검색
검색 팝업 닫기

Ex) Article Title, Author, Keywords

Article

J Vet Clin 2023; 40(6): 429-437

https://doi.org/10.17555/jvc.2023.40.6.429

Published online December 31, 2023

A New Radiation-Shielding Device for Restraining Veterinary Patients

Songyi Kim , Minju Lee , Miju Oh , Yooyoung Lee , Jiyoung Ban , Jiwoon Park , Sojin Kim , Uhjin Kim , Jaepung Han , Dongwoo Chang*

Department of Veterinary Diagnostic Imaging, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea

Correspondence to:*dwchang@cbnu.ac.kr

Received: September 30, 2023; Revised: November 2, 2023; Accepted: November 7, 2023

Copyright © The Korean Society of Veterinary Clinics.

In veterinary medicine, most radiographic images are obtained by restraining patients, inevitably exposing the restrainer to secondary scattered radiation. Radiation exposure can result in stochastic reactions such as cancer and genetic effects, as well as deterministic reactions such as skin burns, cataracts, and bone marrow suppression. Radiation-shielding equipment, including aprons, thyroid shields, eyewear, and gloves, can reduce radiation exposure. However, the risk of radiation exposure to the upper arms, face, and back remains, and lead aprons and thyroid shields are heavy, restricting movement. We designed a new radiation-shielding system and compared its shielding ability with those of conventional radiation-shielding systems. We hypothesized that the new shielding system would have a wider radiation-shielding range and similar shielding ability. The radiation exposure dose differed significantly between the conventional and new shielding systems in the forehead, chin, and bilateral upper arm areas (p < 0.001). When both systems were used together, the radiation- shielding ability was better than when only one system was used at all anatomical locations (p < 0.01). This study suggests that the new radiation-shielding system is essential and convenient for veterinary radiation workers because it is a step closer to radiation safety in veterinary radiography.

Keywords: x-ray, radiation shield, radiation protection, apron, curtain

Radiography is a fundamental, economical, and commonly used modality for diagnosing a wide range of illnesses (7,9). In veterinary medicine, animals are restrained to obtain accurate radiographic images, even if radiographers should not directly hold an animal patient during radiography. When medical X-ray equipment is used, radiation exposure may occur through three major sources: primary X-ray beams, scattered X-rays, and X-ray leakage (17). Although secondary radiation can be dispersed in any direction, most of it is scattered at an angle <45° to the incident beam, and depending on the subject and distance, the exposure dose can be up to 3% of the incident radiation dose (3). Therefore, veterinarians are more likely to be exposed to occupational radiation than doctors and dentists are (3).

Radiation exposure can result in stochastic reactions, such as cancer and genetic effects, and deterministic reactions, such as skin burns, cataracts, and bone marrow suppression (10).

Medical physicists are familiar with the ALARA principle, in which radiation doses should be maintained as low as reasonably achievable (11). Three principles are used to reduce radiation exposure: increasing the distance from the source, decreasing the exposure time, and utilizing the correct shielding equipment. Radiation exposure according to X-ray distance and imaging time may differ depending on the patient's imaging region and compliance; therefore, wearing shielding equipment is the first method for reducing radiation exposure. Radiation-shielding equipment commonly used in veterinary hospitals includes aprons, thyroid shields, glasses, and gloves (8).

Typical aprons shield the chest, abdomen, gonads, and parts of the upper legs, whereas thyroid shields, gloves, and glasses protect the thyroid gland, hands, wrists, and eyes. These accessories protect several parts of the body, but the risk of radiation exposure to the upper arm, face (except the eyes), and back areas of the body remains (20). Aprons and thyroid shields are made of lead and are heavy, restricting movement. Furthermore, wearing them for long periods can result in fatigue, back pain, and spinal diseases (1,6,12,14). Nevertheless, this problem has been addressed by using lead-free aprons and thyroid shields made of bismuth and tungsten, which are lighter than lead (15). However, because wearing radiation-shielding garments while performing radiography is difficult, the rate of filming after wearing these garments remains low (8,19).

Medical doctors use radiation-shielding devices in addition to aprons and thyroid shields to reduce radiation exposure (18). Therefore, veterinary hospitals require additional shielding systems for radiation workers to reduce the number of exposed body parts.

This study aimed to evaluate the radiation-shielding range and performance of a new shielding system compared with those of a conventional radiation-shielding system and to explain the convenience of the new shielding system. We hypothesized that the new shielding system would have a wider radiation-shielding range with a similar shielding ability and that when both systems were used together, the radiation-shielding ability would increase when only one system was used.

Study design

This study investigated the use of a new radiation-shielding system for X-ray radiation protection. The new radiation-shielding system was compared with a conventional shielding system to demonstrate whether it provides better radiation protection over a wide range. The radiation dose measurements for each protective shielding system were compared with those of the control group.

Materials

This study utilized a full-body mannequin and a cylindrical acrylic water phantom (P/N 46-241709G1; GE Healthcafé, Madison, WI, US), 23 cm in diameter and 14 cm in height, filled with distilled water, to simulate a restrained animal patient.

We used a lead-free apron, thyroid shield, glass, gloves, radiation-shield curtain, and head-shield plate for the radiation-shielding system (Fig. 1). A 0.25-mm lead equivalent lead-free apron (Rad-Ban BF2; Drview, Seoul, Korea), a 0.5-mm lead equivalent at the collar and a 0.25-mm lead equivalent upper chest region thyroid shield (Rad-Ban TH; Drview), and 0.13-mm lead equivalent glasses (XR-700, Toray, Tokyo, Japan) were used as conventional radiation-shielding systems. The new radiation-shielding system consists of a radiation-shield curtain and a head-shield plate (Fig. 2). The curtain frame, made of steel, measured 68 cm wide, 60-80 cm long, and 50-60 cm high, and had a five-layered drape made of bismuth across the frame. The shield plate consisted of a 40-cm-wide and 20-cm-long lead acrylic plate across the frame. The frame, drape, and shield plates are detachable. The drape and lead acrylic plates contained a lead equivalent of 0.25 mm. The angle of the shielding plate can be adjusted according to the convenience of the compensator. A pair of 0.25-mm lead equivalent gloves (Raon PGL02; S&C Company, Seoul, Korea) was used in both shielding systems.

Figure 1.Conventional radiation-shielding system: (A) lead-free aprons (Rad-Ban BF2; Drview), (B) thyroid shield (Rad-Ban TH; Drview), (C) glasses (XR-700; Toray, Tokyo, Japan), and (D) gloves (Raon PGL02; S&C Company) were used in both the conventional and new shielding systems. (E) Complete conventional radiation-shielding system when worn.

Figure 2.New radiation-shielding system. (A-C) Radiation-shielding curtain. (A) The curtain frame to which the curtains are attached is made of a steel frame (length, 68 cm; width, 60-80 cm; height, 50-60 cm). (B) The curtain drape is made of a five-layer bismuth material with a lead equivalent of 0.25 mm. (C) Curtain holder with curtain drapes on the X-ray table. (D-F) Head-shielding plate. (D) The head-shielding plate has a 40 × 20-cm lead acrylic plate and a lead equivalent of 0.25 mm, which can be used in the shield curtain. (E) The angle can be adjusted according to the height and convenience of the restrainer. (F) Protecting scatter radiation (red lines) from primary radiation (blue lines).

