scholarly journals Fluoroscopy X-Ray Organ-Specific Dosimetry System (FLUXOR) for Estimation of Organ Doses and Their Uncertainties in the Canadian Fluoroscopy Cohort Study

2021 ◽  
Vol 195 (4) ◽  
Author(s):  
A. Iulian Apostoaei ◽  
Brian A. Thomas ◽  
F. Owen Hoffman ◽  
David C. Kocher ◽  
Kathleen M. Thiessen ◽  
...  
Keyword(s):  
Cohort Study ◽  
Organ Doses ◽  
X Ray ◽  
Organ Specific ◽  
Dosimetry System

HOW MANY DOSEMETERS ARE NEEDED FOR CORRECT MEAN ORGAN DOSE ASSESSMENT WHEN PERFOMING PHANTOM DOSIMETRY? A PHANTOM STUDY EVALUATING LIVER ORGAN DOSE AND INVESTIGATING TLD NUMBERS AND WAYS OF DOSEMETER PLACEMENT

2020 ◽  
Vol 189 (4) ◽  
pp. 475-488
Author(s):  
Peter H Pedersen ◽  
Asger G Petersen ◽  
Svend E Ostgaard ◽  
Torben Tvedebrink ◽  
Søren P Eiskjær
Keyword(s):  
Statistical Difference ◽  
Handling Time ◽  
Statistical Modelling ◽  
Organ Dose ◽  
Dose Assessment ◽  
Organ Doses ◽  
X Ray ◽  
Linear Effect ◽  
Organ Specific ◽  
Dose Measurements

Abstract This study evaluated repeated mean organ dose measurements of the liver by phantom dosimetry and statistical modelling in order to find a way to reduce the number of dosemeters needed for precise organ dose measurements. Thermoluminescent dosemeters were used in an adult female phantom exposed to a biplanar x-ray source at three different axial phantom rotations. Generalised mixed linear effect modelling was used for statistical analysis. A subgroup of five to six organ-specific locations out of 28 yielded mean liver organ doses within 95% confidence intervals of measurements based on all 28 liver-specific dosemeter locations. No statistical difference of mean liver dose was observed with rotation of the phantom either 10° clockwise or counter-clockwise as opposed to the coronal plane. Phantom dosimetry handling time during organ dose measurements can be markedly reduced, in this case the liver, by 79% (22/28), while still providing precise mean organ dose measurements.

scholarly journals The Hanging Chin Sign As A Mortality Predictor In Geriatric Patients At The Emergency Department: A Retrospective Cohort Study

2021 ◽  
Author(s):  
Anneloes NJ Huijgens ◽  
Laurens J van Baardewijk ◽  
Carolina JPW Keijsers
Keyword(s):  
Emergency Department ◽  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Geriatric Patients ◽  
Lateral View ◽  
X Ray ◽  
Hospital Patients ◽  
Chest X Ray

Abstract BACKGROUND: At the emergency department, there is a need for an instrument which is quick and easy to use to identify geriatric patients with the highest risk of mortality. The so- called ‘hanging chin sign’, meaning that the mandibula is seen to project over one or more ribs on the chest X-ray, could be such an instrument. This study aims to investigate whether the hanging chin sign is a predictor of mortality in geriatric patients admitted through the emergency department. METHODS: We performed an observational retrospective cohort study in a Dutch teaching hospital. Patients of ≥ 65 years who were admitted to the geriatric ward following an emergency department visit were included. The primary outcome of this study was mortality. Secondary outcomes included the length of admission, discharge destination and the reliability compared to patient-related variables and the APOP screener.RESULTS: 396 patients were included in the analysis. Mean follow up was 300 days; 207 patients (52%) died during follow up. The hanging chin sign was present in 85 patients (21%). Patients with the hanging chin sign have a significantly higher mortality risk during admission (OR 2.94 (1.61 to 5.39), p < 0.001), within 30 days (OR 2.49 (1.44 to 4.31), p = 0.001), within 90 days (OR 2.16 (1.31 to 3.56), p = 0.002) and within end of follow up (OR 2.87 (1.70 to 4.84),p < 0.001). A chest X-ray without a PA view or lateral view was also associated with mortality. This technical detail of the chest x-ray and the hanging chin sign both showed a stronger association with mortality than patient-related variables or the APOP screener. CONCLUSIONS: The hanging chin sign and other details of the chest x-ray were strong predictors of mortality in geriatric patients presenting at the emergency department. Compared to other known predictors, they seem to do even better in predicting mortality.

