Average Entrance Surface Dose Research Articles

Patients' dosimetry during lumbar radiographic examination (Lat) in certain hospitals at Dhi Qar governorate, Iraq

The work is aimed at investigating the entrance surface dose (ESD) for adult patients undertaking routine lumbar X-ray examination, and therefore ensure that the patients receive no excessive radiation dose during this radiography. This study was conducted at 4 selected hospitals: Al-Hussein Teaching Hospital (AHTH), Al-Nasiriyah Teaching Hospital (ANTH), Al-Haboubi Teaching Hospital (AHTH) and Souq Al-Shuyoukh General Hospital (SASGH) in Dhi Qar, Iraq. The ESD was calculated for 102 adult patients who underwent X-ray examinations of the lumbar spine using the physical parameters (i.e. Tube voltage-kVp, Tube loading- mAs and distance between X-ray tube and detector- SID) from all considered X-ray units, as well as on the X-ray tube output that was measured using an ionization chamber (Rad-Check Plus). The enrolled patients also had their demographic information recorded (gender, weight and height). The finding demonstrated that the average ESD values were (4.886, 4.288, 6.047, 6.378, 5.949, 9.322, 12.731, 4.094) mGy for AHTH1, AHTH2, AHTH3, ANTH1, ANTH2, ANTH3, AHTH, SASGH, respectively. The ESD values were seen to be comparable with internationally recognized sources UNSCEAR 2010, UK 2012, EC, and IAEA and with previously published studies such as those in Sudan 2014, Iran 2020, Nigeria 2019, and Ghana 2023. Finally, further studies must be carried out, and the relevant institutions must conduct continuous training courses for radiographers to ensure that the radiation dose is within the recommended level.

Analisa Pengukuran Entrance Surface Dose (ESD) Menggunakan Optically Stimulated Luminescence Dosimeter (OSLD) Pada Pasien Anak

The surface dose of radiation in conventional diagnostic radiology exams, also known as the entrance surface dose (ESD), is measured to ensure optimal radiation protection for patients. This study aimed to determine and analyze the doses received by pediatric patients who underwent a chest X-ray examination while being treated in the NICU and PICU rooms at Hermina Karawang Hospital. The research involved measuring the radiation dose in pediatric patients using the OSLD nanoDot. This susceptible device can detect low-dose X-ray radiation exposure, especially in pediatric patients. The study was conducted from September to December 2022 and included 35 patients aged 0 to 5. The results of the ESD measurements received by pediatric patients at Hermina Karawang Hospital in the 0-1 year age group were found to be in line with the DRL (Diagnostic Reference Levels) of the United Kingdom (UK) and Austria, which recommend a range of 0.05 – 0.055 mGy. The average ESD value for this age group was 0.05 mGy. Similarly, for the 1-5 year age group, an average ESD value of 0.048 mGy was obtained, below the UK and Austria DRL range of 0.05 – 0.069 mGy. These results indicate that the ESD received by pediatric patients during thoracic examination at Hermina Karawang Hospital is close to the DRL values recommended by the UK and Austria. However, it is essential to note that regardless of the dose received, it must always be justified and optimized to prevent unnecessary radiation exposure. Keywords: ESD, OSLD, unnecessary exposure, paediatric radiation protection, radiation exposure

