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1.  Optimisation of Radiation Exposure to Gastroenterologists and Patients during Therapeutic ERCP 
This study intended to optimize the radiation doses for gastroenterologists and patients during therapeutic endoscopic retrograde cholangiopancreatography (ERCP) and to compare the doses based on available data obtained by other researchers. A total of 153 patients were studied in two Gastroenterology Departments, (group A, 111; group B, 42). Thermoluminescent dosimeters (TLD) were used to measure the staff and patients entrance surface air kerma (ESAK) at different body sites. The mean ESAK and effective doses per procedure were estimated to be 68.75 mGy and 2.74 mSv, respectively. Staff was exposed to a heterogonous doses. The third examiner (trainee) was exposed to a high dose compared with other examiners because no shield was located to protect him from stray radiation. Patients and examiners doses were lower compared to the lowest values found in previous studies taking into consideration the heterogeneity of patients and equipment. Staff doses during ERCP are within the safety limit in the light of the current practice.
PMCID: PMC3622381  PMID: 23589714
2.  Direct measurement of a patient's entrance skin dose during pediatric cardiac catheterization 
Journal of Radiation Research  2014;55(6):1122-1130.
Children with complex congenital heart diseases often require repeated cardiac catheterization; however, children are more radiosensitive than adults. Therefore, radiation-induced carcinogenesis is an important consideration for children who undergo those procedures. We measured entrance skin doses (ESDs) using radio-photoluminescence dosimeter (RPLD) chips during cardiac catheterization for 15 pediatric patients (median age, 1.92 years; males, n = 9; females, n = 6) with cardiac diseases. Four RPLD chips were placed on the patient's posterior and right side of the chest. Correlations between maximum ESD and dose–area products (DAP), total number of frames, total fluoroscopic time, number of cine runs, cumulative dose at the interventional reference point (IRP), body weight, chest thickness, and height were analyzed. The maximum ESD was 80 ± 59 (mean ± standard deviation) mGy. Maximum ESD closely correlated with both DAP (r = 0.78) and cumulative dose at the IRP (r = 0.82). Maximum ESD for coiling and ballooning tended to be higher than that for ablation, balloon atrial septostomy, and diagnostic procedures. In conclusion, we directly measured ESD using RPLD chips and found that maximum ESD could be estimated in real-time using angiographic parameters, such as DAP and cumulative dose at the IRP. Children requiring repeated catheterizations would be exposed to high radiation levels throughout their lives, although treatment influences radiation dose. Therefore, the radiation dose associated with individual cardiac catheterizations should be analyzed, and the effects of radiation throughout the lives of such patients should be followed.
PMCID: PMC4229915  PMID: 24968708
cardiac catheterization; entrance skin dose; pediatric heart disease; dosimetry
3.  Radiation exposure to personnel performing endoscopic retrograde cholangiopancreatography 
Postgraduate Medical Journal  2005;81(960):660-662.
Background: Endoscopic retrograde cholangiopancreatography (ERCP) relies on the use of ionising radiation but risks to operator and patient associated with radiation exposure are unclear. The aim of this prospective study was to estimate the radiation dose received by personnel performing fluoroscopic endoscopic procedures, mainly ERCP.
Methods: Consecutive procedures over a two month period were included. The use of thermoluminescent dosimeters to measure radiation exposure to the abdomen, thyroid gland, and hands of the operator permitted an estimation of the annual whole body effective dose equivalent.
Results: During the study period 66 procedures (61 ERCP) were performed and the estimated annual whole body effective dose equivalent received by consultant operators ranged between 3.35 and 5.87 mSv. These values are similar to those received by patients undergoing barium studies and equate to an estimated additional lifetime fatal cancer risk between 1 in 7000 and 1 in 3500. While within legal safety limits for radiation exposure to personnel, these doses are higher than values deemed acceptable for the general public.
Conclusions: It is suggested that personnel as well as patients may be exposed to significant values of radiation during ERCP. The study emphasises the need to carefully assess the indication for, and to use measures that minimise radiation exposure during any fluoroscopic procedure.
PMCID: PMC1743365  PMID: 16210465
4.  Safety of endoscopic retrograde cholangiopancreatography in pregnancy: Fluoroscopy time and fetal exposure, does it matter? 
AIM: To estimate the fetal radiation exposure using thermoluminescent dosimeters (TLD’s) in pregnant patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) and assess its relevance.
METHODS: Data on thirty-five therapeutic ERCPs conducted in pregnant patients from 2001 to 2009 were retrieved from a prospective database. Techniques to minimize fluoroscopy time were implemented and the fluoroscopy times captured. TLD’s were placed on the mother to estimate the fetal radiation exposure and the results were compared to the maximum allowed dose of radiation to the fetus [0.005 gray (Gy)]. Obstetrics consultations were obtained and the fetus was monitored before and after the ERCP. Fluoroscopy was performed at 75 kVp. ERCP was performed with the patients supine by dedicated biliary endoscopists performing more than 500 cases a year.
