DR数字探测器原理、性能及常规维护方法

本文简要叙述了常用DR数字探测器的原理、性能以及常规维护的方法,旨在提高数字化X线摄影技术的水平。     

骨肉瘤侵袭范围的MRI测量与确定合理切除平面的相关研究

目的 探讨MRI判断肢体骨肉瘤局部侵袭范围的准确性及据此确定保肢术中的安全切除平面。方法 冷冻后的骨肉瘤截肢标本19例，按照MRI确定的相应层面，在断层切片机上切取厚度为0＋5cm的水平断层切片，肉眼测量肿瘤的软组织侵袭范围，并以0．5cm的间隔做连续病理切片，确定显微镜下肿瘤软组织侵袭范围。然后按照MRI确定的相应层面，纵向剖开标本，测量肿瘤的髓内肉眼范围，并以0．5cm的间隔做连续病理切片，确定显微镜下肿瘤的髓内侵袭范围。分别将肿瘤X线、MRI的侵袭范围与肉眼范围和病理侵袭范围进行统计学比较。结果 （1）X线、MRI、肉眼和病理测量的骨肉瘤髓内侵袭范围分别为（11.18±8.64）cm、（15.37±9．73）cm、（14.77±9.38）cm、（14．58±9.51）cm，经统计学分析MRI所确定的髓内侵袭范围与病理侵袭范围之间无显著性差异（P〉0．05）。（2）MRI、肉眼和病理测量的骨肉瘤软组织侵袭范围分别为：横径（6．62±2．23）cm、（6.22±2．21）cm、（6．23±2.38）cm；纵径（7.15±2.37）cm，（6．57±1.80）cm、（6.58±1.94）cm，经统计学分析MRI所确定的软组织侵袭范围与病理侵袭范围之间无显著性差异（P〉0.05）。MRI对骨肉瘤髓内和软组织的测量值均不超过病理范围10mm。结论 在确定骨肉瘤手术切除安全界面上，MRI较X线片有更高的准确性。以MRI为依据，在瘤体外2～3cm处截骨，软组织外1．0～1.5cm作为切除界面是安全可靠的。     

Chest imaging with flat-panel detector at low and standard doses: comparison with storage phosphor technology in normal patients

The purpose of this study was to evaluate the performance of standard-dose and low-dose cesium iodide (CsI)-doted amorphous silicon (a-Si) flat-panel detector technology (FDT) as compared with storage-phosphor technology (SPT) in the depiction of relevant anatomical structures in chest radiography. In 75 patients referred for thoracic CT, digital chest radiographs were randomly obtained with either SPT at a standard dose (speed class S400, n=25), standard-dose FDT (S400, n=25) or FDT at a low dose (S800, n=25). Five radiologists evaluated the visibility of eight pulmonary and mediastinal anatomical structures using a five-point rating scale. To determine statistically significant differences between the three groups, the Mann-Whitney U-test was employed. No statistically significant differences were found in the depiction of eight criteria between SPT and standard-dose or low-dose FDT chest radiographs. The performance of FDT S400 was equal to SPT for most criteria and better for retrocardiac structures and soft tissue. FDT S800 was inferior to both SPT and FDT S400. Standard-dose FDT is equivalent to SPT in the depiction of relevant anatomical structures of the chest. Our results also indicate that a dose reduction of 50% with FDT may result in small but not significant decrease of image quality.     

在线衍生-二极管阵列检测器测定复方氨基酸胶囊中7种氨基酸的含量

目的:建立以在线衍生-二极管阵列检测器联用测定复方氨基酸胶囊中7种氨基酸含量的方法。方法:采用高效液相色谱仪带全自动衍生功能的自动进样器,按预先设置的程序进样,并利用二极管阵列-荧光检测器串联分析。结果:7种氨基酸分离较好,且检测浓度分别在一定范围内与各峰面积积分值呈良好线性关系。结论:本方法操作简便、重现性好、灵敏度高、定量准确,可推广应用。     

高效液相色谱荧光光谱法测定虎杖中的白藜芦醇及白藜芦醇苷含量

目的建立高效液相色谱(HPLC)法,分离和测定虎杖中的白藜芦醇的含量.方法采用NUCLEODUR 100-5 C18柱(250 mm×4.6 mm,5μm);流动相异丙醇和水二元梯度洗脱系统;流速0.6 mL·min-1;荧光检测器激发波长334 nm;发射波长404 nm.结果在选定色谱条件下其白藜芦醇苷和白藜芦醇的线性范围良好,样品加样回收率在96.5%～101.4%,相对标准偏差在0.75%～1.42%.结论本方法精密度好,结果可靠,适合虎杖中白藜芦苷和白藜芦醇的定量分析.     

