YY/T 0744-2018Particular specifications for mobile C-arm X-ray equipment (English PDF)

3.1 Fluoroscopy spot image

An image, which is obtained by superimposing multiple frames of fluoroscopic images collected (has a higher signal-to-noise ratio than ordinary fluoroscopic images).

3.2 Fluoroscopy image subtraction

A digital image processing method, for subtracting fluoroscopic sequence images.

3.3 Radiography image subtraction

Digital image processing method, for subtraction of radiographic sequence images.

Note 1: Compared with "fluoroscopy image subtraction", "radiography image subtraction" has a higher X-ray dose and a higher quality of the subtracted image.

5.1 Working conditions

5.1.1 Environmental conditions

Unless otherwise specified, the working environmental conditions of the C-arm X-ray equipment shall meet the following requirements:

a) Ambient temperature: 10 °C ~ 40 °C;

b) Relative humidity: 30% ~ 75%;

c) Atmospheric pressure: 700 hPa ~ 1060 hPa.

5.1.2 Power conditions

The manufacturer shall describe the power supply conditions, which are used by the product, in the accompanying documents. The working power supply conditions shall meet:

a) Power supply voltage and number of phases: As specified by the manufacturer, the network voltage fluctuation shall not exceed ±10% of the nominal value;

b) Power frequency: 50 Hz ± 1 Hz;

c) Power supply resistance: As specified by the manufacturer, but shall meet the requirements of Table 101 in 10.2.2a) of GB 9706.3-2000;

d) Power capacity: As specified by the manufacturer.

5.2 Electric power

5.2.1 Maximum output electrical power

A C-arm X-ray equipment shall specify the corresponding combination of X-ray tube voltage and X-ray tube current, that results in maximum output electrical power, in fluoroscopy and/or radiography modes.

5.2.2 Nominal electrical power

It shall be stipulated that when the loading time is 0.1 s and the X-ray tube voltage is 100 kV, the maximum constant electric power output, expressed in kilowatts (kW), that can be provided by the X-ray generating device, as the nominal electric power. If this value cannot be pre-selected, it may use the X-ray tube voltage value, which is closest to 100 kV and the closest loading time value, but not shorter than 0.1 s.

The nominal electrical power shall be given, together with a combination of X-ray tube voltage, X-ray tube current, loading time.

5.3 Loading factors and controls

5.3.1 X-ray tube voltage

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

a) The manufacturer shall specify the adjustment range and adjustment method of the X-ray tube voltage;

b) The manufacturer shall specify the deviation of the X-ray tube voltage value, which shall at least meet the requirements of 50.103.1 in GB 9706.3-2000.

5.3.2 X-ray tube current

The X-ray tube current shall meet the following requirements:

a) The manufacturer shall specify the adjustment range and adjustment method of X-ray tube current, in continuous and highest frame rate pulsed fluoroscopy mode;

b) The manufacturer shall specify the deviation of the current value of the X-ray tube, which shall at least meet the requirements of 50.103.2 in GB 9706.3-2000.

5.3.3 Loading time

The loading time shall meet the following requirements:

a) If the loading time display is provided and the single-frame radiography function is provided, the manufacturer shall specify the adjustment range and adjustment method of the loading time, for single-frame radiography;

b) The manufacturer shall specify the deviation of the loading time value, which shall at least meet the requirements of 50.103.3 in GB 9706.3-2000.

5.3.4 Current time product

If the current time product display is provided, the current time product shall meet the following requirements:

a) The manufacturer shall specify the adjustment range and adjustment method of current time product;

b) The manufacturer shall specify the deviation of the current time product, which shall at least meet the requirements of 50.103.4 in GB 9706.3-2000.

5.3.5 Overload protection

shall not be greater than 5 s.

5.4.8 Fluoroscopy imaging stability time

The manufacturer shall specify the fluoroscopic image stabilization time, under continuous and highest pulse fluoroscopic frame rate, which shall not exceed 2 s.

5.4.9 Fluoroscopy recovery time

The fluoroscopy recovery time shall not exceed 5 min.

5.4.10 Fluoroscopic performance during network transmission

In fluoroscopy, if selecting network transmission, it shall not affect the fluoroscopy.

5.4.11 Artifacts

No artifacts affecting clinical application.

