AIM： To prospectively assess the changes in parameters of computed tomography （CT） perfusion pre- and post-transarterial chemoembolization （TACE） of hepatocellular carcinoma （HCC） in different treatment respons...AIM： To prospectively assess the changes in parameters of computed tomography （CT） perfusion pre- and post-transarterial chemoembolization （TACE） of hepatocellular carcinoma （HCC） in different treatment response groups, and to correlate the changes with various responses of HCC to TACE. METHODS： Thirty-nine HCC patients underwent CT perfusion examinations pre-（1 d before TACE） and post-treatment （4 wk after TACE）. The response evaluation criteria for solid tumors （RECIST） were referred to when treatment responses were distributed. Wilcoxon-signed ranks test was used to compare the differences in CT perfusion parameters pre- and post- TACE for different response groups. RESULTS： Only one case had treatment response to CR and the CT perfusion maps of post-treatment lesion displayed complete absence of signals. In the PR treatment response group, hepatic artery perfusion （HAP）, hepatic arterial fracture （HAF） and hepatic blood volume （HBV） of viable tumors post-TACE were reduced compared with pre-TACE （P = 0.001, 0.030 and 0.001, respectively）. In the SD group, all CT perfusion parameters were not significantly different pre- and post-TACE. In the PD group, HAP, HAl=, portal vein perfusion （PVP） and hepatic blood flow （HBF） of viable tumors post-TACE were significantly increased compared with pre-TACE （P = 0.005, 0.012, 0.035 and 0.005, respectively）. CONCLUSION： Changes in CT perfusion parameters of viable tumors are correlated with different responses of HCC to TACE. Therefore, CT perfusion imaging is a feasible technique for monitoring response of HCC to TACE.展开更多
Moving object detection is one of the challenging problems in video monitoring systems, especially when the illumination changes and shadow exists. Amethod for real-time moving object detection is described. Anew back...Moving object detection is one of the challenging problems in video monitoring systems, especially when the illumination changes and shadow exists. Amethod for real-time moving object detection is described. Anew background model is proposed to handle the illumination varition problem. With optical flow technology and background subtraction, a moving object is extracted quickly and accurately. An effective shadow elimination algorithm based on color features is used to refine the moving obj ects. Experimental results demonstrate that the proposed method can update the background exactly and quickly along with the varition of illumination, and the shadow can be eliminated effectively. The proposed algorithm is a real-time one which the foundation for further object recognition and understanding of video mum＇toting systems.展开更多
Obejctive To assess the value of noninvasive three dimensional computed tomographic angiography (3D CTA) in preoperative detection of intracranial arteriovenous malformations (AVMs) Methods A prospective eval...Obejctive To assess the value of noninvasive three dimensional computed tomographic angiography (3D CTA) in preoperative detection of intracranial arteriovenous malformations (AVMs) Methods A prospective evaluation at a single institute over a 2 year period included 23 patients suspected of intracranial AVMs All patients underwent 3D CTA and digital subtraction angiography (DSA) Results from both procedures were compared Results 3D CTA imaging provided excellent visualization of intracranial AVMs The false positive error and false negative error were zero in our sample The details of arterial supply (numerical measure, orientation, caliber and routing) and vascular nidus (size, morphosis and location) provided by 3D CTA images were the same as DSA and the details of venous drainage were an approximate match Additionally, 3D CTA can depict tridimensional anatomical information for AVMs and their relationship to adjacent structures, a function not possible with DSA This assisted the surgeons in making better surgical planning and reduced trauma As a non invasive course, there were no related complications in the course of 3D CTA processing Conclusions DSA is still regarded as the gold standard for intracranial AVMs detection The modality of 3D CTA is accurate, noninvasive, nearly risk free and low price; we could routinely use it instead of or as a supplement to DSA, in the preoperative detection of suspected intracranial AVMs and postoperative radiological follow up 3D CTA adds tridimensional aspect and assists the surgeon in a the more accurate therapeutic scheme Preliminary data suggest that 3D CTA is playing a favorable role in the assessment of patients with intracranial AVMs展开更多
A new interval arithmetic method is proposed to solve interval functions with correlated intervals through which the overestimation problem existing in interval analysis could be significantly alleviated. The correlat...A new interval arithmetic method is proposed to solve interval functions with correlated intervals through which the overestimation problem existing in interval analysis could be significantly alleviated. The correlation between interval parameters is defined by the multidimensional parallelepiped model which is convenient to describe the correlative and independent interval variables in a unified framework. The original interval variables with correlation are transformed into the standard space without correlation,and then the relationship between the original variables and the standard interval variables is obtained. The expressions of four basic interval arithmetic operations, namely addition, subtraction, multiplication, and division, are given in the standard space. Finally, several numerical examples and a two-step bar are used to demonstrate the effectiveness of the proposed method.展开更多
