According to medical regulations, a utility certificate should be compiled for X ray rooms [3]. The protocols of technical tests (PTT) and safety test are the main docu ments for compiling such a certificate [3].The PTT is the aggregate of data about sample, serv ice organization, normative documents, monitoring equipment, and basic utility characteristics of roentgeno diagnostic apparatuses (RDA).The main utility characteristics are anode voltage, anode current, exposure time, electrical charge, linearity of dose dependence on mAsec, radiation yield, spectral composition of X ray radiation, etc. These components of PTT are represented as individual chapters of the cer tificate.1. General chapter. 2. Equipment correspondence to certificate. 3. Electrical safety of RDA. 4. Radiation safe ty. 5. Correspondence of mechanical parameters to tech nical documentation (TD) and standards. 6. Correspon dence of electrical and radiation characteristics of X ray power source to TD and standards. 7. Correspondence of X ray images on different carriers: X ray film, screen, image intensifier, CCD screens, etc. to TD and standards. 8. Correspondence of photolaboratory to TD and stan dards. 9. Correspondence of RDA parameters for tomog raphy, angiography, etc. to TD and standards. 10. Conclusion, remarks, and comments to RDA use.RDA tests include testing for working parameters and compilation of test protocols.Automation of routine testing procedures using spe cial software [1] for RDA monitoring allows test results to be obtained online. The following curves can be plotted: D (mGy) = f (mAsec), U a meas = f (U a set ), etc. The protocols are stored in a database.The results of testing of the TFX 15 in Moscow Municipal Hospital No. 68 are given in Tables 1 3. Table 1 contains data of measurement of basic electrical Fig. 2. Dependence of radiation yield on anode voltage with regression curve. This curve shows a linear increase in the radia tion yield upon increasing the anode voltage. The ordinate is the radiation yield.

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The purpose of this paper is to provide data concerning differences in multislice CT effective dose estimation when using various methods and techniques, determine the reasons for these differences, and submit proposals for improving the estimation accuracy. All the experiments (chest and head exam settings) were conducted using 64-slice CT scanners from various manufacturers. Effective dose estimates have been obtained on the basis of the conventional dose-length product method, absorbed dose distribution curves, and using anthropomorphic phantoms with thermoluminescent dosimeters as a model method. Using the conventional dose-length product method leads to underestimation of effective doses (approximately 16 and 19% for head and chest studies, respectively, on average for all scanners) due to partly neglecting scattered in-patient radiation. Additional differences in dose estimates occur when using the "new" ICRP 103 instead of the "old" ICRP 60 Publication recommendations (13% for chest and 23% for head studies on average). It seems reasonable to calibrate scanners with weighted CT dose index values taking into account complete scattered radiation effects. Dose conversion factors for different studies and patient age must be recalculated in conformity with ICRP Publication 103 recommendations. With implementation of the presented proposals, the discrepancy in effective dose evaluation will not exceed a few percent as compared to anthropomorphic phantom measurements.

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