RESULTS: A total of 35 pregnant patients underwent ERCP and biliary sphincterotomy (14 in first trimester, 11 in second trimester, and 10 in third trimester). Mean maternal age was 25 years (range 16-37 years) and mean gestational age was 18.9 wk (range 4-35 wk). Mean fluoroscopy time was 0.15 min (range 0-1 min). For 23 women, the estimated fetal radiation exposure was almost negligible (< 0.0001 Gy) while for 8 women, it was within the 0.0001-0.0002 Gy range. Three women had an estimated fetal radiation exposure between 0.0002 and 0.0005 Gy and 1 woman had an estimated fetal radiation exposure greater than 0.0005 Gy. Complications included 2 post-sphincterotomy bleeds, 2 post-ERCP pancreatitis, and 1 fatal acute respiratory distress syndrome. One patient developed cholecystitis 2 d after ERCP.
CONCLUSION: ERCP with modified techniques is safe during pregnancy, and estimating the fetal radiation exposure from the fluoroscopy time or measuring it via TLD’s is unnecessary.
PMCID: PMC3627836  PMID: 23596536
Endoscopic retrograde cholangiopancreatography; Pregnancy; Fluoroscopy; Fetal exposure; Pancreaticobiliary disease
5.  Occupational radiation dose to eyes from endoscopic retrograde cholangiopancreatography procedures in light of the revised eye lens dose limit from the International Commission on Radiological Protection 
The British Journal of Radiology  2013;86(1022):20120289.
Endoscopic retrograde cholangiopancreatography (ERCP) is a common procedure that combines the use of X-ray fluoroscopy and endoscopy for examination of the bile duct. Published data on ERCP doses are limited, including staff eye dose from ERCP. Occupational eye doses are of particular interest now as the International Commission on Radiological Protection (ICRP) has recommended a reduction in the dose limit to the lens of the eye. The aim of this study was to measure occupational eye doses obtained from ERCP procedures.
A new eye lens dosemeter (EYE-D™, Radcard, Krakow, Poland) was used to measure the ERCP eye dose, Hp(3), at two endoscopy departments in Ireland. A review of radiation protection practice at the two facilities was also carried out.
The mean equivalent dose to the lens of the eye of a gastroenterologist is 0.01 mSv per ERCP procedure with an undercouch X-ray tube and 0.09 mSv per ERCP procedure with an overcouch X-ray tube. Staff eye dose normalised to patient kerma area product is also presented.
Staff eye doses in ERCP have the potential to exceed the revised ICRP limit of 20 mSv per annum when an overcouch X-ray tube is used. The EYE-D dosemeter was found to be a convenient method for measuring lens dose. Eye doses in areas outside of radiology departments should be kept under review, particularly in light of the new ICRP eye dose limit.
Advances in knowledge:
Occupational eye lens doses from ERCP procedures have been established using a new commercially available dedicated Hp(3) dosemeter.
PMCID: PMC3608047  PMID: 23385992
6.  Dosimetry during intramedullary nailing of the tibia 
Acta Orthopaedica  2009;80(5):568-572.
Background Intramedullary nailing under fluoroscopic guidance is a common operation. We studied the intraoperative radiation dose received by both the patient and the personnel.
Patients and methods 25 intramedullary nailing procedures of the tibia were studied. All patients suffered from tibial fractures and were treated using the Grosse-Kempf intramedullary nail, with free-hand technique for fixation of the distal screws, under fluoroscopic guidance. The exposure, at selected positions, was recorded using an ion chamber, while the dose area product (DAP) was measured with a DAP meter, attached to the tube head. Thermoluminescent dosimeters (TLDs) were used to derive the occupational dose to the personnel, and also to monitor the surface dose on the gonads of some of the patients.
Results The mean operation time was 101 (48–240) min, with a mean fluoroscopic time of 72 seconds and a mean DAP value of 75 cGy·cm2. The surface dose to the gonads of the patients was less than 8.8 mGy during any procedure, and thus cannot be considered to be a contraindication for the use of this technique. Occupational dose differed substantially between members of the operating personnel, the maximum dose recorded being to the operator of the fluoroscopic equipment (0.11 mSv).
Interpretation Our findings underscore the care required by the primary operator not to exceed the dose constraint of 10 mSv per year. The rest of the operating personnel, although they do not receive very high doses, should focus on the dose optimization of the technique.
PMCID: PMC2823322  PMID: 19916691
7.  A comparison between low-dose and standard-dose non-contrasted multidetector CT scanning of the paranasal sinuses 
To compare the image quality of the low-dose to the standard-dose protocol of MDCT scanning of the paranasal sinuses, based on subjective assessment and determine the radiation doses to the eyes and thyroid gland and dose reduction between these two protocols.
Materials and Methods
31 adult patients were scanned. Prior to scanning, thermoluminescent dosimeters (TLDs) were placed at 4 sites: outer canthus of right eye, outer canthus of left eye, inner canthus and anterior neck (thyroid gland). Every patient was scanned twice using the standard-dose protocol (100mAs) followed by the low-dose protocol (40mAs). The images were reviewed by 3 radiologists. Wilcoxon test was used as the test of significance for the image quality assessments. The paired sample t-test was used as the test of significance for the analysis of the radiation doses measured by the TLDs.
