Portable x-ray diagnostic equipment

Scientific-Industrial Association “Spektr”, Moscow. Translated from Meditsinskaya Tekhnika, No. 4, pp. 22–28, July–August, 1992.     

Progress in dental x-ray diagnostic equipment

Moscow Scientific-Research Institute for Diagnostics and Surgery. Translated from Meditsinskaya Tekhnika, No. 2, pp. 35–37, March–April, 1995.     

Update on domestic x-ray diagnostic equipment

All-Russian Scientific-Research and Testing Institute for Medical Engineering, Moscow. Translated from Meditsinskaya Tekhnika, No. 2, pp. 37–39, March–April, 1995.     

Quality assurance measurements in departments of pathology and laboratory medicine

Previously, characteristics of the quality assurance program in each department of pathology and laboratory medicine were the uniqueness of the monitors selected, the thresholds set for activity, and definitions of good performance. In 1989, members of the College of American Pathologists developed and implemented the first nationwide quality assurance program for pathology and laboratory medicine. This program, Q-Probes, has been expanded for 1990; after completion of planning under way for 1991, indicators will be in place for all steps in the total testing process. More than 1100 institutions had subscribed by the first quarter of 1990. Input forms for measurements of clinical indicators of quality are distributed to participants and, after completion, submitted to a central computer facility where keypunching and data manipulations occur. The interpretation of results is enhanced by peer comparisons of the participant data collected. In many circumstances studied, a large proportion of the data are aggregated at extreme ends of the distribution. Because data distributions are nongaussian for the indicators studied, it is recommended that peer comparisons use the 10% to 90% range and that the central tendency be described as the median. Despite large databases for some indicators that exceed by more than 10- to 100-fold those previously reported, extensive categorization may preclude percentile ranking of participants. Critiques are distributed describing practices and suggestions for improvement. Steady improvement of each participant and of nationwide practice patterns are documented by remeasurements.     

Developing a regulatory system for x-ray diagnostic equipment

Moscow Scientific Radiological Research Institute, Ministry of Health of the RSFSR, Moscow. Translated from Meditsinskaya Tekhnika, No. 5, pp. 35–39, September–October, 1991.     

Approaches and problems in the development of x-ray diagnostic equipment

ékran Scientific-Production Association. Spektr Scientific-Production Association. Moscow Scientific Radiological Research Institute, Ministry of Health of the RSFSR. Translated from Meditsinskaya Tekhnika, No. 5, pp. 7–11, September–October, 1991.     

Quality assurance of the molecular diagnostic tests in hematological malignancies

Analyses of nucleic acid sequences in hematological malignancies are now essential in managing patients with hematological malignancies. Because of the impact of the test on decision-making in patient care, its accuracy is quite important. Detection of BCR-ABL mRNA by polymerase chain reaction, one of the most popular molecular diagnostic tests for hematological malignancies, has been used for diagnosis of Philadelphia-positive leukemias. Quality of the test must be assured in the process of diagnostic plan, sampling, measurement(nucleic acid isolation, amplification, detection), report and interpretation. Risk of false-positive results due to contamination of in vitro nucleic acid amplification reactions can be decreased through the use of protocols for contamination control. False-negative results may be caused by variability in BCR breakpoint, and loss or degradation of RNA due to inappropriate procedures as well as an insufficient detection sensitivity. Presence of inhibitors of amplification is also to be considered as a cause of false-negative results. Thus, quality control techniques such as internal standards are mandatory to ensure efficient amplification as well as RNA extraction. For the precise evaluation of minimal residual diseases, accurate and sensitive quantitative analyses are required. For quality assurance of assays in the present status of no commercially available kits, it is particularly important to monitor the clinical validation of the results by correlating them with the patient's status to prove clinically relevant. Staffs need to be trained to be familiar with both molecular pathogenesis and technology so that they can provide informative test results with a high quality.     

Ionometric x-ray diagnostic devices

Scientific-Research Institute for Introscopy, Moscow. Moscow Scientific-Research Institute for Diagnostics and Surgery. Translated from Meditsinskaya Tekhnika, No. 3, pp. 29–31, May–June, 1995.     

Quality assurance in microbiology

Quality assurance (QA) is the total process whereby the quality of laboratory reports can be guaranteed. The term quality control covers that part of QA, which primarily concerns the control of errors in the performance of tests and verification of test results. All materials, equipment and procedures must be adequately controlled. Culture media must be tested for sterility and performance. Each laboratory must have standard operating procedures (SOPs). QA of pre-analytical, analytical and post-analytical stages of microbiological procedures should be incorporated in SOPs. The laboratory must be well lit with dust-free air-conditioned environment. Environmental conditions should be monitored. Supervisory and technical personnel should be well qualified. The laboratory should participate in external and internal quality assurance schemes.     

CdZnTe detector in diagnostic x-ray spectroscopy

A method to utilize CdZnTe (CZT) detectors in diagnostic x-ray spectroscopy is described in this article. Spectral distortion due to transmission of primary x rays, the escape of cadmium- and tellurium-K fluorescent x rays, and tailing was severe in measured x-ray spectra. Therefore, correction for the distortion was performed with the stripping method using response functions. The response functions were calculated with the Monte Carlo method. The Hecht equation was employed to approximate the effects of carrier trapping in the calculations. The parameters in the Hecht equation, the mean-free path (lambda) of electrons and holes, were determined such that the tailing in calculated response functions fit that in measured gamma-ray spectra. Corrected x-ray spectra agreed well with the reference spectra measured with an HPGe detector. The results indicate that CZT detectors are suitable for diagnostic x-ray spectroscopy with appropriate corrections.