GB 17589-2011 English PDFUS$299.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. GB 17589-2011: Specifications for quality assurance test for computed tomography X-ray scanners Status: Valid GB 17589: Historical versions
Basic dataStandard ID: GB 17589-2011 (GB17589-2011)Description (Translated English): Specifications for quality assurance test for computed tomography X-ray scanners Sector / Industry: National Standard Classification of Chinese Standard: C57 Classification of International Standard: 13.280 Word Count Estimation: 13,158 Date of Issue: 2011-12-30 Date of Implementation: 2012-05-01 Older Standard (superseded by this standard): GB/T 17589-1998 Quoted Standard: GB/T 19042.5 Regulation (derived from): Announcement of Newly Approved National Standards No. 23 of 2011 Issuing agency(ies): General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China Summary: This Chinese standard specifies requirements for medical X-ray equipment for computed tomography (computed tomography X-ray scanner, referred CT) for the purpose of quality assurance testing methods and their projects and requirements. This standard applies to CT machine acceptance testing, the use of CT for detecting a state machine and stability testing. This standard does not apply to the production of CT and CT quality control as well as supporting the use of video display systems and hard copy system. GB 17589-2011: Specifications for quality assurance test for computed tomography X-ray scanners---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.Specifications for quality assurance test for computed tomography X-ray scanners ICS 13.280 C57 National Standards of People's Republic of China Replacing GB/T 17589-1998 X-ray computer tomography apparatus Quality assurance testing standards Issued on. 2011-12-30 2012-05-01 implementation People's Republic of China Ministry of Health Standardization Administration of China released ForewordThis standard was drafted in accordance with GB/T 1.1-2009 given rules. This standard replaces GB/T 17589-1998 "X-ray computed tomography apparatus of image quality assurance testing standards." This standard compared with GB/T 17589-1998, the major technical changes as follows. --- The GB/T 17589-1998 in Table 1 is amended as normative appendix; --- Increasing the value of CT to detect a linear content; --- Modify the definition and calculation of noise; --- Modify the project name and the calculation method CTDI; --- Modify the detection of high contrast resolution; --- Modify the project name and test methods can detect low-contrast capability and reconstruction thickness deviation. This standard is proposed and administered by the People's Republic of China Ministry of Health. This standard by the People's Republic of China Ministry of Health is responsible for interpretation. This standard was drafted. Chinese Center for Disease Control Radiation Protection and Nuclear Safety of the medicine. The main drafters of this standard. Yuebao Rong, Wei Dao, Liu Lan Tao. This standard replaces the standards previously issued as follows. --- GB/T 17589-1998. X-ray computer tomography apparatus Quality assurance testing standards1 ScopeThis standard provides for medical X-ray computed tomography apparatus (computedtomographyX-rayscanner, Acronym CT) for the purpose of quality assurance testing methods and projects and requirements. This standard applies to acceptance testing CT machines, CT machines use state testing and stability testing. This standard does not apply to CT machine Production quality control, and supporting the use of CT imaging and display system and hard copy system.2 Normative referencesThe following documents for the application of this standard is essential. For dated references, only the dated version suitable for use herein Member. For undated references, the latest edition (including any amendments) applies to this document. Evaluation and routine testing - Part 3-5 GB/T 19042.5 medical imaging departments. X-ray computed tomography imaging apparatus Performance Acceptance Test3 Terms and DefinitionsThe following terms and definitions apply to this document. 3.1 CT dose index CTdoseindex, CTDI100 Standard cross section along the central axis from -50mm to 50mm to integral dose profile curve, divided by the nominal thickness with a single sweep Product description generating N number of faults, according to equation (1) calculations. CTDI100 = ∫ -50 D (z) N × Tdz (1) Where. T --- nominal thickness; N --- Number of faults arising from a single scan; D (z) --- standard dose cross section along the central axis of the profile curve. Note. A scan consists of many levels. 3.2 Weighted CT dose index weightedCTdoseindex, CTDIw The average value of the phantom center CTDI100 collected CTDI100 and peripheral points collected weighted sum. CTDIw = 13CTDI100, c 3CTDI100, p (2) Where. CTDI100, c --- phantom center collected CTDI100; CTDI100, p --- motif peripheral points collected CTDI100 average. 