枢椎椎板螺钉固定的解剖学与影像学测量比较

Objective To provide the anatomic and radiographic data, verify the clinical application of trans-lamina screws and evaluate the efficacy of our radiographic methods. Methods The anatomic and radiographic measurements of C2 vertebra were conducted on cadavers and living subjects. A total of 96 human adult cadavers and 112 volunteers without upper cervical abnormality were studied in this project. The minimal height (H1), thickness (T), length (L1) of C2 lamina, height of the root of lamina (H2), distance from the entry point to the lateral rim of lamina (L2) and to the lateral rim of lateral mass (L3) were bilaterally measured using calipers. The spino-laminar angles (angle A) were also included. All measurements were taken at the thinnest part of the lamina in the axial and coronal planes. Results The data of males were significantly higher than that of females (EM>P /EM><0.05) except angle A. There was no significant difference in the values of bilateral lamina between group A and group B (EM>P/EM> >0.05).The thickness of the vertebral lamina was less than 6mm in 45% of the specimens. The length of the lamina in all specimens was less than 2.5cm, while only 5% of the specimens had a >3cm distance from the entry point to the rim of lamina. The length from the entry point to the lateral rim of lateral mass ranged from 2.5cm to 4.6cm,with the length longer than 4cm was seen in 4% specimens. BR>Conclusion The preoperative radiographic evaluation is very important to determine the suitable size of screws. The radiographic measurement method we used is simple, accurate and reliable for preoperative measu     

Transpedicular screwing of the seventh cervical vertebra: anatomical considerations and surgical technique

The purpose of this study was first to assess the feasibility of C7 transpedicular screwing with a morphological study and secondly to evaluate the safety of such a surgical technique when guided only by posterior landmarks. Eighteen C7 vertebrae, harvested from fresh human cadavers, were included in this study. First the morphometry of C7 pedicle was performed on computed tomography with multiplanar reconstructions. Results of this quantitative anatomy were compared with the literature data. Secondly 30 pedicle screws, whose placement was guided only by anatomical features on the posterior face of the dorsal arch, were inserted in 15 C7 vertebrae. A second computed tomographic examination was done after the surgical procedure to check the screw placement in both planes. The average pedicular width was 6±1.2 mm and the average height was 5.8±1.1 mm. The pedicle angulation in the transverse plane was 33.3°±6.6°, the pedicle angulation in the sagittal plane was 4.3°±4.5° downward with reference to the lower endplate of C7. The average distance from the entry point of transpedicular screwing to the anterior cortex of the vertebral body was 29±3 mm. Concerning the safety of transpedicular screwing, 63% of screws were found entirely inside the pedicle without any violation of the pedicle cortex. Most of pedicle violations were observed in the transverse plane. No grade II violation of the pedicle was observed. Dimensions of the C7 pedicle are amply compatible with transpedicular fixation using 3.5 mm screws. Such a surgical technique seems to be an interesting option when posterior fixation of C7 is required. Nevertheless morphological guidelines appeared not to be sufficient to ensure safe transpedicular screwing. Laminoforaminotomy is strongly recommended, although it has not been evaluated in this study.

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Electronic Supplementary Material The french version of this article is available in the form of electronic supplementary material and can be obtained by using the Springer Link server located at .

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Vissage pédiculaire de la septième vertèbre cervicale: Bases anatomiques et technique chirurgicale

Résumé Le but de ce travail a été d'évaluer la faisabilité du vissage pédiculaire au niveau de la septième vertèbre cervicale (C7). Nous avons tout d'abord étudié la morphologie des pédicules de C7 en tomodensitométrie hélicoïdale sur 18 vertèbres et comparé nos résultats avec les données de la littérature. Trente vissages pédiculaires de C7 ont ensuite été réalisés sur 15 rachis. La mise en place des vis n'a été guidée que par les repères anatomiques au niveau de l'arc dorsal de C7. Une tomodensitométrie de contrôle a permis de vérifier l'emplacement et l'orientation des vis. La largeur des pédicules était en moyenne de 6±1,2 mm et leur hauteur était de 5,8±1,1 mm. L'angulation transversale du pédicule était de 33,3°±6,6° par rapport au plan sagittal médian. L'angulation sagittale était de +4,3°±4,5° par rapport au plateau inférieur de C7. La longueur de la visée pédiculaire était en moyenne de 29±3 mm. 63% des vis ont été entièrement placées dans le pédicule. La majorité des effractions corticales a été observée dans le plan transversal. Aucune effraction corticale de grade II n'a été observée. Cette étude morphologique des pédicules de la septième vertèbre cervicale confirme que les dimensions des pédicules sont compatibles avec le vissage pédiculaire. Cependant, il est apparu que les seules données morphologiques ne sont pas à elles seules suffisantes pour assurer un vissage pédiculaire en toute sécurité. La réalisation d'une lamino-foraminoplastie est vivement conseillée, bien que non évaluée par notre étude.

