A Microfluidic Cytometer for Quantitative Evaluation of Radiation Dose by γ-H2AX

2014 ◽  
Vol 522-524 ◽  
pp. 1119-1122
Author(s):  
Jun Sheng Wang ◽  
You Nan Song ◽  
Jin Yang Sun ◽  
Hui Chu ◽  
Jin Hu Jiang ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Fluorescence Intensity ◽  
Radiation Effect ◽  
Flow Cytometer ◽  
Detection Sensitivity ◽  
Radiation Doses ◽  
Highly Sensitive ◽  
The Mean ◽  
Optical Focusing ◽  
Immunofluorescence Intensity

Evaluation of radiation dose is very important for the detection of radiation damage. γ-H2AX is a popular biological dosimeter to evaluate the radiation effect. Typically, bulky and expensive commercial flow cytometers are used to detect γ-H2AX. This paper presents a miniaturized and highly sensitive cytometer using a microfluidic chip for evaluating the radiation dose by detecting the mean immunofluorescence intensity of γ-H2AX. A compact optical focusing system and a shift-phase differential amplifier are designed to improve the detection sensitivity. Sample lymphocyte cells are stained by FITC fluorescent dye after being irradiated by UVC. Comparison experiments between the developed miniature cytometer and a commercial flow cytometer were conducted under different radiation doses. The developed microfluidic cytometer can also demonstrate a good linear correlation between the measured fluorescence intensity and the irradiation dose with a detection limit similar to that of the commercial flow cytometer. The developed cytometer can evaluate quantitatively the radiation dose by the mean fluorescence intensity of γ-H2AX with a significantly smaller amount of blood samples than a commercial flow cytometer.

scholarly journals Radiation protection effect of mobile shield barrier for the medical personnel during endoscopic retrograde cholangiopancreatography: a quasi-experimental prospective study

BMJ Open ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. e027729 ◽  
Author(s):  
Kwang Hyun Chung ◽  
Young Sook Park ◽  
Sang Bong Ahn ◽  
Byoung Kwan Son
Keyword(s):  
Radiation Dose ◽  
Prospective Study ◽  
Radiation Protection ◽  
Endoscopic Retrograde Cholangiopancreatography ◽  
Medical Personnel ◽  
Secondary Outcome ◽  
Radiation Doses ◽  
Endoscopic Retrograde ◽  
Quasi Experimental ◽  
The Mean

ObjectiveTo investigate the effectiveness of radiation protection offered by a newly designed mobile shield barrier for medical personnel during endoscopic retrograde cholangiopancreatography (ERCP).DesignQuasi-experimental prospective study.SettingERCP procedures conducted between October 2016 and June 2017 at a single secondary referral hospital that performs approximately 250 therapeutic ERCP procedures annually.InterventionsThe mobile shield barrier was a custom-made 2 mm Pb shielding plate (width: 120 cm, height: 190 cm) with a 0.5 mm Pb window (width: 115 cm, height: 60 cm) on its upper part was used. Four wheels were attached to the bottom to allow easy moving.Primary and secondary outcome measuresThe radiation doses were measured during ERCP using personal thermoluminescence dosimetry (TLD) badges on both sides of the mobile shield barrier (patient’s side: TLD1 and medical staff’s side: TLD2). The radiation doses were also measured on the outer surface of the thyroid shield of the endoscopist (TLD3), and on the chest area inside the protective apron of the endoscopist (TLD4) and the main assistant (TLD5). The TLD was changed and reported once every 3 months. The radiation dose measured by TLD badges were compared.ResultsDuring the study period, a total of 128 ERCP procedures were performed. The mean fluoroscopy time per procedure was 244.9±257.0 s and the mean number of digital radiographs per procedure was 3.7±1.0. TLD1 (outside the barrier) had a mean radiation dose of 26.85±3.47 mSv and all the other TLDs (inside the barrier) had less than 1 mSv (p<0.001). In the post hoc analysis, the difference between TLD1 and others showed a statistical significance; however, there were no significant differences between the TLDs inside the barrier.ConclusionOur mobile shield barrier was useful to reduce the radiation exposure of medical personnel during ERCP.

scholarly journals Radiation Doses and Cancer Risk from CT Pulmonary Angiography Examinations