AIM: To assess the value of gemstone spectral imaging (GSI) in efficacy evaluation in hepatocellular cancer (HCC) after transcatheter arterial chemoembolization (TACE) treatment.METHODS: Thirty patients with HCC under...AIM: To assess the value of gemstone spectral imaging (GSI) in efficacy evaluation in hepatocellular cancer (HCC) after transcatheter arterial chemoembolization (TACE) treatment.METHODS: Thirty patients with HCC underwent GSI, including nonenhanced, arterial, portalvenous and delayed phase scans, after TACE treatment. Arterial phase images were acquired with GSI for reconstruction of virtual nonenhanced images and color overlay images. Digital subtraction angiography (DSA) was performed in all these patients. Two blinded and independent readers evaluated the data in two reading sessions; standard nonenhanced, arterial, portalvenous, and delayed phase images were read in session A, and the optimal monochromatic images, iodine/water based images and spectrum features were read in session B. Sensitivity and specificity were calculated with the DSA data as the reference standard. The sensitivity and specificity were compared using the χ<sup>2</sup> test.RESULTS: DSA revealed 154 lesions in 30 patients, and 100 of them had blood supply. Overall sensitivity and specificity were 72% (72/100) and 77.8% (42/54) for session A, and 97% (97/100) and 94.4% (51/54) for session B, respectively. The sensitivity and specificity of the two reading sessions were significantly different (χ<sup>2</sup> = 23.04, χ<sup>2</sup> = 7.11, P < 0.05).CONCLUSION: Compared with conventional CT, GSI could significantly improve the detection of small and multiple lesions without increasing the radiation dose. Based on spectrum features, GSI could assess tumor homogeneity and more accurately identify residual tumors and recurrent or metastatic lesions during efficacy evaluation and follow-up in HCC after TACE treatment.展开更多
Target detection is the fundamental work for perceiving the behavior of cows using video analysis automatically.The videos captured in farming scenes often suffer from a complex background,which leads to difficulty in...Target detection is the fundamental work for perceiving the behavior of cows using video analysis automatically.The videos captured in farming scenes often suffer from a complex background,which leads to difficulty in detecting the target and inconvenience in the subsequent images analysis.In this study,a method was proposed to detect the moving target accurately for cows based on background subtraction.Firstly,the bounding rectangle of cows was calculated using the frames difference method to extract the local background in frames,which were averaged and spliced into one image as the entire background image.Secondly,the size and location of a cow’s body were determined by the bounding rectangle of cows,and the body area was tracked through the video by the binary images.Thirdly,the summation coefficients on RGB channels were adjusted to improve the contrast between the target and background images.Finally,taking the body area in every frame as reference area,the performance of target detection was evaluated by the reference area to determine the optimal summation coefficients on RGB channels,and then background subtraction was processed again to finish the detection.A total of 129 videos were used to test the detection algorithm,and the accuracy of the algorithm was 88.34%,which was 24.85%higher than the classical background subtraction method.The study shows that the algorithm proposed in this study is feasible to detect the target accurately and timely when cows are walking straight in the farming environment under natural light,and this method can improve the detection performance and is an extension to the classical background subtraction method.展开更多
AIM: The purpose of this study was to compare the diagnostic accuracy of biphasic multi-detector row helical computed tomography (MDCT), digital subtraction angiography (DSA)and Lipiodol computed tomography (CT) in de...AIM: The purpose of this study was to compare the diagnostic accuracy of biphasic multi-detector row helical computed tomography (MDCT), digital subtraction angiography (DSA)and Lipiodol computed tomography (CT) in detection of hypervascular hepatocellular carcinoma (HCC).METHODS: Twenty-eight patients with nodular HCC underwent biphasic MDCT examination: hepatic arterial phase (HAP) 25 s and portal venous phase (PVP) 70 s after injection of the contrast medium (1.5 mL/kg). They also underwent hepatic angiography and intra-arterial infusion of iodized oil. Lipiodol CT was performed 3-4 wk after infusion. MDCT images were compared with DSA and Lipiodol CT images for detection of hepatic nodules.RESULTS: The three imaging techniques had the same sensitivity in detecting nodules ＞20 mm in diameter. There was no significant difference in the sensitivity among HAP-MDCT, Lipiodol CT and DSA for nodules of 10-20 mm in diameter. For the nodules ＜10 mm in diameter, HAP-MDCT identified 47, Lipiodol CT detected 27 (X2= 11.3, P= 0.005＜0.01, HAP-MDCT vs Lipiodol CT) and DSA detected 16(X2= 9.09, P= 0.005＜0.01 vs Lipiodol CT and X2= 29.03,P = 0.005＜0.01 vs HAP-MDCT). However, six nodules ＜10 mm in diameter were detected only by Lipiodol CT.CONCLUSION: MDCT and Lipiodol CT are two complementary modalities. At present, MDCT does not obviate the need for DSA and subsequent Lipiodol CT as a preoperative examination for HCC.展开更多