Of the 30 patients selected for analysis, this study showed no significant difference in the scores for the diagnostic image quality and the anatomical structures assessments between the two protocols. The average calculated mean entrance surface doses and standard deviation for the standard-dose and low-dose protocols were 12.40±1.39 mGy and 5.53±0.82 mGy respectively to the lens and 1.03±0.55 mGy and 0.63±0.53 mGy respectively to the thyroid gland.
The reduction of mAs from 100 to 40 resulted in a significant reduction of the radiation doses to the lens and thyroid gland by 55.4% and 38.8% respectively without causing any significant effect to the diagnostic image quality and assessment of the anatomical structures.
PMCID: PMC3097781  PMID: 21611051
CT Paranasal sinuses; Low-dose Protocol; Chronic sinusitis
8.  Evaluation of radiation exposure dose at double-balloon endoscopy for the patients with small bowel disease 
Nagoya Journal of Medical Science  2016;78(3):245-253.
Double-balloon endoscopy (DBE) is useful for the diagnosis and treatment of small bowel diseases. Although fluoroscopy is used to confirm the position of endoscope at DBE, the endoscopist does not have the knowledge with regard to the radiation exposure dose. In this study, we evaluated the absorbed dose during DBE in patients with suspected or established small bowel diseases. This was a retrospective study in which the estimated fluoroscopic radiation absorbed doses loaded on the small bowel and skin were determined according to the data of the referential X-ray experiment with a human body phantom. The subjects were 415 DBEs preformed in total. The mean small bowel absorbed doses on antegrade and retrograde DBEs were 42.2 and 53.8 mGy, respectively, showing that the organ dose applied in retrograde DBE was significantly higher (P<0.0001). The mean skin absorbed doses of them were 79.2 and 101.0 mGy, respectively, showing that the dose was also significantly higher on retrograde DBE (P<0.0001). Of 27 cases who were applied endoscopic balloon dilation, the mean fluoroscopy time was 16.0 minutes, and mean small bowel and skin absorbed doses were 121.9 and 228.9 mGy, respectively. In conclusion, endoscopist should be careful for reducing the organ exposure dose at DBE, particularly for the lower abdominal region.
Abbreviations: Double-balloon enteroscopy (DBE), endoscopic balloon dilation (EBD), endoscopic mucosal resection (EMR), double-balloon endoscopic retrograde cholangiopancreatography (DBERCP), percutaneous coronary intervention (PCI)
PMCID: PMC4995270  PMID: 27578908
double-balloon endoscopy; radiation exposure; endoscopic balloon dilation; small bowel disease
9.  A Survey of Organ Equivalent and Effective Doses from Diagnostic Radiology Procedures 
ISRN Radiology  2012;2013:204346.
The quantification of radiation risks associated with radiological examinations has been a subject of interest with the increased use of X-rays. Effective dose, which is a risk-weighted measure of radiation to organs in the body associated with radiological examination, is considered a good indicator of radiological risk. We have therefore investigated patient effective doses from radiological examinations. Organ and effective doses were estimated for 94 patients who underwent computed tomography examinations and for 338 patients who had conventional radiography examinations. The OrgDose (version 2) program was used for the estimation of effective doses. The tube potential ranges: 57 kVp to 138 kVp depending on the examination and patient size. The entrance surface doses have a wide range even for the same examination: 0.44–10.31 mGy (abdomen) and 0.66–16.08 mGy (lumbar spine) and the corresponding effective dose ranges 0.025–0.77 mSv and 0.025–0.95 mSv respectively. Effective dose for adult abdomen-pelvic CT examinations ranges 5.4–19.8 mSv with a mean of 13.6 mSv and for pediatrics ranges 2.1–5.5 mSv with a mean of 2.7 mSv. The mean effective dose for adult chest and head CT examinations are 7.9 and 1.8 mSv respectively and for pediatrics are 1.7 and 1.1 mSv.
PMCID: PMC4045519  PMID: 24977137
10.  Investigation of patient dose from common radiology examinations in Isfahan, Iran 
The aim of this study was measurement of the radiation doses received by patients for common radiology examinations in hospitals under control of Isfahan University of Medical Sciences, Iran.
Materials and Methods:
Thermoluminescence (lithium fluoride chips, LiF: Mg, Tl) dosimeter was used to measure patient dose for four (chest, posterior-anterior and lateral and skull anterior-posterior, or posterior-anterior and lateral) common radiographic views in six hospitals (seven X-ray machines). The entrance surface dose was measured on 20 randomly patients for each X-ray room.
The maximum (8.85 ± 0.62 mGy) and the minimum (0.62 ± 0.22 mGy) values of ESD was obtained for X-ray machines of Shimadzu and Varian located in Ashrafi-Khomeini-shahr and Kashani hospitals, respectively. As results shows, the values of ESD of skull were higher than that of chest examinations.
The results of this study indicated that ESD measured doses were slightly greater than the ICRP and NRPB reference doses. Efforts should be made to further lower patient doses while securing image quality. In addition, the need to provide relevant education and training to staff in the radiology sections is of utmost importance.