2019 ◽  
Author(s):  
Hanif Haspi Harun ◽  
Muhammad Khalis Abdul Karim ◽  
Zulkifly Abbas ◽  
Sarawana Chelwan Muniandy ◽  
Akmal Sabarudin ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Cancer Risk ◽  
Organ Dose ◽  
Pulmonary Angiography ◽  
Effective Diameter ◽  
Radiological Protection ◽  
Radiation Doses ◽  
Dose Length Product ◽  
The Mean

The present study aims to investigate radiation doses from Computed Tomography Pulmonary Angiography (CTPA) examinations based on the patient&rsquo;s size and to estimate the probability of cancer risk induced from the examination. Data from 100 patients who had undergone CTPA examinations, such as scanning acquisition parameters, patient demography, as well as radiation dose exposure, were collected and analysed. All subjects which aged above 18 y/o were scanned using a Philips Brilliance 128 multi-detector CT (MDCT) scanner. The mean dose value for Volume Computed Tomography Dose Index (CTDIvol), Dose-Length Product (DLP) and effective dose (E) were 11.06 &plusmn; 7.17 mGy, 400.38 &plusmn; 259.10 mGy.cm and 8.68 &plusmn; 5.47 mSv respectively. In addition, with respective of patient&rsquo;s effective diameter, the mean SSDE value for Group 1, Group 2 and Group 3 were 9.93 &plusmn; 3.89, 13.70 &plusmn; 9.04 and 22.29 &plusmn; 7.35, respectively. Cancer risk per million procedure was calculated based on te recommendation by the International Commission on Radiological Protection Publication 103 report. The organ dose and cancer risk attained for breast, lung and liver were 17.05 &plusmn; 10.40 mGy (194 per one million procedure), 17.55 &plusmn; 10.86 mGy (192 per one million procedure) and 15.04 &plusmn; 9.75 mGy (53 per one million procedure), respectively. In conclusion, CTDIvol underestimated, and SSDE was more accurate in describing the radiation dose. Lung and breast with larger lung effective diameter received the highest dose exposure which increase the probability of the cancer risk. Therefore, it is important to apply optimised protocols in order to reduce patient&rsquo;s exposure during CTPA examination.

Survey of Dental Radiographic Equipment and Radiation Doses in Finland

1988 ◽  
Vol 29 (4) ◽  
pp. 481-485 ◽  
Author(s):  
R. Havukainen
Keyword(s):  
Radiation Dose ◽  
Radiation Safety ◽  
Mean Value ◽  
Radiation Doses ◽  
Effective Dose Equivalent ◽  
Dose Equivalent ◽  
Radiation Dose Exposure ◽  
The Mean ◽  
Skin Doses ◽  
Made In

The radiation dose exposure, and the faults in about 1700 dental units inspected at dental surgeries by the Finnish Centre for Radiation and Nuclear Safety in 1981–1985, were analysed. The mean value of skin doses in the bite-wing projection was about 6.2 mGy, the range 0.5 to 151 mGy. The mean energy imparted per bite-wing examination was estimated as 0.68 mJ and that per panoramic examination as 1.2 mJ. That gives a total imparted energy of about 600 J per year for conventional dental examinations and about 420 J per year for panoramic examinations. This gives a total of 0.13 mJ from conventional and 0.089 mJ from panoramic examinations per inhabitant per year. The collective effective dose equivalent was calculated as about 9 manSv for conventional dental examinations and about 6 manSv for panoramic examinations. Twenty per cent of units had some fault which was capable of decreasing radiation safety. Forty per cent of units were served reparation orders or other remarks were made in inspection documents. Large doses were usually accounted for by incorrect film processing and malfunction of the exposure timer.

scholarly journals Pengaruh Parameter Milliampere-Second (mAs) terhadap Kualitas Citra Dan Dosis Radiasi Pada Pemeriksaan CT scan Kepala Pediatrik

2020 ◽  
Vol 17 (1) ◽  
pp. 1 ◽  
Author(s):  
Muhammad Irsal ◽  
Guntur Winarno
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Linear Regression ◽  
Ct Scan ◽  
Linear Regression Analysis ◽  
Mean Value ◽  
Reference Level ◽  
Radiation Doses ◽  
Average Value ◽  
The Mean

