Estimating the Entrance Surface Dose in the Eyes, Thyroid, and Parotid Gland Regions in Adult and Pediatric Groups: A Cone-Beam Computed Tomography Technique

Purpose: This study aimed to determine the Entrance Surface Dose (ESD) of sensitive organs in Cone-Beam Computed Tomography (CBCT) imaging of the maxillofacial region in the two age groups of adult and pediatric. Materials and Methods: In this work, the measurements were performed using Thermo Luminescent Dosimeters (TLD-GR200). The imaging was performed using a PROMAX 3D CBCT scanner for 30 adults and 20 pediatric patients. The ESD value for each patient in the region of eyes, thyroid, and parotid glands was measured by 15 TLDs during CBCT of maxillofacial. Results: The highest and lowest mean values of ESDs were related to the parotid and thyroid gland regions in adults, 4.77 ± 0.61 mGy and 0.37 ± 0.16 mGy, respectively. In addition, these values were obtained 2.97 ± 0.36 mGy and 0.35 ± 0.12 mGy in pediatric groups as the highest and lowest values in that order. The results showed that the ESD values of the parotid gland regions in maxilla and mandible examinations had a significant difference (P <0.05). In addition, there was a significant difference between the ESD values of the parotid gland regions among the adults and pediatric groups (P <0.05). Conclusion: According to the results, the ESD values in both age groups were higher in the parotid gland region during maxillofacial CBCT examinations. Therefore, it is recommended to set radiation parameters like mAs as low as possible for reducing the patient dose, especially pediatric patients due to the more sensitive organs.

Determination of Entrance Surface Dose of Digital Radiography for Adults at Public Medical Imaging Centers, Erbil

Introduction: Diagnostic X-ray is one of the ionizing radiations, the level of radiation dose received by the patient during medical examination is essential to prevent cancer risks. The aim of this study is to calculate entrance surface dose (ESD) and effective dose (ED) were estimated during chest, and lumber spine for adult patients in three hospitals in Erbil, using NOMEX MULTIMETER and PCXMC software. Material and Methods: The study was conducted in three public hospitals, in Erbil on (250) adult patients, whose ages between (18-70) years, based on the results study, ESD and ED were calculated for chest (PA, lateral), and lumbar spine (AP, lateral) examinations. NOMEX MULTIMETER (PTW, Freiburg), used in measurement of tube voltage, dose, dose rate, time product current, and total filtration automatically during examination. ED was calculated by using PCXMC software (version 2.5). Results: The results of this work are compared with published international literatures. The mean entrance skin dose for examinations of chest (PA, Lat), and lumber spine (AP, Lat) 1.02, 1.06, 2.61 and 3.92 mGy respectively. ED value was from 0.08, 0.19, 0.32, and 0.33 mSv, for chest (PA, Lat), and lumber spine (AP, Lat), respectively. Conclusion: The ESD, and ED were calculated in this work were found to be agreement with the published reference values for chest, and lumber spine set by international levels. ALARA principle should be considered by radiographer, to reduce absorbed dose of adults’ patient undergoing imaging radiography.

Measurement of Entrance Skin Dose in Radiographic Examinations of Pediatric Patients

