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Uvod: Namen uporabe stične zaščite za paciente je zmanjšanje doze na kritične organe. Ta dolgotrajna praksa je privedla do tega, da pacienti in strokovnjaki pričakujejo, da se z njo nadaljuje, vendar čedalje več raziskav vzbuja pomisleke glede učinkovitosti. To je povzročilo nedoslednosti v uporabi ter povzročilo trenja med bolniki, ki zahtevajo zaščito, ter med strokovnjaki, ki ocenjujejo, da je to nepotrebno. Namen: Namen diplomskega dela je bil ugotoviti, kako slovenski radiološki inženirji gledajo na uporabo zaščite, kdaj se jim uporaba zdi primerna ter katero vrsto zaščite bi uporabili pri določenih slikanjih. Zanimalo nas je tudi, pri kom jo uporabljajo, katere dele telesa najbolj pogosto ščitijo, ter kaj menijo o priporočilih iz tujine, ki predlagajo, naj se njena uporaba opusti. Metode dela: V prvem delu diplomskega dela smo uporabili deskriptivno oz. opisno metodo in je obsegal pregled literature. V drugem delu diplomskega dela smo uporabili kvantitativno metodo zbiranja podatkov s pomočjo anketnega vprašalnika. Rezultati: Na anketo je odgovorilo 117 članov ZDRI, do konca pa je anketo rešilo 107 radioloških inženirjev. Ugotovili smo, da anketiranci pri preiskavah ščitijo paciente, v skladu z dobro radiološko prakso, saj so v večini uporabljali ustrezna zaščitna sredstva. Več kot polovici se uporaba zaščit ne zdi smiselna, saj jih je 54,7 % odgovorilo, da bi se strinjali z novejšimi priporočili o opustitvi njene uporabe. 35,8 % jih je odgovorilo, da se jim ta priporočila ne zdijo smiselna. Nazadnje smo ugotovili, da 30 % anketirancev ne bi upoštevalo novih smernic o prenehanju uporabe zaščite, tudi če bi bile sprejete. Razprava in zaključek: Radiološki inženirji večinoma uporabljajo svinčeno zaščito ustrezno, v skladu z dobro radiološko prakso in pri vseh skupinah ljudi, ne glede na vrsto diagnostike, na kateri so zaposleni. Ugotovili smo, da dobro poznajo radiosenzitivne organe, vendar skoraj polovica anketirancev še vedno misli, da so gonade najbolj radiosenzitiven organ, kar pa se je spremenilo v najnovejših smernicah. Več kot polovici anketirancev, se ne zdi smiselna uporaba svinčene zaščite. Veliko jih je prav tako odgovorilo, da bi v primeru sprejetja smernic o prenehanju uporabe svinčenih zaščit, še vedno ščitilo otroke, mlajše ženske in nosečnice Introduction: The main purpose of contact protection for patients is to reduce the dose to critical organs. This longstanding practice has led patients and professionals to expect the practice to continue, however many studies raise conserns about its effectivness. This has led to inconsistencies in use and friction between patients who require protection and professionals who deem it unnecessary. Purpose: The main purpose of the diploma work was to find out how Slovenian radiological engineers view the use of lead protection, when they consider it appropriate to use and what type of protection would they use in specific imaging. We were also interested in knowing who they use it on, which parts of the body are shielded the most, and what they think of recommendations, that suggest the abandonment of patient contact shielding. Methods: In the first part, we used descriptive method, which included a literature review. In the second part of the diploma work, we used a quantitative method of data collection with a survey. Results: 117 ZDRI members responded to the survey, and 107 radiological engineers completed the survey. Respondents shield patients according to good radiological practice, as most of them use the appropriate shielding equipment. More than a half agree with more recent recommendations that suggest the abandonment of the patient shielding. Finally, we discovered that 30 % of respondents would not follow the new guidelines, even if they were adopted. Discussion and conclusion: Radiological engineers generally use lead shielding appropriately, in accordance with good radiological practice adn for all groups of people. We found that they have a good knowledge of radiosensitive organs, but almost half of the respondents still think that the gonads are the most radiosensitive organ, despite the change in the newest guidelines. More than half of the respondents think that we should abandon the usage of lead shielding. Many also said that if guidelines were adopted, they would still protect children, younger women and pregnant women.

We presented a development of a custom lead shield and mouse strainer for targeted irradiation from the gamma-cell chamber. This study was divided into two parts i.e., to (i) fabricate the shield and strainer from a lead (Pb) and (ii) optimize the irradiation to the mice-bearing tumour model with 2 and 8 Gy absorbed doses. The lead shielding was fabricated into a cuboid shape with a canal on the top and a hole on the vertical side for the beam path. Respective deliveries doses of 28 and 75 Gy from gamma-cell were used to achieve 2 and 8 Gy absorbed doses at the tumour sites.

Lead shielding is commonly used in the delivery of superficial radiotherapy albeit that the toxicity of this substance is of concern. The feasibility of using a non-toxic alternative, AttenuFlex™, is assessed using Xstrahl and Sensus treatment units. A series of lead and AttenuFlex™ circular cut outs and applicators were used with superficial beams (1.0–8.5 mm Al HVL) to measure percentage depth dose (PDD), output factors (OF) and surface dose correction factors (DCF). X-ray transmission for each material was determined for each beam quality. For these measurements an Advanced Markus chamber either embedded within a virtual water phantom (PDD, OF, transmission) or placed on the surface of the phantom with entrance window downstream (DCF), was used. The depth of the phantom is 10 cm for PDD and surface OF measurements. DCF(t) measurements were obtained with underlying lead or AttenuFlex™ at depth t = 0.1–10 cm. Additionally, using EBT3 film fluorescent surface doses, to non-target tissue, due to underlying lead or AttenuFlex™ were compared. PDDs and OFs for both materials were within ± 1%. Lead and AttenuFlex™ transmission differences were clinically acceptable, all transmission values were

The radiological safety of the spent resin treatment facility with a14C treatment capacity of 1 ton/day was evaluated in terms of the external and internal exposure of worker according to operation scenario. In terms of external dose, the annual dose for close work for 1 h/day at a distance of more than 1 m (19.8 mSv) satisfied the annual dose limit. For eight hours of close work per day, the annual dose exceeded the dose limit. For remote work of 2,000 h/year, the annual dose was 14.4 mSv. Lead shielding was considered to reduce exposure dose, and the highest annual dose during close work for 1 h/day corresponded to 6.75 mSv. For close work of 2,000 h/year and lead thickness exceeding 1.5 cm, the highest value of annual dose was derived as 13.2 mSv. In terms of internal exposure, the initial year dose was estimated to be 1.14E+03 mSv when conservatively 100% of the nuclides were assumed to leak. The allowable outflow rate was derived as 7.77E-02% and 2.00E-01% for the average limit of 20 mSv and the maximum limit of 50 mSv, respectively, where the annual replacement of the worker was required for 50 mSv.