5.4.12 Digital subtraction imaging performance

5.4.12.1 Imaging performance of radiography image subtraction

If the C-arm X-ray equipment has the radiography image subtraction imaging function, it shall meet the following requirements:

a) The manufacturer shall specify the dynamic range; but at least the thickest one vessel simulation component is visible in all steps;

b) The manufacturer shall specify the contrast sensitivity; but the 0.1 mm vessel simulation component shall be visible, at least in the 0.8 mm copper step;

c) When the two images of the fixed object have the same spatial coordinate characteristics, there shall be no misregistration artifacts.

5.4.12.2 Imaging performance of fluoroscopy image subtraction

If the C-arm X-ray equipment has the function of fluoroscopic image subtraction imaging, it shall meet the following requirements:

a) The manufacturer shall specify the contrast sensitivity; but the 0.4 mm vessel simulation component shall be visible, at least in the 0.8 mm copper step.

b) When the two images of the fixed object have the same spatial coordinate characteristics, there shall be no misregistration artifacts.

Note: See 5.5.2 for dose requirements for high or low contrast mode of 3D imaging.

5.5 Radiation safety

5.5.1 Dosage indication

The dose indication of the C-arm X-ray equipment shall meet the following requirements:

a) The instruction manual shall specify the measurement reference point and calibration information of the dose indication value.

b) During the fluoroscopy process, the air kerma rate shall be continuously indicated in milliGe per minute (mGy/min); refreshed at least once per second; the indication shall be clearly visible in the normal working position.

c) Since the last reset setting, the cumulative value of air kerma, which is generated by all fluoroscopy and radiography shall be continuously indicated in milliGe (mGy); refreshed at least every 5s; OR indicated within 5 s after the end of loading, meanwhile the indication shall be clearly visible in the normal working position.

d) The indicated values of air kerma rate and accumulated air kerma shall be clearly distinguishable.

e) Accuracy of air kerma and air kerma rate:

- The error of the indicated value of air kerma rate, which exceeds 6 mGy/min, shall not be greater than 35%;

- The error of the indicated value of accumulated air kerma energy, which exceeds 100 mGy, shall not be greater than 35%.

f) The C-arm X-ray equipment shall provide an indication of the cumulative dose meet the requirements of radiation dose for medical X-ray radiography and fluoroscopy equipment in IEC 61910-1:2014.

5.5.5 Pediatric examinations

If the equipment is claimed to be suitable for use as a pediatric examination, it shall meet the following requirements:

a) Instructions for use shall include measures for dose reduction in pediatric examinations;

b) The anti-scatter grid should be detachable without tools, BUT it is not suitable for C-arm X-ray equipments, that can be used with navigation equipment.

5.6 Mechanical device performance

5.6.1 Mechanical range of movement

5.6.1.1 Sliding of C-arm

The equipment, whose C-arm can slide along the arc of the track, shall meet the following requirements:

a) The arc sliding angle along the track should not be less than 110°. If there is an angle indication, the deviation, between the indicated value and the actual value, shall be specified by the manufacturer;

b) The manually operated C-arm sliding shall be provided with a locking and positioning device; its braking torque shall not be less than 50 N·m;

c) Manually operated slipping start torque shall not be greater than 40 N·m.

5.6.1.2 C-arm rotation

Equipment, whose C-arm can be rotated along the horizontal axis, shall meet the following requirements:

a) The rotation angle should not be less than ±180°. If there is an angle indication, the deviation, between the indicated value and the actual value, shall be specified by the manufacturer;

b) The manually operated C-arm rotation shall be provided with a locking and positioning device; its braking torque shall not be less than 45 N·m;

c) The rotation starting torque of manual operation shall not be greater than 35 N·m.

5.6.1.3 Movement of C-arm

Equipment, whose C-arm can move vertically and horizontally, shall meet the following requirements:

a) The movement range shall be specified; if there is an indication, the deviation of the indicated value shall be specified by the manufacturer;

b) The movement of manually operated C-arm shall be provided with a locking and positioning device; its braking force shall not be less than 100 N;

c) The starting force shall meet the requirements of 5.5.5 in YY/T 0106-2008.

5.6.1.4 Horizontal swing

For the equipment, whose C-arm can be used for horizontal swing, its swing shall meet the following requirements:

a) The manufacturer shall specify the swing angle and the deviation value of the angle;

b) The swing of manually operated C-arm shall be provided with a locking and positioning device; its braking torque shall not be less than 40 N·m;

c) The swing starting torque of manual operation shall not be greater than 25 N·m.