     

骶骨第1椎弓根倾斜角与耳状面形态的相关性研究

目的　研究骶骨第1椎弓根倾斜角与骶骨耳状面解剖形态的相关性,为骶髂关节骨折脱位经皮骶髂螺钉固定提供解剖学依据。 方法　42块干燥成人骶骨,在大体标本和X线影像上分别测量耳状面和第1椎弓根的相关参数,并分析他们之间的相关性。 结果　耳状面上、下半长轴长比值R1为0.86±0.15,根据其大小可将耳状面分为L型（R1>1）和f型（R1<1）。第1椎弓根倾斜角θ为(25.72±6.69)°,R1与θ呈负相关。 结论　当第1椎弓根倾斜角较小时,其耳状面多为L型,建议手术螺钉的进钉点偏下、小角度向内上;当第1椎弓根倾斜角较大时,其耳状面多为f型,建议手术螺钉的进针点偏上、大角度向内上。     

Morphometric analysis of the thoracolumbar and lumbar pedicles,anatomo-radiologic study

The geometric properties of 380 vertebral pedicles, ranging from T6 to L5, were analysed. Measurement were made directly from the specimens as well as from roentgenograms. The parameters considered were the horizontal and vertical pedicle diameters, pedicle angles in the transverse and sagittal planes, and the transverse and anteroposterior widths of the spinal canal and vertebral body. In addition, the length of the pedicle and the length of the pedicle including the vertebral body to the anterior cortex were measured along the pedicle axis and in a line parallel to the midline of the vertebral body. The smallest horizontal and vertical pedicle diameters were found at vertebral levels from T6 to T10. The correlation between pedicle widths and screw dimensions is obvious. In the transverse plane, the pedicle angle diverged from the vertebral body at all levels, except at T12. In the sagittal plane, the pedicles were angled cephalad from T6 to L3 and slightly caudally at L5. Knowledge of the length of the pedicle to the anterior vertebral body cortex is very important for safe screw purchase. At all levels, with the exception of T12, this length was found to be significantly greater along the pedicle axis than along a line parallel to the midline of the vertebral body.     

Light-dependent plasticity of the morphology of horizontal cell terminals in cone pedicles of fish retinas

Summary Horizontal cell terminals lateral to the synaptic ribbons in goldfish cone pedicles give rise to 0.3 m long, finger-like extensions in the light-adapted state. These structures, called spinules, disappear almost completely after dark adaptation. The ultrastructure of the horizontal cell terminals is characterized by the presence of occasional microtubules, microfilaments and sparse irregular vesicles; in the dark, large multivesicular bodies can also be found. Two types of membrane densities are described in the horizontal cell terminals, one of which is typically located at the tip of the spinules. Their positive reaction to E-PTA makes it probable that the spinules are synaptic structures. Reconstruction of serial sections shows about 12 spinules per terminal in the light but only two in the dark. Formation and disappearance of the spinules takes about 60 min and involves a transitional stage in the form of a spherical structure. Spinules can be found in five other teleost species, with a darkness-induced reduction in number, but not in the horizontal cell terminals of the mudpuppy, turtle and mammals.The morphological changes reported in this paper were first observed in the laboratory of Professor J. P. Raynauld at the Université de Montréal and presented in a preliminary form in Science (Raynauldet al., 1979) and at the 1979 ARVO Meeting.     