Thermoluminescent dosimeters (TLDs) (UD-802AS, Panasonic Co., Japan) were used to measure the cumulative exposure dose for each group. The TLDs were fixed at nine locations on the body: the forehead, chin, thyroid gland, left breast, right and left upper arms, gonad, and right and left upper thighs. The forehead TLD was positioned near the glasses without blocking the field of vision of the mannequin (Fig. 3).

Figure 3.(A) Thermoluminescent dosimeters (TLDs) attached on nine locations of body parts: forehead, chin, thyroid gland, left breast, right and left upper arms, gonad, and right and left upper thighs. (B) In groups using the conventional shielding system, the TLDs for the thyroid, left chest, gonad, and bilateral thigh sites are attached under the apron and thyroid shield (dashed square). Lt., left; Rt., right.

Procedures

There were three experimental groups and one control group. Group 1 wore the new radiation-shielding system with gloves. Group 2 wore both the new radiation-shielding system and the conventional shielding system with gloves. Group 3 wore the conventional shielding system with gloves. Group 4, which served as the control group, did not wear any shielding systems (Table 1, Fig. 4). The settings for the primary radiation were a tube voltage of 70 kV, a tube current of 200 mA (similar to the standard for abdominal radiography), and an exposure time of 500 ms (approximately 20 times longer than the standard exposure time) to ensure that they were as similar as possible to the set tube voltage and current. All groups underwent radiography 10 times under the same conditions. We estimated the shielding ratio of each shielding system using the dose measured at each group’s anatomical site, using the equation below (16). Group 4 was the control group, and groups 1, 2, and 3 were the experimental groups.

Table 1 Ancillary protection equipment usage by group

Shield curtain (with lead plate)ApronThyroid shieldGlassGloves
Group 1OXXXO
Group 2OOOOO
Group 3XOOOO
Group 4XXXXX

O, with ancillary protection equipment; X, without ancillary protection equipment.



Figure 4.Radiation-shielding system of each group. (A, B) Group 1: new radiation-shielding system with lead gloves. (C, D) Group 2: conventional and new radiation-shielding systems with lead gloves. (E, F) Group 3: conventional radiation-shielding system with lead gloves. (G, H) Group 4 (control group): no radiation-shielding system.

Shieldingratio(%)=Dosewithcontrolgroupdosewith  experimeltal groupDosewithcontrolgroupx100

Statistical analysis

Statistical analyses were performed using SPSS for Windows (version 21.0; IBM Corp., Armonk, NY, USA) and Prism version 9.0 (GraphPad Software, San Diego, CA, USA). Data for each anatomical location are expressed as the mean ± standard deviation. For all tests, statistical significance was set at p < 0.05. Data were analyzed using the Kruskal-Wallis test after evaluating normality using the Shapiro–Wilk test. The Bonferroni test was performed for post-hoc analysis.

For each group, ten radiation exposure experiments were performed under the same conditions at all nine anatomical locations. The experimental dose study involved 1080 exposures, resulting in 108 dose readings, and measurements were calculated. After the data were evaluated, the radiation exposure doses in particular anatomical regions varied according to the use of the new radiation-shielding system.

Radiation exposure doses were measured in all experimental and control groups. In group 4 (the control group), the mean radiation exposure dose in the nine locations was 0.686 ± 0.389 mSv (Table 2). Compared to the doses associated with other anatomical regions, the exposure dose was 0.053 ± 0.015 mSv at the left thigh and 0.120 ± 0.095 mSv at the right thigh, which were approximately 7-10 times lower than those of upper body parts on average. The exposure doses in the experimental group were significantly higher than those in the control group, except for the left thigh. The radiation exposure doses for the forehead, chin, and bilateral upper arms using the new radiation-shielding system and those using both the conventional and new shielding systems were remarkably lower than those using the conventional system. The bilateral thigh exposure doses were higher when using the new radiation-shielding system than when using the conventional shielding system. The exposure dose in the thyroid, left chest, and gonad from 0.01 to 0.02 mSv did not differ significantly when using the conventional system, the new shielding system, and when using them together (Figs. 5, 6).

Table 2 Mean radiation exposure dose (mSv) of the nine anatomical locations in the different shielding system groups

Group 1Group 2Group 3Group 4
Forehead0.017 ± 0.0120.017 ± 0.0120.433 ± 0.1020.487 ± 0.072
Chin0.053 ± 0.0580.0101.093 ± 0.1901.197 ± 0.150
Thyroid0.013 ± 0.0060.0100.0100.857 ± 0.261
Left chest0.0100.0100.013 ± 0.0060.853 ± 0.275
Left upper arm0.013 ± 0.0060.0100.693 ± 0.1160.793 ± 0.090
Right upper arm0.017 ± 0.0120.0100.603 ± 0.1690.777 ± 0.070
Gonad0.013 ± 0.0060.013 ± 0.0060.013 ± 0.0060.997 ± 0.254
Left thigh0.043 ± 0.0150.013 ± 0.0060.0100.057 ± 0.015
Right thigh0.063 ± 0.0230.017 ± 0.0120.0100.160 ± 0.026


Figure 5.Column bar box of radiation exposure dose for each anatomical location using different radiation-shielding systems. (A) Group 1 used the new radiation-shielding system. (B) Group 2 used both a conventional and the new radiation-shielding systems. (C) Group 3 used a conventional radiation-shielding system. (D) Group 4 (control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. Exposure doses measured in the control group were higher than those measured at the same anatomical locations in all experimental groups. Exposure doses were significantly higher in group 3 for the head, chin, and bilateral upper arm regions than those in groups 1 and 2. Lt., left; Rt., right.

Figure 6.Column bar box of radiation exposure dose for each group using different radiation-shielding systems. Radiation exposure dose of nine anatomical locations. (A) forehead, (B) chin, (C) thyroid, (D) Lt. chest, (E) Lt. upper arm, (F) Rt. upper arm, (G) gonad, (H) Lt. thigh and (I) Rt. thigh. Group 1 used the new radiation-shielding system. Group 1 used the new radiation-shielding system. Group 2 used both a conventional and the new radiation-shielding systems. Group 3 used a conventional radiation-shielding system. Group 4 (control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. Significant reduction in exposure was observed when the new shielding systems were used in the forehead, chin, and bilateral arm regions, and no significant difference was observed in other locations (groups 1 and 2 vs. group 3). Significant differences in exposure dose were observed when conventional and the novel shielding systems were used on the bilateral thighs, respectively (group 1 vs. group 3). *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001; ns, no significance; Lt, left; Rt, right.

The radiation exposure doses of groups 1, 2, and 3, which are the experimental groups, at all anatomical locations were 0.029 ± 0.028, 0.013 ± 0.009, and 0.320 ± 0.397 mSv, respectively. The exposure dose was significantly higher in group 3 than in groups 1 and 2 (p < 0.01) (Fig. 7).