PMCID: PMC3507008  PMID: 23210070
Diagnostic radiology; patient dose; X-ray examinations
11.  Radiation Doses in Consecutive CT Examinations from Five University of California Medical Centers 
Radiology  2015;277(1):134-141.
The purpose of the analysis was to provide summary data on CT dose derived from a large number of consecutive CT examinations that institutions can use as a starting point for evaluating the CT radiation doses they use in their patients.
To summarize data on computed tomographic (CT) radiation doses collected from consecutive CT examinations performed at 12 facilities that can contribute to the creation of reference levels.
Materials and Methods
The study was approved by the institutional review boards of the collaborating institutions and was compliant with HIPAA. Radiation dose metrics were prospectively and electronically collected from 199 656 consecutive CT examinations in 83 181 adults and 3871 consecutive CT examinations in 2609 children at the five University of California medical centers during 2013. The median volume CT dose index (CTDIvol), dose-length product (DLP), and effective dose, along with the interquartile range (IQR), were calculated separately for adults and children and stratified according to anatomic region. Distributions for DLP and effective dose are reported for single-phase examinations, multiphase examinations, and all examinations.
For adults, the median CTDIvol was 50 mGy (IQR, 37–62 mGy) for the head, 12 mGy (IQR, 7–17 mGy) for the chest, and 12 mGy (IQR, 8–17 mGy) for the abdomen. The median DLPs for single-phase, multiphase, and all examinations, respectively, were as follows: head, 880 mGy · cm (IQR, 640–1120 mGy · cm), 1550 mGy · cm (IQR, 1150–2130 mGy · cm), and 960 mGy · cm (IQR, 690–1300 mGy · cm); chest, 420 mGy · cm (IQR, 260–610 mGy · cm), 880 mGy · cm (IQR, 570–1430 mGy · cm), and 550 mGy · cm (IQR 320–830 mGy · cm); and abdomen, 580 mGy · cm (IQR, 360–860 mGy · cm), 1220 mGy · cm (IQR, 850–1790 mGy · cm), and 960 mGy · cm (IQR, 600–1460 mGy · cm). Median effective doses for single-phase, multiphase, and all examinations, respectively, were as follows: head, 2 mSv (IQR, 1–3 mSv), 4 mSv (IQR, 3–8 mSv), and 2 mSv (IQR, 2–3 mSv); chest, 9 mSv (IQR, 5–13 mSv), 18 mSv (IQR, 12–29 mSv), and 11 mSv (IQR, 6–18 mSv); and abdomen, 10 mSv (IQR, 6–16 mSv), 22 mSv (IQR, 15–32 mSv), and 17 mSv (IQR, 11–26 mSv). In general, values for children were approximately 50% those for adults in the head and 25% those for adults in the chest and abdomen.
These summary dose data provide a starting point for institutional evaluation of CT radiation doses.
© RSNA, 2015
PMCID: PMC4613871  PMID: 25988262
12.  Effective and organ doses using helical 4DCT for thoracic and abdominal therapies 
Journal of Radiation Research  2013;54(5):962-970.
The capacity of 4DCT to quantify organ motion is beyond conventional 3DCT capability. Local control could be improved. However we are unaware of any reports of organ dose measurements for helical 4DCT imaging. We therefore quantified the radiation doses for helical 4DCT imaging. Organ and tissue dose was measured for thoracic and abdominal 4DCT in helical mode using an adult anthropomorphic phantom. Radiation doses were measured with thermoluminescence dosimeter chips inserted at various anatomical sites on the phantom. For the helical thoracic 4DCT, organ doses were 57.2 mGy for the lung, 76.7 mGy for the thyroids, 48.1 mGy for the breasts, and 10.86 mGy for the colon. The effective doses for male and female phantoms were very similar, with a mean value of 33.1 mSv. For abdominal 4DCT imaging, organ doses were 14.4 mGy for the lung, 0.78 mGy for the thyroids, 9.83 mGy for breasts, and 58.2 mGy for the colon (all obtained by using ICRP 103). We quantified the radiation exposure for thoracic and abdominal helical 4DCT. The doses for helical 4DCT were approximately 1.5 times higher than those for cine 4DCT, however the stepwise image artifact was reduced. 4DCT imaging should be performed with care in order to minimize radiation exposure, but the advantages of 4DCT imaging mandates its incorporation into routine treatment protocols.
PMCID: PMC3766296  PMID: 23603303
radiation dose; 4DCT; helical; cine; effective dose
13.  Dose evaluation for skin and organ in hepatocellular carcinoma during angiographic procedure 
The purpose of this study is to evaluate the radiation dose in patients undergoing liver angiographic procedure and verify the usefulness of different dose measurements to prevent deterministic effects. Gafchromic film, MicroMOSFET data and DIAMENTOR device of the X-ray system were used to characterize the examined interventional radiology (IR) procedure.
