scholarly journals Evaluation of Patient Exposure After an Emergency Warm-Up of the CT X-Ray Tube

2020 ◽  
Vol 13 (2) ◽  
pp. 122-126
Author(s):  
Desislava Z. Kostova-Lefterova ◽  
Desislava P. Ivanova ◽  
Filip N. Simeonov ◽  
Anna R. Zagorska ◽  
Kameliya Z. Genova ◽  
...  
Keyword(s):  
Medical Staff ◽  
Personal Monitoring ◽  
Patient Exposure ◽  
University Hospitals ◽  
Warm Up ◽  
X Ray ◽  
Air Kerma ◽  
Medical Physicist

Summary A survey was performed to evaluate patient exposure after a procedure for the CT X-ray tube’s emergency warm-up, with the patient positioned on the table within the CT gantry. Three CT units, situated in three different University hospitals, were included in the survey. The evaluation was performed with AGFA personal monitoring films to visualize the results and discuss them with the radiographers who operate the systems. Additional measurements were performed with the RaySafe X2 system to demonstrate the presence of exposure. The air kerma resulting from implementing the warm-up protocol was evaluated to be higher than 112 μGy, 409 μGy, and 807 μGy for each of the CT units. Those values were underestimated because of the dosimetry equipment used and the methodology. A discussion between medical staff, engineers, and medical physicist was initiated. The practice with unnecessary patient exposure was terminated.

scholarly journals An Approach for Online Determining the Entrance Surface Air Kerma (ESAK) in Digital Radiology

2021 ◽  
Author(s):  
Ibrahim Idris Suliman
Keyword(s):  
Interventional Radiology ◽  
Digital Imaging ◽  
Digital Information ◽  
Patient Exposure ◽  
Digital Radiology ◽  
X Ray ◽  
Air Kerma ◽  
Dicom Header ◽  
Area Product ◽  
Entrance Surface Air Kerma

Abstract An online method is proposed to determine the entrance surface air kerma (ESAK) in digital radiology from console-displayed kerma area product (PKA) data. ESAK values were calculated from X-ray tube outputs and patient exposure factors across five X-ray examinations. The corresponding PKAvalues were taken from the Digital Imaging and Communications in Medicine (DICOM) header. Using linear regression between ESAK and values, the slope and intercept coefficients for each type of X-ray equipment and procedure were determined. The coefficient to determine ESAK from ranged from 59% for a posteroanterior chest to 88% for anteroposterior lumbar spine view X-ray procedures. The results demonstrated the possibility of online estimates of ESAK from a console that displayed using readily available digital information in radiology. The results may have important implications in interventional radiology, where ESAK values are crucial for preventing skin injuries due to prolonged fluoroscopy times.

scholarly journals Dosimetric evaluation of X-ray examinations of paranasal sinuses in pediatric patients

2016 ◽  
Vol 49 (2) ◽  
pp. 79-85 ◽  
Author(s):  
Beatriz de Lucena Villa-Chan Cantalupo ◽  
Aline Carvalho da Silva Xavier ◽  
Clemanzy Mariano Leandro da Silva ◽  
Marcos Ely Almeida Andrade ◽  
Vinícius Saito Monteiro de Barros ◽  
...  
Keyword(s):  
Paranasal Sinuses ◽  
Pediatric Patients ◽  
Radiological Examination ◽  
Patient Exposure ◽  
X Ray ◽  
Thermoluminescent Dosimeters ◽  
Air Kerma ◽  
Radiosensitive Organs ◽  
The City ◽  
Entrance Surface Air Kerma

Abstract Objective: To estimate the entrance surface air kerma (Ka,e) and air kerma in the region of radiosensitive organs in radiographs of pediatric paranasal sinuses. Materials and Methods: Patient data and irradiation parameters were collected in examinations of the paranasal sinuses in children from 0 to 15 years of age at two children's hospitals in the city of Recife, PE, Brazil. We estimated the Ka,e using the X-ray tube outputs and selected parameters. To estimate the air kerma values in the regions of the eyes and thyroid, we used thermoluminescent dosimeters. Results: The Ka,e values ranged from 0.065 to 1.446 mGy in cavum radiographs, from 0.104 to 7.298 mGy in Caldwell views, and from 0.113 to 7.824 mGy in Waters views. Air kerma values in the region of the eyes ranged from 0.001 to 0.968 mGy in cavum radiographs and from 0.011 to 0.422 mGy in Caldwell and Waters views . In the thyroid region, air kerma values ranged from 0.005 to 0.932 mGy in cavum radiographs and from 0.002 to 0.972 mGy in Caldwell and Waters views. Conclusion: The radiation levels used at the institutions under study were higher than those recommended in international protocols. We recommend that interventions be initiated in order to reduce patient exposure to radiation and therefore the risks associated with radiological examination of the paranasal sinuses.

