TY - JOUR
AU - Singh, Narinder Paul
AB - Abstract The present work reports dosimetry data on adult and pediatric patients for some common radiographic examinations during the standard hospital routine. The measurements are the part of quality assurance program to determine radiation exposures to patients in these examinations. The entrance skin doses (ESDs) of the patients were measured from 2451 projection for 12 diagnostic examinations in digital radiography (DR). The ESDs in adult patient were measured using thermoluminescence dosemeters placed on the skin of the patient. In pediatric patients, ESDs were evaluated from the measured air kerma with ionization chamber, patient specific parameters and known values of machine exposure factors during examinations. The third quartile values of ESDs are proposed as local diagnostic reference levels (LDRLs) for radiographic examinations having statistical significant number of exposures (n ≥ 20). The proposed LDRL values are also compared with earlier published LDRL/DRL values. INTRODUCTION The medical exposure is the largest artificial source of exposure to ionization radiation to the world population(1). In radiology, collective radiation doses resulting from the use of x-rays in radiography, computed tomography (CT) scans and interventional procedures has maximum contribution to the medical exposures(2). In diagnostic x-ray procedures radiation doses to the patients are usually low and of the order of few μGy to tens of mGy. The low dose exposures in the radiological examinations increase the risk of stochastic effects, mostly cancer induction in exposed patients. The risk of stochastic effects primarily depends on the magnitude of radiation dose as well as on the anatomical structure irradiated(3–6). The pediatric patients are found to be more radiosensitive as a result the risks of fatal cancer induction increase by 2–3-fold as compared to the adults(7–9). Therefore, all the radiation exposures need to be monitored and optimized to limit the associated radiation risk to the patient without limiting the clinical utility of the diagnostic examinations. The possibilities for optimizing patient doses in diagnostic radiology have been reported by various studies in the literature. The International Commission on Radiation Protection (ICRP) has proposed the concept of diagnostic reference levels (DRLs) for optimization of medical exposures in diagnostic examinations(8, 10). DRLs are the dose levels used in medical imaging to indicate whether the doses received by the patients from specified radiological procedures is unusually high or unusually low. The DRLs act as a threshold or indicator of investigation and evaluated from third-quartile values of entrance skin doses (ESDs) of standard-sized patients for broadly defined types of equipments(11–13). The concept of DRLs becomes a valuable and well accepted tool for dose optimization in adult radiological examinations. However, its application to pediatric radiology has some inherent difficulties related to less number of pediatric exposures performed (around 9% of the total exposures), pediatric data need to be split into age groups and vast variation in body sizes encountered in same age group of children.(14) The European Commission has published detailed guidelines on quality criteria for diagnostic radiographic images in adult and pediatric patients, broadly specifying anatomical structures and image details requirement in radiographic examinations(15, 16). In year 2000, United Kingdom (UK) adopted Ionizing Radiation (Medical Exposure) Regulations (IR (ME) R) 2000, as a legal framework for optimization of medical doses and establishment of DRLs. The National Radiological Protection Board (NRPB) Chilton (UK) set the DRLs based on national patient dose database (NPDD) and suggested that DRLs should be reviewed after every 5 year(17, 18). The American Association of Physicists in Medicine (AAPM) proposed reference values for radiation exposures in radiographic projections, CT, fluoroscopy and dental radiography to compare patient radiation doses and to check the equipment’s performance(13). Health Canada, a federal Department for healthcare in Canada in its safety code 35 recommends to establish DRLs for all x-ray procedures in large medical radiological facilities(19, 20). The Atomic Energy Regulatory Board (AERB), Mumbai (India) published revised safety code(21) in year 2016 for radiation safety in manufacture, supply and use of medical diagnostic x-ray equipments. This safety code has regulatory provisions for the manufacturer, suppliers and the users of x-ray equipments to avoid unwanted exposure. Sonawane et al.(22) estimated skin entrance doses for common medical x-ray diagnostic examination in various diagnostic x-ray centers in India and proposed DRLs for adult radiography using screen film system. However, DRLs in India have not been yet explicitly setup by national regulatory body. The Institute of Physics & Engineering in Medicine (IPEM)(23) suggested that if the national DRLs are not available then DRLs can be set on the bases of local dosimetry data. IPEM also recommends the use of local DRLs (LDRLs) estimated from dose data of different diagnostic examination in individual hospitals to set DRL. The performance of x-ray equipments and radiation exposures to the patients for all procedures performed in a facility can be examined from LDRLs. The ESD can be measured using kerma area product, thermoluminescence dosemeters (TLDs), films, diodes and knowledge of patient specific parameters during radiographic exposures(24, 25). Aim of the present work is to measure ESDs for common radiographic examinations of adult and pediatric patients in a multisite institution and to propose LDRL for digital radiography (DR) in Chandigarh, India. MATERIALS AND METHODS The assessment of the patient doses in the present work was done in accordance with International Atomic Energy Agency (IAEA) recommended protocol(25) for radiographic exposures. We have utilized thermoluminescent dosemeters TLDs (LiF: Mg, Ti) for dose measurement to evaluate