Materials and methods
A liver embolization procedure, the SIRT (Selective Internal Radiation Therapy), was investigated. The exposure parameters from the DIAMENTOR as well as patient and geometrical data were registered. Entrance skin dose map obtained using Gafchromic film (ESDGAF) in a standard phantom as well as in 12 patients were used to calculate the maximum skin dose (MSDGAF). MicroMOSFETs were used to assess ESD in relevant points/areas. Moreover, the maximum value of five MicroMOSFETs array, due to the extension of treated area and to the relative distance of 2–3 cm of two adjacent MicroMOSFETs, was useful to predict the MSD without interfering with the clinical practice. PCXMC vers.1.5 was used to calculate effective dose (E) and equivalent dose (H).
The mean dose-area product (DAPDIAMENTOR) for SIRT procedures was 166 Gycm2, although a wide range was observed. The mean MSDGAF for SIRT procedures was 1090 mGy, although a wide range was experienced. A correlation was found between the MSDGAF measured on a patient and the DAPDIAMENTOR value for liver embolizations. MOSFET and Gafchromic data were in agreement within 5% in homogeneous area and within 20% in high dose gradient regions. The mean equivalent dose in critical organs was 89.8 mSv for kidneys, 22.9 mSv for pancreas, 20.2 mSv for small intestine and 21.0 mSv for spleen. Whereas the mean E was 3.7 mSv (range: 0.5-13.7).
Gafchromic films result useful to study patient exposure and determine localization and amplitude of high dose skin areas to better predict the skin injuries. Then, DAPDIAMENTOR or MOSFET data could offer real-time methods, as on-line dose alert, to avoid any side effects during liver embolization with prolonged duration.
PMCID: PMC3832252  PMID: 24423052
Skin dose measurement; Gafchromic film dosimetry; MOSFET dosimetry; Interventional radiology; Liver embolization
14.  Radiation protection of the ovaries in young scoliosis patients 
European Spine Journal  1998;7(4):278-281.
Concerns in clinical practice arose over the amount of ovarian irradiation received from X-ray examinations in females with scoliosis. This study was instigated to assess the adequancy of ovarian protection in this young and genetically vulnerable group of patients. A total of 283 plain films in 20 patients with scoliosis were reviewed. If the area immediately adjacent to the medial wall of the acetabulum was clearly seen, then this was taken as indicative of ovarian irradiation. In a separate study, the radiation dose in the centre of the X-ray field on the surface of a tissue-equivalent anthropomorphic phantom was measured using thermoluminescent dosimeters. Standard conditions for scoliosis X-ray examination were used. The average age of patients was 21.5 years. The mean number of single X-ray exposures per patient was 14.1 over a mean of 44 months. The mean measured entrance dose to the skin in the 20 patients was 0.08 mGy (equivalent dose = 0.08 mSv). The mean percentage of examinations without lead protection was 18% per patient (range 0–40%). This would have resulted in a mean equivalent dose to the surface of the abdomen of 0.1 mSv per year per patient from the unprotected examinations. The maximum dose received in 1 year was 0.6 mSv. The maximum dose to the unprotected ovary was estimated to be 0.05 mSv from a single examination. The mean total cumulative ovarian dose was calculated as 180 μSv per patient (range 45–355 μSv) over the time period studied. The findings of this study indicate that ovarian protection should be improved. Reasons for this and suggestions for improvement are discussed.
PMCID: PMC3611264  PMID: 9765034
Key words Scoliosis; Radiation; dose; Ovary
15.  Effective and Organ Specific Radiation Doses from Videourodynamics in Children 
The Journal of urology  2013;190(4):1364-1369.
Effective and organ specific doses of ionizing radiation during videourodynamics are unknown. We estimated radiation exposure in children undergoing videourodynamics, and identified patient and examination factors that contribute to higher dosing.
Materials and Methods
Fluoroscopy data were collected from consecutive patients undergoing videourodynamics. Documented dose metrics were used to calculate entrance skin dose after applying a series of correction factors. Effective doses and organ specific doses (ovaries/testes) were estimated from entrance skin dose using Monte Carlo methods on a mathematical anthropomorphic phantom (ages 0, 1, 5, 10 and 15 years). Regression analysis was performed to determine patient and procedural factors associated with higher dosing.
A total of 100 children (45% male, mean ± SD age 9.3 ± 5.7 years) were studied. Diagnoses included neurogenic bladder (73%), anatomical abnormality (14%) and functional/nonneurogenic disorder (13%). Mean fluoroscopy time was 0.17 ± 0.12 minutes. Mean age adjusted entrance skin dose, effective dose, and testis and ovary doses were 2.18 ± 2.00 mGy, 0.07 ± 0.05 mSv, 0.09 ± 0.10 mGy and 0.20 ± 0.13 mGy, respectively. On univariate analysis age, height, weight, body mass index, bladder capacity and fluoroscopy time were associated with effective dose. On multivariate adjusted analysis, body mass index, bladder capacity and fluoroscopy time were independently associated with effective dose.
The average effective dose of ionizing radiation from videourodynamics was less compared to voiding cystourethrogram dose reported in the literature. Greater fluoroscopy time, body mass index and bladder capacity are independently associated with higher dosing.