Figure 7.Column bar box of mean radiation exposure values for all anatomical locations using different radiation-shielding systems. Group 1 used the new radiation-shielding system. Group 2 used both a conventional and the new radiation-shielding systems. Group 3 used a conventional radiation-shielding systems. Group 4 (control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. Significant differences in exposure doses were observed among all groups except groups 1 and 2. p < 0.05 was considered significant. **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001; ns, no significance.

Because the exposures at the thyroid, left chest, gonads, and bilateral thighs were similarly low among the experimental groups, the results were excluded, and the exposure doses at the forehead, chin, and bilateral upper arms were compared again. The exposure doses of groups 1, 2, 3, and 4 were 0.025 ± 0.031, 0.012 ± 0.006, 0.706 ± 0.283, and 0.793 ± 0.296 mSv, respectively (Fig. 8). In the absence of the new radiation-shielding system, the exposure dose was significantly higher (p < 0.001).

Figure 8.Column bar box of mean radiation exposure values for the forehead, chin, and bilateral upper arm areas using different radiation-shielding systems. Group 1 used the new radiation-shielding system. Group 2 used both conventional and the new radiation-shielding systems. Group 3 used a conventional radiation-shielding system. Group 4 (the control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. The exposure dose of group 3 was similar to that of group 4. p < 0.05 was considered significant. ****p ≤ 0.0001; ns, no significance.

The shielding ratio of group 2 at the anatomical positions, except for both thighs, was the same or greater than that of groups 1 and 3, and the shielding ratio at positions deemed to have been shielded was observed to be approximately 93% to 99% in the experimental groups (Table 3). The exposure rate of the left thigh was higher than that of the right thigh in all groups.

Table 3 Shielding ratio (%) of the scattered dose after shielding in different systems

Group 1Group 2Group 3
Forehead96.4096.7511.67
Chin95.3199.168.80
Thyroid98.2198.7698.76
Left chest98.7398.7398.44
Left upper arm98.3498.7312.87
Right upper arm97.8498.7122.92
Gonad98.7098.7098.70
Left thigh24.2175.7981.35
Right thigh60.7188.5093.62

All imaging modalities have been utilized and studied in veterinary medicine; however, X-rays are the most popular for administrative, managerial, and financial reasons (9). In medicine, various suspended radiation protection systems have been studied and used to minimize exposure to various parts of the human body during computed tomography and interventional radiology (18). Although the exposure dose of X-rays is lower than that of fluoroscopy or computed tomography, the radiography number cannot be disregarded because veterinary hospitals have the largest prevalence and the use of X-rays increases yearly (5). Many different types of radiation protection systems are available worldwide. However, to our knowledge, this is the first veterinary medicine invention that uses an X-ray table with a curtain-type radiation-shielding system. Our study shows that this novel radiation-shielding system is a practical alternative to aprons, thyroid shields, and glasses for radiation protection. Additionally, the inconvenience of wearing glasses whenever performing radiography could be reduced owing to a new shielding system that was set up on the X-ray table, and the moisture issues that occurred when wearing glasses were partially resolved.

In the present study, the mean exposure doses to the left chest were the highest among the nine anatomical locations, followed by the gonads and chin. However, in a previous study, the thyroid had a higher radiation exposure than that of the chest and gonads (13), and we believe that this is because of the different phantoms used for the X-rays and the position of the restrainer. The radiation exposure dose to the upper body is 7-10 times higher than that to the bilateral thighs. It is assumed that the scattered radiation coming from the table could make its way to the restrainer’s gonads (2), and there is also the possibility that the table acted as radiation protection.

Both radiation-shielding systems showed high defense capabilities in the left chest, thyroid, and gonad positions. However, when comparing the radiation exposure in the forehead, chin, left arm, and right arm areas, high doses were measured in the conventional shielding group, similar to those in the control group, whereas those using the new shielding tool were measured as low as the left chest, thyroid, and gonad values measured in the same group. These data confirm that the novel shielding system protected a wider scan range against scattered radiation than the range protected by the classical shielding system, including the forehead, chin, and bilateral arms.

When using only the conventional shielding system, the average exposure dose to the forehead, chin, and bilateral upper arms was 0.706 ± 0.283 mSv, and it was calculated as 0.056 ± 0.023 mSv when converted according to the general abdominal radiographic criteria (70 kV, 8 mAs). According to the International Commission on Radiological Protection (ICRP), the annual equivalent dosage for radiation-related personnel is 500 mSv or less for the skin and 150 mSv or less for lenses (4). Based on the current experimental results and ICRP regulations, if 173.6 radiographs are obtained per week arithmetically, the annual skin equivalent dose will be exceeded, and if 52 radiographs are obtained per week arithmetically, the annual lens equivalent dose will be exceeded. Therefore, a new shielding system is needed to ensure the safety of the restrainer in veterinary hospitals.

Finally, a new shielding system in the form of curtains and lead plates was developed. Because the curtain drape is easy to move and both the drape and plate are detachable, correct radiation shielding cannot be achieved.

Inexperienced users may not be able to use it properly, resulting in errors such as excessive gaps in the curtain drapes or use without drapes or lead plates. Therefore, the proper application of this new radiation system must be understood.

In a previous study on the radiation-shielding rate with an apron, the shielding rate for a 0.25-mm lead equivalent apron was 88.82-90.91%; in this study, the shielding rate was 97-98%, which was higher than those reported in previous studies. This is thought to represent the difference between the primary radiation energy and the distance between the scattered radiation and dosimeter.

This study had some limitations. A cylindrical phantom was used in the experiment. Because the direction of scattered radiation caused by the cylindrical phantom may differ from the direction of scattering in an actual patient, it is believed that using the dog phantom can produce more accurate results and that the new shielding system can shield a wider range of radiation than that shielded by the conventional shielding system. However, it is impossible to shield the lower arm area, including the hand. Therefore, wearing gloves during filming is essential.

In conclusion, in this study, a new radiation-shielding system exhibited the same shielding capability as that of a conventional radiation-shielding system, can provide a wider range of radiation shields, and can solve the difficulties of using traditional shielding tools. In addition to the conventional shielding system, we anticipated that the new shielding system will be a new shielding paradigm that will further improve the safety of radiation workers in veterinary hospitals.

This work was supported by Institute for Information & communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (No. 2021-0-00490, Development of Precision Analysis and Imaging Technology for Biological Radio Waves).

