Image Resolution of the Lunar Expert-XL

The Lunar Expert-XL is an example of the latest generation of fan beam densitometers, with the X-ray source and detector array mounted on a C-arm to enable supine lateral imaging. Image resolution for anteroposterior (AP) spine, femur, hand, forearm and lateral morphometry on the Expert-XL were assessed in vitro with the 07-541 Nuclear Associates line pair test pattern. Each scan type was investigated at all available tube currents and scan speeds, and at the maximum, minimum and default bed heights. The effect of soft tissue thickness on resolution was investigated by using varying amounts of Perspex attenuator. The in vitro median lateral (x-axis) resolutions at the default bed height for the default scan types were 0.9 line pairs (lps)/mm for the 5 mA fast AP spine and femur scans, and l.0 lps/mm for 1 mA fast hand, forearm and 5 mA fast morphometry scans. This equates to a resolution of about 1 mm. The best resolution achieved was 1.2 lps/mm (0.83 mm), obtainable on all scan modes with the bed at maximum elevation, but only consistently with the forearm mode. Lower tube current did not affect resolution but did change the range of soft tissue thickness over which an image could be resolved. Turbo scan modes greatly reduced longitudinal (y-axis) resolution but had little effect on lateral resolution. This study demonstrates the importance of including an assessment of resolution when validating new equipment, especially if morphometric investigations are to be conducted. Received: 26 November 1998 / Accepted: 15 February 1999     

Quality-of-Life Outcome After Laparoscopic Adjustable Gastric Banding for Morbid Obesity

Background: The definition of success and failure of a bariatric procedure should include weight loss as well as improvement of comorbidity and quality-of-life (QoL) assessment. QoL measures changes in physical, functional, mental, and social health in order to evaluate benefits of new programs and interventions. Material and Methods: From April 1995 until March 1999, 287 patients underwent laparoscopic adjustable silicone gastric banding (LASGB) at Northwest Hospital Frankfurt a.M. (Germany). In this study, 100 of 287 patients (preoperative mean BMI 48.3 kg/m²; mean age 35.2 years) with a follow-up >18 month were evaluated. All patients underwent anonymous questionnaire (26 questions with a maximum score of 60) about different aspects of QoL outcome after LSAGB. Results: In this study, 4 of 100 patients refused to give an answer to the QoL questions. Therefore 96 patients were evaluated. The QoL auto-evaluation of the patients shows that QoL generally improved after surgery in 92%. Using the scoring system, 44% of patients have excellent, 52% good, and only 4% bad results. The 4 patients who refused had to be classified as failure. General acceptance of LSAGB is wide, but gastrointestinal side effects are recognizable in more than 78% of operated patients. Successful weight loss is followed by an improvement of comorbidities. Conclusions: Safe, effective bariatric procedures increase the quality of life in morbidly obese patients markedly. Bariatric surgeons are committed to support and help their patients until they reach a new quality of life after obesity surgery.     

Ginkgo biloba extract EGb761 reduces the development of amphetamine-induced behavioral sensitization: effects on hippocampal type II corticosteroid receptors

Pretreatment of rats with the extract of Ginkgo biloba termed EGb761 reduced the behavioral sensitization induced by successive -amphetamine administrations (0.5 mg/kg) as estimated by increasing values of locomotor activity. EGb761 pretreatment also prevented the reduced density of [³H]dexamethasone binding sites in the dentate gyrus and the CA1 hippocampal regions of -amphetamine treated animals. These observations suggest that EGb761, by reducing glucocorticoid levels, could modulate the activity of the neuronal systems involved in the expression of the behavioral sensitization.     

Dilution effects on the quality of untreated wastewater used for irrigation along the USA-Mexico border

The Juarez Valley, located along the USA-Mexico border, currently relies on untreated municipal and industrial wastewater from nearby Ciudad Juarez (est. pop. 1.6 million) which has been diluted with water diverted from the Rio Bravo (Rio Grande), and groundwater from underlying aquifers, to irrigate 18000 hectares of crops. The results indicate that dilution does very little to reduce the risks associated with the use of untreated wastewater for irrigation as faecal coliforms levels remained high (> 10 7 cfu/100 ml). Concentrations of heavy metals were low in the raw wastewater and in the mixed waters. However, the practice of diluting raw wastewater seriously degrades significant volumes of high quality waters from the Rio Bravo and from the underlying aquifer, and thus is not an optimal use of the limited high-quality water available to this semi-arid region.     