Note: If the movement of the C-arm is balanced at random, the requirements for braking force or braking torque in 5.6.1.1 to 5.6.1.4 do not apply.

5.6.1.5 Focal point-image receiver distance of C-arm

The focus-image-receiver distance (SID) shall be specified. The deviation value shall be within ±5% of the specified value.

5.6.1.6 Arc depth of C-arm

The maximum vertical depth, from the center of the X-ray beam to the arc wall of the C-arm, shall be specified. The deviation value shall be within ±5% of the specified value.

5.6.1.7 C-arm's opening distance

The minimum distance, from the shell of the X-ray source assembly to the image receiver, shall be specified. The deviation value shall be within the range of ±5% of the specified value.

5.6.2 Movement performance

The movement performance of the C-arm shall meet the following requirements:

6.2.1 Maximum output electrical power

- In the continuous mode, according to the combination of loading factors, which lead to the maximum output electric power, continuously load for more than 30 s; observe whether there is any abnormal phenomenon;

- In the intermittent mode, load according to the combination of loading factors, that lead to the maximum output electric power; observe whether there is any abnormal phenomenon.

6.2.2 Nominal electrical power

Load according to the combination of X-ray tube voltage, X-ray tube current, loading time, which result in the nominal electric power. Observe whether there is any abnormal phenomenon.

6.3 Loading factors and controls

6.3.1 X-ray tube voltage

Carry out test as follows:

a) Verify that the actual operation meets the requirements of 5.3.1 a);

b) The deviation of X-ray tube voltage value shall be carried out, according to the provisions of 50.104.1 in GB 9706.3-2000.

6.3.2 X-ray tube current

Carry out test as follows:

a) Verify that the actual operation meets the requirements of 5.3.2 a);

b) The deviation of the current value of the X-ray tube shall be carried out, according to the provisions of 50.104.2 in GB 9706.3-2000.

6.3.3 Loading time

Carry out test as follows:

a) Verify that the actual operation meets the requirements of 5.3.3 a);

b) The deviation of the loading time value shall be carried out, according to the provisions of 50.104.3 a) in GB 9706.3-2000.

6.3.4 Current time product

Carry out test as follows:

a) Verify that the actual operation meets the requirements of 5.3.4 a);

b) The deviation of the current time product value shall be carried out, according to the provisions of 50.104.4 in GB 9706.3-2000.

6.3.5 Overload protection

Carry out test as follows:

a) Adjust each parameter to the maximum load factor combination value, which is specified by the manufacturer. When any load factor is adjusted to the adjacent increase gear, the load factor condition will not increase.

b) Carry out practical operation and inspection of random files.

c) Practical operation check.

6.4 Imaging performance

6.4.1 Spatial resolution

Carry out the test layout, according to Figure A.1 in the Appendix. Use the multi-function test card, as shown in Figure B.1 in the Appendix, to adjust the SID to the minimum value, which is allowed by the system. Set the image field of view to the value, which is specified in 5.4.1. Select the appropriate organ program. Carry out automatic fluoroscopy or radiography; record spatial resolution values and corresponding load factor combinations. If necessary, add an appropriate attenuator, so that the X-ray tube voltage is within the range of 75 kV ± 7 kV. If the C-arm X-ray equipment has no automatic fluoroscopy or radiography function, manually set the X- ray tube voltage to 75 kV ± 7 kV; manually adjust the tube current or current time product, to the maximum discernible dynamic order wedge number (component 2 in Figure B.1). Record the spatial resolution and the corresponding combination of loading factors. Remove the multi-function test card. Place the detector of the dosimeter, as close as possible to the incident surface of the image receiver. Place a copper plate, which has a thickness of 1.5 mm, in the X-ray beam, AND cover the entire incident surface of the image receiver, to carry out automatic fluoroscopy or radiography. If necessary, adjust the attenuator, so that the combination of loading factors is close to the previously recorded value. If there is no automatic mode, manually set the previously recorded combination of loading factors or close values; perform the fluoroscopy or radiography again. Record the air kerma and air kerma rate of fluoroscopy and radiography, respectively; the dose shall not exceed the specified value in 5.5.2. If the dosimeter detector cannot be placed on the incident surface of the image receiver, it shall be converted, according to the formula (6) in 6.5.2.

If the size of the image receiver is less than 16 cm, the multi-function test card can be moved, so that the pair discrimination card is located in the center of the receiving field.