scholarly journals SECONDARY RADIATION MAPPING

2021 ◽  
pp. 162-166
Author(s):  
Ioannis Vlachos ◽  
Ioannis Kandarakis ◽  
Giorgos Panayiotakis
Keyword(s):  
Dose Rate ◽  
Radiation Protection ◽  
Secondary Radiation ◽  
X Rays ◽  
Scatter Radiation ◽  
X Ray ◽  
Vital Importance ◽  
Water Phantom ◽  
The Mean ◽  
Secondary Dose

Radiation protection for personnel working with X-rays is of vital importance. Several studies have been published regarding the secondary radiation and the shielding requirements to areas that are adjacent to the X-ray units. In this work, secondary radiation in a conventional radiographic room, in terms of dose rate (mSv/hr), as a function of different radiographic exposure factors has been studied. The measurements were performed with a 451P Fluke Biomedical survey meter on a Philips Medio 65 CP-H X-ray generator with a cylindrical water phantom. It was found that the dose rate from the scatter radiation decreases with distance. An added filtration of 2.0 mmAl at 100 kVp reduced the secondary dose rate further by 21.4%. The results of this study may be of value during exposure of personnel that are not protected by shielding materials. Highlights Ÿ It was found that the dose rate from the scatter radiation decreases with distance. An added filtration of 2.0 mmAl at 100 kVp reduced the secondary dose rate further by 21.4%. Ÿ The mean secondary X-ray energies for 60, 80, 100 and 100 kV with 2 mmAl added, were calculated as 34.41, 51.12, 69.03 and 71.29 keV respectively. Ÿ The results of this study are of value during exposure of people such as radiographers, and patients during the use of mobile X-ray units.

scholarly journals Integrity test of lead apron and its effect on personnel and carer

2018 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Omojola Akintayo Daniel ◽  
Isiodu Chinonye Xaviera
Keyword(s):  
Dose Rate ◽  
Integrity Test ◽  
Scatter Radiation ◽  
Lead Apron ◽  
X Ray ◽  
Radiation Workers ◽  
Critical Organ ◽  
The Mean ◽  
Organ Site ◽  
Mean Dose Rate

<p class="Abstract">The use of lead apron is known to protect radiation workers and carers (patient relatives) from the scatter radiation. The study intends to assess the integrity of lead apron by checking for defects and to estimate the mean dose rate to personnel and carers and also to compare the percentage mean absorbance of the apron with the related studies. Ten lead aprons were used involving three vendors. A fluoroscopy unit, floor mounted X-ray unit, survey meter, lead aprons and meter rule were used. Crack and tear were identified with some areas close to the critical organ site. Eighty percent of the aprons showed signs that they were defective. Correlation of the lead aprons mean age and the total number of defective lead aprons were not significant (p=0.866). The mean thickness of the aprons for the three brands affected the percentage absorbance (p&lt;0.001). The mean dose rate was above 20 mSv recommended for radiation workers averaged over a single year. It is recommended that the defective apron close to the critical organ be replaced and those in areas distal from the critical organs be further evaluated using the rejection criteria test before they are replaced.</p>

scholarly journals An Evaluation of Cellular Neural Networks for the Automatic Identification of Cephalometric Landmarks on Digital Images

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
Rosalia Leonardi ◽  
Daniela Giordano ◽  
Francesco Maiorana
Keyword(s):  
Neural Networks ◽  
Cellular Neural Networks ◽  
Automatic Identification ◽  
Cephalometric Analysis ◽  
X Rays ◽  
X Ray ◽  
Automatic Location ◽  
Landmark Identification ◽  
The Mean ◽  
Analogue To Digital