40所军队医院病种病例分型质量评价结果分析

应用病例分型质量费用监控管理软件和ＳＡＳ６．１２统计软件包,对４０所军队医院５０万份病例样本资料进行深入分析,结果显示：病例分型组合数据稳定,分析结果合理。     

Modell eines computergestützten qualitätssicherungssystems in der verbrennungsintensivtherapie

Zusammenfassung Ausgehend von Überlegungen für ein angemessenes Qualitätssicherungssystem im intensiv-medizinischen Bereich werden die Voraussetzungen für ein ganzheitliches Qualitätsmanagementsystem im Krankenhaus entworfen. Die Grundlage für ein dynamisches Qualitätssicherungssystem ist auf der dokumentatorischen Ebene eine umfassende Datenbasis, die auf einer zeitlich und datentechnisch unbegrenzten Patientenakte basiert. Die notwendige Hard- und Softwarestruktur wird durch die konsequente Anwendung einer Client-Server-Architektur gewährleistet. Die ständige Überprüfung der bestehenden Qualitätsziele in einem ökonomischen Regelkreis benötigt ein System mit flexiblen Abfragemechanismen. Dieser informatorische Datenzugriff auf jeder Hierarchieebene der Krankenhausstruktur wird durch das Konzept des Data-Warehouse ermöglicht, das als Datenbanksystem mit subjektorientierten, integrierten, zeitvariablen und beständigen Informationen konzipiert ist.

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A computer-assisted quality-assurance model for burn intensive care applications

The prerequisites for an integrated quality management system for hospitals were developed as a result of considerations regarding the necessity of an appropriate quality-assurance system for the intensive care sector. The basis for a dynamic quality-assurance system on the documentational level is a comprehensive data base containing patient files unlimited in terms of time and data technology. The necessary hardware and software structure will be provided by consistent application of a client-server architecture. Permanent surveillance of existing quality objectives within the scope of an economic close-loop system requires a system with flexible query mechanisms. Informational data access from all hierarchical level within the hospital organization is facilitated by the data warehouse concept, a data base system with subject-oriented, integrated, time-variable, and persistent data.

     

Internal and external quality control in the toxicological analysis of blood and urine samples in the Federal Republic of Germany

Summary Due to a technical rule for dangerous agents (TRGS 410), issued by the Ministry of Labor in the Federal Republic of Germany in 1979, toxicological analyses in biological materials must be carried out under conditions of statistical quality control. This quality-control scheme provides internal and external control programmes. For internal quality control, the results of many years of experience with five commercially available control specimens and one home-made control have been evaluated. The control samples showed good, comparable results over a long period. Except in a few cases, there was good agreement between our results and the assigned values. Since 1982, the German Society of Occupational Medicine has offered eight intercomparison programmes for external quality. In samples from 80–90 laboratories, 6 metals in blood and around 20 inorganic and organic parameters in urine in 2 concentration adjustments have been analysed. Successful participation was certified if both results obtained for one parameter were within the tolerance range (assigned] value ± 3 SD). The average success rate was around 60%.     

A new method for quantification of image distortion due to pile-up in scintillation cameras

Characterization of the count-rate performance of scintillation cameras should include not only the specification of count losses. At high count rates, there is also an image distortion due to the mispositioning of pile-up events. In this paper a simple and clinically relevant procedure to quantify this distortion is presented. The images of a square uniform technetium-99m phantom at high and low count rates are used. The fraction of the total counts being correctly positioned is determined as the peripheral count density divided by the total average count density. This ratio, corrected for the camera non-uniformity at low count rates, is called the positioning ability. According to the National Electrical Manufacturers' Association (NEMA), the system count rate performance with scatter should be reported as the measured count rate giving 20% count losses. In this paper it is suggested that this measure be complemented by a measure of the fraction correct positioned events at this count rate. This fraction, the high count rate positioning ability', can be easily and accurately measured using our method. The method has been tested on two different scintillation cameras. For one of them the high count rate positioning ability was determined as 91% at a measured count rate of 30000 s^–1 with 20% count losses. For the other camera, the corresponding figures were 88% at 59000 s^–1 and close to 100% at 38000 s^–1, before and after the installation of a new pile-up rejection circuit, respectively. Offprint requests to: C. Ceberg     

Motion artifact reduction with three-point ghost phase cancellation.

A novel method for "ghost" artifact suppression is introduced. It suppresses ghosts induced by motion in any direction, as well as other types of quasi-periodic signal modulation. Because it requires neither special hardware nor intensive data processing, it can be easily implemented on conventional magnetic resonance (MR) imagers. The method is based on the concept of decomposition of a ghosted complex image into a ghost mask and ideal image. A set of deliberately designed acquisitions are used to generate a set of ghosted complex images in which the ghost components are related in a simple manner. With use of equations describing image decomposition and ghost correlation, the ideal image can be calculated pixel by pixel. The ideal image obtained (representing the time-averaged spin-density distribution) is shown to be a truer representation of physical reality than the ghost-free image obtained with ordered phase encoding. In this technique, both interview and intraview effects are taken into account. The technique is also useful in simultaneously suppressing ghosts from multifrequency signal modulations such as respiratory and cardiac motions. The method was successfully tested with three time-interleaved, phase-encoding-order-shifted acquisitions. Experimental results have shown that it is a simple but effective technique.     

注射用通脉灵质量标准研究

目的：对注射用通脉灵进行质量标准的研究。方法：采用薄层层析法对处方中药材进行了定性鉴别，并采用分光光度法对总黄酮进行了含量测定，采用比色法对总皂苷进行了含量测定。结果：薄层色谱分离效果好，两种方法回收率RSD均小于3％。结论：该方法较简单，重现性好，可作该制剂质量控制标准。