the ESDs in adult patients. For pediatric patients, ESDs were estimated from exposure parameters and tube output measurement with appropriate back scatter factor (BSF). The TLD (LiF: Mg, Ti) dosemeter is not suitable for dose measurement lower than 0.1 mGy(26) and not used in this study for dosimetry in pediatrics radiography as the radiation exposures to pediatric patients are in μGy range. The examinations were performed in x-ray machines installed either at outpatient department (OPD) or advance trauma center or advance pediatric center of Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India. PGIMER is one of the premier institute in northern India that provides advance treatment facilities to the patients of five neighboring states. The institute has a separate department of radiodiagnosis and imaging which performs ~1500 radiographic exposures on 900 patients every day. The x-ray machines used in the dose measurements met the quality assurance (QA) criterion for kVp, mAs, current, time, focal spot, field size, filtration and radiation output as specified by relevant national regulation(21, 27). This study was conducted under QA category and does not involve any additional radiation exposure to the patients. As the present work fell under QA category, therefore, approval from research ethics board was not required. However, we have taken permission from department ethics committee. Prior informed consent of patient was taken before placing TLDs on his/her skin for dose measurement. The prospective data collection did not change the routine workflow in the department. The dose measurements were performed from September 2015 to October 2016. Information on type of examination, sex, age, height, weight of the patient, focus to table top distance (FTD), field size along with set kVp and mAs were recorded during data collection. Measurements of ESD in adults patients ESDs in adult patients were measured from 189 diagnostic projections for seven examinations, viz. chest (PA), lumbosacral spine (AP and Lat.), cervical spine (AP and Lat.), abdomen (AP), pelvis (AP), knee joint (AP and Lat.) and skull (AP and Lat.). The dose measurements were carried out on three x-ray machines (Model: RADspeed MC, 150 kV, and 800 mA, M/S Shimandzu Corporation, Japan) equipped with retrofit flat panel detector (Model: AERO-DR P-12, 43.2 × 35.5 cm2, Konica Minolta, Japan) using TLD rods (LiF:Mg,Ti, dimensions 1 × 1 × 6 mm3, Harshaw, TLD-100). Before subjecting the TLDs for dose assessment, a batch of 200 TLD-100 was annealed in a furnace at 400°C for 1 h followed by low temperature annealing at 105°C for 2 h. The annealed TLDs were then irradiated with known air kerma of 5 mGy under scatter free geometry as shown in Figure 1a. The air kerma was measured using 75 cm3 shadow free ionization chamber (UnidosE electrometer, PTW, Freiburg, Germany) calibrated to national standards of the German National Laboratory PTB, Braunschweig. The irradiated TLDs were annealed for 15 min at 105°C in the oven to removes low temperature unstable peaks from glow curve of TLDs(28, 29). Irradiated TLDs were readout in a TLD reader system (UL-300, Rexon Components Inc, Beachwood, OH, USA). After readout each TLD rod was assigned an identification number for sorting purposes. The above procedure was repeated three times to check the reproducibility and only those TLDs were selected which had sensitivity within ±5%. The radiographic exposure was measured using batch of three calibrated TLDs kept in thin polyethylene pouches and taped with micropore to patient’s skin near central beam axis of the x-ray field. Figure 1. View largeDownload slide (a) Scatter free geometry used in air kerma measurements in adults and pediatric patient and (b) measurement of pediatric patient’s thickness using customized zig. Figure 1. View largeDownload slide (a) Scatter free geometry used in air kerma measurements in adults and pediatric patient and (b) measurement of pediatric patient’s thickness using customized zig. The ESD was measured using the following relation:   ESD(mGy)=TLD(output)×Ksi×Nk (1)where Ksi is the sensitivity correction factors for the particular TLD and NK is the calibration factor. Ksi is evaluated using relation Ksi=M¯/Mi, where, M¯ is the mean TLD response, Mi is the response of a particular TLD. As exposed TLD measures the radiation backscattered from the patient therefore separate BSF component is not required. Measurements of ESD in pediatric patients ESD data of pediatric patients were collected for 2262 diagnostic projections from 12 examinations, viz. chest (AP and PA), lumbar spine (AP and Lat), thoracic spine (AP and Lat.), cervical spine (AP and Lat.), abdomen (AP), pelvis (AP), hip joints (AP), skull (AP and Lat.), knee joint (AP), wrist (AP), upper extremity (AP) and lower extremity (AP). The ESDs measurements were carried out on x-ray machine (Model: MARS-80, 120 kV, 800 mA, M/S Allengers Medical Systems Ltd, India) equipped with integrated flat panel imager detector (Model: FDX 4343 R, CsI 43 × 43 cm2, Toshiba, Japan) using manual exposure technique. Air kerma was measured using 75 cm3 shadow free ionization chamber mounted on adjustable universal test stand to generate scatter free geometry. The output of x-ray machine varied from 42 to 70 kVp at fix tube loading (PTI) of 10 mAs. Air kerma at the surface of ionization chamber was calculated using the following relation:   K(d)=M×NKQ0×KQ×KTP (2)where M is the electrometer reading, NKQ0 is the calibration factor, KQ is the quality factor at selected kVp and KTP is the temperature and pressure correction factor. The air kerma at table top (K) was determined using the following relation:   K=K(d)×(FCDFTD)2 (3)where FTD is focus to Table distance and FCD is focus to chamber distance. The output of x-ray unit in mGy/mAs at tube loading PTI was evaluated using the following relation:   Y=KPTI (4) The ESD of pediatric patients were deduced using the following relation:   ESD=Y×PTI×(FTDFTD−t)2×BSF (5)where t is patient thickness at beam central axis and BSF is back scatter factor to take into account of scatter