  1. Andrew S, Abdelmonem MR, Kohli S, Dabke H. Evaluation of back pain and lead apron use among staff at a district general hospital. Cureus. 2021; 13: e18859.
    Pubmed KoreaMed CrossRef
  2. Barber J, McNulty JP. Investigation into scatter radiation dose levels received by a restrainer in small animal radiography. J Small Anim Pract. 2012; 53: 578-585.
    Pubmed CrossRef
  3. Hupe O, Ankerhold U. Determination of the dose to persons assisting when X-radiation is used in medicine, dentistry and veterinary medicine. Radiat Prot Dosimetry. 2011; 144: 478-481.
    Pubmed CrossRef
  4. International Commission on Radiological Protection (ICRP). ICRP publication 103. The 2007 recommendations of the international commission on radiological protection. ICRP. 2007.
  5. Kang KM, Suh TY, Kim YS, Yun SJ. Convergence analysis of safety management for radiation workers and diagnostic radiation-generator devices of animal hospital in Korea. J Korea Converg Soc. 2020; 11: 55-61.
  6. Kim SC, Choi JR, Jeon BK. Physical analysis of the shielding capacity for a lightweight apron designed for shielding low intensity scattering X-rays. Sci Rep. 2016; 6: 27721.
    Pubmed KoreaMed CrossRef
  7. Martinez NE, Van Bladel L. Radiation protection challenges in applications of ionising radiation on animals in veterinary practice. Ann ICRP. 2020; 49(1_suppl): 158-168.
    Pubmed CrossRef
  8. Mayer MN, Koehncke NK, Belotta AF, Cheveldae IT, Waldner CL. Use of personal protective equipment in a radiology room at a veterinary teaching hospital. Vet Radiol Ultrasound. 2018; 59: 137-146.
    Pubmed CrossRef
  9. Meomartino L, Greco A, Di Giancamillo M, Brunetti A, Gnudi G. Imaging techniques in veterinary medicine. Part I: radiography and ultrasonography. Eur J Radiol Open. 2021; 8: 100382.
    Pubmed KoreaMed CrossRef
  10. Mettler FA. Medical effects and risks of exposure to ionising radiation. J Radiol Prot. 2012; 32: N9-N13.
    Pubmed CrossRef
  11. Miller DL, Schauer D. The ALARA principle in medical imaging. Philosophy. 2015; 40: 38-40.
  12. Monaco MGL, Carta A, Tamhid T, Porru S. Anti-X apron wearing and musculoskeletal problems among healthcare workers: a systematic scoping review. Int J Environ Res Public Health. 2020; 17: 5877.
    Pubmed KoreaMed CrossRef
  13. Oh H, Sung S, Lim S, Jung Y, Cho Y, Lee K. Restrainer exposure to scatter radiation in practical small animal radiography measured using thermoluminescent dosimeters. Vet Med. 2018; 63: 81-86.
    CrossRef
  14. Papadopoulos N, Papaefstathiou C, Kaplanis PA, Menikou G, Kokona G, Kaolis D, et al. Comparison of lead-free and conventional X-ray aprons for diagnostic radiology. In: World Congress on Medical Physics and Biomedical Engineering. . Munich, Germany. New York: Springer. 2009: 544-546.
    CrossRef
  15. Park HH. The evaluation of performance and usability of bismuth, tungsten based shields. J Radiol Sci Technol. 2018; 41: 611-616.
    CrossRef
  16. Park MH, Kwon DM. Measurement of apron shielding rate for X-ray and gamma-ray. J Radiol Sci Technol. 2007; 30: 245-250.
  17. Park S, Kim M, Kim JH. Radiation safety for pain physicians: principles and recommendations. Korean J Pain. 2022; 35: 129-139.
    Pubmed KoreaMed CrossRef
  18. Savage C, Seale TM IV, Shaw CJ, Angela BP, Marichal D, Rees CR. Evaluation of a suspended personal radiation protection system vs. conventional apron and shields in clinical interventional procedures. Open J Radiol. 2013; 3: 143-151.
    CrossRef
  19. Shirangi A, Fritschi L, Holman CD. Prevalence of occupational exposures and protective practices in Australian female veterinarians. Aust Vet J. 2007; 85: 32-38.
    Pubmed CrossRef
  20. Yoon SY. Measurement and evaluation of radiation exposure doses for radiation workers in veterinary hospitals. [thesis]. Gwangju: Nambu University; 2015.

Article

Original Article

J Vet Clin 2023; 40(6): 429-437

Published online December 31, 2023 https://doi.org/10.17555/jvc.2023.40.6.429

Copyright © The Korean Society of Veterinary Clinics.

A New Radiation-Shielding Device for Restraining Veterinary Patients

Songyi Kim , Minju Lee , Miju Oh , Yooyoung Lee , Jiyoung Ban , Jiwoon Park , Sojin Kim , Uhjin Kim , Jaepung Han , Dongwoo Chang*

Department of Veterinary Diagnostic Imaging, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea

Correspondence to:*dwchang@cbnu.ac.kr

Received: September 30, 2023; Revised: November 2, 2023; Accepted: November 7, 2023

This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In veterinary medicine, most radiographic images are obtained by restraining patients, inevitably exposing the restrainer to secondary scattered radiation. Radiation exposure can result in stochastic reactions such as cancer and genetic effects, as well as deterministic reactions such as skin burns, cataracts, and bone marrow suppression. Radiation-shielding equipment, including aprons, thyroid shields, eyewear, and gloves, can reduce radiation exposure. However, the risk of radiation exposure to the upper arms, face, and back remains, and lead aprons and thyroid shields are heavy, restricting movement. We designed a new radiation-shielding system and compared its shielding ability with those of conventional radiation-shielding systems. We hypothesized that the new shielding system would have a wider radiation-shielding range and similar shielding ability. The radiation exposure dose differed significantly between the conventional and new shielding systems in the forehead, chin, and bilateral upper arm areas (p < 0.001). When both systems were used together, the radiation- shielding ability was better than when only one system was used at all anatomical locations (p < 0.01). This study suggests that the new radiation-shielding system is essential and convenient for veterinary radiation workers because it is a step closer to radiation safety in veterinary radiography.

Keywords: x-ray, radiation shield, radiation protection, apron, curtain

Introduction

Radiography is a fundamental, economical, and commonly used modality for diagnosing a wide range of illnesses (7,9). In veterinary medicine, animals are restrained to obtain accurate radiographic images, even if radiographers should not directly hold an animal patient during radiography. When medical X-ray equipment is used, radiation exposure may occur through three major sources: primary X-ray beams, scattered X-rays, and X-ray leakage (17). Although secondary radiation can be dispersed in any direction, most of it is scattered at an angle <45° to the incident beam, and depending on the subject and distance, the exposure dose can be up to 3% of the incident radiation dose (3). Therefore, veterinarians are more likely to be exposed to occupational radiation than doctors and dentists are (3).

Radiation exposure can result in stochastic reactions, such as cancer and genetic effects, and deterministic reactions, such as skin burns, cataracts, and bone marrow suppression (10).

Medical physicists are familiar with the ALARA principle, in which radiation doses should be maintained as low as reasonably achievable (11). Three principles are used to reduce radiation exposure: increasing the distance from the source, decreasing the exposure time, and utilizing the correct shielding equipment. Radiation exposure according to X-ray distance and imaging time may differ depending on the patient's imaging region and compliance; therefore, wearing shielding equipment is the first method for reducing radiation exposure. Radiation-shielding equipment commonly used in veterinary hospitals includes aprons, thyroid shields, glasses, and gloves (8).

Typical aprons shield the chest, abdomen, gonads, and parts of the upper legs, whereas thyroid shields, gloves, and glasses protect the thyroid gland, hands, wrists, and eyes. These accessories protect several parts of the body, but the risk of radiation exposure to the upper arm, face (except the eyes), and back areas of the body remains (20). Aprons and thyroid shields are made of lead and are heavy, restricting movement. Furthermore, wearing them for long periods can result in fatigue, back pain, and spinal diseases (1,6,12,14). Nevertheless, this problem has been addressed by using lead-free aprons and thyroid shields made of bismuth and tungsten, which are lighter than lead (15). However, because wearing radiation-shielding garments while performing radiography is difficult, the rate of filming after wearing these garments remains low (8,19).