PMCID: PMC4843507  PMID: 23707437
fluoroscopy; pediatrics; radiation dosage; urodynamics
16.  Occupational Radiation Exposure during Endoscopic Retrograde Cholangiopancreatography and Usefulness of Radiation Protective Curtains 
Objective. To evaluate the effectiveness of radiation protective curtains in reducing the occupational radiation exposure of medical personnel. Methods. We studied medical staff members who had assisted in 80 consecutive therapeutic endoscopic retrograde cholangiopancreatography (ERCP) procedures. Use of radiation protective curtains mounted to the X-ray tube was determined randomly for each procedure, and radiation doses were measured with electronic pocket dosimeters placed outside the protective apron. Results. When protective curtains were not used, the mean radiation doses to endoscopists, first assistants, second assistants, and nurses were 340.9, 27.5, 45.3, and 33.1 µSv, respectively; doses decreased to 42.6, 4.2, 13.1, and 10.6 µSv, respectively, when protective curtains were used (P < 0.01). When the patient had to be restrained during ERCP (n = 8), the radiation dose to second assistants without protective curtains increased by a factor of 9.95 (P < 0.01) relative to cases in which restraint was not required. Conclusions. During ERCP, not only endoscopists, but also assistants and nurses were exposed to high doses of radiation. Radiation exposure to staff members during ERCP was reduced with the use of protective curtains.
PMCID: PMC4247933  PMID: 25477956
17.  Radiation exposure and safety practices during pediatric central line placement 
Journal of pediatric surgery  2015;50(6):992-995.
Pediatric surgeons routinely use fluoroscopy for central venous line (CVL) placement. We examined radiation safety practices and patient/surgeon exposure during fluoroscopic CVL.
Fluoroscopic CVL procedures performed by 11 pediatric surgeons in 2012 were reviewed. Fluoroscopic time (FT), patient exposure (mGy), and procedural data were collected. Anthropomorphic phantom simulations were used to calculate scatter and dose (mSv). Surgeons were surveyed regarding safety practices.
386 procedures were reviewed. Median FT was 12.8 seconds. Median patient estimated effective dose was 0.13 mSv. Median annual FT per surgeon was 15.4 minutes. Simulations showed no significant difference (p = 0.14) between reported exposures (median 3.5 mGy/min) and the modeled regression exposures from the C-arm default mode (median 3.4 mGy/min). Median calculated surgeon exposure was 1.5 mGy/year. Eight of 11 surgeons responded to the survey. Only three reported 100% lead protection and frequent dosimeter use.
We found non-standard radiation training, safety practices, and dose monitoring for the 11 surgeons. Based on simulations, the C-arm default setting was typically used instead of low dose. While most CVL procedures have low patient/surgeon doses, every effort should be used to minimize patient and occupational exposure, suggesting the need for formal hands-on training for non-radiologist providers using fluoroscopy.
PMCID: PMC4439316  PMID: 25837269
Radiation Dose; Fluoroscopy; Pediatric; Occupational Exposure
Health physics  2012;103(1):80-99.
In the past 30 years, the numbers and types of fluoroscopically-guided (FG) procedures have increased dramatically. The objective of the present study is to provide estimated radiation doses to physician specialists, other than cardiologists, who perform FG procedures. We searched Medline to identify English-language journal articles reporting radiation exposures to these physicians. We then identified several primarily therapeutic FG procedures that met specific criteria: well-defined procedures for which there were at least five published reports of estimated radiation doses to the operator, procedures performed frequently in current medical practice, and inclusion of physicians from multiple medical specialties. These procedures were percutaneous nephrolithotomy (PCNL), vertebroplasty, orthopedic extremity nailing for treatment of fractures, biliary tract procedures, transjugular intrahepatic portosystemic shunt creation (TIPS), head/neck endovascular therapeutic procedures, and endoscopic retrograde cholangiopancreatography (ERCP). We abstracted radiation doses and other associated data, and estimated effective dose to operators. Operators received estimated doses per patient procedure equivalent to doses received by interventional cardiologists. The estimated effective dose per case ranged from 1.7 – 56μSv for PCNL, 0.1 – 101 μSv for vertebroplasty, 2.5 – 88μSv for orthopedic extremity nailing, 2.0 – 46μSv for biliary tract procedures, 2.5 – 74μSv for TIPS, 1.8 – 53μSv for head/neck endovascular therapeutic procedures, and 0.2 – 49μSv for ERCP. Overall, mean operator radiation dose per case measured over personal protective devices at different anatomic sites on the head and body ranged from 19 – 800 (median = 113) μSv at eye level, 6 – 1180 (median = 75)μSv at the neck, and 2 – 1600 (median = 302) μSv at the trunk. Operators’ hands often received greater doses than the eyes, neck or trunk. Large variations in operator doses suggest that optimizing procedure protocols and proper use of protective devices and shields might reduce occupational radiation dose substantially.
PMCID: PMC3951010  PMID: 22647920
interventional procedure; fluoroscopically-guided procedure; occupational exposure; radiation protection
19.  Severe Obesity is Associated With 3-Fold Higher Radiation Dose Rate During Ureteroscopy 
Urology  2013;82(4):780-785.
To investigate and characterize the association between fluoroscopy radiation dose rate and various patient size metrics during ureteroscopy.