contribution due to presence of patient, as BSF primarily depend on kVp, attenuator thickness, field size and focus to skin distance. In present measurements mean BSF value of 1.28 was used for all field size and for beam quality ranging from 42 to 70 kV. This value corresponds to an average value of backscatter factor and chosen after taking into account the average of field sizes and average of beam qualities used in this study(30). The thickness of the patient body was measured using a customized zig, Figure 1b with graduating marking of 1 mm precision. RESULTS AND DISCUSSIONS The measured minimum, maximum, average, median and third quartile values of the ESDs for adult and pediatric patients are listed in Tables 1 and 2, respectively. The reported data infer that ESDs in adult patient examinations are higher than ESD values in pediatric patients for all respective projections. Table 1 shows that for adult patients, minimum value of ESD is 0.21 mGy for chest (PA) and maximum value is 8.48 mGy for lumbosacral spine (Lat.) projection. The third quartile values of measured ESDs for the radiographic projection having number of exposures (n) ≥ 20 are proposed as LDRLs. The proposed LDRLs for adult patients are also compared with DRL values published by Health Protection Agency of UK in its report HPA-CRCE-034 (2012)(31), Italian DRL values (2000)(32) and DRL values reported by Sonawane et al.(22) in Table 1. It can be seen that third quartile values of ESD reported for abdomen (AP), lumbosacral (AP and Lat.), pelvis (AP) and skull (AP and Lat.) are comparable with values published by HPA-CRCE-034(31) except for chest (PA). The third quartile values of ESDs reported in this study are lower than the Italian DRL values (2000)(32) and DRL values proposed by Sonawane et al.(22) for film screen radiography. The higher value of third quartile ESDs for chest (PA) projection is due to the use of high mAs and low kVp during chest radiography in present study. The higher value reported for chest (PA) projection has agreement with the trend reported by Sonawane et al.(22) for screen film radiography in India. The comparison of third quartile ESDs with earlier reported DRL(22, 31, 32) values for chest (PA), abdomen (AP), lumbosacral (AP), lumbosacral (Lat.) and pelvis (AP) is shown in Figure 2. Table 1. The range (min–max), average, median and third quartile values of the ESDs along with DRL values published by HPA-CRCE-034(31), Italian DRL’s (2000)(32) and Sonawane el al.(22) for adult patients. Examination  No. of exposure (n)  kVp range  mAs range  Age range (y)  Weight range (kg)  Min–max ESDs (mGy)  Avg. ESDs (mGy)  Median ESDs (mGy)  Std. dev.  Third quartile ESDs (mGy)  HPA-CRCE-034(31) (mGy)  Italian DRL’s(32) (mGy)  Sonawane el al.(22) (mGy)  Chest (PA)  40  56–65  5.6–7.6  45–70  60–77  0.22–0.56  0.34  0.35  0.10  0.39*  0.15  0.4  0.68  Abdomen (AP)  23  62–75  16–32  22–60  62–75  1.3–5.90  2.72  2.43  1.12  3.26*  4.4  10  7.08  Lumbosacral spine (AP)  27  68–78  20–28  28–80  58–80  1.12–6.03  3.26  3.21  1.04  3.76*  5.7  10  8.39  Lumbosacral spine (Lat.)  27  72–86  25–40  29–81  64–81  2.36–8.49  5.06  4.98  1.14  5.52*  10  30  15.66  Cervical spine (AP)  11  53–63  6–10  34–85  65–80  1.60–4.92  3.02  2.75  1.08  3.66  —  —  —  Cervical spine (Lat.)  14  55–65  5–20  34–85  59–80  0.70–6.74  3.14  2.90  1.56  3.28  —  —  —  Pelvis (AP)  12  62–84  10–32  18–60  66–85  1.45–5.33  3.21  3.27  1.11  3.65  3.9  10  8.03  Knee (AP)  12  55–65  4.5–10  24–65  64–80  0.95–3.75  2.12  2.03  0.76  2.50  —  —  —  Knee (Lat.)  13  50–65  4.5–7.1  24–67  64–80  0.64–3.23  1.99  1.98  0.73  2.42  —  —  —  Skull (AP)  10  62–80  14–32  27–36  65–80  1.71–3.35  2.36  2.16  0.65  2.86  1.8  5  6.89  Skull (Lat.)  10  60–73  16–18  27–58  65–81  1.04–2.48  1.87  2.23  0.61  2.38  1.1  3  5.16  Examination  No. of exposure (n)  kVp range  mAs range  Age range (y)  Weight range (kg)  Min–max ESDs (mGy)  Avg. ESDs (mGy)  Median ESDs (mGy)  Std. dev.  Third quartile ESDs (mGy)  HPA-CRCE-034(31) (mGy)  Italian DRL’s(32) (mGy)  Sonawane el al.(22) (mGy)  Chest (PA)  40  56–65  5.6–7.6  45–70  60–77  0.22–0.56  0.34  0.35  0.10  0.39*  0.15  0.4  0.68  Abdomen (AP)  23  62–75  16–32  22–60  62–75  1.3–5.90  2.72  2.43  1.12  3.26*  4.4  10  7.08  Lumbosacral spine (AP)  27  68–78  20–28  28–80  58–80  1.12–6.03  3.26  3.21  1.04  3.76*  5.7  10  8.39  Lumbosacral spine (Lat.)  27  72–86  25–40  29–81  64–81  2.36–8.49  5.06  4.98  1.14  5.52*  10  30  15.66  Cervical spine (AP)  11  53–63  6–10  34–85  65–80  1.60–4.92  3.02  2.75  1.08  3.66  —  —  —  Cervical spine (Lat.)  14  55–65  5–20  34–85  59–80  0.70–6.74  3.14  2.90  1.56  3.28  —  —  —  Pelvis (AP)  12  62–84  10–32  18–60  66–85  1.45–5.33  3.21  3.27  1.11  3.65  3.9  10  8.03  Knee (AP)  12  55–65  4.5–10  24–65  64–80  0.95–3.75  2.12  2.03  0.76  2.50  —  —  —  Knee (Lat.)  13  50–65  4.5–7.1  24–67  64–80  0.64–3.23  1.99  1.98  0.73  2.42  —  —  —  Skull (AP)  10  62–80  14–32  27–36  65–80  1.71–3.35  2.36  2.16  0.65  2.86  1.8  5  6.89  Skull (Lat.)  10  60–73  16–18  27–58  65–81  1.04–2.48  1.87  2.23  0.61  2.38  1.1  3  5.16  *The third quartile values of ESD, proposed as LDRLs for examinations, (n) ≥ 20. Table 1. The range (min–max), average, median and third quartile values of the ESDs along with DRL values published by HPA-CRCE-034(31), Italian DRL’s (2000)(32) and Sonawane el al.(22) for adult patients. Examination  No. of exposure (n)  kVp range  mAs range  Age range (y)  Weight range (kg)  Min–max ESDs (mGy)  Avg. ESDs (mGy)  Median ESDs (mGy)  Std. dev.  Third quartile ESDs (mGy)  HPA-CRCE-034(31) (mGy)  Italian DRL’s(32) (mGy)  Sonawane el al.