Medical doctors use radiation-shielding devices in addition to aprons and thyroid shields to reduce radiation exposure (18). Therefore, veterinary hospitals require additional shielding systems for radiation workers to reduce the number of exposed body parts.

This study aimed to evaluate the radiation-shielding range and performance of a new shielding system compared with those of a conventional radiation-shielding system and to explain the convenience of the new shielding system. We hypothesized that the new shielding system would have a wider radiation-shielding range with a similar shielding ability and that when both systems were used together, the radiation-shielding ability would increase when only one system was used.

Materials and Methods

Study design

This study investigated the use of a new radiation-shielding system for X-ray radiation protection. The new radiation-shielding system was compared with a conventional shielding system to demonstrate whether it provides better radiation protection over a wide range. The radiation dose measurements for each protective shielding system were compared with those of the control group.

Materials

This study utilized a full-body mannequin and a cylindrical acrylic water phantom (P/N 46-241709G1; GE Healthcafé, Madison, WI, US), 23 cm in diameter and 14 cm in height, filled with distilled water, to simulate a restrained animal patient.

We used a lead-free apron, thyroid shield, glass, gloves, radiation-shield curtain, and head-shield plate for the radiation-shielding system (Fig. 1). A 0.25-mm lead equivalent lead-free apron (Rad-Ban BF2; Drview, Seoul, Korea), a 0.5-mm lead equivalent at the collar and a 0.25-mm lead equivalent upper chest region thyroid shield (Rad-Ban TH; Drview), and 0.13-mm lead equivalent glasses (XR-700, Toray, Tokyo, Japan) were used as conventional radiation-shielding systems. The new radiation-shielding system consists of a radiation-shield curtain and a head-shield plate (Fig. 2). The curtain frame, made of steel, measured 68 cm wide, 60-80 cm long, and 50-60 cm high, and had a five-layered drape made of bismuth across the frame. The shield plate consisted of a 40-cm-wide and 20-cm-long lead acrylic plate across the frame. The frame, drape, and shield plates are detachable. The drape and lead acrylic plates contained a lead equivalent of 0.25 mm. The angle of the shielding plate can be adjusted according to the convenience of the compensator. A pair of 0.25-mm lead equivalent gloves (Raon PGL02; S&C Company, Seoul, Korea) was used in both shielding systems.

Figure 1. Conventional radiation-shielding system: (A) lead-free aprons (Rad-Ban BF2; Drview), (B) thyroid shield (Rad-Ban TH; Drview), (C) glasses (XR-700; Toray, Tokyo, Japan), and (D) gloves (Raon PGL02; S&C Company) were used in both the conventional and new shielding systems. (E) Complete conventional radiation-shielding system when worn.

Figure 2. New radiation-shielding system. (A-C) Radiation-shielding curtain. (A) The curtain frame to which the curtains are attached is made of a steel frame (length, 68 cm; width, 60-80 cm; height, 50-60 cm). (B) The curtain drape is made of a five-layer bismuth material with a lead equivalent of 0.25 mm. (C) Curtain holder with curtain drapes on the X-ray table. (D-F) Head-shielding plate. (D) The head-shielding plate has a 40 × 20-cm lead acrylic plate and a lead equivalent of 0.25 mm, which can be used in the shield curtain. (E) The angle can be adjusted according to the height and convenience of the restrainer. (F) Protecting scatter radiation (red lines) from primary radiation (blue lines).

Thermoluminescent dosimeters (TLDs) (UD-802AS, Panasonic Co., Japan) were used to measure the cumulative exposure dose for each group. The TLDs were fixed at nine locations on the body: the forehead, chin, thyroid gland, left breast, right and left upper arms, gonad, and right and left upper thighs. The forehead TLD was positioned near the glasses without blocking the field of vision of the mannequin (Fig. 3).

Figure 3. (A) Thermoluminescent dosimeters (TLDs) attached on nine locations of body parts: forehead, chin, thyroid gland, left breast, right and left upper arms, gonad, and right and left upper thighs. (B) In groups using the conventional shielding system, the TLDs for the thyroid, left chest, gonad, and bilateral thigh sites are attached under the apron and thyroid shield (dashed square). Lt., left; Rt., right.

Procedures

There were three experimental groups and one control group. Group 1 wore the new radiation-shielding system with gloves. Group 2 wore both the new radiation-shielding system and the conventional shielding system with gloves. Group 3 wore the conventional shielding system with gloves. Group 4, which served as the control group, did not wear any shielding systems (Table 1, Fig. 4). The settings for the primary radiation were a tube voltage of 70 kV, a tube current of 200 mA (similar to the standard for abdominal radiography), and an exposure time of 500 ms (approximately 20 times longer than the standard exposure time) to ensure that they were as similar as possible to the set tube voltage and current. All groups underwent radiography 10 times under the same conditions. We estimated the shielding ratio of each shielding system using the dose measured at each group’s anatomical site, using the equation below (16). Group 4 was the control group, and groups 1, 2, and 3 were the experimental groups.

Table 1 . Ancillary protection equipment usage by group.

Shield curtain (with lead plate)ApronThyroid shieldGlassGloves
Group 1OXXXO
Group 2OOOOO
Group 3XOOOO
Group 4XXXXX

O, with ancillary protection equipment; X, without ancillary protection equipment..



Figure 4. Radiation-shielding system of each group. (A, B) Group 1: new radiation-shielding system with lead gloves. (C, D) Group 2: conventional and new radiation-shielding systems with lead gloves. (E, F) Group 3: conventional radiation-shielding system with lead gloves. (G, H) Group 4 (control group): no radiation-shielding system.

Shieldingratio(%)=Dosewithcontrolgroupdosewith  experimeltal groupDosewithcontrolgroupx100

Statistical analysis

Statistical analyses were performed using SPSS for Windows (version 21.0; IBM Corp., Armonk, NY, USA) and Prism version 9.0 (GraphPad Software, San Diego, CA, USA). Data for each anatomical location are expressed as the mean ± standard deviation. For all tests, statistical significance was set at p < 0.05. Data were analyzed using the Kruskal-Wallis test after evaluating normality using the Shapiro–Wilk test. The Bonferroni test was performed for post-hoc analysis.

Results

For each group, ten radiation exposure experiments were performed under the same conditions at all nine anatomical locations. The experimental dose study involved 1080 exposures, resulting in 108 dose readings, and measurements were calculated. After the data were evaluated, the radiation exposure doses in particular anatomical regions varied according to the use of the new radiation-shielding system.

