X-ray computed laminography(CL)is used in the fields of industrial inspection and medical imaging.It can provide the internal structure three-dimensional(3D)information of a region of the objects nondestructively.It i...X-ray computed laminography(CL)is used in the fields of industrial inspection and medical imaging.It can provide the internal structure three-dimensional(3D)information of a region of the objects nondestructively.It is important to the clinical diagnosis and the quality control of flat objects like printed circuit boards,aircraft wings and satellite solar panels.With the restriction that the imaging region must be within the X-ray beam formed by the X-ray source and the detector,the imaging field of view of CL is limited by the size of detector.A new CL method with an asymmetric rotational cone-beam scanning geometry,called large field of view CL,is presented to overcome the existing disadvantage.It can extend the imaging region when the imaging spatial resolution keeps the same as that of the conventional CL.It can also improve the imaging spatial resolution when the imaging region keeps the same as that of the conventional CL.The asymmetric configuration can be achieved by offsetting the detector from the conventional symmetric configuration.It does not,however,require new detectors and X-ray source nor alter the scanning mechanical system.The filtered back-projection(FBP)reconstruction algorithm and the data truncation smoothing functions have been deduced to reconstruct the images directly from the data acquired with this asymmetric configuration.We performed numerical studies and experiments to demonstrate and validate the proposed approach. Results in these studies and experiments confirm that the proposed method can enlarge the imaging region and improve the spatial resolution.The proposed approach may find applications in the CL system with the rotational scanning geometry.展开更多
Computed laminography （CL） is an alternative to computed tomography if large objects are to be inspected with high resolution. This is especially true for planar objects. In this paper, we set up a new scanning geom...Computed laminography （CL） is an alternative to computed tomography if large objects are to be inspected with high resolution. This is especially true for planar objects. In this paper, we set up a new scanning geometry for CL, and study the algebraic reconstruction technique （ART） for CL imaging. We compare the results of ART with variant weighted functions by computer simulation with a digital phantom. It proves that ART algorithm is a good choice for the CL system.展开更多
目的观察健步通络熏蒸液治疗膝关节骨性关节炎(knee osteoarthritis,KOA)的疗效,探讨髌下脂肪垫CT扫描在治疗前后的变化及其与疗效的相关性。方法将105例KOA门诊患者随机分为3组,治疗组35例给予健步通络熏蒸液熏洗,30 min/次,每日1次,1...目的观察健步通络熏蒸液治疗膝关节骨性关节炎(knee osteoarthritis,KOA)的疗效,探讨髌下脂肪垫CT扫描在治疗前后的变化及其与疗效的相关性。方法将105例KOA门诊患者随机分为3组,治疗组35例给予健步通络熏蒸液熏洗,30 min/次,每日1次,10次为1个疗程,共连续治疗3个疗程。对照组35例给予玻璃酸钠关节内注射,每次3 mL,1次/6日,共5次。联合组35例给予健步通络熏蒸液熏洗配合玻璃酸钠关节内注射,治疗方法同前两组。3组皆治疗30天。观察临床疗效及治疗前后髌下脂肪垫CT扫描变化,分析其相关性。结果治疗后联合组总有效率(88.57%,31/35)优于对照组(74.29%,26/35)和治疗组(80.00%,28/35),差异有统计学意义(P<0.05);且联合组美国特种外科医院(hospital for special surgery,HSS)膝关节功能评分优于对照组与治疗组(P<0.05)。治疗组与联合组治疗前后髌下脂肪垫的前后径、内外径、上下径均有缩小,密度均有降低(P<0.05);且联合组和治疗组优于对照组(P<0.05)。结论 CT扫描髌下脂肪垫治疗前后的变化主要存在于有中医药治疗的组内,说明CT扫描变化只与能改变髌下脂肪垫理化性质的疗效有关;而中医药治疗是全面、均衡地调节各组织功能与结构,因此,CT可作为中医药治疗各疾病临床疗效观察的较好检查手段。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.50875013)Beijing Municipal Natural Science Foundation(Grant No.4102036)+1 种基金the Aviation Science Foundation of China(Grant No.20070951013)Beijing NOVA Program(Grant No.2009A09)
文摘X-ray computed laminography(CL)is used in the fields of industrial inspection and medical imaging.It can provide the internal structure three-dimensional(3D)information of a region of the objects nondestructively.It is important to the clinical diagnosis and the quality control of flat objects like printed circuit boards,aircraft wings and satellite solar panels.With the restriction that the imaging region must be within the X-ray beam formed by the X-ray source and the detector,the imaging field of view of CL is limited by the size of detector.A new CL method with an asymmetric rotational cone-beam scanning geometry,called large field of view CL,is presented to overcome the existing disadvantage.It can extend the imaging region when the imaging spatial resolution keeps the same as that of the conventional CL.It can also improve the imaging spatial resolution when the imaging region keeps the same as that of the conventional CL.The asymmetric configuration can be achieved by offsetting the detector from the conventional symmetric configuration.It does not,however,require new detectors and X-ray source nor alter the scanning mechanical system.The filtered back-projection(FBP)reconstruction algorithm and the data truncation smoothing functions have been deduced to reconstruct the images directly from the data acquired with this asymmetric configuration.We performed numerical studies and experiments to demonstrate and validate the proposed approach. Results in these studies and experiments confirm that the proposed method can enlarge the imaging region and improve the spatial resolution.The proposed approach may find applications in the CL system with the rotational scanning geometry.
文摘Computed laminography （CL） is an alternative to computed tomography if large objects are to be inspected with high resolution. This is especially true for planar objects. In this paper, we set up a new scanning geometry for CL, and study the algebraic reconstruction technique （ART） for CL imaging. We compare the results of ART with variant weighted functions by computer simulation with a digital phantom. It proves that ART algorithm is a good choice for the CL system.
文摘目的观察健步通络熏蒸液治疗膝关节骨性关节炎(knee osteoarthritis,KOA)的疗效,探讨髌下脂肪垫CT扫描在治疗前后的变化及其与疗效的相关性。方法将105例KOA门诊患者随机分为3组,治疗组35例给予健步通络熏蒸液熏洗,30 min/次,每日1次,10次为1个疗程,共连续治疗3个疗程。对照组35例给予玻璃酸钠关节内注射,每次3 mL,1次/6日,共5次。联合组35例给予健步通络熏蒸液熏洗配合玻璃酸钠关节内注射,治疗方法同前两组。3组皆治疗30天。观察临床疗效及治疗前后髌下脂肪垫CT扫描变化,分析其相关性。结果治疗后联合组总有效率(88.57%,31/35)优于对照组(74.29%,26/35)和治疗组(80.00%,28/35),差异有统计学意义(P<0.05);且联合组美国特种外科医院(hospital for special surgery,HSS)膝关节功能评分优于对照组与治疗组(P<0.05)。治疗组与联合组治疗前后髌下脂肪垫的前后径、内外径、上下径均有缩小,密度均有降低(P<0.05);且联合组和治疗组优于对照组(P<0.05)。结论 CT扫描髌下脂肪垫治疗前后的变化主要存在于有中医药治疗的组内,说明CT扫描变化只与能改变髌下脂肪垫理化性质的疗效有关;而中医药治疗是全面、均衡地调节各组织功能与结构,因此,CT可作为中医药治疗各疾病临床疗效观察的较好检查手段。