(22) (mGy)  Chest (PA)  40  56–65  5.6–7.6  45–70  60–77  0.22–0.56  0.34  0.35  0.10  0.39*  0.15  0.4  0.68  Abdomen (AP)  23  62–75  16–32  22–60  62–75  1.3–5.90  2.72  2.43  1.12  3.26*  4.4  10  7.08  Lumbosacral spine (AP)  27  68–78  20–28  28–80  58–80  1.12–6.03  3.26  3.21  1.04  3.76*  5.7  10  8.39  Lumbosacral spine (Lat.)  27  72–86  25–40  29–81  64–81  2.36–8.49  5.06  4.98  1.14  5.52*  10  30  15.66  Cervical spine (AP)  11  53–63  6–10  34–85  65–80  1.60–4.92  3.02  2.75  1.08  3.66  —  —  —  Cervical spine (Lat.)  14  55–65  5–20  34–85  59–80  0.70–6.74  3.14  2.90  1.56  3.28  —  —  —  Pelvis (AP)  12  62–84  10–32  18–60  66–85  1.45–5.33  3.21  3.27  1.11  3.65  3.9  10  8.03  Knee (AP)  12  55–65  4.5–10  24–65  64–80  0.95–3.75  2.12  2.03  0.76  2.50  —  —  —  Knee (Lat.)  13  50–65  4.5–7.1  24–67  64–80  0.64–3.23  1.99  1.98  0.73  2.42  —  —  —  Skull (AP)  10  62–80  14–32  27–36  65–80  1.71–3.35  2.36  2.16  0.65  2.86  1.8  5  6.89  Skull (Lat.)  10  60–73  16–18  27–58  65–81  1.04–2.48  1.87  2.23  0.61  2.38  1.1  3  5.16  Examination  No. of exposure (n)  kVp range  mAs range  Age range (y)  Weight range (kg)  Min–max ESDs (mGy)  Avg. ESDs (mGy)  Median ESDs (mGy)  Std. dev.  Third quartile ESDs (mGy)  HPA-CRCE-034(31) (mGy)  Italian DRL’s(32) (mGy)  Sonawane el al.(22) (mGy)  Chest (PA)  40  56–65  5.6–7.6  45–70  60–77  0.22–0.56  0.34  0.35  0.10  0.39*  0.15  0.4  0.68  Abdomen (AP)  23  62–75  16–32  22–60  62–75  1.3–5.90  2.72  2.43  1.12  3.26*  4.4  10  7.08  Lumbosacral spine (AP)  27  68–78  20–28  28–80  58–80  1.12–6.03  3.26  3.21  1.04  3.76*  5.7  10  8.39  Lumbosacral spine (Lat.)  27  72–86  25–40  29–81  64–81  2.36–8.49  5.06  4.98  1.14  5.52*  10  30  15.66  Cervical spine (AP)  11  53–63  6–10  34–85  65–80  1.60–4.92  3.02  2.75  1.08  3.66  —  —  —  Cervical spine (Lat.)  14  55–65  5–20  34–85  59–80  0.70–6.74  3.14  2.90  1.56  3.28  —  —  —  Pelvis (AP)  12  62–84  10–32  18–60  66–85  1.45–5.33  3.21  3.27  1.11  3.65  3.9  10  8.03  Knee (AP)  12  55–65  4.5–10  24–65  64–80  0.95–3.75  2.12  2.03  0.76  2.50  —  —  —  Knee (Lat.)  13  50–65  4.5–7.1  24–67  64–80  0.64–3.23  1.99  1.98  0.73  2.42  —  —  —  Skull (AP)  10  62–80  14–32  27–36  65–80  1.71–3.35  2.36  2.16  0.65  2.86  1.8  5  6.89  Skull (Lat.)  10  60–73  16–18  27–58  65–81  1.04–2.48  1.87  2.23  0.61  2.38  1.1  3  5.16  *The third quartile values of ESD, proposed as LDRLs for examinations, (n) ≥ 20. Table 2. The range (min–max), average, median, third quartile values of the ESDs along with LDRLs/DRL values published by NRPB-R318(33), Billinger et al.(34) and Wambani et al.(26) for pediatric patients. Examination  Age (y)  Weight range (kg)  Thickness range (cm)  No. of exposure (n)  kVp range  mAs range  Min–max ESDs (μGy)  Avg. ESDs (μGy)  Median ESDs (μGy)  Std. dev.  Third quartile ESDs (μGy)  NRPB-R318(33) (μGy)  Billinger et al.(34) (μGy)  Wambani et al.(26) (μGy)  Chest (AP)  0  2.7–5.5  4–9  10  45–48  2  38–51  45  48  4.61  49  50  55  50  0–1  2–11  4.5–13  125  44–52  2–3  36–104  73  77  18.90  89*  50  69  50  1–5  2–23  5.7–17  219  46–53  2–3  50–125  95  102  19.52  110*  70  82  60  Chest (PA)  1–5  3.4–30.4  4–17  255  47–53  2–4  25–62  46  44  8.19  53*  70  82  —  5–10  6.7–54  3.5–21  322  46–55  2–4  27–66  53  56  7.95  59*  120  108  —  >10  10.2–60  5.5–22.5  125  50–56  3–5  36–97  65  63  11.35  73*  —  112  —  Abdomen (AP)  0  2–5  6–12  10  49–51  2–3  55–98  81  85  13.83  88  —  100  70  0–1  2.6–11.2  6–13.5  21  48–55  2–4  55–147  101  108  23.61  114*  400  172  80  1–5  7–24.4  4–19  77  50–60  3–5  106–264  178  180  38.00  195*  500  511  130  5–10  13.6–48  8.5–21  48  53–63  4–6  152–406  252  250  58.99  282*  800  966  170  >10  21–60  11.6–25  22  55–65  4–10  195–597  365  350  120.90  488*  1200  —  200  Dorsal spine (AP)  0  1.7–3  5.1–13  3  56–56  3  98–136  118  120  18.99  —  —  —  —  0–1  3–11.6  7–15  19  52–57  3–7  101–321  201  188  71.66  258  —  —  —  1–5  5.4–24  6–17  40  52–65  3–10  105–546  299  292  107.57  353*  —  —  370  5–10  17.1–52  5.5–18.5  19  54–65  4–10  167–680  421  392  157.45  563  —  —  —  >10  27–45  9–19.3  10  50–78  4–10  163–878  498  506  228.88  615  —  —  —  Dorsal spine (Lat.)  0–1  3–8.6  10–13.7  12  54–58  3–7  146–345  250  245  72.89  299  —  —  —  1–5  6.8–24  8–21  31  52–67  4–10  144–594  366  354  113.28  447*  —  —  410  5–10  14.4–52  10–21  14  56–68  2–10  274–886  515  488  161.40  532  —  —  —  >10  27–40.8  14.8–22  10  52–70  5–10  256–893  596  644  176.21  691  —  —  —  Lumbosacral spine (AP)  0  2.8–3.32  7–9  3  51–52  3–4  95–124  105  98  16.48  —  —  —  70  0–1  3.74–10  8–11  6  55–60  3–6  124–274  217  238  56.51  —  —  —  420  1–5  4.2–20  9–15  15  52–63  4–8  134–431  280  287  95.81  352  —  —  —  5–10  5.95–42.2  7–17.2  13  54–65  5–10  186–688  401  395  158.43  469  —  —  —  >10  15.6–51.4  12–20  5  57–64  7–12  352–826  574  616  182.78  —  —  —  —  Lumbosacral spine (Lat.)  0  2.8–3.32  6.5–11  3  53–54  3  101–111  106  106  4.94  —  —  —  —  0–1  3.06–10  9.5–16  5  51–60  3–8  109–436  321  373  129.41  —  —  —  70  1–5  7–15.8  10.8–18  11  55–65  5–8  240–514  360  318  90.00  415  —  —  —  5–10  12–42.2  10–22  10  54–66  6–12  276–893  601  540  216.00  808  —  —  190  >10  28–32.4  13–21.5  2  57–63  7–11  336–810  573  573  334.96  —  —  —  360  Cervical spine (AP)  0–1  5  7.5  1  54  4  138  —  —  —  —  —  —  —  1–5  6.5–14.2  7–10  7  53–57  4–5  138–220  180  179  33.26  —  —  —  170  5–10  15.2–22  6.5–10  8  54–60  4–6  139–292  214  226  51.36  —  —  —  —  >10  30–35.4  11–12  3  55–58  5–8  186–382  262  217  105.10  —  —  —  190  Cervical spine (Lat.)  0–1  4.2  8  1  55  4  139  —  —  —  —  —  —  —  1–5  6.5–14.2  8–9  6  54–55  4–5  139–197  162  158  24.91  —  —  —  90  5–10  15.2–21.2  6.5–8.5  8  55–59  4–6  160–258  199  196  37.88  —  —  —  130  Hip (AP)  1–5  7.6–22.8  4–15.2  27  48–60  2–7  45–356  190  181  56.56  213*  —  —  50  5–10  10–28  4–13  14  53–60  4–7  138–356  205  189  60.11  236  —  —  140  >10  10.8–44.8  6–15  11  54–65  4–10  145–557  300  210  153.62  441  —  —  150  Pelvis (AP)  0–1  2.5–12.8  5–12  11  52–59  3–5  99–222  146  132  49.84  189  500  —  —  1–5  5.1–29  5.5–15.2  43  53–62  3–4  99–240  149  145  36.32  171*  600  —  —  5–10  10.8–47  5–24  29  48–60  4–8  143–478  257  266  79.49  299*  700  —  —  >10  10.8–57.8  4.9–20  24  54–68  4–10  127–727  362  332  169.03  498*  2000  —  —  Skull (AP)  0–1  5–8.6  8–12  13  60–65  