Purpose: Chest X-rays (CXRs) are the most common radiological tests performed in the intensive care unit (ICU). The purpose of the current study was to investigate the relationship between the performance CRX in ICU and the patient’s confirmed pathologic finding. Methods: This retrospective study was evaluated 50 ICU chest X-rays were retrieved from the Picture Archiving and Communication System (PACS) of the different Saudi Hospitals in Al-Medina (February - April 2017). Frequency Distribution, Ratio and Linear Regression were used for statistical analysis. Result: This study demonstrated that based on analyzing the data, 92% of chest X-ray requests were used among 50 ICU patients to confirm the diagnosis, and a significant relationship was found between the use of chest X-rays between the ICU patients and the patient's confirmed pathologic finding which may mean that chest X-ray had a great role in confirming the disease or its complications. There has been a recommendation to perform daily CRX for patients with severe cardiopulmonary disease or receiving mechanical ventilation, as well as immediate CXR imaging for all patients who have had endotracheal tubes, feeding tubes, vascular catheters, and chest tubes. The most effective principle of radiation protection is distance, when performing an X-ray, the technologist must be at least six feet (1.5 to 2 m) from the radiation source. If the technician needs to be close to the radiation source, wearable lead shields and thyroid collars can protect the radiation-sensitive areas of the body. Conclusion: The chest X-ray of ICU patients was an important diagnostic tool that would affect patient management; however, it may also be a tool that can lead to serious complications for patient. A small sample size was used in this investigation that results in unconfirmed information, the future research using a large sample size is needed to carry out a more reliable and valid information.

Highlights • Up to twelve mice can be treated simultaneously. • Inhalation anesthesia minimizes discomfort, allowing fractionated treatment protocols. • The in-house developed devices give accurate radiation doses on the intended areas., This technical note describes two devices to enable accurate irradiation of mice on clinical linac-based systems. To study the effects of radiation in murine, preclinical animal models, controlled and accurate dosing is important. This is not only important when specific volumes need to be irradiated, but also when the whole animal body is irradiated. To enable both purposes, we designed two devices. One device to administer Total Body Irradiation (TBI) simultaneously to six, free walking mice, and a second device, denoted as target box, in which we irradiate specific parts of the mice whilst organs-at-risk (OAR) are protected. In this latter device, we can position the mice in multiple ways. One configuration allows to sedate twelve mice simultaneously by isoflurane inhalation anesthesia and protect the body by lead shielding to allow radiation of the head only. Alternatively, the target box can be used to sedate maximal 4 mice simultaneously to irradiate the flank or paws only. All these setups allow high experimental throughput and thus a minimal occupation of the clinical equipment. As measured, the delivered radiation dosages in the regions of interest were accurate for both devices. In this technical note, we describe the design and build of these devices.

BACKGROUND CONTEXT Intraoperative three-dimensional (3D) computed tomography (CT) imaging has become increasingly popular in spine surgery. Previous spine surgeon radiation exposure research has focused largely on procedures using fluoroscopy, however, few studies have been performed on the subject since the introduction of the 3D imaging systems. As a result, concerns have re-emerged over surgeon radiation exposure and the effectiveness of operating room (OR) protocols for decreasing workplace radiation. Current radiation safety guidelines require surgeons wear full body protective lead while any type of radiation is being administered during surgery. As a result, local institutions do not allow for the use of free-standing lead shields for sole radiation protection in the operating room. However, there is no data available to demonstrate whether the additional personal lead is required, or if in fact the lead shield alone is sufficient. PURPOSE This study investigated the effectiveness of a free-standing lead shield in reducing spine surgeon radiation exposure in the operating room during intraoperative imaging. STUDY DESIGN/SETTING A prospective clinical research study at a large, tertiary care center. PATIENT SAMPLE Twenty-seven patients undergoing instrumented spinal procedures between June and August 2019. OUTCOME MEASURES Fluoroscopy time, total fluoroscopy dose delivered, 3D dose delivered, total 3D spins, number of HD spins, number of standard spins, number of fluoroscopic images, number of spine levels operated on, patient size setting, shield distance from patient, radiation dose in front of shield, radiation dose behind shield. METHODS Twenty-seven instrumented spinal procedures using the O-Arm Imaging System (Medtronic, Minneapolis, MN) were observed to determine radiation exposure to a spine surgeon standing behind a lead shield in the OR. Two thermoluminescent dosimeters were used to measure scatter radiation in front of and behind lead shields. Both fluoroscopy and intraoperative CT based radiation exposure was recorded. The dosimeter readings were compared to determine the degree of radiation attenuation by the lead shield. Regression analysis of the exposure values from behind the shield, shield distance from the patient, and radiation dose delivered by the imaging system was utilized to estimate the number of cases required to surpass annual exposure limits. Case numbers were calculated for the highest “worst case” and “average case” exposure values. The safe annual occupation exposure limit determined by the National Council on Radiation Protection is five roentgen equivalent man (rem) or 50,000 microsieverts (μSv). RESULTS Average surgeon radiation exposure per case was 0.694 μSv (SD: 0.501, Range: 0.105–2.167) behind the lead shield compared to 14.577 μSv (SD: 9.864, Range: 2.185–44.492) in front of the lead shield. The average radiation dose reduction by the lead shield was 13.962 μSv (SD: 9.49, Range: 2.08–42.72) per case, which is equivalent to an average of 95.65% (SD: 1.71) radiation attenuation by lead shielding. If surgeons stand behind lead shields in the OR, the annual number of 3D image-guided spinal procedures required to surpass exposure limits is 15,479 and 67,060 based on “worst case” and “average case” analyses, respectively. CONCLUSIONS Our study demonstrates standing behind intraoperative lead shields is very effective at decreasing radiation exposure to surgeons. Additionally, surgeon radiation doses behind lead shielding fall far below annual exposure limits. Surgeons should not need additional protective equipment when a lead shield is used.