The empirical formula for calculating the incident air Kerma in intraoral radiographic imaging

2021 ◽  
pp. 20210117
Author(s):  
Zoran Mirkov ◽  
Katarina M Rajković ◽  
Jovan B Stanković ◽  
Dario Faj
Keyword(s):  
Empirical Formula ◽  
Measurement Data ◽  
Radiographic Imaging ◽  
Relative Percentage ◽  
X Ray ◽  
Air Kerma ◽  
Final Formula ◽  
Average Patient ◽  
The Mean ◽  
Fitted Function

Objectives: The aim of this paper is to determine the empirical formula for calculating the incident air kerma (Ki), used as a patient dose descriptor in the intraoral radiographic imaging. Methods: The data for the formula were collected during the regular annual inspection of intraoral dental X-ray units in 2018, 2019 and early 2020. The measurement data of 50 X-ray units were processed to develop the formula. Exposure factors for imaging molars of the upper jaw of an average patient in a clinical setting were used in the measurement. The formula validity was statistically evaluated using coefficient of correlation, standard error of the fitted function and the mean relative percentage deviation. Results: measurement values of the radiation doses and calculated values obtained by using the final formula showed good agreement - the mean relative percentage deviation values less than ±15%. Conclusions: Although there are differences in X-ray units, voltages, manufacturers and device architectures (single-phase and high-frequency), the measurement data comply well with computed ones in all cases.

SU-GG-I-62: Entrance Skin Air Kerma of National Lung Screening Trial Chest X-Ray Exams

2010 ◽  
Vol 37 (6Part3) ◽  
pp. 3115-3115
Author(s):  
P Judy ◽  
R Kruger ◽  
C Cagnon ◽  
M Flynn ◽  
J Seibert ◽  
...  
Keyword(s):  
X Ray ◽  
Air Kerma ◽  
National Lung Screening Trial ◽  
Chest X Ray ◽  
Lung Screening ◽  
Screening Trial

Comparison of the air-kerma standards of the NRPA, the STUK, the SSM and the LNE-LNHB in low-energy and mammography x-ray ranges (EURAMET.RI(I)-S14)

Metrologia ◽  
2018 ◽  
Vol 55 (1A) ◽  
pp. 06008-06008
Author(s):  
H Bjerke ◽  
J Plagnard ◽  
J-M Bordy ◽  
A Kosunen ◽  
C Lindholm ◽  
...  
Keyword(s):  
Low Energy ◽  
X Ray ◽  
Air Kerma

INFLUENCE OF NEW MASS ENERGY-ABSORPTION COEFFICIENTS FROM ICRU REPORT NO. 90 ON AIR KERMA TO DOSE EQUIVALENT CONVERSION COEFFICIENTS

2018 ◽  
Vol 185 (1) ◽  
pp. 27-33
Author(s):  
Katharina Bairlein ◽  
Oliver Hupe
Keyword(s):  
Energy Absorption ◽  
Radiation Protection ◽  
Cross Sections ◽  
Mass Energy ◽  
Dose Equivalent ◽  
Absorption Coefficients ◽  
X Ray ◽  
Air Kerma ◽  
Conversion Coefficients ◽  
Operational Quantities

Abstract In Report No. 90 of the International Commission on Radiation Units and Measurements (ICRU), new mass energy-absorption coefficients are listed which are based on renormalized Scofield photoeffect cross-sections. The mass energy-absorption coefficients are the basis for the conversion coefficients from air kerma to the operational quantities listed in ISO 4037-3. Although ICRU does not give a recommendation if these new mass energy-absorption coefficients should be applied instead of the values used so far, an examination of the possible consequences for radiation protection quantities is necessary. We calculated the conversion coefficients for the X-ray qualities specified in ISO 4037-1 with the new mass energy-absorption coefficients and with the mass energy-absorption coefficients used so far to determine the deviations. Our calculations show that the change of the conversion coefficients due to the new values from ICRU Report No. 90 is negligible.

scholarly journals [P101] Are occupational doses of medical staff incurred in interventional procedures related to patient exposure

2018 ◽  
Vol 52 ◽  
pp. 129
Author(s):  
Agnieszka Szumska ◽  
Maciej Budzanowski ◽  
Renata Kopeć
Keyword(s):  
Medical Staff ◽  
Interventional Procedures ◽  
Patient Exposure

scholarly journals Effects of aluminum-copper alloy filtration on photon spectra, air kerma rate and image contrast

2004 ◽  
Vol 15 (3) ◽  
pp. 214-219 ◽  
Author(s):  
Andréa Gonçalves ◽  
João Manuel Domingos de Almeida Rollo ◽  
Marcelo Gonçalves ◽  
Francisco Haiter Neto ◽  
Frab Norberto Bóscolo
Keyword(s):  
Copper Alloy ◽  
Good Alternative ◽  
Image Contrast ◽  
X Ray ◽  
Air Kerma ◽  
Aluminum Copper Alloy ◽  
Aluminum Filter ◽  
Photon Spectra ◽  
Aluminum Filtration ◽  
Air Kerma Rate

This study evaluated the performance of aluminum-copper alloy filtration, without the original aluminum filter, for dental radiography in terms of x-ray energy spectrum, air kerma rate and image quality. Comparisons of various thicknesses of aluminum-copper alloy in three different percentages were made with aluminum filtration. Tests were conducted on an intra-oral dental x-ray machine and were made on mandible phantom and on step-wedge. Depending on the thickness of aluminum-copper alloy filtration, the beam could be hardened and filtrated. The use of the aluminum-copper alloy filter resulted in reductions in air kerma rate from 8.40% to 47.33%, and indicated the same image contrast when compared to aluminum filtration. Aluminum-copper alloy filtration may be considered a good alternative to aluminum filtration.

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