Radiation Safety in Children in Children’s Medical Center Hospital

Background: Diagnostic radiology studies in children harbor more radiation hazards than in adults due to their small size and higher cellular proliferation rate. Therefore, reducing the radiation burden to children should be top priority. Measurement of radiation dose is the first step to this goal. Nevertheless, we do not know whether the radiation of portable radiographs at our hospital meets the standards or not. Objectives: This study aims at measuring the primary and scattered radiation at different distances from patients. This eventually would help us to keep the radiation to minimum. Methods: This study was conducted on 84 patients from 4 different wards (U1-U2) in our hospital in 2017. After obtaining ethical approval from ethical committee and also written consent from parents, all patients who needed portable X-ray were included in our study. A thermo-luminescent dosimeter was placed on the patient’s chest to measure the entrance surface dose (ESD), while Geiger-Muller dosimeters located at one and two-meter distances from the X-ray tube used to scale the scattered radiation. Then, data were analyzed in SPSS 16. Results: The average ESD was 0.3873, 0.3867, 0.3700, and 0.4033 millisievert (mSv) in U1 to U4 respectively, whereas the scattered radiation doses measured as 0.00986, 0.00750, 0.01250, 0.1014 at one-meter and 0.00250, 0.00220, 0.00238, 0.00314 mSv at two-meter distances. There was no significant difference in radiation dose between those units (P > 0.05). Conclusions: Radiation received by patients in this study was three to four times higher than the standard dose. Significant scattered radiation was also detected at one and two-meter distances. To reduce radiation, improvement of exposure protocols such as reducing mAs and using proper shielding is emphasized.

P006] DRL’s in mammography: Results from 3 dose audits

Purpose We compare the results of 3 dose audits (2013, 2015 and 2017) for bilateral mammography screening exams performed in a full field digital mammography unit GE Senographe DS. We estimated the average entrance surface dose (ESD) for a sample of at least 50 standard breasts. The results were compared with the European DRL - ESD of the 3rd quartile of the dose survey. We estimated average absorbed dose to the glandular tissue within breast (AGD) for a wide range of breast thicknesses, and converted it into effective dose. Data was presented to the staff to induce a process of optimization as team effort. Methods For each dose audit we selected a sample of more than 150 bilateral mammography screening exams. The percentage glandularity was determined using the qualitative method described by Byng (1994) and compared with Dance (2000) empirical formula. AGD was determined from measurements of the output and exposure data using appropriate conversion factors from IAEA (2007), Dance (2000), Dance (2009). Effective doses were determined using ICRP 103 breast tissue weighting factor 0.12. Results Results (2013): ESD = 5.8 mGy for cranio caudal (CC) and ESD = 6.1 mGy for medio lateral oblique (MLO) projections. These results are considerably below the European DRL’s (10 mGy). E ranged from: E = 0.28 mSv for small breasts (34.5 ± 4.5 mm) to E = 0.69 mSv for very large breasts (84.5 ± 4.5 mm) with larger compressed breast thickness associated with a higher AGD (E); Results (2015): around 30% increase in DRLs: ESD = 8.6 mGy CC and ESD = 8.7 mGy MLO; E ranged from E = 0.38 mSv for small breasts (34.5 ± 4.5 mm) to E = 0.75 mSv for very large breasts (84.5 ± 4.5 mm); Results (2017): within 5% of 2013. Conclusions The 30% increase in the dose results in 2015 resulted from the increased use of Contrast Enhanced Automatic Optimization of Parameters (AOP CNR) mode. This action was investigated and corrected. Dose audits are important part of a quality assurance program.

Radiation Reduction in Low Dose Pulsed Fluoroscopy versus Standard Dose Continuous Fluoroscopy during Fluoroscopically-Guided Lumbar Punctures: A Prospective Controlled Study.