Introduction: This study intended to assess the effectiveness of application the mobile X-ray barriers (lead-wall) in reducing the radiation dose to interventionists during the brain angiography procedures. Moreover, the radiation dose of patients also evaluated to assess whether the application of lead-wall affects the patient’s dose or not? Material and method: Two interventionists took part in this study. Thermoluminescent dosimeters (TLD-100) were used to monitor the doses to interventionists. 1st-interventionist routinely used lead-wall and 2nd-interventionist didn’t use it. Demographic information of patients and radiation dose information was also recorded. Results: The results of measurements showed that the radiation dose of the 1st-interventionist was 83.57% lower than the 2nd-interventionist (p = 0.04). The amount of dose/min and DAP/min of the 1st-interventionist’s patients were 33.50% and 17.54% less than the 2nd-interventionist’s patients (p = 0.006) and (p = 0.0004). Discussion and conclusion: The results showed that application of lead wall can effectively reduce the occupational dose and it doesn’t lead to increase the patient’s dose.

The aim of the study was to assess the effect of the shielding material and its' thickness on the measured skin dose to the breasts to the breast during the CT examination of the head. The helical and axial head CT was performed on an anthropomorphic phantom (PBU 60). Two types of shielding were tested – lead and non-lead (antimony-bismuth) shielding. Measurements with different thicknesses were performed and the shielding efficiency was compared between both materials. Skin dose to the breasts was measured with an Educational Direct Dosimeter (EDD-30). The shielding efficiency during both scanning protocols indicated an increased dose reduction with the thicker equivalent thickness in both shielding materials. Dose reduction was the highest at 0.5 mm equivalent thickness for both materials; lead shielding reduced the dose by 91% and 83%, the antimony-bismuth shielding by 90% and 86%, during the axial and helical head CT protocol, respectively. Statistically significant differences were found between both materials of the same equivalent thickness (0.175, 0.25 and 0.5 mm) during the helical protocol in the favor of the antimony-bismuth shielding. During the axial protocol there was no statistically significant differences. Shielding of radiosensitive organs can prevent unnecessary exposure of radiosensitive organs outside the primary beam. Due to the significant decrease of radiation dose to the breasts and many other positive attributes, the antimony-bismuth shielding instead of the lead shielding should be considered, especially during the helical CT scan of the head.

BACKGROUND CONTEXT Biopsy is important to obtain microbiological and histopathological diagnosis in spine infections and tumors. To date, there have been no prospective randomized trials comparing fluoroscopic guided and computed tomography (CT) transpedicular biopsy techniques. The goal of this study was to evaluate the accuracy, safety, and diagnostic outcome of these two diagnostic techniques. PURPOSE To evaluate the accuracy, safety, and diagnostic outcome of fluoroscopic guided and CT transpedicular biopsy techniques. STUDY DESIGN Prospective randomized trial. PATIENT SAMPLE Sixty consecutive patients with clinical symptoms and radiological features suggestive of spinal infection or malignancy were recruited and randomized into fluoroscopic or CT guided spinal biopsy groups. Both groups were similar in terms of patient demographics, distribution of spinal infections and malignancy cases, and the level of biopsies. OUTCOME MEASURES The primary outcome measure was diagnostic accuracy of both methods, determined based on true positive, true negative, false positive, and false negative biopsy findings. Secondary outcome measures included radiation exposure to patients and doctors, complications, and postbiopsy pain score. METHODS A transpedicular approach was performed with an 8G core biopsy needle. Specimens were sent for histopathological and microbiological examinations. Diagnosis was made based on biopsy results, clinical criteria and monitoring of disease progression during a 6-month follow up duration. Clinical criteria included presence of risk factors, level of inflammatory markers and magnetic resonance imaging findings. Radiation exposure to patients and doctors was measured with dosimeters. RESULTS There was no significant difference between the diagnostic accuracy of fluoroscopic and CT guided spinal biopsy (p=0.67) or between the diagnostic accuracy of spinal infection and spinal tumor in both groups (p=0.402 for fluoroscopy group and p=0.223 for CT group). Radiation exposure to patients was approximately 26 times higher in the CT group. Radiation exposure to doctors in the CT group was approximately 2 times higher compared to the fluoroscopic group if a lead shield was not used. Lead shields significantly reduced radiation exposure to doctors anywhere from 2 to 8 times. No complications were observed for either group and the differences in postbiopsy pain scores were not significant. CONCLUSIONS The accuracy, procedure time, complication rate and pain score for both groups were similar. However, radiation exposure to patients and doctors were significantly higher in the CT group without lead protection. With lead protection, radiation to doctors reduced significantly.

Background The air kerma radiation doses have gained much attention since the operating room interventional radiology is a place where medical staff are exposed to a fluoroscopy environment and gain a cumulative dose during the uterine artery embolization procedure. Objective We aimed to evaluate the radiation dose received by medical staff by applying a flat X-ray machine in the surgical room during uterine artery embolization. Methods An ATOM humanoid model was laid on the operating table and simulated a patient. The scattered radiation dose received by the radiologist, anesthetist and radiologic technologist was evaluated. The scintillation detector was adopted. The measurement points were 50 cm, 100 cm and 150 cm above the floor, representing the limbs, abdomen and thyroid level, respectively. We compared the X-rays under different tube voltages of 70, 80, and 90, respectively and frames per second (FPS) of 30, 15, and 7.5, respectively. We configured the dose level per pulse of 40 nGy with a fixed detector. Results In Section 1, when the tube voltage was 70 kVp and 7.5 FPS, the average radiation doses of limbs, abdomen and thyroid level was 0.48, 1.3 and 1.9 μSv/min respectively. When the tube voltage was 80 kVp and the fluoroscopy decreases from 30 FPS to 7.5 FPS, 58% of the radiation dose was reduced. When the tube voltage was 90 kVp, the radiation dose in the lead garment increased 31-177% in comparison to when the tube voltage was 80 kVp. Sections 2 and 3 were far away from the central ray, so the highest radiation dose 100 cm above the floor were 0.05 and 0.02 μSv/min. Conclusions Lead garment can effectively reduce medical staff from occupational doses with an average attenuation rate of 90%. 80 kVp was most commonly used. Fluoroscopy 7.5 FPS was used 100 cm above the floor in A section and the lowest radiation dose was 1.33 μSv/min. The operator should decrease the duration of X-rays or adopt suspended lead shielding to decrease the radiation dose received by the operator. When kVp increases, the penetration increases. Decreasing FPS cannot decrease occupational doses of medical staff.