Radiographers are responsible for administering radiation doses according to the principle of As Low As Reasonably Achievable (ALARA), to optimize the use of CT parameters to produce good image quality by minimizing radiation doses. The purpose of this study was to determine the effect of mAs parameters on image quality and radiation dose received by pediatric CT head examination patients. The research method to perform image processing results of examination using radiant viewer and analysis of value Contrast to noise ratio (CNR) as a parameter of image quality and CTDIvol to determine the estimated radiation dose, then an analysis is performed to determine whether there is an influence of mAs on the CNR and CTDIvol values. The mean value of kV 116 ± 8.28, the mean value of parameter mAs 161.5 ± 63.46, the mean SNR parameter value is 7.5 ± 0.8, the mean return value of CNR parameter was 0.318 ± 0.291, the mean value of the CTDIvol parameter is 18.68 mGy ± 4.55 mGy, the average value of DLP parameters was 408.7 mGy x cm ± 105.2 mGy x cm, the mean value of parameter DLP is 441.2 mGy x cm ± 155.2 mGy x cm. With linear regression analysis of test results between mAs to CNR is R2 = 0.045. then to the results of linear regression between mAs against CTDI is R2 = 0704, the estimated radiation dose limit for the average value of CTDIvol 18.68 mGy and the average value of DLP 408.7 mGy x cm, this means the protocol CT scan of the head of the pediatric use is still within safe limits by Diagnostic Reference Level of BAPETEN in 2018 to pediatric head CT examination

The Employment of 197Hg EDTA in Kidney Scanning

1965 ◽  
Vol 05 (01) ◽  
pp. 56-67
Author(s):  
I. Pál ◽  
J. Földes ◽  
I. Krasznai
Keyword(s):  
Radiation Dose ◽  
Renal Cortex ◽  
Radiation Doses ◽  
Intravenous Pyelography ◽  
Edta Complex

SummaryThe authors investigated the use of 197Hg EDTA complex for kidney scanning. They describe the physical, biological and toxicological properties of the compound; its distribution within the organism, its excretion with urine and faeces and its uptake by the kidneys. The authors have established that the renal cortex selectively secretes the material which makes it suitable for kidney scanning. Some scintigrams of both normal and pathologic kidneys are presented.Finally a detailed discussion of the dosimetry is included. The radiation doses due to 197Hg EDTA are compared with those due to 203Hg-neohydrin and to intravenous pyelography. This comparison shows clearly that the use of 197Hg EDTA considerably decreases the radiation dose to the patient.

Radiation Minimisation and Outcome Maximisation in Cardiac Computed Tomograpy

2010 ◽  
Vol 6 (1) ◽  
pp. 15
Author(s):  
James P Earls ◽  
Jonathon A Leipsic ◽  
◽  
Keyword(s):  
Radiation Dose ◽  
Dose Reduction ◽  
New Technologies ◽  
Cardiac Computed Tomography ◽  
Substantial Reduction ◽  
Radiation Doses ◽  
Tube Current ◽  
Prospective Triggering ◽  
Effective Radiation ◽  
Selection Of

Recent reports have raised general awareness that cardiac computed tomography (CT) has the potential for relatively high effective radiation doses. While the actual amount of risk this poses to the patient is controversial, the increasing concern has led to a great deal of research on new CT techniques capable of imaging the heart at substantially lower radiation doses than was available only a few years ago. Methods of dose reduction include optimised selection of user-defined parameters, such as tube current and voltage, as well as use of new technologies, such as prospective triggering and iterative reconstruction. These techniques have each been shown to lead to substantial reduction in radiation dose without loss of diagnostic accuracy. This article will review the most frequently used and widely available methods for radiation dose reduction in cardiac CT and give practical advice on their use and limitations.

scholarly journals Sources of Variability in the Response of Labeled Microspheres and B Cells during the Analysis by a Flow Cytometer

2021 ◽  
Vol 22 (15) ◽  
pp. 8256
Author(s):  
Adolfas K. Gaigalas ◽  
Yu-Zhong Zhang ◽  
Linhua Tian ◽  
Lili Wang
Keyword(s):  
B Cells ◽  
Laser Beam ◽  
Cross Section ◽  
Mean Fluorescence Intensity ◽  
Numerical Aperture ◽  
Flow Cytometer ◽  
Fluorescence Signal ◽  
Minor Importance ◽  
Reliable Measure ◽  
The Mean