Purpose:The purpose of this study was to evaluate radiation dose reduction in fluoroscopically guided lumbar punctures (FGLP) using “pulsed fluoroscopy in a low dose mode” compared with the commonly used “continuous fluoroscopy in a standard dose mode” while maintaining the technical success.Materials and Methods:Thirty-five consecutive patients who underwent FGLP divided randomly to seventeen patients in the control group with standard dose continuous FGLP and eighteen patients in the study group with low-dose low-frame-rate of 3 frames per second (fps) FGLP. Entrance surface dose measurements from a dosimeter device were recorded as well as the dose area product (DAP).Results:A total of 35 patients with average age of 52 years (range: 15–87 [±17 standard deviation [SD]]) were evaluated. Average entrance surface dose of the study group was significantly lower (3.81 mGy [range: 0.21–11.14, [±2.8 SD]]) compared with the control group (22.45 mGy [range: 1.23–73.44, [±19.41 [SD]]). The average DAP of the study group (10 mGy·cm2 [range: 1–41, [±9.8 SD]]) was also significantly lower than the control group (65 mGy·cm2 [range: 5–199, [±53 SD]]). Success rate was similar between the study and control groups.Conclusion:Low dose pulsed fluoroscopy of 3 fps significantly reduces radiation exposure by about 600% compared with standard dose continuous fluoroscopy in FGLP. Utilizing this radiation saving strategy will allow to dramatically reduce radiation exposure, without impacting the technical success rate.

Assessment of Breast Doses in Mammography Screening

Thermoluminescent dosimeters (TLD-100H) were in use for the assessment of average glandular dose to breast in mammography screening with GE machine, King Abdul Aziz University Hospital for 45 mm breast compressed thickness, 26 kVp, 100 mAs and Mo/Mo target/filter combination. Reader’s calibration factor for the TLDs was generated with the same exposure parameters using RadCal mammo ionization chamber as reference. The calibration factor was reproduced within 3% standard deviation. Several sets of selected TLD-100H placing in different configurations were exposed to X-ray beam under identical exposure condition as it was used for generation of calibration factor. The entrance surface doses were calculated by using the measured net TL-response and the calibration factor. Thereafter, the average glandular doses (AGD) were calculated. The measured average entrance surface dose (AGD) at the reference position (6 cm laterally centered from the chest edge wall) was 7.704 mGy with less than 2% standard deviation. The calculated average glandular dose to the breast at the reference location has been found to be 1.429 ± 0.037 mGy.Bangladesh J. Nuclear Med. 18(2): 161-167, July 2015

Evaluation of the Entrance Surface Dose (ESD) and Radiation Dose to the Radiosensitive Organs in Pediatric Pelvic Radiography

Background Patients' dosimetry is crucial in order to enhance radiation protection optimization and to deliver low radiation dose to the patients in a radiological procedure. The aim of this study was to assess the entrance surface dose (ESD) and radiation dose to the radiosensitive organs in pediatric pelvic radiography. Materials and Methods The studied population included 98 pediatric patients of both genders referred to anteroposterior (AP) projection of pelvic radiography. The radiation dose was directly measured using high radiosensitive cylindrical lithium fluoride thermo-luminescent dosimeters (TLD-GR200). Two TLDs were placed at the center point of the radiation field to measure the ESD of pelvis. Moreover for each patient, 2 TLDs were placed upon each eyelid, 2 TLDs upon each breast, 2 TLDs upon the surface anatomical position of the thyroid gland and finally 2 TLDs at the surface anatomical position of the gonads to measure the received dose. Results The ESD ± standard deviation for AP pelvic radiography was obtained 591.7±76 µGy. Statistically significant difference was obtained between organs located outside and inside of the radiation field with respect to dose received (P<0.001), as well as between the average dose received by the breast and lens of the eyes (P<0.05). There was no difference between boys and girls with respect to average ESD, while the testes dose was statistically non-significantly lower than ovaries dose. Conclusion The ESD received by patients are relatively accordance to the international recommendations. However further reduction in patients' dose in achievable by adherence to the radiation protection optimization guidelines. The data presented in our study will serve as a baseline needed for deriving local reference doses for pediatric pelvic radiography in our hospital. The study is expected to increase the awareness of medical professionals about the radiation doses in pediatric pelvic radiography.