Background Conventional computed tomography angiography （CTA） is time consuming, user-dependent and has poor image quality in skull base region. This study assessed the feasibility of a new method, dual energy CTA f...Background Conventional computed tomography angiography （CTA） is time consuming, user-dependent and has poor image quality in skull base region. This study assessed the feasibility of a new method, dual energy CTA for depicting the cerebral artery.Methods Phantom scan was done with head CTA sequences on dual source CT and 64 spiral CT for radiation dose calculation. Dual energy CTA was done with dual source CT on 36 patients who were suspected of having cerebral vascular disease. Three series axial images in 0.75 mm thick, 0.4 mm increment were acquired, which were named with 80 kV, 140 kV and merged images; 80 kV and 140 kV images were transferred into dual energy software, and maximum intensity projection （MIP） image was generated quickly by dual energy bone remove （DEBR group）; merged images were transferred into In Space software to acquire MIP image through manual conventional bone remove （CoBR group）. Post processing time and reading time were compared. Image qualities of the two groups were compared, mainly focusing on skull base segments of internal carotid artery and bone subtraction. ANOVA and SNK tests were applied for radiation dose comparison. Student＇s t test and Wilcoxon rank sum test were applied for assessing differences between data for significance. Cohen＇s kappa was used for interobserver agreement. Results Radiation dose of phantom scan showed dual energy CTA was between digital bone subtraction and conventional CTA. The post processing time and reading time were much shorter in DEBR than CoBR, and image quality in skull base was much higher in DEBR than CoBR （P〈0.01）. There was no significant difference for suprasellar vessels between two groups （P〉0.5）. Interobserver agreement for all vessel segments was excellent （kappa=0.97）. Conclusions Dual energy CTA is a reliable, new modality for depicting cerebral artery, overcoming the limitation of conventional CTA in the skull base region. It can save much time in post processing and reading than conventional C展开更多
INTRODUCTIONIntervention therapy has become one of the maintherapies of hepatic cancer.Theintroduction of hepatic arterial perfusion andembolization has provided opportunities for asecondary operation on patients with...INTRODUCTIONIntervention therapy has become one of the maintherapies of hepatic cancer.Theintroduction of hepatic arterial perfusion andembolization has provided opportunities for asecondary operation on patients with intermediateand advanced cancer,thus展开更多
Background： Sagittal translation （ST） is an accidental event that surgeons commonly encounter during a spinal osteotomy in the correction of kyphosis in ankylosing spondylitis （AS）. However, there is a paucity of...Background： Sagittal translation （ST） is an accidental event that surgeons commonly encounter during a spinal osteotomy in the correction of kyphosis in ankylosing spondylitis （AS）. However, there is a paucity of effective techniques to prevent ST. The purpose of this study was to propose a pedicle subtraction osteotomy （PSO） with a cage as a method to prevent ST and to explore the efficacy and feasibility of this method in the treatment of kyphosis in AS. Methods： We retrospectively reviewed 89 consecutive patients with AS kyphosis who underwent a PSO （Group B, 46 patients） or a PSO with a cage （Group A, 43 patients） from February 2009 to December 2013. Pre- and post-operative radiographic results were reviewed. ST and complications were analyzed in both groups. Clinical assessment was performed using the Scoliosis Research Society-22 （SRS-22） outcomes metric. The patients were followed up for at least 2 years. Results： Group A achieved the same re-alignment of the kyphotic spine as Group B. Two （4.7%） of the 43 patients in Group A and 14 （30.4%） of the 46 patients in Group B had intraoperative ST （2＂2 = 10.020, P = 0.002）. Significant differences were identified between the two groups in the height change of the osteotomized column. SRS-22 scores improved significantly in both groups. Seven patients experienced neurologic complications （1 in Group A and 6 in Group B）. Eight patients had cerebrospinal fluid leakage （2 in Group A and 6 in Group B）. Conclusion： PSO with a cage significantly avoided ST during the osteotomy procedure and might represent a new, safe, and feasible choice tbr treating patients with AS kyphosis.展开更多
基金The Science Technology Program of Beijing Education Committee: KM200810025002