OBJECTIVES: The purpose of this study was to evaluate the effect of placing small lead shields on the temple region of the skull to reduce radiation dose to the lens of the eye during interventional fluoroscopically-guided procedures and cone-beam computed tomography (CBCT) scans of the head. METHODS: EGSnrc Monte-Carlo code was used to determine the eye lens dose reduction when using lateral lead shields for single x-ray projections, CBCT scans with different protocols, and interventional neuroradiology procedures with the Zubal computational head phantom. A clinical C-Arm system was used to take radiographic projections and CBCT scans of anthropomorphic head phantoms without and with lead patches, and the images were compared to assess the effect of the shields. RESULTS: For single lateral projections, a 0.1 (0.3) mm thick lead patch reduced the dose to the left-eye lens by 40% to 60% (55% to 80%) from 45° to 90° RAO and to the right-eye lens by around 30% (55%) from 70° to 90° RAO. For different CBCT protocols, the reduction of lens dose with a 0.3 mm thick lead patch ranged from 20% to 53% at 110 kVp. For CBCT scans of the anthropomorphic phantom, the lead patch introduced streak artifacts that were mainly in the orbital regions but were insignificant in the brain region where most neuro-interventional activity occurs. CONCLUSION: The dose to the patient’s eye lens can be reduced considerably by placing small lead shields over the temple region of the head without substantially compromising image quality in neuro-imaging procedures.

Heating induced by radio frequency (RF) energy may appear in tissues near implants located in a human subject undergoing magnetic resonance imaging examination. Lead shielding was proposed to reduce such heating below dangerous levels. In this article, we employed 3-D electromagnetic (EM) and thermal co-simulations to quantify the effectiveness of metallic shielding in the presence of two large sets of nonuniform incident fields at 128 MHz. Specifically, we used a lead EM model (LEM) and computed the RF responses, i.e., the net dissipated power and net temperature increase, above background, at the electrodes. We considered a set of single electrode leads with both straight and helical wires, comparing regular unshielded configurations to different implementations of a metallic shield. The lead length, the relative permittivity of the insulator material, and the lead electrode geometry were all independently varied. For leads with helical wires we observed that: 1) the metallic shield significantly modified the LEM; 2) in most cases, the RF responses substantially increased if metallic shielding was applied; and 3) the net temperature increase in close proximity to the shield can be substantially higher than the net temperature increase in close proximity to the lead electrode. Leads with helical and straight wires exhibited significantly different behavior. Using the results obtained from generic straight wire leads to predict the results for leads with helical wires can be significantly misleading.

Adjuvant radiotherapy is an important treatment modality after breast-conserving surgery. Due to its proximity, radiation therapy for the left breast can often lead to an escalated heart dose that can result in heart diseases. The purpose of this study was to evaluate the heart dose reduction by using lead shields surrounding the left breast. The doses of a 3D conformal radiotherapy (3D-CRT) plan, an intensity-modulated radiotherapy (IMRT) plan, and volumetric-modulated arc therapy (VMAT) to the left breast tumor in a CIRS ATOM anthropomorphic female adult phantom were measured by optically stimulated luminescence dosimeters (OSLDs). To protect critical organs, the skin around the target area was covered by lead shields of two different thicknesses (0.125 mm and 0.25 mm). The results showed that compared to IMRT and 3D-CRT, VMAT provided better planning target volume (PTV) coverage, a better conformity index (CI), and homogeneity index (HI). With the use of lead shields, the thyroid dose was reduced by 5.12–27.5% and 20.51–30%, respectively, the heart dose was reduced by 49.41–50.12% and 56.38–57.42%, respectively, and the lung dose was reduced by 1.23–45.22% and 0.98–57.83%, respectively. Although the clinical application of lead shields was rare, this study verified that it could effectively decrease the heart dose from 4.31 ± 0.09 Gy to 1.88–2.18 Gy, thereby potentially reducing the risk of associated heart diseases by 14.8%. Further works to implement this method into clinical practice are needed.

Veterinary workers use lead shielding for protection against harm from ionizing radiation during diagnostic imaging. Surface lead on shielding has been reported as a potential exposure hazard. The purpose of this prospective, analytical, descriptive study was to measure surface lead on lead-containing shielding in the field service and small animal radiology areas of a veterinary teaching hospital, and to examine potential risk factors for surface lead. Surface lead on a convenience sample of 54 lead shielding items was measured in a commercial laboratory using inductively coupled plasma mass spectrometry. The median and range of surface lead for aprons, thyroid collars, and gloves were 3.6 μg/dm2 (range, 1.3-22.4 μg/dm2 ), 23.1 μg/dm2 (range, 2.6-116 μg/dm2 ), and 134 μg/dm2 (range, 1.5-155 μg/dm2 ), respectively. In the final multivariable analysis, the mean surface lead on thyroid collars and gloves was higher than on aprons (relative differences 4.8, 95% confidence interval [CI] 2.2, 10.5, P