A stochastic model of the flow cytometer measurement process was developed to assess the nature of the observed coefficient of variation (CV%) of the mean fluorescence intensity (MFI) from a population of labeled microspheres (beads). Several sources of variability were considered: the total number of labels on a bead, the path through the laser beam, the optical absorption cross-section, the quantum yield, the numerical aperture of the collection optics, and the photoelectron conversion efficiency of the photomultiplier (PMT) cathode. The variation in the number of labels on a bead had the largest effect on the CV% of the MFI of the bead population. The variation in the path of the bead through the laser beam was minimized using flat-top lasers. The variability in the average optical properties of the labels was of minor importance for beads with sufficiently large number of labels. The application of the bead results to the measured CV% of labeled B cells indicated that the measured CV% was a reliable measure of the variability of antibodies bound per cell. With some modifications, the model can be extended to multicolor flow cytometers and to the study of CV% from cells with low fluorescence signal.

scholarly journals Recent Advances in Quenchbody, a Fluorescent Immunosensor

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1223
Author(s):  
Jinhua Dong ◽  
Hiroshi Ueda
Keyword(s):  
Fluorescence Intensity ◽  
Fluorescent Dyes ◽  
Antibody Fragment ◽  
Disease Diagnosis ◽  
Disease Biomarkers ◽  
Highly Sensitive ◽  
Physiologically Active Substances ◽  
New Type ◽  
Antigen Antibody ◽  
Active Substances

The detection of viruses, disease biomarkers, physiologically active substances, drugs, and chemicals is of great significance in many areas of our lives. Immunodetection technology is based on the specificity and affinity of antigen–antibody reactions. Compared with other analytical methods such as liquid chromatography coupled with mass spectrometry, which requires a large and expensive instrument, immunodetection has the advantages of simplicity and good selectivity and is thus widely used in disease diagnosis and food/environmental monitoring. Quenchbody (Q-body), a new type of fluorescent immunosensor, is an antibody fragment labeled with fluorescent dyes. When the Q-body binds to its antigen, the fluorescence intensity increases. The detection of antigens by changes in fluorescence intensity is simple, easy to operate, and highly sensitive. This review comprehensively discusses the principle, construction, application, and current progress related to Q-bodies.

scholarly journals Optimal Radiation Dose For Stage III Lung Cancer – Should “Definitive” Radiation Doses Be Used in the Pre-Operative Setting?

2021 ◽  
pp. 100201
Author(s):  
Areo G. Saffarzadeh ◽  
Maureen Canavan ◽  
Benjamin J. Resio ◽  
Samantha L. Walters ◽  
Kaitlin M. Flores ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Radiation Dose ◽  
Stage Iii ◽  
Radiation Doses

Diagnostic Reference Levels for Common Orthopedic Hand and Wrist Procedures Using Intraoperative mini C-arm Fluoroscopy

Hand ◽  
2021 ◽  
pp. 155894472199425
Author(s):  
Kiran R. Madhvani ◽  
Matthew J. R. Clark ◽  
Alex A. J. Kocheta
Keyword(s):  
Radiation Dose ◽  
Fracture Fixation ◽  
Wrist Fracture ◽  
Radiation Doses ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Audit Data ◽  
Small Joint ◽  
Open Fixation ◽  
Phalangeal Fracture

Background: Diagnostic reference levels are radiation dose levels in medical radiodiagnostic practices for typical examinations for groups of standard-sized individuals for broadly defined types of equipment. This study aimed to contribute to national diagnostic reference levels for common hand and wrist procedures using mini C-arm fluoroscopy. Small joint and digital fracture procedure diagnostic reference levels have not been reported in significant numbers previously with procedure-level stratification. Methods: Data were collected from fluoroscopy logbooks and were cross-referenced against the audit log kept on fluoroscopy machines. A total of 603 procedures were included. Results: The median radiation dose for wrist fracture open fixation was 2.73 cGycm2, Kirschner wiring (K-wiring) procedures was 2.36 cGycm2, small joint arthrodesis was 1.20 cGycm2, small joint injections was 0.58 cGycm2, and phalangeal fracture fixation was 1.05 cGycm2. Conclusions: Wrist fracture fixation used higher radiation doses than phalangeal fracture fixation, arthrodeses, and injections. Injections used significantly less radiation than the other procedures. There are significant differences in total radiation doses when comparing these procedures in hand and wrist surgery. National and international recommendations are that institutional audit data should be collected regularly and should be stratified by procedure type. This study helps to define standards for this activity by adding to the data available for wrist fracture diagnostic reference levels and defining standards for digital and injection procedures.

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