Several efforts have been made to completely automate cephalometric analysis by automatic landmark search. However, accuracy obtained was worse than manual identification in every study. The analogue-to-digital conversion of X-ray has been claimed to be the main problem. Therefore the aim of this investigation was to evaluate the accuracy of the Cellular Neural Networks approach for automatic location of cephalometric landmarks on softcopy of direct digital cephalometric X-rays. Forty-one, direct-digital lateral cephalometric radiographs were obtained by a Siemens Orthophos DS Ceph and were used in this study and 10 landmarks (N, A Point, Ba, Po, Pt, B Point, Pg, PM, UIE, LIE) were the object of automatic landmark identification. The mean errors and standard deviations from the best estimate of cephalometric points were calculated for each landmark. Differences in the mean errors of automatic and manual landmarking were compared with a 1-way analysis of variance. The analyses indicated that the differences were very small, and they were found at most within 0.59 mm. Furthermore, only few of these differences were statistically significant, but differences were so small to be in most instances clinically meaningless. Therefore the use of X-ray files with respect to scanned X-ray improved landmark accuracy of automatic detection. Investigations on softcopy of digital cephalometric X-rays, to search more landmarks in order to enable a complete automatic cephalometric analysis, are strongly encouraged.

Isoelastic Cementless Total Hip Replacement in Rheumatoid Arthritis. Long-Term Results

1992 ◽  
Vol 2 (2) ◽  
pp. 43-46
Author(s):  
U. Fusco ◽  
R. Capelli ◽  
A. Avai ◽  
M. Gerundini ◽  
L. Colombini ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Hip Replacement ◽  
The Other ◽  
Long Term Results ◽  
X Rays ◽  
X Ray ◽  
The Mean ◽  
Cementless Total Hip Replacement

Between 1980 and 1987 we have implanted 46 isoelastic cementless THR in 40 patients affected with rheumatoid arthritis. We have reviewed 38 hips clinically and by X-ray. The mean follow-up was 8,5 years. Harris hip scores ranged from 30.6 preoperatively to 73,4 post-operatively when reviewed. While on the other hand Merle D'Aubigné hip scores ranged from 7,06 pre-operatively to 15,59 post-operatively. All patients have been satisfied, and X-rays showed an improvement for both Charnely and Gruen X-ray score.

scholarly journals X-Rays from Wolf-Rayet Stars Observed by the Einstein Observatory

1982 ◽  
Vol 99 ◽  
pp. 589-595
Author(s):  
W. T. Sanders ◽  
J. P. Cassinelli ◽  
K. A. van der Hucht
Keyword(s):  
Mean Value ◽  
Spectral Energy ◽  
X Rays ◽  
X Ray ◽  
Total Luminosity ◽  
Hydrogen Emission Lines ◽  
Flux Level ◽  
The Mean ◽  
Einstein Observatory ◽  
Thin Source

Preliminary results of three X-ray surveys are presented. Out of a sample of 20 stars, X-rays were detected from four Wolf-Rayet stars and two 08f+ stars. The detected stars have about the same mean value as 0 stars for the X-ray to total luminosity ratio, LX/L = 10−7, but exhibit a much larger variation about the mean. The spectral energy distributions are also found to be like that of 0 stars in that they do not exhibit large attenuation of X-rays softer than 1 keV. This indicates that for both the 0 stars and WR stars much of the X-ray emission is coming from hot wisps or shocks in the outer regions of the winds and not from a thin source at the base of the wind. The general spectral shape and flux level place severe restrictions on models that attribute the lack of hydrogen emission lines to extremely high temperatures of the gas in the wind.

The Utility of Preoperative Magnetic Resonance Imaging for Determining the Flexibility of Sagittal Imbalance

Neurosurgery ◽  
2017 ◽  
Vol 83 (3) ◽  
pp. 465-470
Author(s):  
Akshay Sharma ◽  
Sina Pourtaheri ◽  
Jason Savage ◽  
Iain Kalfas ◽  
Thomas E Mroz ◽  
...  
Keyword(s):  
Lumbar Lordosis ◽  
Surgical Planning ◽  
Pelvic Incidence ◽  
Sagittal Imbalance ◽  
X Rays ◽  
Resonance Imaging ◽  
Patient Counseling ◽  
X Ray ◽  
Preoperative Magnetic Resonance ◽  
The Mean