Radioisotopes Production Plant of Nuclear Center of Mexico (ININ) prepares weekly radiopharmaceuticals such as sodium iodohippurate and metaiodobenzylguanidine, these compounds are called labeled molecules. The processes for the preparation of these compounds are carried out individually, that is, a different marking process is applied for each compound, and they are carried out in a glove box. Due to the way these processes operate, they present radiological safety risks, difficulty in manipulating each process because they are carried out manually, that is, the operator of the process manually introduces the radioactive material, non-radioactive chemical compounds and the material of laboratory such as lead shielding disposable syringes, vials containing reagents and other devices, that is, there is no device to replace the operator's hands such as manipulators, pistons or vacuum systems that can automate processes to a certain extent. To improve these drawbacks, this work shows a semi-automated equipment, in which the preparation of the preparation processes of the three compounds can be carried out, that is, in the same equipment the sodium iodohippurate and metaiodobenzylguanidine are obtained, also that the equipment is in a hot cell in order to minimize radiation safety risks. The team will work in a semi-automated way, so that there is a minimum exposure to radiation directly, by the personnel in charge of labeling molecules. The routine industrial production with this equipment begins with the fabrication of 9 marked doses of sodium iodohippurate of 2.73 mCi of iodine-131, each vial comprising 4.5 mL of saline solution, and a product containing the indicated molecules of 0.5 mL with a marked percentage of 95.6%. This study is innovative in that it presents a new design of equipment for identifying molecules, which is comprised of electrical, mechanical, vacuum, and air extraction systems.

This study aimed to compare the head dose of a cardiologist to scrub and scout nurses during cardiac angiography.A correlational longitudinal quantitative design was used to examine the relationship between the variable of occupational dose to the medical operator when compared with the dose to the scrub and scout nurses.A quantitative analysis was performed on data collected during coronary angiograms (N = 612) for one cardiologist and 22 nurses performing either the scrub or scout role between May 2015 and February 2017. Analysis was based on log-transformed dose levels and reported as geometric means and associated 95% confidence intervals.It was found that scrub nurses received on average 41% more head dose than the cardiologist during diagnostic procedures and 52% higher doses during interventional cases.Nurses working in fluoroscopic cardiovascular procedures should be provided with appropriate training and protective equipment, notably lead skull caps, to minimize their occupational radiation exposure.There is a notable lack of research evaluating the occupational head and eye exposure to nurses involved in fluoroscopic procedures. This study found that during diagnostic coronary angiograms, the scrub nurses received 41% more occupational head dose than the cardiologist and 52% higher head doses during interventional cases. Radial access resulted in higher doses to scrub nurses than femoral artery access. It is advisable that staff wear protective lead glasses and skull caps and use appropriately positioned ceiling mounted lead shields to minimize the risk of adverse effects of occupational exposure to ionizing radiation.目的: 这项研究的目的是比较心脏血管造影期间心脏病专家对擦洗和侦察护士的头部造成的辐射量。 设计: 采用相关的纵向定量设计,研究了医护人员职业剂量与擦洗护士和侦察护士职业剂量的关系。 方法: 在2015年五月至2017年二月期间,对一名心脏病专家和22名护士在冠状动脉造影期间收集的数据(人数为612)进行了定量分析。分析基于对数转换剂量水平,并以几何平均值和相关的95%置信区间进行报告。 结果: 结果发现,在诊断过程中,擦洗护士的平均头部辐射量比心脏科医生高41%,在介入性病例中的平均头部辐射量高52%。 结论: 从事透视心血管手术的护士应获得适当的培训和防护设备,特别是头盖骨,以尽量减少其职业辐射暴露。 影响: 在评估从事透视手术的护士的职业性头部和眼睛暴露方面,研究明显不足。这项研究发现,在诊断冠状动脉造影时,擦洗护士比心脏科医生多接受41%的职业性头部辐射量,在介入性病例中多接受52%的头部辐射量。桡动脉通路比股动脉通路对擦洗护士产生的辐射量更高。建议工作人员佩戴铅防护眼镜和头罩,并使用适当位置的吸顶式铅防护罩,以尽量减少职业暴露于电离辐射而产生的不利影响。.

Background Trans-radial approach for cardiac catheterisation procedures has long been associated with high operator and patient radiation dose. The aim of the present study was to determine the effect of pelvic and radial shields on decreasing coronary procedure radiation doses. Methods A total of 418 patients randomly underwent diagnostic and therapeutic cardiac procedures with and without the pelvic and rad-board lead shields during the procedures. The operator and patient doses were then determined by means of a personal dosimeter and dose area product (DAP), respectively. Results The shields decreased the operator radiation dose by 40% in coronary angiography (CA) and by 45% during angioplasty (PCI). These results were achieved at the cost of increased patient radiation dose. Conclusion Pelvic lead shields combined with rad-board shields are highly effective in reducing operator radiation dose in trans-radial approach, but it is only achieved at the cost of increased patient DAP.

The nuclear heat and the shut-down dose rate (SDDR) in the ITER upper port 18 (UP18) were estimated to provide the nuclear heat load for the structural analysis of UP18 and to provide the basis for the further SDDR mitigation strategy of UP18. In addition, the contribution of UP18 to the coil nuclear heating was also estimated to ensure the safe operation of superconducting coils. The UP18 MCNP model has been developed based on the actual CAD model, which was integrated into C-Model, the global MCNP model for ITER. While ITER UP18 accommodates three tenant systems of VUV(Vacuum Ultra-Violet)-edge Spectrometer, Neutron Activation System (NAS), and Upper Vertical Neutron Camera (UVNC), detailed models of VUV-edge and NAS were included in the UP18 MCNP model and UVNC was represented as conceptual stainless steel boxes due to lack of detailed model. For SDDR estimation, overall SDDR at the UP18 interspace was estimated as well as the SDDR contributions from tenant systems. The SDDR result includes the crosstalk from neighboring ports which are filled with general port models included in C-Model. Several SDDR mitigation options were also evaluated such as to use low Co contents material, to place B4C shielding at the rear box of port plug and to use lead shielding at the interspace floor. The results indicate that evaluated options can contribute to the mitigation of SDDR in interspace, and especially to place B4C shielding at the rear box region of port plug structure can effectively mitigate the SDDR behind the closure plate.