Fluoroscopy data were collected from 100 patients undergoing ureteroscopy for stone disease. Radiation dose rates were determined from fluoroscopy dose and time. Estimated entrance skin dose was calculated from air kerma (AK) by applying correction factors. Effective dose (ED) was estimated with Monte Carlo–based simulation software. Patient size metrics included body mass index (BMI), anterior-posterior (AP) midline distance, AP transrenal thickness, and region of interest (ROI) pixel value magnitude on computed tomography scout. Univariate and multivariate regression analyses were performed to determine the association between AK dose rate and patient size metrics, adjusting for laterality and stone location.
Obese patients (>30 kg/m2) comprised 46% of the cohort. Mean fluoroscopy time, displayed AK, entrance skin dose, and ED were 4.2 ± 6.0 second, 1.2 ± 2.1 mGy, 1.2 ± 2.2 mGy, and 0.08 ± 0.15 mSv, respectively. Mean AK dose rate and ED dose rates were 0.30 ± 0.23 mGy/second and 0.021 ± 0.016 mSv/second, respectively. Compared with the nonobese category, the highest BMI category (≥35 kg/m2) had over a 3-fold higher mean AK rate (0.50 vs 0.16 mGy/second). On univariate and multivariate analysis, BMI, AP midline distance, AP transrenal thickness, and computed tomography scout region of interest pixel value magnitude were each significantly associated with dose rate.
Larger patients experience higher radiation dose rates under fluoroscopy. Severely obese patients receive 3-fold higher dose rates compared with nonobese patients. Given the higher incidence of stone disease in obese patients, all attempts should be made to minimize radiation exposure during ureteroscopy.
PMCID: PMC4843513  PMID: 23958504
20.  Dosimetric evaluation of X-ray examinations of paranasal sinuses in pediatric patients* 
Radiologia Brasileira  2016;49(2):79-85.
To estimate the entrance surface air kerma (Ka,e) and air kerma in the region of radiosensitive organs in radiographs of pediatric paranasal sinuses.
Materials and Methods
Patient data and irradiation parameters were collected in examinations of the paranasal sinuses in children from 0 to 15 years of age at two children's hospitals in the city of Recife, PE, Brazil. We estimated the Ka,e using the X-ray tube outputs and selected parameters. To estimate the air kerma values in the regions of the eyes and thyroid, we used thermoluminescent dosimeters.
The Ka,e values ranged from 0.065 to 1.446 mGy in cavum radiographs, from 0.104 to 7.298 mGy in Caldwell views, and from 0.113 to 7.824 mGy in Waters views. Air kerma values in the region of the eyes ranged from 0.001 to 0.968 mGy in cavum radiographs and from 0.011 to 0.422 mGy in Caldwell and Waters views . In the thyroid region, air kerma values ranged from 0.005 to 0.932 mGy in cavum radiographs and from 0.002 to 0.972 mGy in Caldwell and Waters views.
The radiation levels used at the institutions under study were higher than those recommended in international protocols. We recommend that interventions be initiated in order to reduce patient exposure to radiation and therefore the risks associated with radiological examination of the paranasal sinuses.
PMCID: PMC4851475  PMID: 27141129
Dosimetria; Radiografia; Seios paranasais; Pediatria; Dosimetria termoluminescente
21.  Measurement of Entrance Skin Dose and Calculation of Effective Dose for Common Diagnostic X-Ray Examinations in Kashan, Iran 
Global Journal of Health Science  2015;7(5):202-207.
The knowledge of the radiation dose received by the patient during the radiological examination is essential to prevent risks of exposures. The aim of this work is to study patient doses for common diagnostic radiographic examinations in hospitals affiliated to Kashan University of Medical sciences, Iran. The results of this survey are compared with those published by some national and international values. Entrance surface dose (ESD) was measured based on the exposure parameters used for the actual examination and effective dose (ED) was calculated by use of conversion coefficients calculated by Monte Carlo methods. The mean entrance surface dose and effective dose for examinations of the chest (PA, Lat), abdomen (AP), pelvis (AP), lumbar spine (AP, Lat) and skull (AP, Lat) are 0.37, 0.99, 2.01, 1.76, 2.18, 5.36, 1.39 and 1.01 mGy, and 0.04, 0.1, 0.28, 0,28, 0.23, 0.13, 0.01 and 0.01 mSv, respectively. The ESDs and EDs reported in this study, except for examinations of the chest, are generally lower than comparable reference dose values published in the literature. On the basis of the results obtained in this study can conclude that use of newer equipment and use of the proper radiological parameter can significantly reduce the absorbed dose. It is recommended that radiological parameter in chest examinations be revised.
PMCID: PMC4803878  PMID: 26156930
entrance skin dose; effective dose; common diagnostic x-ray examination
22.  Practical dosimetry methods for the determination of effective skin and breast dose for a modern CT system, incorporating partial irradiation and prospective cardiac gating 
The British Journal of Radiology  2012;85(1011):237-248.
For CT coronary angiography (CTCA), a generic chest conversion factor returns a significant underestimate of effective dose. The aim of this manuscript is to communicate new dosimetry methods to calculate weighted CT dose index (CTDIw), effective dose, entrance surface dose (ESD) and organ dose to the breast for prospectively gated CTCA.