Patient dose considerations for routine megavoltage cone-beam CT imaging

Megavoltage cone-beam CT (MVCBCT), the recent addition to the family of in-room CT imaging systems for image-guided radiation therapy (IGRT), uses a conventional treatment unit equipped with a flat panel detector to obtain a three-dimensional representation of the patient in treatment position. MVCBCT has been used for more than two years in our clinic for anatomy verification and to improve patient alignment prior to dose delivery. The objective of this research is to evaluate the image acquisition dose delivered to patients for MVCBCT and to develop a simple method to reduce the additional dose resulting from routine MVCBCT imaging. Conventional CT scans of phantoms and patients were imported into a commercial treatment planning system (TPS: Phillips, Pinnacle) and an arc treatment mimicking the MVCBCT acquisition process was generated to compute the delivered acquisition dose. To validate the dose obtained from the TPS, a simple water-equivalent cylindrical phantom with spaces for MOSFETs and an ion chamber was used to measure the MVCBCT image acquisition dose. Absolute dose distributions were obtained by simulating MVCBCTs of 9 and 5 monitor units (MU) on pelvis and head and neck patients, respectively. A compensation factor was introduced to generate composite plans of treatment and MVCBCT imaging dose. The article provides a simple equation to compute the compensation factor. The developed imaging compensation method was tested on routinely used clinical plans for prostate and head and neck patients. The quantitative comparison between the calculated dose by the TPS and measurement points on the cylindrical phantom were all within 3%. The dose percentage difference for the ion chamber placed in the center of the phantom was only 0.2%. For a typical MVCBCT, the dose delivered to patients forms a small anterior-posterior gradient ranging from 0.6 to 1.2 cGy per MVCBCT MU. MVCBCT acquisitions in the pelvis and head and neck areas deliver slightly more dose than current portal imaging but render soft tissue information for positioning. Overall, the additional dose from daily 9 MU MVCBCTs of prostate patients is small compared to the treatment dose (<4%). Dose-volume histograms of compensated plans for pelvis and head and neck patients imaged daily with MVCBCT showed no additional dose to the target and small increases at low doses. The results indicate that the dose delivered for MVCBCT imaging can be precisely calculated in the TPS and therefore included in the treatment plan. This allows simple plan compensations, such as slightly reducing the treatment dose, to minimize the total dose received by critical structures from daily positioning with MVCBCT. The proposed compensation factor reduces the number of MU per treatment beam per fraction. Both the number of fractions and the beam arrangement are kept unchanged. Reducing the imaging volume in the cranio-caudal direction can further reduce the dose delivered for MVCBCT. This is a useful feature to eliminate the imaging dose to the eyes or to focus on a specific region of interest for alignment.     

Technical considerations for implementation of x-ray CT polymer gel dosimetry

Gel dosimetry is the most promising 3D dosimetry technique in current radiation therapy practice. X-ray CT has been shown to be a feasible method of reading out polymer gel dosimeters and, with the high accessibility of CT scanners to cancer hospitals, presents an exciting possibility for clinical implementation of gel dosimetry. In this study we report on technical considerations for implementation of x-ray CT polymer gel dosimetry. Specifically phantom design, CT imaging methods, imaging time requirements and gel dose response are investigated. Where possible, recommendations are made for optimizing parameters to enhance system performance. The dose resolution achievable with an optimized system is calculated given voxel size and imaging time constraints. Results are compared with MRI and optical CT polymer gel dosimetry results available in the literature.     

Three-dimensional hip morphology analysis using CT transverse sections to automate diagnoses and surgery managements

This paper describes an image analysis method that evaluates bone morphology of hip structures including the femur stem, trochanter, neck and head, acetabulum, and pelvis to automate hip diagnoses and surgical managements. On every CT transverse section, radial B-spline curves are used to approximate the ellipse-like acetabulum and femur head and stem. The femur neck is approximated as trapezoid-like and the pelvis horizontally symmetrical structure. The centers of the ellipse-like structures from transverse sections are used to determine 3D axes of the femur stem, head, and acetabulum. The centerlines of the neck or the pelvis on the sections are used to determine the neck axis or pelvis centerplane. Boundary changes of these structures are recognized as concave, convex and hole features that are then identified as fractures, tumors, and spurs. Based on the geometric evaluations of these structures and features, hip surgeries including tumor dissect and bone graft, open reduction using plates, screws and nails, and arthroplasty are automatically managed to achieve the normal hip function including dissection of tumors and reduction of dislocations and angular deviations between the hip structures. This prototype system can be used as a qualitative and quantitative tool for the diagnosis of various hip diseases and for the planning of accurate surgical procedures. A series of examples and four case studies illustrate this automated method can be used to accurately diagnose hip diseases and manage hip surgeries, and train operators.     

