RADIATION DOSES TO THE EYE LENS AND FOREHEAD OF INTERVENTIONAL RADIOLOGISTS: HOW HIGH AND ON WHAT GROUNDS?

2020 ◽  
Vol 190 (2) ◽  
pp. 150-157
Author(s):  
M Psarras ◽  
A Ploussi ◽  
E Carinou ◽  
E Brountzos ◽  
S C Spiliopoulos ◽  
...  

Abstract The aim of the study was to measure and evaluate the radiation dose to the eye lens and forehead of interventional radiologists (IRs). The study included 96 procedures (lower-limb percutaneous transluminal angioplasties, embolisations/chemoembolisations and vertebroplasties) performed by 6 IRs. A set of seven thermoluminescence dosemeters was allocated to each physician. The highest dose per procedure was found for the left eye lens of the primary operator in vertebroplasties (1576 μSv). Left and right eye doses were linearly correlated to left and right forehead doses, respectively. A workload-based estimation of the annual dose to participating IRs revealed that the occupational dose limit for the eye lens can be easily exceeded. The left eye dose of ΙRs must be routinely monitored on a personalised basis. Τhe left eye dose measurement provides a reliable assessment of the ipsilateral forehead dose, along with valid estimations for the right eye and right forehead doses.

2020 ◽  
Vol 189 (2) ◽  
pp. 157-162
Author(s):  
Carlo Giordano ◽  
Ivo Monica ◽  
Fabrizio Quattrini ◽  
Elena Villaggi ◽  
Rossana Gobbi ◽  
...  

Abstract Data were collected from 642 orthopaedic interventions during which the images produced by X-rays were recorded. By examining these images, it is possible to determine the time that the orthopaedic surgeons’ hands were exposed to the direct radiation beam. The procedures with greater exposure to the direct beam were those involving the hand (median 15 s) and the wrist (median 13 s). Two surgeons wore a ring to measure the absorbed dose at the fingers: one on the dominant hand and the other on the non-dominant hand. The two surgeons performed 34 and 48 operations, respectively, in 14 months. The total doses measured with the rings were 2.30 and 1.04 mSv, respectively. The images of the interventions were examined, determining how much each individual hand was exposed. The interventional reference point (IRPeff (left or right)) was calculated by comparing the doses at the IRP with the exposure times of the right or the left hand. Summing the IRPeff of the two surgeons in 14 months, it is obtained the maximum values of 2.87 mGy for the left hand of one and 6.74 mGy for the right hand of the other, which are of the order of 1/100 of the annual dose limit for the extremities.


2015 ◽  
Vol 8 (7) ◽  
pp. 736-740 ◽  
Author(s):  
Marta Sans Merce ◽  
Amine M Korchi ◽  
Lisa Kobzeva ◽  
Jérôme Damet ◽  
Gorislav Erceg ◽  
...  

BackgroundProtection of the head and eyes of the neurointerventional radiologist is a growing concern, especially after recent reports on the incidence of brain cancer among these personnel, and the revision of dose limits to the eye lens. The goal of this study was to determine typical occupational dose levels and to evaluate the efficiency of non-routine radiation protective gear (protective eyewear and cap). Experimental correlations between the dosimetric records of each measurement point and kerma area product (KAP), and between whole body doses and eye lens doses were investigated.MethodsMeasurements were taken using thermoluminescent dosimeters placed in plastic bags and worn by the staff at different places. To evaluate the effective dose, whole body dosimeters (over and under the lead apron) were used.ResultsThe mean annual effective dose was estimated at 0.4 mSv. Annual eye lens exposure was estimated at 17 mSv when using a ceiling shield but without protective glasses. The protective glasses reduced the eye lens dose by a factor of 2.73. The mean annual dose to the brain was 12 mSv; no major reduction was observed when using the cap. The higher correlation coefficients with KAP were found for the dosimeters positioned between the eyes (R2=0.84) and above the apron, and between the eye lens (R2=0.85) and the whole body.ConclusionsUnder the specific conditions of this study, the limits currently applicable were respected. If a new eye lens dose limit is introduced, our results indicate it could be difficult to comply with, without introducing additional protective eyewear.


2020 ◽  
Vol 26 (1) ◽  
pp. 45-53
Author(s):  
Misbah Ahmad ◽  
Iftkhar Ahmad ◽  
Aakif Ullah Khan ◽  
Amin Ali Khan ◽  
Kamran Ali Shah ◽  
...  

AbstractThe imperative use of ionizing radiation in medicine causes the inevitable occupational exposure of the medical workers during the course of routine duties. The magnitude of health risk due to such radiation exposures has been described in terms of occupational radiation doses. In this context, it is obligatory to monitor, measure and document the radiation dose of occupationally exposed medical workers. This study aims to review the whole-body occupational radiation exposures of medical workers in Pakistan. Specifically, online literature published during 2000-2018 was reviewed for the occupational radiation exposures of Pakistani medical workers. Analysis of the extracted personal dosimetry data revealed that the total number of monitored medical occupational workers was 26046. The range of total cumulative and annual average effective doses was 94-15785 Person-mSv and 0.66-7.37 mSv, respectively. A significant number of the workers (25477; ~98%) received an annual dose below 5 mSv, while only 18 workers received an occupational exposure exceeding the annual dose limit of 20 mSv. It is expected that this study will provide a useful reference for evaluating and improving radiation protection and safety policies in the country.