Abstract BACKGROUND Scoliosis X-rays are the gold standard for assessing preoperative lumbar lordosis; however, particularly for flexible lumbar deformities, it is difficult to predict from these images the extent of correction required, as standing radiographs cannot predict the thoracolumbar alignment after intraoperative positioning. OBJECTIVE To determine the utility of preoperative MRI in surgical planning for patients with flexible sagittal imbalance. METHODS We identified 138 patients with sagittal imbalance. Radiographic parameters including pelvic incidence and lumbar lordosis were obtained from images preoperatively. RESULTS The mean difference was 2.9° between the lumbar lordosis measured on supine MRI as compared to the intraoperative X-rays, as opposed to 5.53° between standing X-rays and intraoperative X-ray. In patients with flexible deformities (n = 24), the lumbar lordosis on MRI measured a discrepancy of 3.08°, as compared to a discrepancy of 11.46° when measured with standing X-ray. CONCLUSION MRI adequately determined which sagittal deformities were flexible. Furthermore, with flexible sagittal deformities, lumbar lordosis measured on MRI more accurately predicted the intraoperative lumbar lordosis than that measured on standing X-ray. The ability to preoperatively predict intraoperative lumbar lordosis with positioning helps with surgical planning and patient counseling regarding expectations and risks of surgery.

scholarly journals 1700 Using Intra-Operative Imaging as A Tool to Provide Peer Review, Scoring, Feedback and Education for Hand and Wrist Trauma Cases - A Quality Improvement Project

2021 ◽  
Vol 108 (Supplement_6) ◽  
Author(s):  
A Smith ◽  
A Thompson ◽  
P Stanier ◽  
J Rooker ◽  
I Lowdon
Keyword(s):  
Final Report ◽  
X Rays ◽  
Improvement Project ◽  
X Ray ◽  
Constructive Feedback ◽  
Wrist Trauma ◽  
Specific Feedback ◽  
The Mean ◽  
Mean Time

Abstract Aim To improve the efficiency of intraoperative hand trauma x-ray review, introduce a scoring system for quality of fixation achieved and use this as an education and feedback tool for trainees. Method A large QI project in 2019 demonstrated that intra-operative images taken using the mini C-arm were not being reviewed. In March 2020 the first QI cycle introduced an Access database to ensure that as cases were removed from the trauma board, they were added to a review list. Each x-ray was also scored in the trauma meeting (good, acceptable, poor) to assess the radiographic quality of fixation. The second QI cycle identified the named surgeon for each case, allowing surgeon specific feedback. Finally, we trained all qualified users of the mini C-arm to upload their own images after each case, reducing the mean time to upload. Results This QI project has improved the review rate of mini C-arm images from 30% to 100% and every x-ray is scored. The mean time to review images has reduced from 4 days to less than 24 hours. All trainees can access their scores for imaged hand and wrist trauma and receive written constructive feedback. Conclusions This project ensures appropriate and prompt review of all hand and wrist trauma cases allowing early identification of any concerns. All x-rays are scored, and this process acts as an educational prompt in the trauma meeting. A final report can be printed for each trainee which can be uploaded to their portfolio to document their surgical progress.

SECONDARY RADIATION FROM X-RAY FILTERS: I. SINGLE-METAL FILTERS

1942 ◽  
Vol 20a (11) ◽  
pp. 185-194
Author(s):  
G. A. Wrenshall ◽  
H. J. Nichols
Keyword(s):  
Intensity Distribution ◽  
Ionization Chamber ◽  
Operating Conditions ◽  
Secondary Radiation ◽  
X Rays ◽  
X Ray ◽  
Chamber Method ◽  
Aluminium Copper ◽  
Standard Operating

Using an ionization chamber method, the intensity distribution and quality of forward transmitted secondary X-rays from filters of aluminium, copper, tin, and lead have been measured under standard operating conditions. Geometrical arrangements of X-ray tube, defining apertures, filter, and receiver commonly used in medical and industrial radiology are employed. Suggestions for minimizing the intensity of the secondary radiation reaching the receiver from single-metal filters are submitted.

