnosis, enormous costs, and radiation risk, must be addressed. Complementary biomarkers and technical improvement are expected in the field of lung cancer screening in the near future.展开更多
Objective To evaluate the value of the clinical use of CT perfusion imaging (CTPI) and CT subtraction angiography (CTSA) for diagnosing acute ischemic cerebrovascular disease (AICVD). Methods Twenty-four patients with...Objective To evaluate the value of the clinical use of CT perfusion imaging (CTPI) and CT subtraction angiography (CTSA) for diagnosing acute ischemic cerebrovascular disease (AICVD). Methods Twenty-four patients with AICVD onset within 24 hours were examined with regular CT, CTPI, and CTSA. Some cases received CTPI, magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), digital subtraction angiography (DSA) or single photon emission computer tomography (SPECT) during follow-up examinations.Results Of the 24 cases, 11 had negative results from regular CT scans 3-6 hours after onset of stroke in 6 cases, 6-12 hours in 3 cases, and 12-24 hours in 2 cases. Ten of these cases were then confirmed by CTPI as having ischemic lesions, 2 with middle cerebral artery occlusion (MCAO), and 1 case with transient ischemic attack (TIA) with CTPI negative. Of the 24 cases, 13 had positive results from regular CT, 9 were diagnosed with ischemic lesions larger by using CTPI than regular CT, 1 case had MCAO and 1 had internal carotid artery occlusion (ICAO). There were 4 cases with ischemic lesions observed with regular CT having nearly the same range as that of lacunar infarctions using CTPI. Another 4 cases had more than 2 lesion areas. The peak time (PT), mean transit time (MTT) and relative flow (RF) of 24 cases were markedly different. The sides of ischemic lesions compared to each other and the core of the lesion compared to peripheral zones were also altered significantly (P<0.01).Conclusions Combined CTPI with CTSA can detect acute ischemic lesions at early and hyper-early stages and could distinguish between TIA, lacunar infarction and a larger area of infarction. Using semiquantitative blood perfusion analysis status, CTPI with CTSA could define position, area and range of the ischemic lesion and penumbra. These scans can also analyze the brain blood perfusion status. It is important to early diagnose the occlusion of the entire division of the internal carotid artery or middle cerebral artery and it is m展开更多
目的探讨全面触发工具（GTT）在我国住院患者药物不良事件（ADE）评估中的应用。方法根据Institute for Heahhcare Improvement Global Trigger Tool for Measuring Adverse Events及我国具体用药情况，选出14项触发器。自广西医科大学...目的探讨全面触发工具（GTT）在我国住院患者药物不良事件（ADE）评估中的应用。方法根据Institute for Heahhcare Improvement Global Trigger Tool for Measuring Adverse Events及我国具体用药情况，选出14项触发器。自广西医科大学第一附属医院医院信息系统随机抽取2013年1—12月出院病历300份进行审查，筛选触发器阳性病历进行ADE判定、分级以及累及器官和系统分析，计算触发器检出率，并与同年度医院ADE自愿上报率进行比较。结果300份病历涉及300例患者，其中触发器阳性者59例，占19．67％；共检出触发器阳性72例次（检出1项触发器者48例、2项触发器者9例、3项触发器者2例）。对触发器阳性者进行ADE判定，确定ADE共64例次，涉及患者49例，ADE检出率为16．33％（49／300）。64例次ADE中53例次（82．81％）为E级，6例次（9．38％）为F级，5例次（7．81％）为H级。损害器官以胃肠系统最多，共21例次，临床表现为呕吐（20例次）和腹泻（1例次）。同年度医院ADE自愿上报率为0．43％（286／66395），与经触发器检出的ADE发生率16．33％比较，差异有统计学意义（χ2=1479．589，P〈0．001）。结论GTT可较自愿上报系统发现更多的ADE。展开更多
文摘Management of rectal cancer has evolved over the years. In this condition preoperative investigations assist in deciding the optimal treatment. The relation of the tumor edge to the circumferential margin (CRM) is an important factor in deciding the need for neoadjuvant treatment and determines the prognosis. Those with threatened or involved margins are offered long course chemoradiation to enable R0 surgical resection. Endoanal ultrasound (EUS) is useful for tumor (T) staging; hence EUS is a useful imaging modality for early rectal cancer. Magnetic resonance imaging (MRI) is useful for assessing the mesorectum and the mesorectal fascia which has useful prognostic significance and for early identification of local recurrence. Computerized tomography (CT) of the chest, abdomen and pelvis is used to rule out distant metastasis. Identification of the malignant nodes using EUS, CT and MRI is based on the size, morphology and internal characteristics but has drawbacks. Most of the common imaging techniques are suboptimal for imaging following chemoradiation as they struggle to differentiate fibrotic changes and tumor. In this situation, EUS and MRI may provide complementary information to decide further treatment. Functional imaging using positron emission tomography (PET) is useful, particularly PET/CT fusion scans to identify areas of the functionally hot spots. In the current state, imaging has enabled the multidisciplinary team of surgeons, oncologists, radiologists and pathologists to decide on the patient centered management of rectal cancer. In future, functional imaging may play an active role in identifying patients with lymph node metastasis and those with residual and recurrent disease following neoadjuvant chemoradiotherapy.