RESULTS OF CZECH NATIONAL STUDY OF RADIATION EXPOSURE FROM RADIOTHERAPY OF NON-MALIGNANT DISEASES, IN PARTICULAR OF HEEL SPURS

2019 ◽  
Vol 186 (2-3) ◽  
pp. 386-390
Author(s):  
V Dufek ◽  
H Zackova ◽  
L Kotik ◽  
I Horakova
Keyword(s):  
Czech Republic ◽  
Clinical Practice ◽  
Radiation Exposure ◽  
Effective Dose ◽  
National Study ◽  
Malignant Diseases ◽  
Organ Doses ◽  
The Czech Republic ◽  
X Ray ◽  
Effective Doses

Abstract About 26 000 patients are treated per year with radiotherapy for non-malignant diseases in the Czech Republic. Approximately 75% of them are treated on X-ray therapy units and most of these patients undergo radiotherapy of heel spurs. The evaluation of radiation exposure of these patients was based on measured organ doses and on data from clinical practice. Collective effective doses for particular diagnoses were calculated in order to compare doses resulting from different diagnoses treated on X-ray therapy units. The collective effective dose from radiotherapy of heel spurs in the Czech Republic in 2013 was evaluated to 77 manSv. It represents 25.6% of the total collective effective dose for all diagnoses of radiotherapy for non-malignant diseases treated on X-ray therapy units.

scholarly journals AN AUTOMATED DOSIMETRY SYSTEM FOR COMPUTED TOMOGRAPHY X-RAY SCANNERS USING SILICON P-I-N DIODES.

1980 ◽  
Vol 39 (6) ◽  
pp. 1020 ◽  
Author(s):  
John J. Lanza ◽  
Walter Mauderli ◽  
Lawrence Fitzgerald ◽  
Genevieve Roessler
Keyword(s):  
Computed Tomography ◽  
X Ray ◽  
Dosimetry System

Estimating Radiation Dose to Major Organs in Dental X-Ray Examinations: A Phantom Study

2020 ◽  
Author(s):  
Yong Li ◽  
Bingsheng Huang ◽  
Jun Cao ◽  
Tianqi Fang ◽  
Guoqing Liu ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Reference Level ◽  
Radiation Doses ◽  
Diagnostic Reference Level ◽  
Effective Radiation Dose ◽  
Organ Doses ◽  
X Ray ◽  
Absorbed Doses ◽  
Males And Females ◽  
Effective Radiation

Abstract The radiation doses absorbed by major organs of males and females were studied from three types of dental X-ray devices. The absorbed doses from cone-beam computed tomography (CBCT), panoramic and intraoral X-ray machines were in the range of 0.23–1314.85 μGy, and were observed to be high in organs and tissues located in or adjacent to the irradiated area, there were discrepancies in organ doses between male and female. Thyroid, salivary gland, eye lens and brain were the organs that received higher absorbed doses. The organ absorbed doses were considerably lower than the diagnostic reference level for dental radiography in China. The calculated effective radiation doses for males and females were 56.63, 8.15, 2.56 μSv and 55.18, 8.99, 2.39 μSv, respectively, when using CBCT, the panoramic X-ray machine and intraoral X-ray machine. The effective radiation dose caused by CBCT was much higher than those of panoramic and intraoral X-ray machines.

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