Paediatric radiotherapy comes at the expense of increased risk of late effects due to out-of-field dose caused not only by the treatment itself but also by image guidance. This study examined how the out-of-field dose to selected radiosensitive organs was affected by applying a 1 mm lead shielding during delivery of volumetric-modulated arc therapy (VMAT) for paediatric brain cancer. The study also investigated how the out-of-field dose to the same organs was affected by the use of flattening-filter free (FFF) beams. Out-of-field doses to the thyroid, breast and testes were measured using thermoluminescence dosimeters inserted in two anthropomorphic phantoms equivalent to a 1-year and 5-year old child. Coplanar VMAT plans were prepared for 6 MV and 6 MV FFF photon beams and delivered using a Varian TrueBeam linear accelerator, with and without lead shielding applied to the phantoms. The measured out-of-field doses were as large as 200,9 cGy for the whole treatment, with associated secondary cancer risk being as large as 1,1%. Shielding of the phantoms was found to decrease the out-of-field dose by up to 24%. The use of 6 MV FFF beams yielded a decrease in the dose to the testes by 21–42% compared to 6 MV, while in one case increasing the dose to the thyroid by 18%. The observation that only doses to organs distant to the primary irradiated volume were significantly decreased for FFF can be explained by an increase in internal scatter caused by the softer energy spectrum of the Varian FFF beam.

Knowledge of radiation exposure in equine radiography is very limited. A study evaluating operator exposure confirmed the benefits of shielding, but exposure to personnel holding cassettes was not evaluated. This is an analytic study with the objective to measure and compare radiation exposures to personnel using a handheld generator with and without lead shielding. A cadaveric hindlimb was suspended to mimic standing position. Two dosimeters were placed at each of six locations from the generator and cassette to mimic locations of hands, trunk, and thyroid of personnel. At each location, one dosimeter was unshielded and the other was shielded. Six anatomic projections were performed, including lateromedial projections of the foot, metatarsophalangeal joint, tarsus, and stifle, as well as caudolateral–craniomedial oblique and caudocranial stifle projections. Comparisons between radiographer versus cassette holder exposure values were compared using the Wilcoxon signed rank test. Exposure was significantly (P

The purpose of this study was to quantify the dose reduction resulting from the use of lead aprons for pediatric chest CT as a function of the distance between the apron and the bottom of the scan range.Semianthropomorphic phantoms of the head, abdomen, and pelvis were placed adjacent to a chest phantom to mimic the habitus of a 5-year-old child. A chest CT scan was performed, and a point dosimeter was used to measure the radiation dose at points within and outside the scan range. A lead apron was placed 1, 5, and 10 cm from the bottom of the CT scan range, and the measurements were repeated. The weighted-average dose was calculated for each measurement position.The weighted-average dose within and outside the scan range was 1.7 and 0.067 mGy, respectively. The mean (percentage) dose reduction outside the scan range resulting from use of the lead apron was 0.013 mGy (19.1%), 0.007 mGy (10.1%), and 0.003 mGy (4.3%) when the lead apron was placed at distances of 1, 5, and 10 cm from the bottom of the scan range, respectively. The corresponding total percentage dose reduction (including the dose from the primary scan) was 0.7%, 0.4%, and 0.2%, respectively.As the lead apron was placed farther from the scan range, the amount of dose reduction diminished. The reduction in dose was extremely small compared with the overall dose from the examination. The small dose reduction gained from the use of lead shielding over the abdomen and pelvis during chest CT examination of pediatric patients may not outweigh the associated potential risks of artifacts and infection.

Purpose - There is a paucity of literature comparing patient and staff dose during coronary angiography (CA), implantable cardiac devices, permanent pacemakers (PPM) and electrophysiology (EP) procedures and little noting dose to staff other than cardiologists. This study sought to compare patient and occupational dose to staff during a range of fluoroscopically guided cardiac procedures. Methods - Radiation dose levels for the patients (n=1651), cardiologists (n=24), scrub (n=32) and scout nurses (n=35) were measured in a prospective single-centre study between February 2017 and August 2019. A comparison of dose during CA, device implantation, PPM insertion and EP studies was performed. Three Philips angiographic units were used, and DoseAware badges were worn on the temple of staff. Results - Results indicated that occupational dose during PPM was (statistically) significantly higher than other procedures. The cardiologist had the highest measured mean dose during biventricular implantable cardioverter defibrillators; levels were approximately five times that of ‘normal’ pacemaker insertions. Transcatheter aortic valve implantations (TAVI) were associated with relatively high mean doses for both staff and patients and had a statistically significant higher (>2 times) mean patient dose area product than all other categories. TAVI workups were also related to higher mean cardiologist and scrub nurse dose. It was observed that the mean scrub nurse dose can exceed that of the cardiologist. Scout nurses had the highest mean staff dose during EP studies. Conclusions - Given the significantly higher temple dose associated with PPM insertion, cardiologists should consider utilizing ceiling mounted lead shields, lead glasses and/or skull caps where possible. Efforts should also be made to minimize the use of DSA during TAVI and TAVI workups to reduce cardiologist, nurse and patient dose.

Surface contamination was quantified over a distributed source of activated potassium bromide from three detonations of Radiological Dispersal Devices (RDDs) at the Idaho National Laboratory Radiological Response Training Range, with a maximum sampled area of 19,900 m2, to provide a baseline comparison with other rapid, remote mapping methods. Measurements were obtained with a cerium bromide sensor collimated to a field of view of 3.14 m2, using lead shielding, and towed behind a ground vehicle. Sensor response correction factors for activated potassium bromide were calculated through simulation with SWORD to obtain activity per meter-squared. Continuous maps were produced by interpolating coverage from lawnmower raster scans. Radiological data was overlaid with aerial imagery from an automated unmanned aerial vehicle flight to provide contextual geological information relative to contamination levels. The contamination distribution measurements will be compared to unmanned aerial vehicle methods in future work.