文摘Based on the existing component models in the Pspice software package, a combined model for Insulat- ed the Bipolar Transistor (IGBT) is established, in which a non - linear is introduced to represent the parasitic capacitance. Using this model, computerized simulation is conducted for the FB - ZVZCS - PWM soft - ewitching converter,the switching and energy-transferring characteristics of the components are analyzed.The simulation results are testified by experiments.It is proved that by abopting appropriate models,computerized simulation becomes an effective tool for investigation of arc welding inverter power source.
文摘Background Although transient ischemic attacks （TIA） is a clinical diagnosis, imaging findings are important for its diagnosis and treatment. This study evaluated the value and limitations of conventional CT, CT cerebral perfusion imaging and transcranial Doppler sonography （TCD） in patients with TIA. Methods Conventional CT, CT cerebral perfusion imaging and TCD were performed in 20 patients with TIA. After regular CT examination, d-0-second dynamic scans were performed on selected slice, while 40 ml of nonionic contrast materials was bolus-injected through antecubital vein with power injector. These dynamic images were processed with the perfusion software package on workstation. Cerebral blood flow （CBF） and time to peak （3~FP） were measured in specific regions of the brain. TCD was also performed in 20 patients with TIA. Comparative analysis was made on the basis of the results of conventional CT, CT cerebral perfusion imaging and TCD.Results In the 20 patients with TIA, conventional CT turned out to be normal. However, persisting abnormal perfusion changes corresponding to clinical symptoms were found in 13 cases with the prolonged TFP. The other 7 cases were normal. TFP of the affected side （ 11.6 ± 3.0） s was significantly prolonged （ t =4. 782 ,P 〈0. 01 ） in comparison with the contralateral side （8.8 ± 1.5 ） s. The difference in CBF was not statistically significant （t = 1. 912, P =0. 073） between the affected side [ （223.9 ±19.6） ml ·min^-1 ·L^-1 ] and the contralateral side [ （227.7 ± 19. 8） ml · min^-1· L^-1 ] . TCD revealed severe stenosis or occlusion of the carotid artery in 10 patients, arteriosclerosis in 6 patients, blood speed decrease in 2 patients, vasospasm in 1 patient. Conclusions Conventional CT can exclude intracerebral diseases. Perfusion CT provides valuable hemodynamic information and shows the extent of perfusion disturbances. TCD can demonstrate abnormalities of the involved arteries in patients with TIA. The combination of these thr
基金financially supported by the Major State Fundamental Research Project of China(Nos.2011CB201201and2010CB226802)the National Natural Science Foundation of China(No.51204113)the Youth Science and Technology Fund of Sichuan Province(No.2012JQ0031)
文摘In current research, a series of triaxial tests, which were employed to simulate three typical mining lay-outs (i.e., top-coal caving, non-pillar mining and protected coal seam mining), were conducted on coal by using MTS815 Flex Test GT rock mechanics test system, and the fracture networks in the broken coal samples were qualitatively and quantitatively investigated by employing CT scanning and 3D reconstruc-tion techniques. This work aimed at providing a detail description on the micro-structure and fracture-connectivity characteristics of rupture coal samples under different mining layouts. The results show that: (i) for protected coal seam mining layout, the coal specimens failure is in a compression-shear manner and oppositely, (ii) the tension-shear failure phenomenon is observed for top-coal caving and non-pillar mining layouts. By investigating the connectivity features of the generated fractures in the direction of r1 under different mining layouts, it is found that the connectivity level of the fractures of the samples corresponding to non-pillar mining layout was the highest.
文摘Objective： To explore the application of the spiral computerized tomography （CT） image three-dimensional （ 3D ） reconstruction technique associated with the conventional radiography in the diagnosis and treatment of severe talar neck fracture. Methods： Using the multi-slice spiral CT image 3D reconstruction technique, we analysed Ⅱ cases of talar neck fracture. The fractures were reduced and fixed through a minimal incision and internal fixation with titanium cannulated lag screws. Results. In the Ⅱ cases, the results of CT image 3D reconstruction were in concordance with plain radiograph in 6 case of Hawkins type Ⅱ. And the remaining 5 cases of Hawkins types Ⅲ and Ⅳ could not be classified exactly only by radiographs, one of whom was misdiagnosed. After using the CT image 3D reconstruction, the 5 cases were classified exactly before osteosynthesis. The classifications of these Ⅱ cases were confirmed finally by surgical findings. The duration of operation were 45-Ⅰ40 min, averaging 8Ⅰ min （including the duration of C-arm fluoroscopy）. X-ray exposure time was 6-58 seconds, averaging 22 seconds. The blood loss was less than Ⅰ00 ml. The fracture union was achieved in 3 months. No nonunion, talus avascular necrosis or joint surface collapse occurred. Postoperative follow-up was from Ⅰ to 25 months. According to Hawkins score, excellent result was found in 6 type Ⅱ cases and Ⅰ type Ⅲ case; good result in I type Ⅲ case with both medial and lateral malleolar fracture, Ⅰ type Ⅲ with medial malleolus fractures and Ⅰ open type Ⅲ; fair result in Ⅰ open type Ⅳ with lateral malleolus fracture. Conclusions ： By using the multl-slice spiral CT image 3D reconstruction associated with radiography to diagnose and treat severe talar neck fractures, the accuracy of diagnosis can be improved obviously. Based on this technique, more consummate operational plan can be designed and performed so as to achieve a better therapeutic effect.