4–8  147–496  338  348  84.35  390  800  690  170  1–5  6.6–20  8–18.5  18  54–65  4–9  54–205  140  147  50.61  182  1100  880  210  5–10  5.95–49.4  8.5–18  21  52–69  4–14  55–393  197  189  99.88  241*  1100  998  220  >10  23–37  12–19  10  56–68  5–10  222–614  473  525  124.64  568  1100  1123  300  Skull (Lat.)  0–1  3.17–8.6  10.2–12  12  58–63  5–7  89–401  286  288  79.16  346  500  700  140  1–5  7.5–20  8–14.5  13  58–62  5–14  91–330  174  164  64.04  199  800  506  170  5–10  9–52  7.2–17  11  54–67  5–14  73–419  178  136  113.65  234  800  557  200  Wrist (AP)  0–1  3.06–11.6  1–3.5  11  45–54  2–3  35–95  66  60  22.61  93  —  —  —  1–5  5.5–35  1–4.2  81  43–54  1–3  25–113  59  56  16.83  67*  —  —  —  5–10  5.95–46  1–4  54  45–54  2–4  41–126  78  77  21.06  93*  —  —  —  >10  18–50  1–4.4  24  44–56  2–5  38–161  90  87  35.10  99*  —  —  —  Knee (AP)  0–1  5.4–9.5  2.5–5  2  50  2–3  50–80  65  78  25.53    —  —  —  1–5  9.4–20  4–8.5  17  49–55  2–4  50–141  93  100  27.34  102  —  —  —  5–10  13.2–68  3–9.5  38  47–57  2–5  59–173  117  115  33.02  140*  —  —  —  >10  18–42.8  3–9.5  15  52–56  3–5  88–180  138  142  29.07  160  —  —  —  Upper extremity  0  1.75  2  1  50  3  85  —  —      —  —  —  0–1  3.06–8  1–6  10  45–53  2–4  35–116  79  90  25.89  93  —  —  30  1–5  7–23  1–8  26  45–56  2–4  35–159  90  91  26.57  94*  —  —  40  5–10  9.6–73.4  1–14.5  76  47–54  2–5  38–199  99  94  35.08  120*  —  —  50  >10  18–68  1–7  26  45–55  2–5  54–200  99  95  34.79  125*  —  —  50  Lower extremity  0  2.5–2.8  2.3–3  2  50–54  2  50–58  54  54  5.47  —  —  —  30  0–1  3–8.6  1.5–4  10  47–54  2–3  42–95  78  88  20.67  91  —  —  30  1–5  5.7–54  1.5–8  47  47–55  2–4  43–136  85  91  18.66  98*  —  —  40  5–10  13.2–68  2–10  47  46–56  2–5  50–212  123  131  40.82  141*  —  —  50  >10  13.8–50  2–15  34  50–56  2–5  51–238  155  159  39.13  180*  —  —  50  Examination  Age (y)  Weight range (kg)  Thickness range (cm)  No. of exposure (n)  kVp range  mAs range  Min–max ESDs (μGy)  Avg. ESDs (μGy)  Median ESDs (μGy)  Std. dev.  Third quartile ESDs (μGy)  NRPB-R318(33) (μGy)  Billinger et al.(34) (μGy)  Wambani et al.(26) (μGy)  Chest (AP)  0  2.7–5.5  4–9  10  45–48  2  38–51  45  48  4.61  49  50  55  50  0–1  2–11  4.5–13  125  44–52  2–3  36–104  73  77  18.90  89*  50  69  50  1–5  2–23  5.7–17  219  46–53  2–3  50–125  95  102  19.52  110*  70  82  60  Chest (PA)  1–5  3.4–30.4  4–17  255  47–53  2–4  25–62  46  44  8.19  53*  70  82  —  5–10  6.7–54  3.5–21  322  46–55  2–4  27–66  53  56  7.95  59*  120  108  —  >10  10.2–60  5.5–22.5  125  50–56  3–5  36–97  65  63  11.35  73*  —  112  —  Abdomen (AP)  0  2–5  6–12  10  49–51  2–3  55–98  81  85  13.83  88  —  100  70  0–1  2.6–11.2  6–13.5  21  48–55  2–4  55–147  101  108  23.61  114*  400  172  80  1–5  7–24.4  4–19  77  50–60  3–5  106–264  178  180  38.00  195*  500  511  130  5–10  13.6–48  8.5–21  48  53–63  4–6  152–406  252  250  58.99  282*  800  966  170  >10  21–60  11.6–25  22  55–65  4–10  195–597  365  350  120.90  488*  1200  —  200  Dorsal spine (AP)  0  1.7–3  5.1–13  3  56–56  3  98–136  118  120  18.99  —  —  —  —  0–1  3–11.6  7–15  19  52–57  3–7  101–321  201  188  71.66  258  —  —  —  1–5  5.4–24  6–17  40  52–65  3–10  105–546  299  292  107.57  353*  —  —  370  5–10  17.1–52  5.5–18.5  19  54–65  4–10  167–680  421  392  157.45  563  —  —  —  >10  27–45  9–19.3  10  50–78  4–10  163–878  498  506  228.88  615  —  —  —  Dorsal spine (Lat.)  0–1  3–8.6  10–13.7  12  54–58  3–7  146–345  250  245  72.89  299  —  —  —  1–5  6.8–24  8–21  31  52–67  4–10  144–594  366  354  113.28  447*  —  —  410  5–10  14.4–52  10–21  14  56–68  2–10  274–886  515  488  161.40  532  —  —  —  >10  27–40.8  14.8–22  10  52–70  5–10  256–893  596  644  176.21  691  —  —  —  Lumbosacral spine (AP)  0  2.8–3.32  7–9  3  51–52  3–4  95–124  105  98  16.48  —  —  —  70  0–1  3.74–10  8–11  6  55–60  3–6  124–274  217  238  56.51  —  —  —  420  1–5  4.2–20  9–15  15  52–63  4–8  134–431  280  287  95.81  352  —  —  —  5–10  5.95–42.2  7–17.2  13  54–65  5–10  186–688  401  395  158.43  469  —  —  —  >10  15.6–51.4  12–20  5  57–64  7–12  352–826  574  616  182.78  —  —  —  —  Lumbosacral spine (Lat.)  0  2.8–3.32  6.5–11  3  53–54  3  101–111  106  106  4.94  —  —  —  —  0–1  3.06–10  9.5–16  5  51–60  3–8  109–436  321  373  129.41  —  —  —  70  1–5  7–15.8  10.8–18  11  55–65  5–8  240–514  360  318  90.00  415  —  —  —  5–10  12–42.2  10–22  10  54–66  6–12  276–893  601  540  216.00  808  —  —  190  >10  28–32.4  13–21.5  2  57–63  7–11  336–810  573  573  334.96  —  —  —  360  Cervical spine (AP)  0–1  5  7.5  1  54  4  138  —  —  —  —  —  —  —  1–5  6.5–14.2  7–10  7  53–57  4–5  138–220  180  179  33.26  —  —  —  170  5–10  15.2–22  6.5–10  8  54–60  4–6  139–292  214  226  51.36  —  —  —  —  >10  30–35.4  11–12  3  55–58  5–8  186–382  262  217  105.10  —  —  —  190  Cervical spine (Lat.)  0–1  4.2  8  1  55  4  139  —  —  —  —  —  —  —  1–5  6.5–14.2  8–9  6  54–55  4–5  139–197  162  158  24.91  —  —  —  90  5–10  15.2–21.2  6.5–8.5  8  55–59  4–6  160–258  199  196  37.88  —  —  —  130  Hip (AP)  1–5  7.6–22.8  4–15.2  27  48–60  2–7  45–356  190  181  56.56  213*  —  —  50  5–10  10–28  4–13  14  53–60  4–7  138–356  205  189  60.11  236  —  —  140  >10  10.8–44.8  6–15  11  54–65  4–10  145–557  300  210  153.62  441  —  —  150  Pelvis (AP)  0–1  2.5–12.8  5–12  11  52–59  3–5  99–222  146  132  49.84  189  500  —  —  1–5  5.1–29  5.5–15.2  43  53–62  3–4  99–240  149  145  36.32  171*  600  —  —  5–10  10.8–47  5–24  29  48–60  4–8  143–478  257  266  79.49  299*  700  —  —  >10  10.8–57.8  4.9–20  24  54–68  4–10  127–727  362  332  169.03  498*  2000  —  —  Skull (AP)  0–1  5–8.6  8–12  13  60–65  4–8  147–496  338  348  84.35  390  800  690  170  1–5  6.6–20  8–18.5  18  54–65  4–9  54–205  140  147  50.61  182  1100  880  210  5–10  5.95–49.4  8.5–18  21  52–69  4–14  55–393  197  189  99.88  241*  1100  998  220  >10  23–37  12–19  10  56–68  5–10  222–614  473  525  124.64  568  1100  1123  300  Skull (Lat.)  0–1  3.17–8.6  