Study of Common Requested Radiographs and Relative Exposure Dose in Qassim State

The objective of the article was to study the common requested radiographs and relative exposure dose in Qassim state in Kingdom of Saudi Arabia. The method was retrospective and analytical study for collected variables as radiographs, relative entrance surface dose (ESD) and the effective dose, patient age, gender and causative factors. The analysis with excel software revealed that: the common requested radiographs were skull, abdomen and chest with male incidence as 75%, 72.2% and 64% respectively relative to whole sample. Traffic accident (71%) and fall-down (45%) were the most causative factors among male and female respectively, with injuries as skull fissure fracture (77%) and intracranial hemorrhage (23%). The skull radiographs noted among the age group of 11-21 years and peaking at 36% among the age group of 22-32 years. The requested abdominal radiographs appeared among the age group of 13-21 years; with frequency of (19%) and peaking at 30% among the age group of 22-30 years; with injuries as spleen ruptures (42%) and liver (27%). The chest radiographs observed among age group of 3-13 years; with frequency of 4% and peaking among age groups of 14-24 & 25-35 years old with frequencies of 19% and 21% respectively, and injuries as Ribs fracture (55%), ribs dislocation (15%), pierced lung (20%) hemorrhage (10%). The average ESD for <i>abdomen, skull and the chest radiographs</i> were 1.93±0.8, 1.53±0.6 and 0.21±0.2 mGy which were increase linearly following the aging. And the average effective doses were 0.24±0.1, 0.1±0.1 and 0.4±0.2 mSv respectively.

A cross-sectional study of the radiation dose and image quality of X-ray equipment used in IVR.

There are case reports of injuries caused by the radiation from interventional radiology (IVR) X‐ray systems. Therefore, the management of radiation doses in IVR is important. However, no detailed report has evaluated image quality for a large number of IVR X‐ray systems. As a result, it is unclear whether the image quality of the X‐ray equipment currently used in IVR procedures is optimal. We compared the entrance surface doses and image quality of multiple IVR X‐ray systems. This study was conducted in 2014 at 13 medical facilities using 18 IVR X‐ray systems. We evaluated image quality and simultaneously measured the radiation dose. Entrance surface doses for fluoroscopy (duration, 1 min) and cineradiography (duration, 10 s) are measured using a 20‐cm‐thick acrylic plate and skin dose monitor. The image quality (such as spatial resolution and low‐contrast detectability) of both fluoroscopy and cineradiography was evaluated using a QC phantom. For fluoroscopy, the average entrance surface dose using the 20‐cm‐thick acrylic plate was 13.9 (range 2.1–28.2) mGy/min. For cineradiography, the average entrance surface dose was 24.6 (range 5.1–49.3) mGy/10 s. We found positive correlations between radiation doses and image quality scores, in general, especially for fluoroscopy. The differences in surface dose among the 18 IVR X‐ray systems were high (max/min, 9.7‐fold for cineradiography; 13.4‐fold for fluoroscopy). The differences in image quality scores (spatial resolution, low‐contrast detectability, and dynamic range) were also very large. In general, there tended to be a correlation between radiation dose and image quality. Periodical measurements of the radiation dose and image quality of the X‐ray equipment used for cineradiography and fluoroscopy in IVR are necessary. The need to minimize patient exposure requires that the dose be reduced to the minimum level that will generate an image with an acceptable degree of noise.PACS number(s): 87.57.C, 87.57.uq, 87.59.B, 87.59.bf, 87.59.C, 87.59.cf, 87.59.Dj

