What should we know about radiation protection of C-arm fluoroscope?


C-arm fluoroscopy machine, also known as C-arm, C-ARM X-ray machine, is one of the commonly used equipment in orthopedics, mainly used in a variety of surgery, imaging, photography and other work. It can be directly used in the intraoperative positioning of orthopedics surgery, diagnosis and inspection of osteopathy, reduction, nail and other effects, as well as cooperate with the development of a variety of minimally invasive surgery, removal of metal foreign bodies in the body and other treatment has played a unique role.

C-arm fluoroscope will produce certain radiation in the process of use, which can bring varying degrees of harm to medical personnel and patients. How to implement safety protection measures for medical personnel and patients during the operation to reduce the harm of X-ray to human body to a greater extent?

What is the radiation protection of C-arm fluoroscope? What is the focus of personal protection?

First, time protection

1. On the premise of satisfying image quality, shorten the time and frequency of X-ray exposure as far as possible.

2. Intermittent perspective method is adopted to control the time of full exposure.

Two, distance protection

1. Avoid exposing your hands directly.

2. When the distance is doubled, the radiation drops to 1/4.

3. Orderly placement of items in the operating room as far as possible to reduce scattering and secondary radiation.

4, 2 meters away from C-arm perspective machine, equivalent to full protection.

5. If the ball tube and the enhancer are placed horizontally, they should stand on the side of the enhancer as far away as possible.

So two meters away from the machine, the Xray is close to zero?

The answer is: not necessarily. Radiation is definitely not zero at a distance of 2 meters from the C-arm fluoroscope. If no personal protection measures are taken, the annual absorbed dose must exceed the national safety standard. Even if you wear a 0.5mm lead equivalent, it’s only 99% lower, not zero.

Three, shielding protection

1. The operating room has lead protective wall.

2. The operating room is equipped with enough movable screens and personal protective equipment.

3. Note that crystals and thyroid glands are organs to be highly vigilant, so lead bibs and lead glasses are also essential.

So how do we choose lead glasses and lead clothing?

A: Glasses with 0.5 mm lead equivalent can absorb 99 percent of radiation. Try to buy glasses with side protection. Lead suits have lead equivalent of 0.25mm, 0.35mm and 0.5mm. For 100kV perspective, 0.25mm lead equivalent lead coat can reduce the radiation dose by 90%; A 0.5mm lead suit reduces scatter line damage by 97%.

4. Try to operate the ball tube under the bed.

C-arm perspective machine receiver as close to the shooting site as possible: The closer the receiver is to the patient, the more X-rays can be effectively received through the patient, and the corresponding ball tube is further away from the patient, the patient is exposed to less radiation, so the C-arm fluoroscope receiver can be as close to the shooting site as possible under the condition of meeting the asepsis requirements, so that the film quality is high, and the emission intensity is not too large. Magnification mode should be avoided for image size, as halving the field of view increases the dose rate to a factor of four.

5. Everyone hides behind the screen when the radiation is released.

So are we safe behind the lead screen?

The answer is: not necessarily. Rays hitting other equipment materials in the operating room can excite new scattering lines, which are rare but present and easily overlooked in actual protection. Since human mammary gland, gonad, eye lens and thyroid gland are sensitive organs to radiation, comprehensive personal protection should be taken.

Does the C-arm fluoroscope in the operating room emit a lot of radiation?

In general, a conventional stationary desktop X-ray device has about 0.1 millisieverts of radiation, and a single X-ray has almost negligible effects on a person, since the average person can receive about 50 millisieverts of radiation in a year. Compared with traditional X-ray inspection equipment, C-arm fluoroscope has a smaller amount of radiation, fast imaging, and basically will not cause too much impact on the human body.

If some patients’ conditions are complicated and the operation is difficult, the amount of radiation they receive will increase correspondingly when the C-arm fluoroscopy machine is used for confirmation several times during the operation, which may have an impact on the human body.

In addition, different manufacturers of C-arm perspective machine, its radiation size is not the same. In the case of Perlove Medical’s PLX119C, a large flat-panel integrated C-arm, the amount of radiation leaked when loaded is small, about one-third of the CFDA industry standard.

This C-arm fluoroscope uses the high frequency and high voltage generator technology independently developed by Perlove Medical. In the composition ratio of X-ray emitted by the C-ARM fluoroscope, hard rays, which have little harm to human body, account for a relatively high proportion, while soft rays, which are easy to be absorbed by biological tissues, account for a relatively low proportion.

In addition, the C-arm fluoroscope uses a large plate size of 30*30cm, which provides a wide field of vision and shows the entire lumbar vertebra in a single exposure. For example, “pedicle screw fixation” requires the pedicle screw to be inserted from the back of the vertebral body to the front of the vertebral body to achieve tricolumn fixation. The need to maintain a multi-cone operation during the procedure requires that the image be as low as possible showing the full lumbar vertebra. With PLX119C, the entire lumbar spine can be imaged in a single exposure, reducing the number of exposures and the radiation dose required for surgery.


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