数字X线机（DR）的质量控制与保证

文章在对DR系统拟定测试项目并对DR拍片机进行定期测试和整理分析结果的基础上,总结出一套使DR系统高效、可靠、稳定运行,获取高质量数字图像的质量控制与保证计划。     

Biograph 64 TruePoint PET／CT的主要技术参数及应用

对PET／CT设备的基本结构、主要参数及其在肿瘤系统、心血管系统和神经系统中的临床应用价值进行了简要介绍。64层PET／CT在冠心病诊断和治疗指导中具有特别的意义．它可将^18F-FDG的PET心肌代谢与64层CT冠脉成像同机同时进行，确定心肌活性及供血冠状动脉分布，对治疗方案的选择起决定性作用。     

Use of gamma-spectrometry for simultaneous determination of 210Pb, 73As, 109Cd, 203Hg and 59Fe distribution and excretion in rats at low doses

γ-Spectrometry permits the identification and quantification of different γ-isotopes in the same aliquot. To estimate the sensitivity and discriminative power of a comparably small and inexpensive 8% germanium detector, we determined the detection limits for simultaneously applied ²¹⁰Pb, ⁷³As, ¹⁰⁹Cd, ²⁰³Hg and ⁵⁹Fe. The concentration of Fe and of each of the four potential environmental contaminants was determined in aliquots from all organs and tissues 10 days after simultaneous i.v. administration (2 μmol/kg body weight) to adult and growing iron-deficient and iron-adequate rats. Relating these values to the total size of each organ permitted to derive a whole body distribution pattern for all five isotopes in each individual animal. Cumulative renal and faecal excretion values were determined during the 10 day distribution period to calculate the half-lives for both excretory pathways for all five isotopes simultaneously. Distribution and excretion values corresponded well to literature data. Extrapolation of the results showed that the detector would be sensitive enough to discriminate and quantify the five metals at human dietary exposure levels. The results recommend to use γ-spectrometry to investigate kinetic aspects of interactions between toxic and essential trace metals, because the method reduces the number of required animals drastically.     

Theoretical basis for long-term measurements of equilibrium factors using LR 115 detectors

In this paper, we propose a method to determine the equilibrium factor using a bare LR 115 detector. The partial sensitivities ρ_i of the LR 115 detector to ²²²Rn and its alpha-emitting short-lived progeny, ²¹⁸Po and ²¹⁴Po, were investigated. We first determined the distributions of lengths of major and minor axes of the perforated alpha tracks in the LR 115 detector produced by ²²²Rn, ²¹⁸Po and ²¹⁴Po through Monte Carlo simulations. The track parameters were calculated using a track development model with a published V function, by assuming a removed active layer of 6.54 μm. The distributions determined for different alpha emitters were found to completely overlap with one another. This implied equality of partial sensitivities for radon and its progeny, which was also confirmed through analytical considerations. Equality of partial sensitivities makes possible convenient measurements of the proxy equilibrium factor F_p, which is defined in the present work as (F₁+F₃) and is equal to the ratio between the sum of concentrations of the two alpha emitting radon progeny (²¹⁸Po+²¹⁴Po) to the concentration of radon gas (²²²Rn). In particular, we have found F_p=(ρ/ρ_itC₀)−1, where ρ (track/m²) is the total track density on the detector, ρ_i=0.288×10⁻² m, t is the exposure time and C₀ (Bq/m³) is the concentration of ²²²Rn. If C₀ is known (e.g. from a separate measurement), we can obtain F_p. The proxy equilibrium factor F_p is also found to be well correlated with the equilibrium factor between radon gas and its progeny through the Jacobi room model. This leads to a novel method for long-term determination of the equilibrium factor.     

Spätergebnisse nach transduodenaler Sphincterotomie und Sphincterplastik aufgrund der Erfahrungen von 18 Jahren (unter besonderer Berücksichtigung der Analyse unbefriedigender Resultate)

Zusammenfassung Die Verfasser haben in 18 Jahren 289 transduodenale Sphincterotomien und 87 Sphincterplastiken durchgeführt (295 Patienten bei der ersten und 81 Patienten bei weiteren Gallenoperationen). Im unmittelbaren postoperativen Stadium verstarben 20 Patienten (5,3%), die Sektionsergebnisse zeigen jedoch, daß die Sphincteroperation lediglich für den Tod von 10 Patienten (2,6%) verantwortlich gemacht werden kann. Von den anderen 356 Patienten konnten wir nur 270 (75,8%) 1–11 Jahre postoperativ untersuchen. Das Spätergebnis ist in 89,6% ausgezeichnet bzw. gut. Zur Klärung der unbefriedigenden Ergebnisse wurden klinische, labormedizinische, radiologische und endoskopische Untersuchungen durchgeführt. Die unbefriedigenden Ergebnisse können in 6,6% auf bilio-pankreatische, in 0,7% auf extrabiliäre organische und in 1,5% auf nicht-organische Ursachen zurückgeführt werden. Die Bedeutung der endoskopischen Untersuchung zur Klärung der Gründe der unbefriedigenden Operationsergebnisse nach Sphincteroperationen wird hervorgehoben.

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Late results of transduodenal sphincterotomy and sphincteroplasty based on 18 years of experience (with special respect to the analysis of unsatisfactory results)

Summary In the course of 18 years the authors performed transduodenal sphincterotomy on 289 and sphincteroplasty on 87 patients. The operations were connected, in 295 cases with prismary in 81 cases with repeated biliary surgery. Twenty of the patients (5.3%) died during the immediate postoperative period. However, on the grounds of autopsy data the death of only 10 patients (2.6%) can be attributed to the surgery of the sphincter. Out of the 356 surviving patients 270 were available for a follow-up study and were examined 1–11 years after the operation. Late results of the operation were found excellent or good in 89.6% of the patients. To clear up the unsatisfactory results clinical, laboratory, radiological, and endoscopic examinations were carried out. The unsatisfactory results can be explained by biliopancreatic (6.6%), organic extrabiliary (0.7%) and non-organic (1.5%) reasons. The authors emphasize the significance of endoscopic examinations following the surgery of the sphincter in the elucidation of the causes of unsatisfactory results.