文摘AIM： To prospectively assess the changes in parameters of computed tomography （CT） perfusion pre- and post-transarterial chemoembolization （TACE） of hepatocellular carcinoma （HCC） in different treatment response groups, and to correlate the changes with various responses of HCC to TACE. METHODS： Thirty-nine HCC patients underwent CT perfusion examinations pre-（1 d before TACE） and post-treatment （4 wk after TACE）. The response evaluation criteria for solid tumors （RECIST） were referred to when treatment responses were distributed. Wilcoxon-signed ranks test was used to compare the differences in CT perfusion parameters pre- and post- TACE for different response groups. RESULTS： Only one case had treatment response to CR and the CT perfusion maps of post-treatment lesion displayed complete absence of signals. In the PR treatment response group, hepatic artery perfusion （HAP）, hepatic arterial fracture （HAF） and hepatic blood volume （HBV） of viable tumors post-TACE were reduced compared with pre-TACE （P = 0.001, 0.030 and 0.001, respectively）. In the SD group, all CT perfusion parameters were not significantly different pre- and post-TACE. In the PD group, HAP, HAl=, portal vein perfusion （PVP） and hepatic blood flow （HBF） of viable tumors post-TACE were significantly increased compared with pre-TACE （P = 0.005, 0.012, 0.035 and 0.005, respectively）. CONCLUSION： Changes in CT perfusion parameters of viable tumors are correlated with different responses of HCC to TACE. Therefore, CT perfusion imaging is a feasible technique for monitoring response of HCC to TACE.
基金This project was supported by the foundation of the Visual and Auditory Information Processing Laboratory of BeijingUniversity of China (0306) and the National Science Foundation of China (60374031).
文摘Moving object detection is one of the challenging problems in video monitoring systems, especially when the illumination changes and shadow exists. Amethod for real-time moving object detection is described. Anew background model is proposed to handle the illumination varition problem. With optical flow technology and background subtraction, a moving object is extracted quickly and accurately. An effective shadow elimination algorithm based on color features is used to refine the moving obj ects. Experimental results demonstrate that the proposed method can update the background exactly and quickly along with the varition of illumination, and the shadow can be eliminated effectively. The proposed algorithm is a real-time one which the foundation for further object recognition and understanding of video mum＇toting systems.
文摘Obejctive To assess the value of noninvasive three dimensional computed tomographic angiography (3D CTA) in preoperative detection of intracranial arteriovenous malformations (AVMs) Methods A prospective evaluation at a single institute over a 2 year period included 23 patients suspected of intracranial AVMs All patients underwent 3D CTA and digital subtraction angiography (DSA) Results from both procedures were compared Results 3D CTA imaging provided excellent visualization of intracranial AVMs The false positive error and false negative error were zero in our sample The details of arterial supply (numerical measure, orientation, caliber and routing) and vascular nidus (size, morphosis and location) provided by 3D CTA images were the same as DSA and the details of venous drainage were an approximate match Additionally, 3D CTA can depict tridimensional anatomical information for AVMs and their relationship to adjacent structures, a function not possible with DSA This assisted the surgeons in making better surgical planning and reduced trauma As a non invasive course, there were no related complications in the course of 3D CTA processing Conclusions DSA is still regarded as the gold standard for intracranial AVMs detection The modality of 3D CTA is accurate, noninvasive, nearly risk free and low price; we could routinely use it instead of or as a supplement to DSA, in the preoperative detection of suspected intracranial AVMs and postoperative radiological follow up 3D CTA adds tridimensional aspect and assists the surgeon in a the more accurate therapeutic scheme Preliminary data suggest that 3D CTA is playing a favorable role in the assessment of patients with intracranial AVMs
基金supported by the National Natural Science Foundation for Excellent Young Scholars(Grant 51222502)the National Natural Science Foundation of China(Grant 11172096)the Funds for State Key Laboratory of Construction Machinery(SKLCM2014-1)
文摘A new interval arithmetic method is proposed to solve interval functions with correlated intervals through which the overestimation problem existing in interval analysis could be significantly alleviated. The correlation between interval parameters is defined by the multidimensional parallelepiped model which is convenient to describe the correlative and independent interval variables in a unified framework. The original interval variables with correlation are transformed into the standard space without correlation,and then the relationship between the original variables and the standard interval variables is obtained. The expressions of four basic interval arithmetic operations, namely addition, subtraction, multiplication, and division, are given in the standard space. Finally, several numerical examples and a two-step bar are used to demonstrate the effectiveness of the proposed method.