Dose Reduction to the Thyroid Gland in Pediatric Chest Radiography

Background It is remain a main concern that pediatric chest radiographies contribute to the significant radiation exposure to the thyroid gland as a more susceptible organ to radiation induced cancer. The aim of this study was to assessment the entrance surface dose (ESD) of pediatric chest radiography compared to the diagnostic reference levels (DRL) and evaluation the efficacy of the lead (Pb) shield in radiation dose reduction to the thyroid gland. Materials and Methods After assessing each patient against specific inclusion-exclusion criteria, 40 pediatric patients who were undergoing anterior-posterior (AP) projection of the chest x-ray were considered eligible for this study. The ESD of the chest and also ESD of thyroid gland with and without a 1 mm butterfly-shaped lead shield which placed on the thyroid gland were measured using high sensitive thermo luminescent dosimeters (TLD-GR 200). Results The average of ESD for chest radiography was 0.068+ 0.04 mGy (0.021 - 0.232 mGy). The unshielded average thyroid ESD was 0.065+0.053 mGy compared to the shielded average thyroid ESD of 0.001 + 0.034 mGy. The use of Pb-shield produced a statistically significant decrease in the average thyroid dose by about 97% (P< 0.001). Conclusion It seems that the Pb-thyroid shield has potential to reduced radiation dose significantly without compromising image quality. The use of thyroid shield in the AP projection of pediatric chest radiography may be an effective method to reduce patient's radiation risk and its usage should be encouraged. Key Words: chest x-ray, pediatrics, radiation exposure, thyroid gland

Evaluation of Manual Angulation Fixed Focal Approach Using Flat Panel Detector in Digital Radiography of Scoliosis

Scoliosis patient underwent numerous spine radiographs during their monitor and treatment period, thus, may expose them to high accumulative radiation dose. In this study, the diagnostic performance of the flat panel detector (FPD) fixed focal approach with manual angulation was evaluated in term of accuracy and consistency of Cobb angle measurement, spatial accuracy as well as radiation dose to the patients compared to the conventional photostimulable phosphor (PSP) approach. Cobb angle measurements were evaluated with two special constructed human vertebrae phantoms. The intraclass correlation coefficients (ICC) for interobserver variation and percentage of accuracy in Cobb angle measurement were calculated. The significant differences in angle measurement between both approaches were assessed. The spatial accuracy was evaluated with TO.M1 phantom. Dose measurements were performed with radiochromic film and 20 cm polymethyl methacrylate (PMMA) slabs. The FPD fixed focal approach showed excellent interobserver reproducibility (ICC, r = 0.99, p 0.05) for the Cobb angle measured from both approaches. The FPD fixed focal approach resulted in higher accuracy (3%) of angle measurement compared to the conventional PSP approach. The spatial accuracy was within the recommended limit of AAPM report 93. An average entrance surface dose (ESD) reduction of 20% was achieved with FPD fixed focal approach. We developed and evaluated a manual tube angulation method which facilitates the use of existing FPD digital radiography system to produce full spine image. It has good consistency and high accuracy in the measurement of Cobb angle. The acquired images are suitable for angle measurement for scoliosis patients with substantial dose reduction.

Radiation exposure to patients during endoscopic retrograde cholangiopancreatography: A multicentre study in Finland

PurposeEndoscopic retrograde cholangiopancreatography (ERCP) has the potential for high patient dose, which is why attention is required regarding radiation protection. The available data about patient radiation doses in ERCP show a large variation that needs to be further investigated. The aim of this study was to determine the radiation doses to patients during ERCP, evaluate the risk of radiation-induced injury and to calculate the effective dose (ED) in patients who underwent an ERCP procedure. MethodsA multicentre study which included ten hospitals was carried out in Finland. A total of 227 patient radiation doses in ERCP were recorded during a 4-month period in 2012. Entrance surface dose (ESD) was estimated by using thermoluminescent dosimeters (TLD) implemented in one of the hospitals. ED was calculated from dose area product (DAP) measurements. The data were analysed with the IBM SPSS Statistics version 21 (2012) software. ResultsThe patient radiation doses in ERCP varied significantly in this study. The mean DAP was 5.15 (0.08–57.00) Gy cm², fluoroscopy time 2.4 (0.03–22.2) min and the number of X-ray images was 2.5 (0–14). A strong linear correlation was observed between the DAP and fluoroscopy time. The average ESD and ED in ERCP was 10 mGy and 1 mSv, respectively. ConclusionPatients received a greater radiation dose in therapeutic ERCP compared to diagnostic ERCP. The increase in frequency and complexity of ERCP procedures indicates the possibility of an increase in radiation exposure to patient. The results suggest that efforts at optimization and dose reduction in ERCP should be made.