10.2–12  12  58–63  5–7  89–401  286  288  79.16  346  500  700  140  1–5  7.5–20  8–14.5  13  58–62  5–14  91–330  174  164  64.04  199  800  506  170  5–10  9–52  7.2–17  11  54–67  5–14  73–419  178  136  113.65  234  800  557  200  Wrist (AP)  0–1  3.06–11.6  1–3.5  11  45–54  2–3  35–95  66  60  22.61  93  —  —  —  1–5  5.5–35  1–4.2  81  43–54  1–3  25–113  59  56  16.83  67*  —  —  —  5–10  5.95–46  1–4  54  45–54  2–4  41–126  78  77  21.06  93*  —  —  —  >10  18–50  1–4.4  24  44–56  2–5  38–161  90  87  35.10  99*  —  —  —  Knee (AP)  0–1  5.4–9.5  2.5–5  2  50  2–3  50–80  65  78  25.53    —  —  —  1–5  9.4–20  4–8.5  17  49–55  2–4  50–141  93  100  27.34  102  —  —  —  5–10  13.2–68  3–9.5  38  47–57  2–5  59–173  117  115  33.02  140*  —  —  —  >10  18–42.8  3–9.5  15  52–56  3–5  88–180  138  142  29.07  160  —  —  —  Upper extremity  0  1.75  2  1  50  3  85  —  —      —  —  —  0–1  3.06–8  1–6  10  45–53  2–4  35–116  79  90  25.89  93  —  —  30  1–5  7–23  1–8  26  45–56  2–4  35–159  90  91  26.57  94*  —  —  40  5–10  9.6–73.4  1–14.5  76  47–54  2–5  38–199  99  94  35.08  120*  —  —  50  >10  18–68  1–7  26  45–55  2–5  54–200  99  95  34.79  125*  —  —  50  Lower extremity  0  2.5–2.8  2.3–3  2  50–54  2  50–58  54  54  5.47  —  —  —  30  0–1  3–8.6  1.5–4  10  47–54  2–3  42–95  78  88  20.67  91  —  —  30  1–5  5.7–54  1.5–8  47  47–55  2–4  43–136  85  91  18.66  98*  —  —  40  5–10  13.2–68  2–10  47  46–56  2–5  50–212  123  131  40.82  141*  —  —  50  >10  13.8–50  2–15  34  50–56  2–5  51–238  155  159  39.13  180*  —  —  50  *The third quartile values of ESD, proposed as LDRLs for examinations, (n) ≥ 20. Table 2. The range (min–max), average, median, third quartile values of the ESDs along with LDRLs/DRL values published by NRPB-R318(33), Billinger et al.(34) and Wambani et al.(26) for pediatric patients. Examination  Age (y)  Weight range (kg)  Thickness range (cm)  No. of exposure (n)  kVp range  mAs range  Min–max ESDs (μGy)  Avg. ESDs (μGy)  Median ESDs (μGy)  Std. dev.  Third quartile ESDs (μGy)  NRPB-R318(33) (μGy)  Billinger et al.(34) (μGy)  Wambani et al.(26) (μGy)  Chest (AP)  0  2.7–5.5  4–9  10  45–48  2  38–51  45  48  4.61  49  50  55  50  0–1  2–11  4.5–13  125  44–52  2–3  36–104  73  77  18.90  89*  50  69  50  1–5  2–23  5.7–17  219  46–53  2–3  50–125  95  102  19.52  110*  70  82  60  Chest (PA)  1–5  3.4–30.4  4–17  255  47–53  2–4  25–62  46  44  8.19  53*  70  82  —  5–10  6.7–54  3.5–21  322  46–55  2–4  27–66  53  56  7.95  59*  120  108  —  >10  10.2–60  5.5–22.5  125  50–56  3–5  36–97  65  63  11.35  73*  —  112  —  Abdomen (AP)  0  2–5  6–12  10  49–51  2–3  55–98  81  85  13.83  88  —  100  70  0–1  2.6–11.2  6–13.5  21  48–55  2–4  55–147  101  108  23.61  114*  400  172  80  1–5  7–24.4  4–19  77  50–60  3–5  106–264  178  180  38.00  195*  500  511  130  5–10  13.6–48  8.5–21  48  53–63  4–6  152–406  252  250  58.99  282*  800  966  170  >10  21–60  11.6–25  22  55–65  4–10  195–597  365  350  120.90  488*  1200  —  200  Dorsal spine (AP)  0  1.7–3  5.1–13  3  56–56  3  98–136  118  120  18.99  —  —  —  —  0–1  3–11.6  7–15  19  52–57  3–7  101–321  201  188  71.66  258  —  —  —  1–5  5.4–24  6–17  40  52–65  3–10  105–546  299  292  107.57  353*  —  —  370  5–10  17.1–52  5.5–18.5  19  54–65  4–10  167–680  421  392  157.45  563  —  —  —  >10  27–45  9–19.3  10  50–78  4–10  163–878  498  506  228.88  615  —  —  —  Dorsal spine (Lat.)  0–1  3–8.6  10–13.7  12  54–58  3–7  146–345  250  245  72.89  299  —  —  —  1–5  6.8–24  8–21  31  52–67  4–10  144–594  366  354  113.28  447*  —  —  410  5–10  14.4–52  10–21  14  56–68  2–10  274–886  515  488  161.40  532  —  —  —  >10  27–40.8  14.8–22  10  52–70  5–10  256–893  596  644  176.21  691  —  —  —  Lumbosacral spine (AP)  0  2.8–3.32  7–9  3  51–52  3–4  95–124  105  98  16.48  —  —  —  70  0–1  3.74–10  8–11  6  55–60  3–6  124–274  217  238  56.51  —  —  —  420  1–5  4.2–20  9–15  15  52–63  4–8  134–431  280  287  95.81  352  —  —  —  5–10  5.95–42.2  7–17.2  13  54–65  5–10  186–688  401  395  158.43  469  —  —  —  >10  15.6–51.4  12–20  5  57–64  7–12  352–826  574  616  182.78  —  —  —  —  Lumbosacral spine (Lat.)  0  2.8–3.32  6.5–11  3  53–54  3  101–111  106  106  4.94  —  —  —  —  0–1  3.06–10  9.5–16  5  51–60  3–8  109–436  321  373  129.41  —  —  —  70  1–5  7–15.8  10.8–18  11  55–65  5–8  240–514  360  318  90.00  415  —  —  —  5–10  12–42.2  10–22  10  54–66  6–12  276–893  601  540  216.00  808  —  —  190  >10  28–32.4  13–21.5  2  57–63  7–11  336–810  573  573  334.96  —  —  —  360  Cervical spine (AP)  0–1  5  7.5  1  54  4  138  —  —  —  —  —  —  —  1–5  6.5–14.2  7–10  7  53–57  4–5  138–220  180  179  33.26  —  —  —  170  5–10  15.2–22  6.5–10  8  54–60  4–6  139–292  214  226  51.36  —  —  —  —  >10  30–35.4  11–12  3  55–58  5–8  186–382  262  217  105.10  —  —  —  190  Cervical spine (Lat.)  0–1  4.2  8  1  55  4  139  —  —  —  —  —  —  —  1–5  6.5–14.2  8–9  6  54–55  4–5  139–197  162  158  24.91  —  —  —  90  5–10  15.2–21.2  6.5–8.5  8  55–59  4–6  160–258  199  196  37.88  —  —  —  130  Hip (AP)  1–5  7.6–22.8  4–15.2  27  48–60  2–7  45–356  190  181  56.56  213*  —  —  50  5–10  10–28  4–13  14  53–60  4–7  138–356  205  189  60.11  236  —  —  140  >10  10.8–44.8  6–15  11  54–65  4–10  145–557  300  210  153.62  441  —  —  150  Pelvis (AP)  0–1  2.5–12.8  5–12  11  52–59  3–5  99–222  146  132  49.84  189  500  —  —  1–5  5.1–29  5.5–15.2  43  53–62  3–4  99–240  149  145  36.32  171*  600  —  —  5–10  10.8–47  5–24  29  48–60  4–8  143–478  257  266  79.49  299*  700  —  —  >10  10.8–57.8  4.9–20  24  54–68  4–10  127–727  362  332  169.03  498*  2000  —  —  Skull (AP)  0–1  5–8.6  8–12  13  60–65  4–8  147–496  338  348  84.35  390  800  690  170  1–5  6.6–20  8–18.5  18  54–65  4–9  54–205  140  147  50.61  182  1100  880  210  5–10  5.95–49.4  8.5–18  21  52–69  4–14  55–393  197  189  99.88  241*  1100  998  220  >10  23–37  12–19  10  56–68  5–10  222–614  473  525  124.64  568  1100  1123  300  Skull (Lat.)  0–1  3.17–8.6  10.2–12  12  58–63  5–7  89–401  286  288  79.16  