Analytical models for multi-slice helical CT performance parameters

One of the most recent technological advancements in computed tomography (CT) is the introduction of multi-slice CT (MSCT). When combined with the helical scan mode, MSCT offers significant improvements in volume coverage, isotropic spatial resolution, and contrast utilization. Although experimental studies have been conducted on MSCT performance, there is a lack of theoretical analysis on the slice sensitivity profile (SSP) and noise performance. In this paper, we derive several closed-form expressions, for linear interpolation based helical reconstruction algorithms, to characterize these performance parameters under different detector configurations and acquisition modes. Following the common practice, the expressions are explicitly described for regions near the iso-center, although the same approach can be used to describe system performances away from the iso-center. These models are validated against phantom experiments.     

基于数学形态学的CT图像肝脏肿瘤提取研究

目的 肝脏肿瘤的提取是肝脏三维可视化、手术规划和模拟的基础,而当前肿瘤分割存在干预过多和分割效果不佳的问题.方法 本文通过对腹部CT图像进行高斯平滑以去除图像噪声和细密纹理,计算出图像的形态学梯度并用高、低帽变换进行增强,再根据用户选择点计算内部和外部标记符,然后基于控制标记符的分水岭算法分割图像,提取出腹部CT图像中的病变组织.结果 实验结果表明,该算法能够在较少的人工干预下快速分割出肝脏病变组织.结论 该算法实现了腹部CT图像中肝脏病变组织的提取.     

Some experimental design and analysis considerations for cytogenetics studies

Cytogenetic analysis has been used for several years in attempts to detect the mutagenic effects of suspect agents. Yet there remain many questions related to statistical analysis. While several procedures have been and are being used, many unfortunately are not always appropriate for the types of data actually obtained. Two general analysis approaches are discussed together with ways to insure that the test assumptions are reasonably met. Because assay sensitivity is a major concern, the sample size issue is discussed with examples for specific situations.     

Segmentation of liver tumors for CT images based on mathematical morphology

目的 肝脏肿瘤的提取是肝脏三维可视化、手术规划和模拟的基础,而当前肿瘤分割存在干预过多和分割效果不佳的问题.方法 本文通过对腹部CT图像进行高斯平滑以去除图像噪声和细密纹理,计算出图像的形态学梯度并用高、低帽变换进行增强,再根据用户选择点计算内部和外部标记符,然后基于控制标记符的分水岭算法分割图像,提取出腹部CT图像中的病变组织.结果 实验结果表明,该算法能够在较少的人工干预下快速分割出肝脏病变组织.结论 该算法实现了腹部CT图像中肝脏病变组织的提取.     

Accessory parameters in the histopthology of hepatitis C. Comparative analysis

Fifty three consecutive cases of chronic hepatitis C ("b" series) were considered and strictly (numerically and qualitatively) compared with the series ("a") reported by Scheuer et al. Two groups (gr.) respectively inclusive of chronic persistent hepatitis, chronic lobular hepatitis and mild/moderate chronic active hepatitis (gr. I) and severe chronic active hepatitis, developing cirrhosis and established cirrhosis (gr. II) were identified, studied and scored according to the following accessory histological parameters: "lymphoid aggregates and follicles" (LA&F), "bile duct damage" (BDD), "acidophil bodies" (AB), "lymphocytic infiltration of sinusoids" (LIS) and "fatty changes" (FC). In order to interpret the results the "b" series was further examined in relation to lobular "spotty necrosis" (SN) and subtle morphology of FC (type of vacuolarity and topography). Moreover dysplasia (in "a" and "b") and other minor accessory parameters (in "b" only) were briefly considered. In conclusion the comparison of "b" versus "a" confirms a characteristic histomorphological pattern in chronic hepatitis C. As far as the major accessory parameters are concerned the reproducibility was acceptable for BDD and FC, but inadequate for LA&F, LIS and AB. In particular the following points seem to be the most critical challenges: reassessment of the morphological criteria for LA&F, LIS and AB; improvement of the analysis of FC; elucidation of the relation between LIS, AB, SN and LA&F; ascertainment of sensibility and specificity of the accessory parameters in relation to "grading", "staging", differential diagnosis, post-therapy evaluation and non histological findings.     