Potassium is known for its effect on modifiable chronic diseases like hypertension, cardiac disease, diabetes (type-2), and bone health. In this study, a new method, neutron generator based neutron activation analysis (NAA), was utilized to measure potassium (K) in mouse carcasses. A DD110 neutron generator based NAA assembly was used for irradiation.Thirty-two postmortem mice (n= 16 males and 16 females, average weight $$22.02\pm 1.3$$ 22.02 ± 1.3 and $$17.9\pm 1.1$$ 17.9 ± 1.1 g) were employed for this study. Soft-tissue equivalent mouse phantoms were prepared for the calibration. All mice were irradiated for 10 minutes, and the gamma spectrum with 42K was collected using a high efficiency, high purity germanium (HPGe) detector. A lead shielding assembly was designed and developed around the HPGe detector to obtain an improved detection limit. Each mouse sample was irradiated and measured twice to reduce uncertainty. The average potassium concentration was found to be significantly higher in males $$(2846 \pm 525 \upmu g/g)$$ ( 2846 ± 525 μ g / g ) compared to females $$(2116.2 \pm 432 \upmu g/g)$$ ( 2116.2 ± 432 μ g / g ) . We also observed a significant correlation between potassium concentration and the weight of the mice. The detection limit for potassium quantification with the NAA system was 46 ppm. The radiation dose to the mouse was approximately 56 $${ \pm 1.6 }$$ ± 1.6 mSv for 10-min irradiation. In conclusion, this method is suitable for estimating individual potassium concentration in small animals. The direct evaluation of total body potassium in small animals provides a new way to estimate potassium uptake in animal models. This method can be adapted later to quantify potassium in the human hand and small animals in vivo. When used in vivo, it is also expected to be a valuable tool for longitudinal assessment, kinetics, and health outcomes.

This study investigated lead concentrations in the hairs of radiographers working in the radiological departments of general hospitals that used lead shielding for radiation protection. We collected scalp hair samples from 32 radiographers working in four radiology departments with lead shielding and 18 administration personnel in the same hospitals without lead shielding. Samples were analyzed for lead concentrations by inductively coupled plasma mass spectrometry. As a result, lead concentrations in the hairs of the radiological technologists were significantly higher than those in the administration staffs (0.72 ± 0.51 vs. 0.19 ± 0.27 μg/g, P

X-ray radioactive rays are widely used with the continuous development of radioactive medicine and nuclear technology applications, as well as lead shielding material pollutions new no lead shielding material was needed. In this paper, the main properties of metal tungsten and bismuth as X-ray shielding materials were studied for the protection people avoid the 150 kV X-rays by the Monte Carlo method is used to study. According to simulation with 2 kg/m2, results show that performance of single metal material tungsten iron is superior to that of bismuth material. Tungsten-bismuth better than bismuth-tungsten with the case of equal-quality double-layer metal. The protection performance is better when the metal-mixed tungsten-bismuth ratio is 0.5: 0.5 or the tungsten ratio is large. The research provides effective support for the development of textile radiation protection materials.

The spherical fuel elements are adopted in the high-temperature gas-cooled reactor pebble-module (HTR-PM). The fuel elements will be discharged continuously from the reactor core and transported into the fuel transport pipelines during the reactor operation, leading to spatially varying dose outside the pipeline. In this case, the dose evaluation faces two major challenges, including dynamic source terms and pipelines with varying lengths and shapes. This study tries to handle these challenges for HTR-PM through comprehensive calculations using the QAD-CGA program and to design the corresponding shielding of the pipeline. During the calculation, it is assumed that a spherical fuel element stays in different positions of the pipelines in turn, and the corresponding dose contributions were calculated. By integrating the dose contributions at different positions, the dose at the points of interest can be obtained. The total dose is further determined according to the assumed fuel elements transport speed of 5 m/s and total 6000 fuel elements transportation per day. Two types of fuel transport pipelines and two source terms were considered, i.e., the spent fuel element transport pipelines with corresponding spent fuel source term and the different burn-up fuel element transport pipelines with the average burn-up fuel source term. Doses at different points of interest were calculated with no shielding scenario and with lead shielding of different thicknesses scenario. To evaluate the shielding effect, the dose limit of the orange radiation zone of HTR-PM and the radiation damage thresholds from NCRP report No.51 were both adopted. The calculated results show that, for pipelines that transport the spent fuel, a 4 cm lead shielding will be enough. And for pipelines that transport fuel elements with different burn-up, a 5 cm lead shielding will be added. The method and results can provide valuable reference for other work of HTR-PM.

Some concepts in nuclear radiation physics are abstract and intellectually demanding. In the present paper, an “MCHP platform” (MCHP was an acronym for Monte Carlo simulations + Human Phantoms) was proposed to provide assistance to the students through visualization. The platform involved Monte Carlo simulations of interactions between ionizing radiations and the Oak Ridge National Laboratory (ORNL) adult male human phantom. As an example to demonstrate the benefits of the proposed MCHP platform, the present paper investigated the variation of the absorbed photon dose per photon from a 137Cs source in three selected organs, namely, brain, spine and thyroid of an adult male for concrete and lead shields with varying thicknesses. The results were interesting but not readily comprehensible without direct visualization. Graphical visualization snapshots as well as video clips of real time interactions between the photons and the human phantom were presented for the involved cases, and the results were explained with the help of such snapshots and video clips. It is envisaged that, if the platform is found useful and effective by the readers, the readers can also propose examples to be gradually added onto this platform in future, with the ultimate goal of enhancing students’ understanding and learning the concepts in an undergraduate nuclear radiation physics course or a related course.

In the measurement of gamma spectra by the low background gamma spectrometer system using the HPGe detector, lead shields have been often used for preventing from gamma rays in background radiation. Rely on the laboratory facilities, lead shielding geometry can be different. Gamma rays from the measured radioactive source interact with matter as the lead shield, then enter the HPGe detector and contribute the backscattering area of the gamma spectrum. Basing on that, this work presents estimating the influence of the lead shielding geometry on the gamma spectra. The MCNP5 code was used to simulate the gamma spectra of 137Cs, 54Mn, 60Co and 22Na measured by the gamma spectrometer system with the lead shield having cylinder or square prism shape. The effectiveness of simulation modelling based on the MCNP5 code was validated by comparison of experimental and calculated gamma spectra. The results showed that using the lead shield shaped cylinder, backscattering gammas contribute from 3.68% to 5.23% more than using the lead shield shaped square prism.