Dose audit for patients undergoing two common radiography examinations with digital radiology systems.

We aimed to determine the radiation doses delivered to patients undergoing general examinations using computed or digital radiography systems in Turkey. Radiographs of 20 patients undergoing posteroanterior chest X-ray and of 20 patients undergoing anteroposterior kidney-ureter-bladder radiography were evaluated in five X-ray rooms at four local hospitals in the Ankara region. Currently, almost all radiology departments in Turkey have switched from conventional radiography systems to computed radiography or digital radiography systems. Patient dose was measured for both systems. The results were compared with published diagnostic reference levels (DRLs) from the European Union and International Atomic Energy Agency. The average entrance surface doses (ESDs) for chest examinations exceeded established international DRLs at two of the X-ray rooms in a hospital with computed radiography. All of the other ESD measurements were approximately equal to or below the DRLs for both examinations in all of the remaining hospitals. Improper adjustment of the exposure parameters, uncalibrated automatic exposure control systems, and failure of the technologists to choose exposure parameters properly were problems we noticed during the study. This study is an initial attempt at establishing local DRL values for digital radiography systems, and will provide a benchmark so that the authorities can establish reference dose levels for diagnostic radiology in Turkey.

Predictive Factors of Radiation Dose in ERCP

The use of fluoroscopy to aid endoscopic retrograde cholangiopancreatography (ERCP) places both the patient and the endoscopy staff at the risk of radiation-induced injury. Previous reports have demonstrated a linear relationship between radiation dose and fluoroscopy duration. To identify predictive factors of fluoroscopy time and radiation exposure to patients undergoing ERCP by using pulsed fluoroscopy. Four hundred and four consecutive ERCPs performed from January 2010 to November 2010 at 2 tertiary centers in Spain were prospectively studied. Patients and procedural variables were analyzed. Philips BV Pulsera mobile fluoroscopy system was used on the endoscopy unit. Entrance surface dose, dose-area product, and fluoroscopy time were recorded for each patient. A total of 404 ERCPs on 404 consecutive patients were studied (mean age 73 y). The average entrance surface dose and dose-area product were 12.0 mGy and 0.37 mGy/m2, respectively. Mean fluoroscopy time was 2.31 minutes. The biliary ducts were adequately visualized in 371 (92%) cases. After analysis with a univariable model, the factors found to significantly increase the radiation dose (P75>19.6 mGy) were as follows: alkaline phosphatase serum levels (P=0.047), balloon dilation (P=0.005), biliary stent placement (P=0.001), and ERCP diagnosis (P=<0.0001). In a multivariate analysis, only stent insertion significantly increased the radiation dose (risk ratio 4.75; 95% confidence interval, 1.84-7.63). In this prospective analysis, multiple factors affected the radiation dose. Stent insertion was the only independent predictor significantly associated with prolonged fluoroscopy.

A method to derive appropriate exposure parameters from target exposure index and patient thickness in pediatric digital radiography