3.3 CT value CTnumber CT image voxel corresponding to each pixel of the X-ray attenuation average. Note. CT Hounsfield value is usually used as a unit, referred to as HU. Using (3), the attenuation values measured in accordance with internationally harmonized turn Hounsfield scale CT values replaced. CT value substance substance = μ -μ water μ water × 1000 (3) Where. Linear attenuation coefficient μ substance --- ROIs substance. Linear attenuation coefficient μ water --- water. According to the above definition of CT value scale, then there must be. water CT value 0HU, air CT value -1000HU. 3.4 Voxel voxel Is an imaging layer in artificial division, several small basic unit in a rectangular array. 3.5 Dose profile curve doseprofile On a standard cross-sectional central axis dose distribution with the correlation function of its position. 3.6 The full width at half maximum fulwidthathalf-maximum Half the maximum distance between two points on the dose profile curve. 3.7 High contrast resolution high-contrastresolution Spatial resolution spatialresolution In the object with the background on the difference in the degree of attenuation of noise sufficiently large as compared with the case where, CT imaging distinguish objects of different sizes ability. Note. In general, the attenuation coefficient difference between the object and the background of the result for the corresponding CT value difference 100HU above is considered to be large enough. 3.8 The average CT value meanCTnumber The average of all the pixel values of CT in a special area of interest. 3.9 Noise noise In homogeneous mass image, given its regional variation in the average value CT. Available in the size of the region of interest of a uniform substance CT Divided by the standard deviation value of the contrast scale representation. 3.10 Nominal thickness nominaltomographyslicethickness CT machine is selected on the control panel and indicating the layer thickness. 3.11 ROIs regionofinterest, ROI Within a given time images of particular interest to the local area. 3.12 Sensitivity profile curve sensitivityprofile As a function of position in the vertical correlation response volume CT system on a straight line fault plane. 3.13 Reconstruction thickness reconstructedslicethickness The half-scan field at the center of a cross-sectional imaging sensitivity curve full width. 3.14 Pitch pitch 360 ° from the tube and the diagnostic bed with ratio of the total width of the imaging detector for each rotation. P = dMS (4) Where. d --- tube each 360 ° rotation diagnostic bed moving distance; M --- tube each 360 ° rotation of the tomographic image of a number; S --- each piece of tomographic images of the nominal thickness. 3.15 Uniformity uniformity The entire scan field, the consistency of a homogeneous mass imaging CT values. 3.16 Baseline baselinevalue Reference X-ray diagnostic equipment function parameters. After the acceptance or status is qualified, from the initial stability testing obtained Value, or by the respective standard values given. 3.17 Low-contrast detectability ability lowcontrastdetectability CT machine can identify the minimum size of the image low-contrast detail. 3.18 Acceptance Testing acceptancetest X-ray diagnostic equipment after installation or major repairs, as identified compromising image quality performance indicators into compliance with the agreed value Line testing. 3.19 State detection statustest Detecting device for evaluating the state carried out, usually once a year to detect the state. 3.20 Stability testing constancytest To determine the X-ray diagnostic imaging equipment or under given conditions for the formation of the initial state whether the change in relative control standards and still meet In testing.4 DetectionPositioning accuracy of 4.1 Diagnosis bed 4.1.1 minimum scale of 1mm, an effective length of 500mm near the straightedge diagnosis fixed bed of moving bed, and to ensure that the ruler Parallel to the direction of movement of the bed and the bed surface can indicate as a ruler tick mark pointer. 4.1.2 ensure that the bed load of about 70kg. 4.1.3 were given the diagnosis of bed "into 300mm" and "back 300mm" instruction. 4.1.4 record forward, back the start and end point values shown on the ruler, measure the positioning error and homing error. 4.2 optical positioning accuracy 4.2.1 motif detection 4.2.1.1 detector module having a body with a surface clear alignment marks, embedded within the specific shape of the object, the shape of the object, the position of Should mold surface alignment mark with strict spatial relations. 4.2.1.2 The detection module body is placed in the center line of the radiation field is fixed, the mold body axis perpendicular to the scanning cross section, so that all surfaces of the phantom trimming Marking and locating light coincide. 4.2.1.3 the head of clinical common exposure conditions, the total thickness of less than 3mm imaging collimator axial scanning mode to obtain positioning light Markable layer image, comparing the image with a standard shape and positional relationship between the level of a particular object are the same, if the same, then the alignment light, accurate. 4.2.1.4 4.2.1.3 If the two do not match, the scan back and forth perpendicular to the axis of the level of fine-tuning die body in accordance with 4.2.1.3 Scanning conditions, ultimately consistent with the nominal level of the image, according to the mold body to adjust the distance along the axis, positioning light to determine the degree of deviation. 