文摘AIM: To assess the value of gemstone spectral imaging (GSI) in efficacy evaluation in hepatocellular cancer (HCC) after transcatheter arterial chemoembolization (TACE) treatment.METHODS: Thirty patients with HCC underwent GSI, including nonenhanced, arterial, portalvenous and delayed phase scans, after TACE treatment. Arterial phase images were acquired with GSI for reconstruction of virtual nonenhanced images and color overlay images. Digital subtraction angiography (DSA) was performed in all these patients. Two blinded and independent readers evaluated the data in two reading sessions; standard nonenhanced, arterial, portalvenous, and delayed phase images were read in session A, and the optimal monochromatic images, iodine/water based images and spectrum features were read in session B. Sensitivity and specificity were calculated with the DSA data as the reference standard. The sensitivity and specificity were compared using the χ<sup>2</sup> test.RESULTS: DSA revealed 154 lesions in 30 patients, and 100 of them had blood supply. Overall sensitivity and specificity were 72% (72/100) and 77.8% (42/54) for session A, and 97% (97/100) and 94.4% (51/54) for session B, respectively. The sensitivity and specificity of the two reading sessions were significantly different (χ<sup>2</sup> = 23.04, χ<sup>2</sup> = 7.11, P < 0.05).CONCLUSION: Compared with conventional CT, GSI could significantly improve the detection of small and multiple lesions without increasing the radiation dose. Based on spectrum features, GSI could assess tumor homogeneity and more accurately identify residual tumors and recurrent or metastatic lesions during efficacy evaluation and follow-up in HCC after TACE treatment.
基金financially support ed by the general program from the National Natural Science Foundation of China under grant 61473235.
文摘Target detection is the fundamental work for perceiving the behavior of cows using video analysis automatically.The videos captured in farming scenes often suffer from a complex background,which leads to difficulty in detecting the target and inconvenience in the subsequent images analysis.In this study,a method was proposed to detect the moving target accurately for cows based on background subtraction.Firstly,the bounding rectangle of cows was calculated using the frames difference method to extract the local background in frames,which were averaged and spliced into one image as the entire background image.Secondly,the size and location of a cow’s body were determined by the bounding rectangle of cows,and the body area was tracked through the video by the binary images.Thirdly,the summation coefficients on RGB channels were adjusted to improve the contrast between the target and background images.Finally,taking the body area in every frame as reference area,the performance of target detection was evaluated by the reference area to determine the optimal summation coefficients on RGB channels,and then background subtraction was processed again to finish the detection.A total of 129 videos were used to test the detection algorithm,and the accuracy of the algorithm was 88.34%,which was 24.85%higher than the classical background subtraction method.The study shows that the algorithm proposed in this study is feasible to detect the target accurately and timely when cows are walking straight in the farming environment under natural light,and this method can improve the detection performance and is an extension to the classical background subtraction method.