Little information exists concerning appropriate exposure and measuring overall patient dose in pediatric digital radiography. To establish a convenient method of appropriate exposure from target exposure index (EI) and thickness in pediatric digital radiography and estimate patient entrance-surface dose (ESD) and dose-area product (DAP) associated with chest, abdomen and pelvis radiography. A formula was deduced to calculate appropriate mAs changed with children's weight and height. EI was used to control image quality. With this formula, dose-optimized procedures were carried out. Data were collected from 180 pediatric examinations, including chest, abdomen and pelvis anterior-posterior (AP) projections. The children were divided into the following age bands: newborns (0-28days), infants (28days-2years) and older children (2-7years). In each age band, ten children were exposed with the calculated appropriate mAs and EI values were kept steady in appropriate range (referred as target group) and ten children were exposed to the factors routinely used in practice (referred to as the routine group). DAP to children was measured with a DAP meter, and ESD was calculated using measured DAP and data from the National Radiological Protection Board. Data were compared between groups. ESD ranges in the target group were 32-202μGy (chest AP), 57-333μGy (abdomen AP) and 52-372μGy (pelvis AP). For every radiographic procedure, chi-square Student's t tests showed a significant difference in average ESD and DAP between the two groups (P < 0.005). Most ESD values from the routine group were two times higher than those from the target group. The study established a convenient method to set appropriate exposure parameters (mAs) to reach a target EI using the child's weight and height in pediatric radiography. By this method, ESD and DAP can be significantly reduced in children.

Radiation doses to paediatric patients and comforters undergoing chest X rays

Pneumonia is an important cause of hospital admission among children in the developed world and it is estimated to be responsible for 3-18 % of all paediatric admissions. Chest X ray is an important examination for pneumonia diagnosis and for evaluation of complications. This study aims to determine the entrance surface dose (ESD), organ, effective doses and propose a local diagnostic reference level. The study was carried out at the university hospital of Larissa, Greece. Patients were divided into three groups: organ and effective doses were estimated using National Radiological Protection Board software. The ESD was determined by thermoluminescent dosemeters for 132 children and 76 comforters. The average ESD value was 55 ± 8 µGy. The effective dose for patients was 11.2 ± 5 µSv. The mean radiation dose for comforter is 22 ± 3 µGy. The radiation dose to the patients is well within dose constraint, in the light of the current practice.

Management of patient doses and diagnostic reference levels in X-ray radiography in Lithuania

Management of patient doses and determination of national or local diagnostic reference levels (DRLs) are important parts of a quality control program in X-ray diagnostics. In Lithuania, national DRLs for specific radiographic examinations are comparatively higher than those recommended by the European Commission (EC) and the International Atomic Energy Agency (IAEA). A survey of entrance surface doses (ESDs) was performed to investigate the reasons for exceeding the European and the IAEA DRLs. The first measurements showed that the average ESD for standard patients and for all examinations exceeded DRLs at approximately 25 % of the hospitals. The main problems were the use of low kilovolt technique, the lack of automatic exposure control systems or improper adjustment of them as well as inadequate training of the staff. After corrective actions, the ESD measurements were repeated. The results showed that the average patient doses were reduced almost everywhere. An additional patient dose survey for establishing new DRLs in radiography taking into account the advantages of new equipment to indicate directly the kerma area product (KAP) values was done. The ESD values were calculated from the KAP-values. The data were analysed, and the average and third quartile values were calculated. The new DRLs, in terms of ESDs, were reduced significantly in almost all radiography examinations. They are equal or lower than the IAEA and EC DRLs. Especially at thorax spine LAT, lumbar spine LAT, hip joint AP, pelvis AP and abdomen AP they are half the IAEA DRLs.