Background: To measure the entrance skin dose in radiographic examinations of pediatric patients in King Khalid Hospital, Majmaah, Saudi Arabia Introduction: Children have been given special attention since they are often regarded as especially vulnerable to potential hazards. The pediatric population is more susceptible to radiation than the adult population for certain tumor types. Objective: The aim of this study is to determine the amount of Entrance Surface Dose (ESD) received by pediatric patients attending the emergency department. Method: Traumatic department registers for pediatric patients attending the King Khalid hospital (Majmaah, Saudi Arabia) between 1st February and 31st December 2018 were retrospectively studied for all diagnostic (plain radiographs examinations) imaging did on pediatric (<18 years old) trauma patients. The entrance surface dose was used to calculate the total radiation dose for each patient. One hundred and twenty patients encountered the inclusion criteria of the study, and their doses (chest, skull, and extremities) were assessed. Results: The mean of radiation exposure factors were 65.4 ± 7.9 (71.3 – 89.9) and 1.3 ± 0.2 (0.3–2.5) for X-ray tube potential (kVp) and current (mAs), respectively. The measured dose for pediatric patients were 0.10 ± 0.02 (0.09 – 0.37), 0.18 + 0.04 (0.06 -0.59) and 0.09 + 0.03 (0.03 -0.45) for chest, skull, and extremities, respectively. The mean Entrance surface dose received by trauma patients was 0.03-0.59 mGy. 51.7% (62 patients) of the patients received ≤ 0.25 mGy while around 48.3% (58 patients) received ≥ 0.26 mGy radiation dose from those examinations. Conclusion: Trauma patients attending to traumatic radiology department obtain substantial Entrance surface dose from chest, skull, and extremities imaging procedures within their initial assessment. The radiation exposure can also be lowered by optimizing each examination. Therefore more studies are recommended for this task. The results obtained can be used as the basis for local reference dosages for X-ray examinations.

Entrance Surface Dose (ESD) Measurement During Pediatric Chest X-Rays

Introduction Given the high radiation tissue sensitivity of pediatric patients, it is necessary to monitor their received dose in order to optimize radiation protection. The first aim of this study was to evaluate of the entrance surface dose (ESD) in pediatric patients undergoing chest x-ray at the main hospital of Dezful, Iran. The second aim was to compare our results with the established dose reference levels (DRL). Materials and Methods The studied population included 204 pediatric patients less than 15 year who were referred to chest x-ray. A calibrated dose area product meter (DAP-meter) with permanent installation on x-ray unit was used to radiation dose measurements. For each patient, the demographic data, exposure parameters and the dose read by DAP-meter were recorded and ESD was calculated using standard mathematical formula. Results The average value of ESD was 119 μGy in patients less than 15 years. This value was 51.3, 122.3, 131.5 and 171.2 μGy for the age groups less than 1 year, 1 to 5 year, 5 to 10 year and 10 to 15 year, respectively. A statistical significant difference was seen between ESD values ​​in different age groups (P<0.001), whereas no statistical difference was seen between ESD values in ​ girls and boys (P =0.993). Conclusion Pediatric patients in hospital investigated (except age group less than 1 year) are subjected to unnecessary radiation exposure, especially due to use of non-optimize x-ray protocols.

ESTIMATION OF ENTRANCE SURFACE DOSE (ESD) AS A DOSE PROFILE FOR PATIENTS UNDERGOING RADIOGRAPHY EXAMINATION BASED ON TUBE OUTPUT MEASUREMENT

Background: Radiography examinations are the most widely used and indispensable tools in medical imaging. The dose received by the patient should be known to prevent the risk of radiation exposure. Patient dose in radiography examination can be best estimated in terms of entrance surface dose (ESD). ESD value can be obtained by using the recorded dose viewer installed on the device. However, not all devices have this feature. Other methods can be conducted using thermoluminescence dosimeter (TLD) although it practically requires a high cost. Purpose: The study aims to estimate the ESD as a dose profile for patients undergoing radiography examination using tube output. Method: The patient data and exposure factors were retrospectively recorded for 263 patients. The ESD was estimated from the measurements of the X-ray tube output and recorded exposure factors. Results: The ESD value varied from 0.002 to 0.41 mGy. In the thorax PA, thorax LAT, cervical LAT, cervical AP, skull AP, skull LAT, genu LAT and waters was found (0,23±0.05) mGy, (0,09±0,05) mGy, (0,07±0,04) mGy, (0,13±0,08) mGy, (0,03±0,01) mGy, (0,06±0,02) mGy, (0,04±0,00) mGy (0,04±0,02) mGy, respectively. These results were further used to determine the Local Diagnostic Reference Level (LDRL) value. Conclusion: The results revealed that LDRL fell below the national DRL value and international reference