4.2.2 film detection 4.2.2.1 Select an unexposed film in a dark room with black paper wrapped tightly and keep it neat. 4.2.2.2 In the paper side of the direction perpendicular to the longitudinal direction draw two straight lines, a straight line distance of 10cm or more, respectively, with a needle through the two straight lines 2 and 3 holes, hole diameter should be as small as possible and should not exceed the maximum diameter of 1mm, hole spacing at least greater than 5cm. 4.2.2.3 The perforated with small holes on the film flat on the examining table, the film coincides with the central axis of rotation and CT center will first have to wear two Linear positioned within the aperture of light projected on the film coincides with the CT machine positioning within the set mode, choose a lower exposure conditions, minimum Nominal thickness, the use of single-axial scan mode to scan. 4.2.2.4 and then pan the film, will wear a straight line with three holes positioned outside the projection of light on the film coincides with the CT machine outside the given set Bit mode, using the same exposure conditions 4.2.2.3 scan. 4.2.2.5 final rinse scanned film were measured inside, positioned between the outer light corresponding scanning line of the image on the film and the line in a spin Turn on the central axis of the pitch, the pitch as an inner and outer locating the light of deviation. 4.3 gantry angle precision 4.3.1 center with a clear mark of rectangular motifs, the phantom center coincides with the center of the fault wild, and the level fixed, according to 4.2 optical positioning accuracy of test results, adjust the position of the mold body to determine the level of the scan, so scan through the phantom center level. 4.3.2 commonly used in clinical use for scanning head scanning conditions. 4.3.3 motif stationary rack tilted at an angle, in accordance with the conditions in 4.3.2 scanned again. 4.3.4 ranging use workstation software, distance between the upper and lower edges of the cross-sectional image measurement phantoms, were recorded as L1 and L2. 4.3.5 using the equation (5) calculate the actual value of the gantry angle, compared with the set value, determines the accuracy of the gantry tilt angle. α = arccosL1L2 (5) Where. α --- gantry angle size. --- From the upper and lower edges of the transverse images, phantom between the vertical scan L1. The distance between the upper and lower edges of the cross-sectional image after L2 --- rack inclination angle α motif. 4.4 Reconstruction thickness deviation 4.4.1 for axial slice thickness deviation measured using phantom embedded with a homogeneous background high contrast markers, markers have determined The geometry, through its geometrical position reflects imaging reconstruction thickness; spiral CT machine for measuring the thickness of a sheet deviation or marker Beads, the attenuation coefficient of not less than the marker material is aluminum, to ensure high signal to noise ratio, and the Z-axis direction of the maximum thickness or diameter should be Between 0.05mm ~ 0.1mm. 4.4.2 The phantom axis perpendicular to the scanning level and placed in the scanning field center fixed. 4.4.3 According to the head of exposure conditions, the image reconstruction set the nominal thickness, axial or helical scan. 4.4.4 adjusted according to the mold body image viewing conditions specification window width and position, and for the record, layer thickness measurements reconstruction. 4.4.5 For axial scan reconstruction thickness variation measurement, current measurement methods There are two common motif. a) Method One. adjust the window width to a minimum, change the window level until the marker image just completely disappeared, record the CT values, namely CTmax, under the window width and position conditions, measured CT value marker near background is CTbackground, the CT value of half-height CT values from the two and a half, denoted CThm, and then re-adjust the window level to CThm, this time measuring markers Length, full width at half maximum (FWHM), and then using a fixed geometric relationship markers, calculated layer thickness measurements reconstruction; this Methods commonly used to set the layer thickness is greater than 5mm thickness deviation detection reconstruction. b) Method two. labels used in the method of determining the geometric relationship with minute details, by counting the number of details and Combined with the geometric relationship between the details of the calculated thickness measurements reconstruction, the method can be used to detect and set the layer thickness relative to the diameter of details Close rebuilding thickness deviation. 