EVALUATION OF RADIATION DOSE IN DIFFERENT POSITIONS AROUND THE PATIENT TABLE DURING INTERVENTIONAL CARDIOLOGY PROJECTIONS

2019 ◽  
Vol 188 (2) ◽  
pp. 199-204
Author(s):  
Y Lahfi ◽  
A Ismail
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Dose Rate ◽  
Radiation Protection ◽  
Interventional Cardiology ◽  
X Ray ◽  
Dose Rates ◽  
Patient Table ◽  
The Right

Abstract The aim of the present study was to evaluate the radiation exposure around the patient table as relative to the cardiologist position dose value. The dose rates at eight points presuming staff positions were measured for PA, LAO 30° and RAO 30° radiographic projections, and then normalized to the cardiologist’s position dose-rate value. The results show that in PA and RAO 30° projections, the normalized dose rate was higher by 9–22% at the right side of the table at a distance of 50 cm, while it was higher up to 31% at the left side for the same measured points in the LAO 30°. The differences of normalized dose rates for the both table sides were lower and decreased at farther positions. The obtained results correspond to the recommendations of staff radiation protection in Cath-labs with regards to X-ray tube and detector positions.

scholarly journals The reflexion of X-rays from the ‘anti-phase nuclei’ of AuCu 3

1943 ◽  
Vol 181 (987) ◽  
pp. 360-368 ◽  
Keyword(s):  
Mean Value ◽  
X Rays ◽  
Integral Breadth ◽  
X Ray ◽  
Structure Factors ◽  
Unit Cells ◽  
The Mean

Jones & Sykes have observed that the superlattice lines in X-ray photographs of AuCu 3 , are not always as sharp as the main lines, and that the broadening depends markedly on the indices of the line. They explain these phenomena by assuming that the crystals of AuCu 3 contain many ‘anti-phase nuclei’ in which the superlattice is organized in different ways. In the present paper it is shown that the integral breadth of a reflexion from a crystal in which all the unit cells are not the same is λ J 0 /cos θ ƒ J t dt , where J t is the mean value of the product FF* of the structure factors of two unit cells separated a distance t in the hkl direction. Detailed calculations are made of the broadening to be expected from five different ways in which the nuclei can ‘change step’. Closest agreement with the observed broadening is given by a manner of ‘ changing step ’ in which the gold atoms avoid one another.

Analisis Paparan Radiasi Hambur di Ruang Isolasi COVID-19 RSUD Kraton Kabupaten Pekalongan

2021 ◽  
Vol 1 (1) ◽  
pp. 22-25
Author(s):  
Heryani Heryani ◽  
Nurul Firdausi Nuzula ◽  
Ari Dwi Reskianto ◽  
Ryan Wahyu Widhianto
Keyword(s):  
Radiation Exposure ◽  
X Rays ◽  
Scatter Radiation ◽  
Isolation Room ◽  
Water Phantom ◽  
Limit Value ◽  
Measurement Results ◽  
One Year ◽  
The Right ◽  
Radiological Examinations

Analysis of Distributed Radiation Exposure in The Covid-19 Isolation Room in Kraton Re¬gional Hospital, Pekalongan Regency. Since Covid-19 was declared a world pandemic by WHO, isolation rooms have become a place that is often used to deal with pandemics. Radiological examinations or X-rays are used as a supporting examination in the diagnosis of Covid-19. So it is necessary to adjust the Covid protocol in the examination so that there is no transmission of the virus and the effects of unnecessary radiation. Isolation rooms used for radiological examinations of Covid-19 patients need to be reviewed for safety to comply with procedures. The purpose of this paper is to analyze the scattering radiation exposure in the Seruni isolation room of RSUD Kraton, Pekalongan Regency. The data in this paper were taken by measuring the amount of scatter radiation exposure in room B of the isolation room Seruni RSUD Kraton Pekalongan Regency, on February 16, 2021. This measurement was carried out with a water phantom as object with the highest exposure factor for thorax examination, namely 70 kV and 16 mAs and carried out at several points around the water phantom object with a distance of 2 meters from the source. The measurement results of scattered radiation exposure are then compared with the Dose Limit Value (NBD) for the general public of 1 mSv in one year. Analysis of the measure¬ment of scatter radiation exposure in the Seruni isolation room at Kraton Hospital, Pekalongan Regency, still experienced leaks and the exposure value exceeded tolerance. The measurement results in the hallway of the Seruni room are 676 Sv/h, in addition to the radiographer (2 meters on the left side of the phantom) it is 627.12 Sv/h, at a distance of 2 meters the right side of the phantom is 287.04 Sv/h, and a distance of 2 meters in front of the hall phantom of 676 Sv/h. The follow-up that needs to be done to optimize radiation protection is to install at least 3 scattering radiation shields.

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