Author(s):  
O. I. Admakin ◽  
I. A. Solop ◽  
A. D. Oksentyuk

Relevance. The narrowing of the maxilla is one of the most common pathologies in orthodontics. Recent studies show that the narrowing is always asymmetric which is connected to the rotation of the maxilla. To choose the treatment correctly one need a calculation that reveals the asymmetry, which is impossible with using standard indexes.Purpose – to compare efficiency of indexes of Pont and Korkhause with the Kernott's method in patients with narrowing of the maxilla.Materials and methods. The study involved 35 children aged from 8 to 12 years old undergoing dental treatment in the University Children's Clinical Hospital of the First Moscow State Medical University with no comorbidities. For every patient a gypsum model was prepared and after that to carry out the biometrical calculation. In this study two indexes were used: Pont's index and Korkhause's; using this standard analysis the narrowing of the maxilla was revealed. After using Pont's Index and Korkhaus analysis all the models were calculated by the method of Kernott with Kernott's dynamic pentagon.Results. As a result of the analysis of the control diagnostic models a narrowing of the maxilla in 69% of cases (n = 24) was revealed in all cases, the deviation of the size of the dentition was asymmetric. Thus, 65% of the surveyed models showed a narrowing on the right. This narrowing was of a different severity and averaged 15 control models.Conclusions. This shows that for the biometrics of diagnostic models it is necessary to use methods that allow to estimate the width of the dentition rows on the left and on the right separately. To correct the asymmetric narrowing of the dentition, it is preferable to use non-classical expanding devices that act equally on the left and right sides separetly.


2019 ◽  
Author(s):  
Bashayer Hassan Shuaib ◽  
Rahaf Hisham Niazi ◽  
Ahmed Haitham Abduljabbar ◽  
Mohammed Abdulraheem Wazzan

BACKGROUND Radiology now plays a major role to diagnose, monitoring, and management of several diseases; numerous diagnostic and interventional radiology procedures involve exposure to ionizing radiation. Radiology now plays a major role to diagnose, monitoring, and management of several diseases; numerous diagnostic and interventional radiology procedures involve exposure to ionizing radiation. OBJECTIVE This study aimed to discover and compare the awareness level of radiation doses, protection issues, and risks among radiology staff in Jeddah hospitals. METHODS A cross-sectional survey containing 25 questions on personal information and various aspects of radiation exposure doses and risks was designed using an online survey tool and the link was emailed to all radiology staff in eight tertiary hospitals in Jeddah. The authors were excluded from the study. A P-value of < .05 was used to identify statistical significance. All analyses were performed using SPSS, version 21. RESULTS Out of 156 participants the majority 151 (96.8%) had poor knowledge score, where the mean scores were 2.4±1.3 for doses knowledge, 2.1±1.1for cancer risks knowledge, 2.3±0.6 for general information, and 6.7±1.9 for the total score. Only 34.6% of the participants were aware of the dosage of a single-view chest x-ray, and 9.0% chose the right answer for the approximate effective dose received by a patient in a two-view. 42.9% were able to know the correct dose of CT abdomen single phase. There is a significant underestimation of cancer risk of CT studies especially for CT abdomen where only 23.7% knew the right risk. A p-value of <0.05 was used to identify statistical significance. No significant difference of knowledge score was detected regarding gender (P =.2) or work position (P=.66). CONCLUSIONS Our survey results show considerable inadequate knowledge in all groups without exception. We recommended a conscientious effort to deliver more solid education and obtain more knowledge in these matters and providing periodic training courses to teach how to minimize the dose of radiation and to avoid risk related. CLINICALTRIAL not applicable


2021 ◽  
Vol 193 (1) ◽  
pp. 43-54
Author(s):  
Yasuda Mitsuyoshi ◽  
Funada Tomoya ◽  
Sato Hisaya ◽  
Kato Kyoichi

Abstract As chest x rays involve risks of patients falling, radiologic technologists (technologists) commonly assist patients, and as the assistance takes place near the patients, the eye lenses of the technologists are exposed to radiation. The recommendations of the International Commission on Radiological Protection suggest that the risk of developing cataracts due to lens exposure is high, and this makes it necessary to reduce and minimize the exposure. The present study investigated the positions of technologists assisting patients that will minimize exposure of the eye lens to radiation. The results showed that it is possible to reduce the exposure by assisting from the following positions: 50% at the sides rather than diagonally behind, 10% at the right side of the patient rather than the left and 40% at 250 mm away from the patient. The maximum reduction with radiation protection glasses was 54% with 0.07 mmPb and 72% with 0.88 mmPb.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sanda Iacobas ◽  
Bogdan Amuzescu ◽  
Dumitru A. Iacobas

