YY/T 0741-2018Particular specifications for digital X-ray radiography system (English PDF)

3.1 Digital radiography system

It uses digital X-ray image detector technology to realize the X-ray photography; generally, it consists of X-ray generating device, digital X-ray imaging device, and ancillary equipment.

3.4 Imaging time

The time, from the exposure to the screen displaying, required for the normal image satisfying the diagnostic needs.

3.5 Information management

Software measures for managing the patient information, such as appointments, registrations, modifications, deletions, queries, statistics, backup management, etc.

3.6 Low contrast resolution

Under specified measurement conditions, the lowest contrast details between specified shape and area that can be distinguished from a uniform background condition, expressed in %.

3.10 Effect image area

Maximum effective area for detector imaging.

3.11 Artifact

A structure that is clearly visible on an image. It neither reflect the internal structure of the object, nor can it be explained by noise or system modulation transfer functions.

3.12 Erasure thoroughness

After the previous image signal is read, part of all of the previous image generated in the subsequent image due to incomplete signal removal.

5.1 Working conditions

5.1.1 Environmental conditions

Unless otherwise specified, the working and environmental conditions of the DR system shall satisfy as follows.

5.1.2 Power supply conditions

The operating power supply conditions of the DR system shall satisfy as follows.

5.2 Electric power

5.2.1 Maximum output electric power

It shall be specified in the product technical requirements for the corresponding combination between voltage and current of X-ray tube with maximum output electric power.

5.3 Loading factors and control

5.3.1 X-ray tube voltage

The X-ray tube voltage shall meet the following requirements.

5.3.3 Loading time

If there is an indication for loading time, it shall meet the following requirements.

a) It shall be specified in product technical requirements for adjustment range and

5.3.5 Anti-overload

The DR system shall take the anti-overload measures, ensuring that the selection of loading factor shall not exceed the rated capacity of the X-ray tube. It shall satisfy the maximum loading factor combination given in the instruction manual.

5.3.6 Automatic exposure control

The DR system shall be equipped with Automatic Exposure Control (AEC) function.

The repeatability of the radiation output in the AEC mode shall satisfy the coefficient of variation for the air kerma measurement value no greater than 0.05.

5.4.4 Flat uniform

The manufacturer shall specify the maximum flat uniformity of DR, the used SID, and loading factor. Unless otherwise is specified by the manufacturer, it is specified by the image that the ratio between the standard deviation of the gray value on sampling point R and the mean value of the gray value on the sampling point Vm shall be no greater than 2.5%. Namely, formula (2).

5.6 Network and software

5.6.1 Network communication

It shall conform to the DICOM3.0 standard; the manufacturer shall provide a declaration of conformity for DICOM3.0 standard in accompanying file.

5.6.3 Imaging time

The imaging time shall be no more than 12s.

5.7 Plug and socket of high voltage cable

Unless otherwise specified, it shall meet the requirements for relevant type, basic dimension, marking, connection specified in GB/T 10151.

5.8 Appearance

The appearance of the DR system shall be neat and beautiful; the surface shall be smooth with uniform luster; free of scars, cracks, and the like defects.

5.9 Environmental test

It shall meet the requirement of YY/T 0291. The initial, intermediate or final test items shall include at least the contents of 5.4.1, 5.4.2, 5.4.3, 5.5.4.

6.1 Test conditions

6.1.1 Environmental conditions

It shall conform to the provisions of 5.1.1.

6.1.2 Power supply conditions

The test power supply conditions are as follows.

6.2 Electric power

6.2.1 Maximum output electric power

The DR system operating in an intermittent mode is loaded in the combination with the loading factors that cause the maximum output electric power; then observe whether there is an abnormality.

6.3 Loading factor and control

6.3.1 X-ray tube voltage

It shall be performed as per the following methods.

6.3.3 Loading time

It shall be performed as per the following methods.

6.3.4 Current time product

It shall be performed as per the following methods.

6.3.5 Anti-overload

It shall be performed as per the following methods.

Adjust the parameters of the DR system to the maximum load factor combination value specified in the instruction manual. When readjust any loading factor to the adjacent increase shift, the loading factor condition shall not be increased any more or the DR system is in the overload state. For the DR system with continuous adjustment of the X-ray tube voltage, when the operating voltage value of the anti-overload device is higher than the maximum X-ray tube voltage value (but not exceeding 5kV) specified in the instruction manual, it shall not be exposed and/or alarmed.

6.3.7 Correspondence between X-ray field and image receiving surface

It shall be performed as per the following methods.

6.3.8 Dose area product indication

It shall be performed as per the following methods.

Place the X-ray dosimeter detector in an appropriate position in the X-ray beam, such as on the image receiver surface or bed surface. Adjust the X-ray filed dimension to 15cm×15cm or other proper dimensions. Take photograph to dose area product that is displayed by the equipment is greater than 5µGy·m2; multiply the measured dose value by the ray filed area at the air kerma dosimeter detector. It can also be measured directly by the dose area product meter. Calculate the error between displayed value and the measured value.

6.3.9 Pediatric photography requirements

Actual operation and inspection.

6.4 Imaging performance

6.4.1 Spatial resolution

Test and arrange the multi-function test card shown in Figure B.1 according to Figure A.1.Adjust SID to be the normal clinical use distance; set the visual field of the image to be the maximum effect image area of the plate; select the typically clinical protocol specified by the manufacturer; manually set the X-ray tube voltage to be 75kV±7kV;

AEC automatic exposure. If required, adjust the window width and position; record the spatial resolution value and corresponding loading factor combination.

6.4.10 Quantum detection efficiency

Check the manufacturer's accompanying file.

6.5 Performance of mechanical device

6.5.1 Scope of mechanical motion

In practice, measure the range of rotation angle by the angle gauge; the minimum division scale of the angle gauge is no greater than 0.5°. The range of motion the longitudinal, lateral, and vertical directions is measured by a length gauge.

6.5.2 Length indication value

In practice, measure by the length gauge.

6.5.3 Angle indication value

In practice, measure by the angle gauge.

6.5.4 Braking

In practice, measure by a dynamometer.

6.5.5 Load bearing

The patient support device is in a horizontal state and in most unfavorable position at work; uniformly distribute 135kg load on the 168cm×37.5cm support surface for 1min; observe whether it can work normally.

For pedals and chairs, uniformly distribute 135kg load on the 0.1m² support surface for 1min; observe whether it can work normally.

6.7 Plug and socket of high voltage cable

In case when the manufacturer specified otherwise, inspection according to the method specified by the manufacturer; otherwise, inspect according to the relevant type, basic dimension, marking, connection specified in GB/T 10151.

6.8 Appearance

Visual examination.

6.9 Environmental test

The environmental test shall be performed as per the provisions of YY/T 0291.

6.10 Safety requirements

It shall be performed as per the provisions of GB 9706.1, GB 9706.3, GB 9706.11, GB 9706.12, GB 9706.14, GB 9706.15 and YY 0505.