Radiation exposure doses were measured in all experimental and control groups. In group 4 (the control group), the mean radiation exposure dose in the nine locations was 0.686 ± 0.389 mSv (Table 2). Compared to the doses associated with other anatomical regions, the exposure dose was 0.053 ± 0.015 mSv at the left thigh and 0.120 ± 0.095 mSv at the right thigh, which were approximately 7-10 times lower than those of upper body parts on average. The exposure doses in the experimental group were significantly higher than those in the control group, except for the left thigh. The radiation exposure doses for the forehead, chin, and bilateral upper arms using the new radiation-shielding system and those using both the conventional and new shielding systems were remarkably lower than those using the conventional system. The bilateral thigh exposure doses were higher when using the new radiation-shielding system than when using the conventional shielding system. The exposure dose in the thyroid, left chest, and gonad from 0.01 to 0.02 mSv did not differ significantly when using the conventional system, the new shielding system, and when using them together (Figs. 5, 6).

Table 2 . Mean radiation exposure dose (mSv) of the nine anatomical locations in the different shielding system groups.

Group 1Group 2Group 3Group 4
Forehead0.017 ± 0.0120.017 ± 0.0120.433 ± 0.1020.487 ± 0.072
Chin0.053 ± 0.0580.0101.093 ± 0.1901.197 ± 0.150
Thyroid0.013 ± 0.0060.0100.0100.857 ± 0.261
Left chest0.0100.0100.013 ± 0.0060.853 ± 0.275
Left upper arm0.013 ± 0.0060.0100.693 ± 0.1160.793 ± 0.090
Right upper arm0.017 ± 0.0120.0100.603 ± 0.1690.777 ± 0.070
Gonad0.013 ± 0.0060.013 ± 0.0060.013 ± 0.0060.997 ± 0.254
Left thigh0.043 ± 0.0150.013 ± 0.0060.0100.057 ± 0.015
Right thigh0.063 ± 0.0230.017 ± 0.0120.0100.160 ± 0.026


Figure 5. Column bar box of radiation exposure dose for each anatomical location using different radiation-shielding systems. (A) Group 1 used the new radiation-shielding system. (B) Group 2 used both a conventional and the new radiation-shielding systems. (C) Group 3 used a conventional radiation-shielding system. (D) Group 4 (control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. Exposure doses measured in the control group were higher than those measured at the same anatomical locations in all experimental groups. Exposure doses were significantly higher in group 3 for the head, chin, and bilateral upper arm regions than those in groups 1 and 2. Lt., left; Rt., right.

Figure 6. Column bar box of radiation exposure dose for each group using different radiation-shielding systems. Radiation exposure dose of nine anatomical locations. (A) forehead, (B) chin, (C) thyroid, (D) Lt. chest, (E) Lt. upper arm, (F) Rt. upper arm, (G) gonad, (H) Lt. thigh and (I) Rt. thigh. Group 1 used the new radiation-shielding system. Group 1 used the new radiation-shielding system. Group 2 used both a conventional and the new radiation-shielding systems. Group 3 used a conventional radiation-shielding system. Group 4 (control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. Significant reduction in exposure was observed when the new shielding systems were used in the forehead, chin, and bilateral arm regions, and no significant difference was observed in other locations (groups 1 and 2 vs. group 3). Significant differences in exposure dose were observed when conventional and the novel shielding systems were used on the bilateral thighs, respectively (group 1 vs. group 3). *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001; ns, no significance; Lt, left; Rt, right.

The radiation exposure doses of groups 1, 2, and 3, which are the experimental groups, at all anatomical locations were 0.029 ± 0.028, 0.013 ± 0.009, and 0.320 ± 0.397 mSv, respectively. The exposure dose was significantly higher in group 3 than in groups 1 and 2 (p < 0.01) (Fig. 7).

Figure 7. Column bar box of mean radiation exposure values for all anatomical locations using different radiation-shielding systems. Group 1 used the new radiation-shielding system. Group 2 used both a conventional and the new radiation-shielding systems. Group 3 used a conventional radiation-shielding systems. Group 4 (control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. Significant differences in exposure doses were observed among all groups except groups 1 and 2. p < 0.05 was considered significant. **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001; ns, no significance.

Because the exposures at the thyroid, left chest, gonads, and bilateral thighs were similarly low among the experimental groups, the results were excluded, and the exposure doses at the forehead, chin, and bilateral upper arms were compared again. The exposure doses of groups 1, 2, 3, and 4 were 0.025 ± 0.031, 0.012 ± 0.006, 0.706 ± 0.283, and 0.793 ± 0.296 mSv, respectively (Fig. 8). In the absence of the new radiation-shielding system, the exposure dose was significantly higher (p < 0.001).

Figure 8. Column bar box of mean radiation exposure values for the forehead, chin, and bilateral upper arm areas using different radiation-shielding systems. Group 1 used the new radiation-shielding system. Group 2 used both conventional and the new radiation-shielding systems. Group 3 used a conventional radiation-shielding system. Group 4 (the control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. The exposure dose of group 3 was similar to that of group 4. p < 0.05 was considered significant. ****p ≤ 0.0001; ns, no significance.

The shielding ratio of group 2 at the anatomical positions, except for both thighs, was the same or greater than that of groups 1 and 3, and the shielding ratio at positions deemed to have been shielded was observed to be approximately 93% to 99% in the experimental groups (Table 3). The exposure rate of the left thigh was higher than that of the right thigh in all groups.

Table 3 . Shielding ratio (%) of the scattered dose after shielding in different systems.

Group 1Group 2Group 3
Forehead96.4096.7511.67
Chin95.3199.168.80
Thyroid98.2198.7698.76
Left chest98.7398.7398.44
Left upper arm98.3498.7312.87
Right upper arm97.8498.7122.92
Gonad98.7098.7098.70
Left thigh24.2175.7981.35
Right thigh60.7188.5093.62

Discussion

All imaging modalities have been utilized and studied in veterinary medicine; however, X-rays are the most popular for administrative, managerial, and financial reasons (9). In medicine, various suspended radiation protection systems have been studied and used to minimize exposure to various parts of the human body during computed tomography and interventional radiology (18). Although the exposure dose of X-rays is lower than that of fluoroscopy or computed tomography, the radiography number cannot be disregarded because veterinary hospitals have the largest prevalence and the use of X-rays increases yearly (5). Many different types of radiation protection systems are available worldwide. However, to our knowledge, this is the first veterinary medicine invention that uses an X-ray table with a curtain-type radiation-shielding system. Our study shows that this novel radiation-shielding system is a practical alternative to aprons, thyroid shields, and glasses for radiation protection. Additionally, the inconvenience of wearing glasses whenever performing radiography could be reduced owing to a new shielding system that was set up on the X-ray table, and the moisture issues that occurred when wearing glasses were partially resolved.

In the present study, the mean exposure doses to the left chest were the highest among the nine anatomical locations, followed by the gonads and chin. However, in a previous study, the thyroid had a higher radiation exposure than that of the chest and gonads (13), and we believe that this is because of the different phantoms used for the X-rays and the position of the restrainer. The radiation exposure dose to the upper body is 7-10 times higher than that to the bilateral thighs. It is assumed that the scattered radiation coming from the table could make its way to the restrainer’s gonads (2), and there is also the possibility that the table acted as radiation protection.