Development of DNA array filter useful for the analysis of Th1/Th2 balance]

DNA arrays are useful for determining the expression levels of a number of genes at once. We utilized this technique to evaluate the Th1/Th2 balance in vivo. Immune responses are controlled by two types of helper T cells, Th1 and Th2. Once the balance of Th1/Th2 immunity is disrupted, various immune diseases can develop. Thus, it is important to evaluate the Th1/Th2 balance in each patient for diagnosis, treatment and/or prophylaxis of immune diseases. We have identified a number of genes specifically expressed in Th1 or Th2 cells, and developed a DNA array filter spotted with these genes. We confirmed that this filter is useful for the evaluation of changes in the immune balance in vivo. Clinical application of this technology may lead to the tailor-made therapy of immune diseases through the evaluation of the immune balance in each patient.     

双侧股骨近端对称性及解剖形态的三维重建研究

目的建立正常成人双侧股骨近端的三维模型,分析双侧股骨近端形态并测量解剖形态的相关参数,研究双侧股骨近端的对称性及解剖形态。方法选取50例正常成人双侧股骨近端CT扫描数据,其中男性27例,女性23例;年龄20～65岁,平均年龄44.52岁。扫描参数:扫描层厚0.625 mm,扫描电压120 kV,扫描电流100 mA。扫描范围:自双侧股骨头上10 mm至小转子中点平面下50 mm。将双侧股骨近端CT薄层扫描数据利用Mimics 10.01软件进行三维重建,将左侧股骨与右侧股骨镜像模型相配准,对配准后模型进行三维测量,并测量左右股骨近端的形态参数,使用SPSS 16.0软件对测量结果进行统计分析。结果股骨近端形态和髓腔内部结构有明显的个体差异性,双侧股骨近端形态及内部结构具有高度对称性。股骨头直径为(45.71±4.08)mm,股骨头高度为(53.61±5.43)mm,偏心距为(39.91±5.07)mm,股骨颈中央直径为(36.71±3.75)mm,颈干角为(127.88±6.28)°,股骨颈长度(46.61±4.74)mm,小粗隆中点所在平面的髓腔内径为(26.21±4.59)mm,其中偏心距、颈干角与白种人形态参数相比,差异有显著统计学意义(P<0.01);提供了一种验证双侧股骨对称性的新方法。结论正常成人双侧股骨内外部形态存在一定的对称性,变异较小,为股骨形态的测量提供理论依据;三维重建更利于对股骨近端形态参数的测量;新配准方法的提出对于临床中股骨近端骨折的诊治具有重大意义。     

肺硬化性血管瘤的CT影像学特点

目的分析肺硬化性血管瘤的CT表现,提高此疾病的影像学诊断能力。方法分析9例经病理证实的PSH的CT表现。结果CT平扫均表现为边界清楚的圆形或椭圆形肿块性病灶,9例病灶中均未见囊变、钙化。1例病灶周边可见"空气新月征"。增强后8例病灶均匀强化,1例不均匀强化;增强后CT值介于78～120Hu之间。结论中年女性CT征象表现为单发、圆形或椭圆形、边界清楚伴有重度均匀强化或空气新月征的肺内肿块时,应考虑到PSH的诊断。     

三维CT精确重建颅颌面部组织的形态学特征

背景：头影测量技术是正畸术前临床诊断与矫治计划设计的重要手段,精确的头影测量可为矫治设计提供可靠的依据。三维CT重建技术可重建出清晰、立体、真实的颅颌面解剖形态。 目的：综述CT三维重建后的头影测量在口腔正畸中的临床应用,并与传统的X射线头影测量对比。 方法：由第一作者于2010-09进行检索,检索PubMed数据库(http://www.ncbi.nlm.nih.gov/pubmed/)及CNKI数据库(http://dlib3.cnki.net/KNS50/)1996-01/2010-09有关正畸头影测量的文献,英文以“three-dimensional cephalometry,cephalometric measurements”为检索词,中文以“三维测量,头影测量”为检索词,排除重复研究或内容较陈旧的文献。 结果与结论：计算机初步检索文献共114篇,根据纳入、排除标准,最后选择中英文文献共27篇进一步分析。三维CT重建头影测量技术作为一种理想的头影测量方法,以其高效、准确、快捷的优点,已广泛应用于临床。软硬组织的三维立体重建与测量分析系统以其强大的优势,终将取代现有的二维头影测量分析系统。