文摘Lung cancer is among the most frequently diagnosed cancers worldwide and the leading cause of cancer death in both males and females. Screening for lung cancer coupled with earlier intervention has long been studied as an approach to mortality reduction. However, minimal progress was achieved until recently, when low- dose spiral computed tomography （LDCT） screening demonstrated a 20% reduction in mortality from lung cancer in a randomized controlled trial （RCT）, the National Lung Screening Trial, from the United States. On the basis of this finding, LDCT has been recommended for lung cancer screening in high-risk populations by several clinical guidelines. However, results from the following independent RCTs in Europe failed to show consistent conclusions. In addition, intractable problems gradually emerged with the progress of LDCT screening. This paper summarizes and discusses the main observations and challenges of LDCT screening for lung cancer. Before spreading implementation of LDCT screening, challenges, including high false-positive rates, overdiagnosis, enormous costs, and radiation risk, must be addressed. Complementary biomarkers and technical improvement are expected in the field of lung cancer screening in the near future.
文摘Objective To evaluate the value of the clinical use of CT perfusion imaging (CTPI) and CT subtraction angiography (CTSA) for diagnosing acute ischemic cerebrovascular disease (AICVD). Methods Twenty-four patients with AICVD onset within 24 hours were examined with regular CT, CTPI, and CTSA. Some cases received CTPI, magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), digital subtraction angiography (DSA) or single photon emission computer tomography (SPECT) during follow-up examinations.Results Of the 24 cases, 11 had negative results from regular CT scans 3-6 hours after onset of stroke in 6 cases, 6-12 hours in 3 cases, and 12-24 hours in 2 cases. Ten of these cases were then confirmed by CTPI as having ischemic lesions, 2 with middle cerebral artery occlusion (MCAO), and 1 case with transient ischemic attack (TIA) with CTPI negative. Of the 24 cases, 13 had positive results from regular CT, 9 were diagnosed with ischemic lesions larger by using CTPI than regular CT, 1 case had MCAO and 1 had internal carotid artery occlusion (ICAO). There were 4 cases with ischemic lesions observed with regular CT having nearly the same range as that of lacunar infarctions using CTPI. Another 4 cases had more than 2 lesion areas. The peak time (PT), mean transit time (MTT) and relative flow (RF) of 24 cases were markedly different. The sides of ischemic lesions compared to each other and the core of the lesion compared to peripheral zones were also altered significantly (P<0.01).Conclusions Combined CTPI with CTSA can detect acute ischemic lesions at early and hyper-early stages and could distinguish between TIA, lacunar infarction and a larger area of infarction. Using semiquantitative blood perfusion analysis status, CTPI with CTSA could define position, area and range of the ischemic lesion and penumbra. These scans can also analyze the brain blood perfusion status. It is important to early diagnose the occlusion of the entire division of the internal carotid artery or middle cerebral artery and it is m
文摘目的探讨全面触发工具（GTT）在我国住院患者药物不良事件（ADE）评估中的应用。方法根据Institute for Heahhcare Improvement Global Trigger Tool for Measuring Adverse Events及我国具体用药情况，选出14项触发器。自广西医科大学第一附属医院医院信息系统随机抽取2013年1—12月出院病历300份进行审查，筛选触发器阳性病历进行ADE判定、分级以及累及器官和系统分析，计算触发器检出率，并与同年度医院ADE自愿上报率进行比较。结果300份病历涉及300例患者，其中触发器阳性者59例，占19．67％；共检出触发器阳性72例次（检出1项触发器者48例、2项触发器者9例、3项触发器者2例）。对触发器阳性者进行ADE判定，确定ADE共64例次，涉及患者49例，ADE检出率为16．33％（49／300）。64例次ADE中53例次（82．81％）为E级，6例次（9．38％）为F级，5例次（7．81％）为H级。损害器官以胃肠系统最多，共21例次，临床表现为呕吐（20例次）和腹泻（1例次）。同年度医院ADE自愿上报率为0．43％（286／66395），与经触发器检出的ADE发生率16．33％比较，差异有统计学意义（χ2=1479．589，P〈0．001）。结论GTT可较自愿上报系统发现更多的ADE。