Both radiation-shielding systems showed high defense capabilities in the left chest, thyroid, and gonad positions. However, when comparing the radiation exposure in the forehead, chin, left arm, and right arm areas, high doses were measured in the conventional shielding group, similar to those in the control group, whereas those using the new shielding tool were measured as low as the left chest, thyroid, and gonad values measured in the same group. These data confirm that the novel shielding system protected a wider scan range against scattered radiation than the range protected by the classical shielding system, including the forehead, chin, and bilateral arms.

When using only the conventional shielding system, the average exposure dose to the forehead, chin, and bilateral upper arms was 0.706 ± 0.283 mSv, and it was calculated as 0.056 ± 0.023 mSv when converted according to the general abdominal radiographic criteria (70 kV, 8 mAs). According to the International Commission on Radiological Protection (ICRP), the annual equivalent dosage for radiation-related personnel is 500 mSv or less for the skin and 150 mSv or less for lenses (4). Based on the current experimental results and ICRP regulations, if 173.6 radiographs are obtained per week arithmetically, the annual skin equivalent dose will be exceeded, and if 52 radiographs are obtained per week arithmetically, the annual lens equivalent dose will be exceeded. Therefore, a new shielding system is needed to ensure the safety of the restrainer in veterinary hospitals.

Finally, a new shielding system in the form of curtains and lead plates was developed. Because the curtain drape is easy to move and both the drape and plate are detachable, correct radiation shielding cannot be achieved.

Inexperienced users may not be able to use it properly, resulting in errors such as excessive gaps in the curtain drapes or use without drapes or lead plates. Therefore, the proper application of this new radiation system must be understood.

In a previous study on the radiation-shielding rate with an apron, the shielding rate for a 0.25-mm lead equivalent apron was 88.82-90.91%; in this study, the shielding rate was 97-98%, which was higher than those reported in previous studies. This is thought to represent the difference between the primary radiation energy and the distance between the scattered radiation and dosimeter.

This study had some limitations. A cylindrical phantom was used in the experiment. Because the direction of scattered radiation caused by the cylindrical phantom may differ from the direction of scattering in an actual patient, it is believed that using the dog phantom can produce more accurate results and that the new shielding system can shield a wider range of radiation than that shielded by the conventional shielding system. However, it is impossible to shield the lower arm area, including the hand. Therefore, wearing gloves during filming is essential.

In conclusion, in this study, a new radiation-shielding system exhibited the same shielding capability as that of a conventional radiation-shielding system, can provide a wider range of radiation shields, and can solve the difficulties of using traditional shielding tools. In addition to the conventional shielding system, we anticipated that the new shielding system will be a new shielding paradigm that will further improve the safety of radiation workers in veterinary hospitals.

Source of Funding

This work was supported by Institute for Information & communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (No. 2021-0-00490, Development of Precision Analysis and Imaging Technology for Biological Radio Waves).

Conflicts of Interest

The authors have no conflicting interests.

Fig 1.

Figure 1.Conventional radiation-shielding system: (A) lead-free aprons (Rad-Ban BF2; Drview), (B) thyroid shield (Rad-Ban TH; Drview), (C) glasses (XR-700; Toray, Tokyo, Japan), and (D) gloves (Raon PGL02; S&C Company) were used in both the conventional and new shielding systems. (E) Complete conventional radiation-shielding system when worn.
Journal of Veterinary Clinics 2023; 40: 429-437https://doi.org/10.17555/jvc.2023.40.6.429

Fig 2.

Figure 2.New radiation-shielding system. (A-C) Radiation-shielding curtain. (A) The curtain frame to which the curtains are attached is made of a steel frame (length, 68 cm; width, 60-80 cm; height, 50-60 cm). (B) The curtain drape is made of a five-layer bismuth material with a lead equivalent of 0.25 mm. (C) Curtain holder with curtain drapes on the X-ray table. (D-F) Head-shielding plate. (D) The head-shielding plate has a 40 × 20-cm lead acrylic plate and a lead equivalent of 0.25 mm, which can be used in the shield curtain. (E) The angle can be adjusted according to the height and convenience of the restrainer. (F) Protecting scatter radiation (red lines) from primary radiation (blue lines).
Journal of Veterinary Clinics 2023; 40: 429-437https://doi.org/10.17555/jvc.2023.40.6.429

Fig 3.

Figure 3.(A) Thermoluminescent dosimeters (TLDs) attached on nine locations of body parts: forehead, chin, thyroid gland, left breast, right and left upper arms, gonad, and right and left upper thighs. (B) In groups using the conventional shielding system, the TLDs for the thyroid, left chest, gonad, and bilateral thigh sites are attached under the apron and thyroid shield (dashed square). Lt., left; Rt., right.
Journal of Veterinary Clinics 2023; 40: 429-437https://doi.org/10.17555/jvc.2023.40.6.429

Fig 4.

Figure 4.Radiation-shielding system of each group. (A, B) Group 1: new radiation-shielding system with lead gloves. (C, D) Group 2: conventional and new radiation-shielding systems with lead gloves. (E, F) Group 3: conventional radiation-shielding system with lead gloves. (G, H) Group 4 (control group): no radiation-shielding system.
Journal of Veterinary Clinics 2023; 40: 429-437https://doi.org/10.17555/jvc.2023.40.6.429

Fig 5.

Figure 5.Column bar box of radiation exposure dose for each anatomical location using different radiation-shielding systems. (A) Group 1 used the new radiation-shielding system. (B) Group 2 used both a conventional and the new radiation-shielding systems. (C) Group 3 used a conventional radiation-shielding system. (D) Group 4 (control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. Exposure doses measured in the control group were higher than those measured at the same anatomical locations in all experimental groups. Exposure doses were significantly higher in group 3 for the head, chin, and bilateral upper arm regions than those in groups 1 and 2. Lt., left; Rt., right.
Journal of Veterinary Clinics 2023; 40: 429-437https://doi.org/10.17555/jvc.2023.40.6.429

Fig 6.

Figure 6.Column bar box of radiation exposure dose for each group using different radiation-shielding systems. Radiation exposure dose of nine anatomical locations. (A) forehead, (B) chin, (C) thyroid, (D) Lt. chest, (E) Lt. upper arm, (F) Rt. upper arm, (G) gonad, (H) Lt. thigh and (I) Rt. thigh. Group 1 used the new radiation-shielding system. Group 1 used the new radiation-shielding system. Group 2 used both a conventional and the new radiation-shielding systems. Group 3 used a conventional radiation-shielding system. Group 4 (control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. Significant reduction in exposure was observed when the new shielding systems were used in the forehead, chin, and bilateral arm regions, and no significant difference was observed in other locations (groups 1 and 2 vs. group 3). Significant differences in exposure dose were observed when conventional and the novel shielding systems were used on the bilateral thighs, respectively (group 1 vs. group 3). *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001; ns, no significance; Lt, left; Rt, right.
Journal of Veterinary Clinics 2023; 40: 429-437https://doi.org/10.17555/jvc.2023.40.6.429

Fig 7.

Figure 7.Column bar box of mean radiation exposure values for all anatomical locations using different radiation-shielding systems. Group 1 used the new radiation-shielding system. Group 2 used both a conventional and the new radiation-shielding systems. Group 3 used a conventional radiation-shielding systems. Group 4 (control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. Significant differences in exposure doses were observed among all groups except groups 1 and 2. p < 0.05 was considered significant. **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001; ns, no significance.
Journal of Veterinary Clinics 2023; 40: 429-437https://doi.org/10.17555/jvc.2023.40.6.429

Fig 8.