We aim to demonstrate the unique use of embedded lead eye shields in an electron wax bolus when treating the nasal dorsum. A patient presented to the clinic with squamous cell carcinoma of the nasal dorsum requiring treatment with en face electrons. A 3D customized wax bolus was designed and imported into the treatment planning system (TPS) to calculate the dose distribution. Due to high lens dose, the bolus was customized further to create 2 milled open slots in the wax, over the lens of eye, to allow lead sheets totaling 4 mm to be slid into the wax. The patient was brought back to the clinic to be scanned with the wax bolus fitting snugly over the nose, eyes, and cheek regions. The 3D milled insert holes were contoured on the CT in the TPS, assigned HU of 2758, to mimic the lead insertion. The lens dose with lead inserts was compared to the plan without lead insert. To further confirm the lens dose, EBT3 films were placed on the right and left eye under the bolus, and nose dorsum on the first day of treatment. The maximum dose of right lens, as calculated in the TPS with the simulated lead shields in place, decreased from 989.5cGy to 457cGy. The maximum dose of left lens decreased from 1085.4cGy to 501cGy. The dose readings from EBT3 films were in good agreement with the TPS, with deviation of 3.32%, 0.26%, and 3.44% for right lens, left lens, and nose, respectively. Daily positioning deviations compared to the plan were 0.65 ± 0.16cm and 0.63 ± 0.29cm for right eye and left eye, respectively. This novel device demonstrated the feasibility, in terms of dose calculation accuracy in the TPS and fabrication, of using customized bolus with lead inserts to conveniently shield the lens of the eyes in an electron treatment for the nose, enabling a streamlined daily setup.

Breast cancer is the fifth most common cause of death worldwide. Currently, one of the standard treatments for breast cancer is radiation therapy (RT). On the other hand, mouse models have been used in pre-clinical studies for breast cancer RT, requiring dedicated shielding to exposure the breast region. In this work, we considered the values of the lead attenuation coefficient and the tenth reducing layer for a 60Co irradiator and developed a lead shielding device for breast cancer-bearing mice to be exposed to localized breast RT. Five-kg of lead were exposed to temperature of 340ºC and inserted into an aluminum mold previously adjusted to the dimensions of the device. After solidification, the device was shaped into a cylinder with dimension of 14 x 15 x 7 cm (height x width x thickness, respectively). A round cut-out for breast exposure of 1 cm in diameter was made at 5 cm from the basis of the device. For shielding device validation, we performed calibrations to establish a dose of 10 Gy in the target. Fifteen CaSO4:Dy thermoluminescent dosimeters were distributed along a 50 mL conical tube to simulate the mouse position inside the shielding. The shielding device was placed at a fixed distance of 10 cm from the target for optimal exposure time. After irradiation, the dosimeters were read on a thermoluminescent reader. According to our results, we were able to develop a body-shielding device that assured the required dose for RT of breast cancer in mice.

Background Healthcare workers occupationally exposed to 18F-FDG cannot wear protective equipment, such as lead aprons, since the interaction between high energy radiation (511 keV) and metal increases the dose of radiation absorption. The objective of this study was to evaluate the shielding efficacy of a plastic polymer against the toxicogenomic effects of ionizing radiation in human lymphocytes, using cytokinesis-block micronucleus assays. Methods Human peripheral blood lymphocytes were isolated from three subjects and cultured under standard conditions. The cultures were exposed to 300 mCi of 18F-FDG at a distance of 10 cm for 10 min, in the absence of shielding or with lead, polymer, and lead + polymer shields. Results Lead shielding was found to increase the number of counts detected by Geiger-Müller radiation monitors as a consequence of the photoelectron effect. Conversely, the lead + polymer shield reduced the number of counts. The lead, polymer, and lead + polymer shields significantly reduced the frequency of micronuclei, nucleoplasmic bridges, and nuclear buds induced by ionizing radiation. Regarding cytotoxicity, only the lead + polymer shield re-established the cell cycle at the level observed for the negative control. Conclusions Lead aprons that are internally coated with polymer increased the radiological protection of individuals occupationally exposed to 18F-FDG PET/CT, especially during examinations.

Deep underground environments are ideal for low background searches due to the attenuation of cosmic rays by passage through the earth. However, they are affected by backgrounds from $\gamma$-rays emitted by $^{40}$K and the $^{238}$U and $^{232}$Th decay chains in the surrounding rock. The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a liquid xenon TPC located within the Davis campus at the Sanford Underground Research Facility, Lead, South Dakota, at the 4,850-foot level. In order to characterise the cavern background, in-situ $\gamma$-ray measurements were taken with a sodium iodide detector in various locations and with lead shielding. The integral count rates (0--3300~keV) varied from 596~Hz to 1355~Hz for unshielded measurements, corresponding to a total flux in the cavern of $1.9\pm0.4$~$\gamma~$cm$^{-2}$s$^{-1}$. The resulting activity in the walls of the cavern can be characterised as $220\pm60$~Bq/kg of $^{40}$K, $29\pm15$~Bq/kg of $^{238}$U, and $13\pm3$~Bq/kg of $^{232}$Th., Comment: 11 pages, 9 figures

Presently, public members are exposed to sources of ionizing radiation, and health risks due to radiation exposures should be a concern. This study aims to calculate the whole-body cumulative radiation exposure of taxi drivers. Also, this study will provide the effect of using a simple lead shield and three types of glass shield AVT6, TZN-D, and SLGC-E5, by calculating the effective annual dose of the taxi drivers that work in medical centers. Two MIRD phantoms as a driver and patient, a sample body of a taxi, pure lead, and glass sheets as a shield, were simulated using the MCNP code. We assumed that the patients had undergone the brain, liver, and kidney SPECT imaging by injecting 99mTC-HMPAO, 99mTC-sulfur colloid, and 99mTC-DMSA with the activity of 740MBq, 185MBq, and 333MBq, respectively. These shields are simulated on two sides of the driver, in the back and right side. The annual effective dose was calculated for 0–3.5 g/cm2 area densities. It was observed that the 0.45, 1.09, 1.28, and 2.11 g/cm2 of Pb, TZN-D, AVT6, and SLGC-E5 respectively decrease the effective dose below the allowed limit. According to the results, using the lead shield, the effective dose was reduced by a factor up to 7.25 times. It is recommended that taxi drivers wear a 0.4 mm lead shield or its equivalent when they have Tc-99 m injected patients.