Radiation Dose of Interventional Radiology System Using a Flat-Panel Detector

Currently, cardiac interventional radiology equipment has tended toward using flat-panel detectors (FPDs) instead of image intensifiers (IIs) because FPDs offer better imaging performance. However, the radiation dose from an FPD in cardiac interventional radiology is not clear. The purpose of our study was to measure the radiation doses during cineangiography and fluoroscopy of many cardiac radiology systems that use FPDs or IIs, in clinical settings. This study examined 20 radiology systems in 15 cardiac catheterization laboratories (11 used FPD and nine used II). The entrance surface doses with digital cineangiography and fluoroscopy were compared for the 20 systems using acrylic plates (20-cm thick) and a skin dose monitor. For fluoroscopy, the average entrance surface doses of the 20-cm-thick acrylic plates were identical for FPD (average +/- SD, 16.63 +/- 7.89 mGy/min; range, 5.7-26.4 mGy/min; maximum/minimum, 4.63) and II (17.81 +/- 12.52 mGy/min; range, 6.5-42.2 mGy/min; maximum/minimum, 6.49) (p = 0.799). For digital cineangiography, the average entrance surface dose of the 20-cm-thick acrylic plate was slightly lower with FPD (29.68 +/- 16.40 mGy/10 s; range, 8.9-58.5 mGy/10 s; maximum/minimum, 6.57) than with II (38.50 +/- 33.71 mGy/10 s; range, 15.2-117.1 mGy/10 s; maximum/minimum, 7.70), although the difference was not significant (p = 0.487). We found that the average entrance doses of cineangiography and fluoroscopy in FPD systems were not significantly different from those in II systems. Hence, FPDs did not inherently reduce the radiation dose, although FPDs possess good detective quantum efficiency. Therefore, to reduce the radiation dose of cardiac interventional radiology systems, even FPD systems, practical measures are necessary.

Evaluasi Dosis Glandular dalam Pemeriksaan Mammografi

Telah dilakukan pengukuran dosis rata-rata Glandular (mean glandular dose) pada pemeriksaan mammografi dengan menggunakan Thermoluminiscence Dosimeter (TLD) terhadap 49 pasien. Dosis yang terbaca pada TLD adalah Entrance Surface Dose (ESD) dengan nilai rata-rata yang didapat 7.6(±’b1 3.9) mGy. Untuk konversi ke nilai mean glandular dose, nilai ESD dikalikan dengan nilai Dgn (ESD dengan factor konversi average glandular dose per unit exposure) yang terkonversi dengan memperhitungkan prosentase glandular terhadap adipose. Data Dgn diperoleh dari perhitungan Jhon M Boone yang menggunakan metode Monte Carlo yang masih tergantung dari nilai HVL dan ketebalan payudara. Prosentase glandular terhadap adipose dihitung dengan menggunakan metoda analisa film Nooriah Djamal. Kemudian nilai Dgn 0% glandular untuk kontribusi adipose maupun Dgn 100% glandular untuk kontribusi glandular diperoleh dari table Dgn Boone. Nilai MGD yang diperoleh adalah 1.818 (±’b1 0.615) mGy. Nilai masih dibawah limit yang direkomendasikan FDA (Foor and Drug Administration) yaitu &lt;3mGy.

The use of gonadal shielding in singular common diagnostic radiographic procedures

AbstractThe aim of this study was to make recommendations regarding when the use of gonadal shielding is significant in reducing gonad dose for common diagnostic procedures. Two separate literature reviews were conducted and the data compared. The first review proposed to determine average entrance surface doses (ESD) for common diagnostic procedures and the second to determine a threshold for exposure to the gonads below which risk of genetic effects was negligible. By comparing accepted ESD and associated gonad doses with the threshold dose, recommendations for each procedure could be made. This recommendation would be that either gonadal shielding is significant in reducing risk of genetic effects for this examination, or that gonadal shielding would make no difference because the doses involved are negligible. Common procedures were selected as well as common series, based on the fact that these procedures contribute relatively high dose to the gonads. A threshold dose to the gonads was established to be 10 mGy. Below this level of exposure, genetic risk to the gonads is considered negligible. It was found that none of the series or individual exams contributed significant dose to the gonads (dose levels above the 10 mGy threshold). It should be noted, however, that this recommendation applies only to individual patients receiving individual exposures. The effect of repeat examinations or the risk to a population of patients was not considered. It was also found that gonadal shielding may alleviate fears of radiation exposure in patients. It was recommended that for all individual examinations/series included in this study that gonadal shielding was unnecessary because the doses involved present negligible genetic risk to the patient. However, best practice in radiography includes upholding the ‘As low as reasonably achievable’ principle (ALARA) and considering the fears of patients, and it is for this reason that gonadal shielding should be used.