Figure 8.Column bar box of mean radiation exposure values for the forehead, chin, and bilateral upper arm areas using different radiation-shielding systems. Group 1 used the new radiation-shielding system. Group 2 used both conventional and the new radiation-shielding systems. Group 3 used a conventional radiation-shielding system. Group 4 (the control) did not use any radiation-shielding systems. Boxes: mean; error bars: standard deviation. The exposure dose of group 3 was similar to that of group 4. p < 0.05 was considered significant. ****p ≤ 0.0001; ns, no significance.
Journal of Veterinary Clinics 2023; 40: 429-437https://doi.org/10.17555/jvc.2023.40.6.429

Table 1 Ancillary protection equipment usage by group

Shield curtain (with lead plate)ApronThyroid shieldGlassGloves
Group 1OXXXO
Group 2OOOOO
Group 3XOOOO
Group 4XXXXX

O, with ancillary protection equipment; X, without ancillary protection equipment.


Table 2 Mean radiation exposure dose (mSv) of the nine anatomical locations in the different shielding system groups

Group 1Group 2Group 3Group 4
Forehead0.017 ± 0.0120.017 ± 0.0120.433 ± 0.1020.487 ± 0.072
Chin0.053 ± 0.0580.0101.093 ± 0.1901.197 ± 0.150
Thyroid0.013 ± 0.0060.0100.0100.857 ± 0.261
Left chest0.0100.0100.013 ± 0.0060.853 ± 0.275
Left upper arm0.013 ± 0.0060.0100.693 ± 0.1160.793 ± 0.090
Right upper arm0.017 ± 0.0120.0100.603 ± 0.1690.777 ± 0.070
Gonad0.013 ± 0.0060.013 ± 0.0060.013 ± 0.0060.997 ± 0.254
Left thigh0.043 ± 0.0150.013 ± 0.0060.0100.057 ± 0.015
Right thigh0.063 ± 0.0230.017 ± 0.0120.0100.160 ± 0.026

Table 3 Shielding ratio (%) of the scattered dose after shielding in different systems

Group 1Group 2Group 3
Forehead96.4096.7511.67
Chin95.3199.168.80
Thyroid98.2198.7698.76
Left chest98.7398.7398.44
Left upper arm98.3498.7312.87
Right upper arm97.8498.7122.92
Gonad98.7098.7098.70
Left thigh24.2175.7981.35
Right thigh60.7188.5093.62

References

  1. Andrew S, Abdelmonem MR, Kohli S, Dabke H. Evaluation of back pain and lead apron use among staff at a district general hospital. Cureus. 2021; 13: e18859.
    Pubmed KoreaMed CrossRef
  2. Barber J, McNulty JP. Investigation into scatter radiation dose levels received by a restrainer in small animal radiography. J Small Anim Pract. 2012; 53: 578-585.
    Pubmed CrossRef
  3. Hupe O, Ankerhold U. Determination of the dose to persons assisting when X-radiation is used in medicine, dentistry and veterinary medicine. Radiat Prot Dosimetry. 2011; 144: 478-481.
    Pubmed CrossRef
  4. International Commission on Radiological Protection (ICRP). ICRP publication 103. The 2007 recommendations of the international commission on radiological protection. ICRP. 2007.
  5. Kang KM, Suh TY, Kim YS, Yun SJ. Convergence analysis of safety management for radiation workers and diagnostic radiation-generator devices of animal hospital in Korea. J Korea Converg Soc. 2020; 11: 55-61.
  6. Kim SC, Choi JR, Jeon BK. Physical analysis of the shielding capacity for a lightweight apron designed for shielding low intensity scattering X-rays. Sci Rep. 2016; 6: 27721.
    Pubmed KoreaMed CrossRef
  7. Martinez NE, Van Bladel L. Radiation protection challenges in applications of ionising radiation on animals in veterinary practice. Ann ICRP. 2020; 49(1_suppl): 158-168.
    Pubmed CrossRef
  8. Mayer MN, Koehncke NK, Belotta AF, Cheveldae IT, Waldner CL. Use of personal protective equipment in a radiology room at a veterinary teaching hospital. Vet Radiol Ultrasound. 2018; 59: 137-146.
    Pubmed CrossRef
  9. Meomartino L, Greco A, Di Giancamillo M, Brunetti A, Gnudi G. Imaging techniques in veterinary medicine. Part I: radiography and ultrasonography. Eur J Radiol Open. 2021; 8: 100382.
    Pubmed KoreaMed CrossRef
  10. Mettler FA. Medical effects and risks of exposure to ionising radiation. J Radiol Prot. 2012; 32: N9-N13.
    Pubmed CrossRef
  11. Miller DL, Schauer D. The ALARA principle in medical imaging. Philosophy. 2015; 40: 38-40.
  12. Monaco MGL, Carta A, Tamhid T, Porru S. Anti-X apron wearing and musculoskeletal problems among healthcare workers: a systematic scoping review. Int J Environ Res Public Health. 2020; 17: 5877.
    Pubmed KoreaMed CrossRef
  13. Oh H, Sung S, Lim S, Jung Y, Cho Y, Lee K. Restrainer exposure to scatter radiation in practical small animal radiography measured using thermoluminescent dosimeters. Vet Med. 2018; 63: 81-86.
    CrossRef
  14. Papadopoulos N, Papaefstathiou C, Kaplanis PA, Menikou G, Kokona G, Kaolis D, et al. Comparison of lead-free and conventional X-ray aprons for diagnostic radiology. In: World Congress on Medical Physics and Biomedical Engineering. . Munich, Germany. New York: Springer. 2009: 544-546.
    CrossRef
  15. Park HH. The evaluation of performance and usability of bismuth, tungsten based shields. J Radiol Sci Technol. 2018; 41: 611-616.
    CrossRef
  16. Park MH, Kwon DM. Measurement of apron shielding rate for X-ray and gamma-ray. J Radiol Sci Technol. 2007; 30: 245-250.
  17. Park S, Kim M, Kim JH. Radiation safety for pain physicians: principles and recommendations. Korean J Pain. 2022; 35: 129-139.
    Pubmed KoreaMed CrossRef
  18. Savage C, Seale TM IV, Shaw CJ, Angela BP, Marichal D, Rees CR. Evaluation of a suspended personal radiation protection system vs. conventional apron and shields in clinical interventional procedures. Open J Radiol. 2013; 3: 143-151.
    CrossRef
  19. Shirangi A, Fritschi L, Holman CD. Prevalence of occupational exposures and protective practices in Australian female veterinarians. Aust Vet J. 2007; 85: 32-38.
    Pubmed CrossRef
  20. Yoon SY. Measurement and evaluation of radiation exposure doses for radiation workers in veterinary hospitals. [thesis]. Gwangju: Nambu University; 2015.

Vol.41 No.1 February 2024

qrcode
qrcode
The Korean Society of Veterinary Clinics

pISSN 1598-298X
eISSN 2384-0749

Stats or Metrics

Share this article on :

  • line