AbstractMyocardium transcriptomes of left and right atria and ventricles from four adult male C57Bl/6j mice were profiled with Agilent microarrays to identify the differences responsible for the distinct functional roles of the four heart chambers. Female mice were not investigated owing to their transcriptome dependence on the estrous cycle phase. Out of the quantified 16,886 unigenes, 15.76% on the left side and 16.5% on the right side exhibited differential expression between the atrium and the ventricle, while 5.8% of genes were differently expressed between the two atria and only 1.2% between the two ventricles. The study revealed also chamber differences in gene expression control and coordination. We analyzed ion channels and transporters, and genes within the cardiac muscle contraction, oxidative phosphorylation, glycolysis/gluconeogenesis, calcium and adrenergic signaling pathways. Interestingly, while expression of Ank2 oscillates in phase with all 27 quantified binding partners in the left ventricle, the percentage of in-phase oscillating partners of Ank2 is 15% and 37% in the left and right atria and 74% in the right ventricle. The analysis indicated high interventricular synchrony of the ion channels expressions and the substantially lower synchrony between the two atria and between the atrium and the ventricle from the same side.


2012 ◽  
Vol 25 (0) ◽  
pp. 222 ◽  
Author(s):  
Michael J. Proulx ◽  
Achille Pasqualotto ◽  
Shuichiro Taya

The topographic representation of space interacts with the mental representation of number. Evidence for such number–space relations have been reported in both synaesthetic and non-synaesthetic participants. Thus far most studies have only examined related effects in sighted participants. For example, the mental number line increases in magnitude from left to right in sighted individuals (Loetscher et al., 2008, Curr. Biol.). What is unclear is whether this association arises from innate mechanisms or requires visual experience early in life to develop in this way. Here we investigated the role of visual experience for the left to right spatial numerical association using a random number generation task in congenitally blind, late blind, and blindfolded sighted participants. Participants orally generated numbers randomly whilst turning their head to the left and right. Sighted participants generated smaller numbers when they turned their head to the left than to the right, consistent with past results. In contrast, congenitally blind participants generated smaller numbers when they turned their head to the right than to the left, exhibiting the opposite effect. The results of the late blind participants showed an intermediate profile between that of the sighted and congenitally blind participants. Visual experience early in life is therefore necessary for the development of the spatial numerical association of the mental number line.


VLSI Design ◽  
1998 ◽  
Vol 6 (1-4) ◽  
pp. 379-384 ◽  
Author(s):  
Ganesh Rajagopalan ◽  
Vadali Mahadev ◽  
Timothy S. Cale

We discuss our approach to using the Riemann problem to compute surface profile evolution during the simulation of deposition, etch and reflow processes. Each pair of segments which represents the surface is processed sequentially. For cases in which both segments are the same material, the Riemann problem is solved. For cases in which the two segments are different materials, two Riemann problems are solved. The material boundary is treated as the right segment for the left material and as the left segment for the right material. The critical equations for the analyses are the characteristics of the Riemann problem and the ‘jump conditions’ which represent continuity of the surface. Examples are presented to demonstrate selected situations. One limitation of the approach is that the velocity of the surface is not known as a function of the surface angle. Rather, it is known for the angles of the left and right segments. The rate as a function of angle must be assumed for the explicit integration procedure used. Numerical implementation is briefly discussed.


2014 ◽  
Vol 117 (5) ◽  
pp. 535-543 ◽  
Author(s):  
Justin A. R. Lang ◽  
James T. Pearson ◽  
Arjan B. te Pas ◽  
Megan J. Wallace ◽  
Melissa L. Siew ◽  
...  

At birth, the transition to newborn life is triggered by lung aeration, which stimulates a large increase in pulmonary blood flow (PBF). Current theories predict that the increase in PBF is spatially related to ventilated lung regions as they aerate after birth. Using simultaneous phase-contrast X-ray imaging and angiography we investigated the spatial relationships between lung aeration and the increase in PBF after birth. Six near-term (30-day gestation) rabbits were delivered by caesarean section, intubated and an intravenous catheter inserted, before they were positioned for X-ray imaging. During imaging, iodine was injected before ventilation onset, after ventilation of the right lung only, and after ventilation of both lungs. Unilateral ventilation increased iodine levels entering both left and right pulmonary arteries (PAs) and significantly increased heart rate, iodine ejection per beat, diameters of both left and right PAs, and number of visible vessels in both lungs. Within the 6th intercostal space, the mean gray level (relative measure of iodine level) increased from 68.3 ± 11.6 and 70.3 ± 7.5%·s to 136.3 ± 22.6 and 136.3 ± 23.7%·s in the left and right PAs, respectively. No differences were observed between vessels in the left and right lungs, despite the left lung not initially being ventilated. The increase in PBF at birth is not spatially related to lung aeration allowing a large ventilation/perfusion mismatch, or pulmonary shunting, to occur in the partially aerated lung at birth.


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