346  500  700  140  1–5  7.5–20  8–14.5  13  58–62  5–14  91–330  174  164  64.04  199  800  506  170  5–10  9–52  7.2–17  11  54–67  5–14  73–419  178  136  113.65  234  800  557  200  Wrist (AP)  0–1  3.06–11.6  1–3.5  11  45–54  2–3  35–95  66  60  22.61  93  —  —  —  1–5  5.5–35  1–4.2  81  43–54  1–3  25–113  59  56  16.83  67*  —  —  —  5–10  5.95–46  1–4  54  45–54  2–4  41–126  78  77  21.06  93*  —  —  —  >10  18–50  1–4.4  24  44–56  2–5  38–161  90  87  35.10  99*  —  —  —  Knee (AP)  0–1  5.4–9.5  2.5–5  2  50  2–3  50–80  65  78  25.53    —  —  —  1–5  9.4–20  4–8.5  17  49–55  2–4  50–141  93  100  27.34  102  —  —  —  5–10  13.2–68  3–9.5  38  47–57  2–5  59–173  117  115  33.02  140*  —  —  —  >10  18–42.8  3–9.5  15  52–56  3–5  88–180  138  142  29.07  160  —  —  —  Upper extremity  0  1.75  2  1  50  3  85  —  —      —  —  —  0–1  3.06–8  1–6  10  45–53  2–4  35–116  79  90  25.89  93  —  —  30  1–5  7–23  1–8  26  45–56  2–4  35–159  90  91  26.57  94*  —  —  40  5–10  9.6–73.4  1–14.5  76  47–54  2–5  38–199  99  94  35.08  120*  —  —  50  >10  18–68  1–7  26  45–55  2–5  54–200  99  95  34.79  125*  —  —  50  Lower extremity  0  2.5–2.8  2.3–3  2  50–54  2  50–58  54  54  5.47  —  —  —  30  0–1  3–8.6  1.5–4  10  47–54  2–3  42–95  78  88  20.67  91  —  —  30  1–5  5.7–54  1.5–8  47  47–55  2–4  43–136  85  91  18.66  98*  —  —  40  5–10  13.2–68  2–10  47  46–56  2–5  50–212  123  131  40.82  141*  —  —  50  >10  13.8–50  2–15  34  50–56  2–5  51–238  155  159  39.13  180*  —  —  50  Examination  Age (y)  Weight range (kg)  Thickness range (cm)  No. of exposure (n)  kVp range  mAs range  Min–max ESDs (μGy)  Avg. ESDs (μGy)  Median ESDs (μGy)  Std. dev.  Third quartile ESDs (μGy)  NRPB-R318(33) (μGy)  Billinger et al.(34) (μGy)  Wambani et al.(26) (μGy)  Chest (AP)  0  2.7–5.5  4–9  10  45–48  2  38–51  45  48  4.61  49  50  55  50  0–1  2–11  4.5–13  125  44–52  2–3  36–104  73  77  18.90  89*  50  69  50  1–5  2–23  5.7–17  219  46–53  2–3  50–125  95  102  19.52  110*  70  82  60  Chest (PA)  1–5  3.4–30.4  4–17  255  47–53  2–4  25–62  46  44  8.19  53*  70  82  —  5–10  6.7–54  3.5–21  322  46–55  2–4  27–66  53  56  7.95  59*  120  108  —  >10  10.2–60  5.5–22.5  125  50–56  3–5  36–97  65  63  11.35  73*  —  112  —  Abdomen (AP)  0  2–5  6–12  10  49–51  2–3  55–98  81  85  13.83  88  —  100  70  0–1  2.6–11.2  6–13.5  21  48–55  2–4  55–147  101  108  23.61  114*  400  172  80  1–5  7–24.4  4–19  77  50–60  3–5  106–264  178  180  38.00  195*  500  511  130  5–10  13.6–48  8.5–21  48  53–63  4–6  152–406  252  250  58.99  282*  800  966  170  >10  21–60  11.6–25  22  55–65  4–10  195–597  365  350  120.90  488*  1200  —  200  Dorsal spine (AP)  0  1.7–3  5.1–13  3  56–56  3  98–136  118  120  18.99  —  —  —  —  0–1  3–11.6  7–15  19  52–57  3–7  101–321  201  188  71.66  258  —  —  —  1–5  5.4–24  6–17  40  52–65  3–10  105–546  299  292  107.57  353*  —  —  370  5–10  17.1–52  5.5–18.5  19  54–65  4–10  167–680  421  392  157.45  563  —  —  —  >10  27–45  9–19.3  10  50–78  4–10  163–878  498  506  228.88  615  —  —  —  Dorsal spine (Lat.)  0–1  3–8.6  10–13.7  12  54–58  3–7  146–345  250  245  72.89  299  —  —  —  1–5  6.8–24  8–21  31  52–67  4–10  144–594  366  354  113.28  447*  —  —  410  5–10  14.4–52  10–21  14  56–68  2–10  274–886  515  488  161.40  532  —  —  —  >10  27–40.8  14.8–22  10  52–70  5–10  256–893  596  644  176.21  691  —  —  —  Lumbosacral spine (AP)  0  2.8–3.32  7–9  3  51–52  3–4  95–124  105  98  16.48  —  —  —  70  0–1  3.74–10  8–11  6  55–60  3–6  124–274  217  238  56.51  —  —  —  420  1–5  4.2–20  9–15  15  52–63  4–8  134–431  280  287  95.81  352  —  —  —  5–10  5.95–42.2  7–17.2  13  54–65  5–10  186–688  401  395  158.43  469  —  —  —  >10  15.6–51.4  12–20  5  57–64  7–12  352–826  574  616  182.78  —  —  —  —  Lumbosacral spine (Lat.)  0  2.8–3.32  6.5–11  3  53–54  3  101–111  106  106  4.94  —  —  —  —  0–1  3.06–10  9.5–16  5  51–60  3–8  109–436  321  373  129.41  —  —  —  70  1–5  7–15.8  10.8–18  11  55–65  5–8  240–514  360  318  90.00  415  —  —  —  5–10  12–42.2  10–22  10  54–66  6–12  276–893  601  540  216.00  808  —  —  190  >10  28–32.4  13–21.5  2  57–63  7–11  336–810  573  573  334.96  —  —  —  360  Cervical spine (AP)  0–1  5  7.5  1  54  4  138  —  —  —  —  —  —  —  1–5  6.5–14.2  7–10  7  53–57  4–5  138–220  180  179  33.26  —  —  —  170  5–10  15.2–22  6.5–10  8  54–60  4–6  139–292  214  226  51.36  —  —  —  —  >10  30–35.4  11–12  3  55–58  5–8  186–382  262  217  105.10  —  —  —  190  Cervical spine (Lat.)  0–1  4.2  8  1  55  4  139  —  —  —  —  —  —  —  1–5  6.5–14.2  8–9  6  54–55  4–5  139–197  162  158  24.91  —  —  —  90  5–10  15.2–21.2  6.5–8.5  8  55–59  4–6  160–258  199  196  37.88  —  —  —  130  Hip (AP)  1–5  7.6–22.8  4–15.2  27  48–60  2–7  45–356  190  181  56.56  213*  —  —  50  5–10  10–28  4–13  14  53–60  4–7  138–356  205  189  60.11  236  —  —  140  >10  10.8–44.8  6–15  11  54–65  4–10  145–557  300  210  153.62  441  —  —  150  Pelvis (AP)  0–1  2.5–12.8  5–12  11  52–59  3–5  99–222  146  132  49.84  189  500  —  —  1–5  5.1–29  5.5–15.2  43  53–62  3–4  99–240  149  145  36.32  171*  600  —  —  5–10  10.8–47  5–24  29  48–60  4–8  143–478  257  266  79.49  299*  700  —  —  >10  10.8–57.8  4.9–20  24  54–68  4–10  127–727  362  332  169.03  498*  2000  —  —  Skull (AP)  0–1  5–8.6  8–12  13  60–65  4–8  147–496  338  348  84.35  390  800  690  170  1–5  6.6–20  8–18.5  18  54–65  4–9  54–205  140  147  50.61  182  1100  880  210  5–10  5.95–49.4  8.5–18  21  52–69  4–14  55–393  197  189  99.88  241*  1100  998  220  >10  23–37  12–19  10  56–68  5–10  222–614  473  525  124.64  568  1100  1123  300  Skull (Lat.)  0–1  3.17–8.6  10.2–12  12  58–63  5–7  89–401  286  288  79.16  346  500  700  140  1–5  7.5–20  8–14.5  13  58–62  5–14  91–330  174  164  64.04  199  800  506  170  5–10  9–52  7.2–17  11  54–67  5–14  73–419  178  136  113.65  234  800  557  200  Wrist (AP)  0–1  3.06–11.6  1–3.5  11  45–54  2–3  35–95  66  60  22.61  93  —  —  —  1–5  5.5–35  1–4.2  81  43–54  1–3  25–113  59  56  16.83  67*  —  —  —  5–10  5.95–46  1–4  54  45–54  2–4  41–126  78  77  21.06  93*  —  —  —  >10  18–50  1–4.4  24  44–56  2–5  38–161  90  87  35.10  99*  —  —  —  Knee (AP)  0–1  5.4–9.5  2.5–5  2  50  2–3  50–80  65  78  25.53    —  —  —  1–5  9.4–20  4–8.5  17  49–55  2–4  50–141  93  100  27.34  102  —  —  —  5–10  13.2–68  3–9.5  38  47–57  2–5  59–173  117  115  33.02  140*  —  —  —  >10  18–42.8  3–9.5  15  52–56  3–5  88–180  138  142  29.07  160  —  —  —  Upper extremity  0  1.75  2  1  50  3  85  —  —      —  —  —  0–1  3.06–8  1–6  10  45–53  2–4  35–116  79  90  25.89  93  —  —  30  1–5  7–23  1–8  26  45–56  2–4  35–159  90  91  26.57  94*  —  —  40  5–10  9.6–73.4  1–14.5  76  47–54  2–5  38–199  99  94  35.08  120*  —  —  50  >10  18–68  1–7  26  45–55  2–5  54–200  99  95  34.79  125*  —  —  50  Lower extremity  0  2.5–2.8  2.3–3  2  50–54  2  50–58  54  54  5.47  —  —  —  30  0–1  3–8.6  1.5–4  10  47–54  2–3  42–95  78  88  20.67  91  —  —  30  1–5  5.7–54  1.5–8  47  47–55  2–4  43–136  85  91  18.66  98*  —  —  40  5–10  13.2–68  2–10  47  46–56  2–5  50–212  123  131  40.82  141*  —  —  50  >10  13.8–50  2–15  34  50–56  2–5  51–238  155  159  39.13  180*  —  —  50  *The third quartile values of ESD, proposed as LDRLs for examinations, (n) ≥ 20. Figure 2. View largeDownload slide Comparison of third quartile values of ESD for adult patient in chest (PA), abdomen (AP), lumbosacral (AP), lumbosacral (Lat.) and pelvis (AP) examinations with earlier measurements. Figure 2. View largeDownload slide Comparison of third quartile values of ESD for adult patient in chest (PA), abdomen (AP), lumbosacral (AP), lumbosacral (Lat.) and pelvis (AP) examinations with earlier measurements. Previous studies on pediatric patients had reported DRL values by adopting different grouping criterion based on either age or weight of pediatric patients. The NRPB (UK) in its report NRPB-R318(33), suggested that in addition to the patient age and weight, thickness of the patient is also a crucial factor for setting DRL in pediatrics. NRPB-R318(33) and Billinger et al.(34) reported DRL values for five standard sizes of patients based on age and grouped them into newborn, 1 year old, 5 year old, 10 year old and 15 year old, whereas, Tsapaki et al.(35) reported pediatric radiation dose data in interventional cardiology procedures on pediatrics, grouping them in three age categories of <1 year, 1–10 year and more than 10 years. Wambani et al.(26) studied the pediatric dose data categorizing into five age groups of <1, 1–12, 13–60, 61–120 and 121 months and above. In present study, pediatric patients are arranged into five age groups of 0 (<1 month), 0–1, 1–5, 5–10 and >10 years. Table 2 shows that measured ESD has minimum value of 36 μGy for chest (AP) projection in age group of 0–1 years and maximum value of 893 μGy for lumbosacral spine (Lat.) and dorsal spine (Lat.) for the age group of 5–10 years. The ESDs value for all other pediatric radiographic exposures included in the study lies between these minimum and maximum values. Table 2 also compares third quartile values of ESDs with LDRLs/DRLs values published by NRPB-R318(33), Billinger et al.(34) and Wambani et al.(26). It can be seen from Table 2 that third quartile ESD values reported in this study for all the projection are lower than values reported by NRPB-R318(33) and Billinger et al.(34) except for chest (AP) projection for the patients in age groups of 0–1 years and 1–5 years. The measured higher third quartile ESD for chest (AP) projection was due to the fact that chest (AP) examinations for pediatric patients below 5 years were performed in supine position with reduced focus to skin distance as compared to chest (PA) view. The measured third quartile ESDs are also compared with earlier reported LDRL/DRL(26, 33, 34) values for chest (AP), abdomen (AP), skull (AP) and skull (Lat.) in Figure 3. It is pertinent to mention that higher risk to pediatric patients undergoing radiological examination is due to the influence of age on the organ specific risk factor and a part on proximity of critical radiosensitive organs to the organ under radiographic examination as compared to adult counterparts. Therefore, in pediatric radiography attention should be given to adequate and proper collimation of radiation field to avoid unnecessary irradiation of organs not required for diagnosis. The present study has demonstrated that use of DR technology reduces the patient’s radiation exposure and helps in maintaining the ALARA principle. Figure 3. View largeDownload slide Comparison of third quartile values of ESD for pediatric patient in (a) chest (AP), (b) abdomen (AP), (c) skull (AP) and (d) skull (Lat.) examinations with earlier measurements. Figure 3. View largeDownload slide Comparison of third quartile values of ESD for pediatric patient in (a) chest (AP), (b) abdomen (AP), (c) skull (AP) and (d) skull (Lat.) examinations with earlier measurements. CONCLUSION This study has reported ESD data in adult and pediatric patients for common radiographic examinations in DR systems installed in the tertiary care hospital and research institute. The third quartile values of ESD for radiographic projections, (n ≥ 20) are proposed as LDRL. These LDRL values can be taken as QA parameters in the institute for comparison and optimization of radiation doses to the patients from these radiographic procedures and serves to provide useful baseline data for other x-ray installations in the region. It is recommended that LDRLs should be established in every x-ray department, during radiographic examination applicable LDRL/DRL values should not exceed and radiation audit of patient doses should be incorporated in routine practice. 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TI - DOSIMETRY OF ADULT AND PEDIATRIC PATIENTS FOR COMMON DIGITAL RADIOGRAPHY EXAMINATIONS
JO - Radiation Protection Dosimetry
DO - 10.1093/rpd/ncx293
DA - 2018-01-12
UR - https://www.deepdyve.com/lp/oxford-university-press/dosimetry-of-adult-and-pediatric-patients-for-common-digital-oRgxZ4adHS
SP - 1
VL - Advance Article
IS - 
DP - DeepDyve
ER -