基金Supported by the Medical Science Research Fund of Sichuan Province,No. 200054
文摘AIM: The purpose of this study was to compare the diagnostic accuracy of biphasic multi-detector row helical computed tomography (MDCT), digital subtraction angiography (DSA)and Lipiodol computed tomography (CT) in detection of hypervascular hepatocellular carcinoma (HCC).METHODS: Twenty-eight patients with nodular HCC underwent biphasic MDCT examination: hepatic arterial phase (HAP) 25 s and portal venous phase (PVP) 70 s after injection of the contrast medium (1.5 mL/kg). They also underwent hepatic angiography and intra-arterial infusion of iodized oil. Lipiodol CT was performed 3-4 wk after infusion. MDCT images were compared with DSA and Lipiodol CT images for detection of hepatic nodules.RESULTS: The three imaging techniques had the same sensitivity in detecting nodules ＞20 mm in diameter. There was no significant difference in the sensitivity among HAP-MDCT, Lipiodol CT and DSA for nodules of 10-20 mm in diameter. For the nodules ＜10 mm in diameter, HAP-MDCT identified 47, Lipiodol CT detected 27 (X2= 11.3, P= 0.005＜0.01, HAP-MDCT vs Lipiodol CT) and DSA detected 16(X2= 9.09, P= 0.005＜0.01 vs Lipiodol CT and X2= 29.03,P = 0.005＜0.01 vs HAP-MDCT). However, six nodules ＜10 mm in diameter were detected only by Lipiodol CT.CONCLUSION: MDCT and Lipiodol CT are two complementary modalities. At present, MDCT does not obviate the need for DSA and subsequent Lipiodol CT as a preoperative examination for HCC.
文摘Background Conventional computed tomography angiography （CTA） is time consuming, user-dependent and has poor image quality in skull base region. This study assessed the feasibility of a new method, dual energy CTA for depicting the cerebral artery.Methods Phantom scan was done with head CTA sequences on dual source CT and 64 spiral CT for radiation dose calculation. Dual energy CTA was done with dual source CT on 36 patients who were suspected of having cerebral vascular disease. Three series axial images in 0.75 mm thick, 0.4 mm increment were acquired, which were named with 80 kV, 140 kV and merged images; 80 kV and 140 kV images were transferred into dual energy software, and maximum intensity projection （MIP） image was generated quickly by dual energy bone remove （DEBR group）; merged images were transferred into In Space software to acquire MIP image through manual conventional bone remove （CoBR group）. Post processing time and reading time were compared. Image qualities of the two groups were compared, mainly focusing on skull base segments of internal carotid artery and bone subtraction. ANOVA and SNK tests were applied for radiation dose comparison. Student＇s t test and Wilcoxon rank sum test were applied for assessing differences between data for significance. Cohen＇s kappa was used for interobserver agreement. Results Radiation dose of phantom scan showed dual energy CTA was between digital bone subtraction and conventional CTA. The post processing time and reading time were much shorter in DEBR than CoBR, and image quality in skull base was much higher in DEBR than CoBR （P〈0.01）. There was no significant difference for suprasellar vessels between two groups （P〉0.5）. Interobserver agreement for all vessel segments was excellent （kappa=0.97）. Conclusions Dual energy CTA is a reliable, new modality for depicting cerebral artery, overcoming the limitation of conventional CTA in the skull base region. It can save much time in post processing and reading than conventional C
文摘INTRODUCTIONIntervention therapy has become one of the maintherapies of hepatic cancer.Theintroduction of hepatic arterial perfusion andembolization has provided opportunities for asecondary operation on patients with intermediateand advanced cancer,thus
文摘Background： Sagittal translation （ST） is an accidental event that surgeons commonly encounter during a spinal osteotomy in the correction of kyphosis in ankylosing spondylitis （AS）. However, there is a paucity of effective techniques to prevent ST. The purpose of this study was to propose a pedicle subtraction osteotomy （PSO） with a cage as a method to prevent ST and to explore the efficacy and feasibility of this method in the treatment of kyphosis in AS. Methods： We retrospectively reviewed 89 consecutive patients with AS kyphosis who underwent a PSO （Group B, 46 patients） or a PSO with a cage （Group A, 43 patients） from February 2009 to December 2013. Pre- and post-operative radiographic results were reviewed. ST and complications were analyzed in both groups. Clinical assessment was performed using the Scoliosis Research Society-22 （SRS-22） outcomes metric. The patients were followed up for at least 2 years. Results： Group A achieved the same re-alignment of the kyphotic spine as Group B. Two （4.7%） of the 43 patients in Group A and 14 （30.4%） of the 46 patients in Group B had intraoperative ST （2＂2 = 10.020, P = 0.002）. Significant differences were identified between the two groups in the height change of the osteotomized column. SRS-22 scores improved significantly in both groups. Seven patients experienced neurologic complications （1 in Group A and 6 in Group B）. Eight patients had cerebrospinal fluid leakage （2 in Group A and 6 in Group B）. Conclusion： PSO with a cage significantly avoided ST during the osteotomy procedure and might represent a new, safe, and feasible choice tbr treating patients with AS kyphosis.