4.4.6 thickness deviation measurement method for the reconstruction of spiral CT machine is. with helical scan mode scanning markers, and a nominal thickness of 1/10 The image reconstruction interval, and the total width of the Z-axis direction of image reconstruction of at least 3 times the nominal thickness; with an appropriate ROI (e.g. thin markers Tablets, the ROI is set for 2 times the diameter of the sheet, if it is micron beads, then the ROI set point. ) Measurements to obtain a series of helical sweep Image description sheet or the average CT values beads material; record the average CT value for the Z axis as a function of the horizontal curve, and determine the FWHM function curve, that is, as the FWHM of thickness measurements reconstruction. Note 1. The reconstruction of the thickness of CT machine is referred to the default image reconstruction thickness. Note 2. For older spiral CT machine, it is difficult to achieve a nominal thickness of 1/10 of the reconstructed image, you can fine-tune the scanning starting point to get multiple sets of image reconstruction, measuring The average amount of CT values for these center of the image and make the curve, determine FWHM. Note 3. For multi-slice CT, currently limited to the detection of multi-axial scan reconstruction slice thickness, testing phantoms having a defined geometric position markers Z Axis direction should be long enough, if the length does not meet the needs of multi-scanning, can be divided according to the layout of the detector array open, detect, and Z-axis center to ensure phantom markers as part of the array to be detected in the same scan levels. Note 4. having used to determine the geometry of the high-contrast markers mold body should clearly be able to detect the smallest thickness d, the minimum thickness according to equation (6) Calculation get. d = T/cosθ (6) Where. The thickness of the T --- markers; θ --- marker level scanning angle formed. 4.5 CT dose index 4.5.1 The use of human tissue-equivalent material homogeneous cylindrical phantom head die having a diameter of 160mm, the phantom diameter of 320mm, respectively, in the Heart and 10mm from the surface there may be placed at a dose probe hole, relative error dose measuring instrument should be less than 5%, and has been calibrated. 4.5.2 The headform or phantom placed scanning field center, the axis of the cylindrical molded body with an effective level of vertical center of the scanning probe, the scanning probe With its central location level. 4.5.3 respectively, according to the head and body commonly used in clinical conditions axial scan. 4.5.4 Records dosimeter readings and calculated CTDI100 and CTDIw according to formula (1) and (2). 4.6 CT value (water), noise and uniformity 4.6.1 using the homogeneous aqueous cylindrical phantom. 4.6.2 the mold body cylindrical axis perpendicular to the scanning level and in the scanning field center, the middle level of the cylindrical scan. 4.6.3 using the scanning head scanning conditions, and each radiation dose scan mode at the position of the center of the body should not exceed 50mGy. 4.6.4 Select the center of the image is about 500 pixels in size (about one-tenth of the mold body area) ROI, measure the ROI of the average CT Value, standard deviation, wherein the average CT value of water as measured CT value, standard deviation divided by the contrast scale as noise measurement value n, See equation (7). n = σ CT water air water -CT × 100% (7) Where. standard deviation σ water --- water phantom ROI measured; CT Water --- water measured CT values; Air --- CT CT value of air measurements. CT Water -CT air --- contrast ruler. 4.6.5 Also in the image corresponds to the circumference of the watch clockwise 3,6,9,12 point, according to the motif of about 10mm at the edge of the image, select about ROI 500 pixels size, the average CT values were measured four ROI, wherein the center of the image and 4.5.4 ROI average CT Value as the maximum difference value of the uniformity measurement. 4.7 high contrast resolution 4.7.1 uses can be evaluated by direct observation or using phantom image transfer function (modulatedtransfer by calculating modulation function, MTF) evaluate the spatial resolution high-contrast motifs, calculated MTF motif description and corresponding high contrast resolution measurements Methods According to GB/T 19042.5. 4.7.2 for direct observation image motif should be evaluated with periodic detail, the spacing between the periodic structure that should be a single week Equal to the width of the details of their own, effective attenuation coefficient differences in the details of the periodic effective attenuation coefficient and homogeneous background caused by CT values The difference should be greater than 100HU. 4.7.3 The phantom placed in the center of the scan field, and the cylinder axis perpendicular to the scanning level. 4.7.4 4.5.3 with scanning conditions. 4.7.5 The molded body image viewing conditions or manual adjustment to achieve observer status clear that the details of most, but not greater than the window bit thin Section CT CT value and the background value of the difference. 4.7.6 can distinguish count was recorded minimum size or MTF curve corresponding to 10% of the value of the spatial frequency detail as spatial periodicity Discrimination of measuring value. 4.7.7 If a special algorithm to obtain high contrast resolution should first recording method according to 4.6.6 High Contrast the special algorithm corresp......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB 17589-2011_English be delivered?Answer: Upon your order, we will start to translate GB 17589-2011_English as soon as possible, and keep you informed of the progress. 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