CTDIw in 32 cm diameter Perspex phantom was measured using an adapted technique, accounting for the segmented scan characteristic. Gafchromic XRCT film (International Speciality Products, New Jersey, NJ) was used to measure the distribution and magnitude of ESD. Breast dose was measured using high sensitivity metal oxide semiconductor field-effect transistors and compared to the computer based imaging performance assessment of CT scanners (ImPACT) dosimetry calculations.
For a typical cardiac scan the mean ESD remained broadly constant (7–9 mGy) when averaged over the circumference of the Perspex phantom. Typical absorbed dose to the breast with prospectively gated protocols was within the range 2–15 mGy. The subsequent lifetime attributable risk (LAR) of cancer incidence to the breast was found at 0.01–0.06 for a 20-year-old female. This compares favourably to 100 mGy (LAR ∼0.43) for a retrospectively gated CTCA.
Care must be taken when considering radiation dosimetry associated with prospectively gated scanning for CTCA and a method has been conveyed to account for this. Breast doses for prospectively gated CTCA are an order of magnitude lower than retrospectively gated scans. Optimisation of cardiac protocols is expected to show further dose reduction.
PMCID: PMC3473996  PMID: 21896660
23.  Prospective Measurement of Patient Exposure to Radiation During Pediatric Ureteroscopy 
The Journal of urology  2012;187(4):10.1016/j.juro.2011.12.013.
Little data have been reported regarding radiation exposure during pediatric endourologic procedures, including ureteroscopy (URS). We sought to measure radiation exposure during pediatric URS and identify opportunities for exposure reduction.
We prospectively observed URS procedures as part of a quality improvement initiative. Pre-operative patient characteristics, operative factors, fluoroscopy settings and radiation exposure were recorded. Our outcomes were entrance skin dose (ESD, in mGy) and midline dose (MLD, in mGy). Specific modifiable factors were identified as targets for potential quality improvement.
Direct observation was performed on 56 consecutive URS procedures. Mean patient age was 14.8 ± 3.8 years (range 7.4 to 19.2); 9 children were under age 12 years. Mean ESD was 46.4 ± 48 mGy. Mean MLD was 6.2 ± 5.0 mGy. The most important major determinant of radiation dose was total fluoroscopy time (mean 2.68 ± 1.8 min) followed by dose rate setting, child anterior-posterior (AP) diameter, and source to skin distance (all p<0.01). The analysis of factors affecting exposure levels found that the use of ureteral access sheaths (p=0.01) and retrograde pyelography (p=0.04) were significantly associated with fluoroscopy time. We also found that dose rate settings were higher than recommended in up to 43% of cases and ideal C-arm positioning could have reduced exposure 14% (up to 49% in some cases).
Children receive biologically significant radiation doses during URS procedures. Several modifiable factors contribute to dose and could be targeted in efforts to implement dose reduction strategies.
PMCID: PMC3810162  PMID: 22341275
Nephrolithiasis; Pediatrics; Kidney; Stone; Urolithiasis
24.  Surgeon Radiation Exposure in Hip Arthroscopy 
Orthopaedic Journal of Sports Medicine  2015;3(7 suppl2):2325967115S00142.
Hip arthroscopy is an established field within orthopaedic surgery. The majority of the procedures involve repairs of the acetabular labrum and arthroscopic treatment of femoroacetabular impingement (FAI). The procedures are being performed with increasing frequency annually. Fluoroscopic guidance is recommended during these procedures, and radiation exposure to the surgeon, staff, and patient remains a valid concern. The purpose of this study is to measure radiation exposure to the surgeon during hip arthroscopy and determine if this exposure remains below recommended annual occupational radiation exposure thresholds recommended by the International Committee on Radiological Protection (IRCP).
Prospectively, radiation exposure was measured for a single surgeon at a single outpatient facility for all hip arthroscopic procedures over a three-year period. A radiation dosimeter was worn outside of the surgeon's chest on the lead apron. Standard pre-operative and intra-operative imaging was used for all patients. Radiation readings were prospectively measured for deep dose equivalent (DDE), lens dose equivalent (LDE), and shallow dose equivalent (SDE). The cumulative radiation exposure was tabulated in millirem (mrem), converted to milli-Sieverts (mSv) (standard measurement used by the IRCP) and then the per-patient exposure calculated as well as annual exposure for 100 hip arthroscopies per year.
Between July 2011 and July 2014, 209 patients underwent a total of 280 hip arthroscopy procedures at a single facility by a single surgeon. There were 90 labral repairs, 83 femoroplasties, 26 acetabuloplasties, 66 labral debridements, 8 trochanteric bursectomies, and 7 iliopsoas releases. The cumulative DDE was 183 mrem (1.83 mSv), LDE 183 mrem (1.83 mSv), and SDE 176 mrem (1.76 mSv). The calculated per patient exposure for the surgeon was DDE 0.875 mrem (0.00875 mSv), LDE 0.875 mrem (0.00875 mSv), and SDE 0.842 mrem (0.00843 mSv). Calculated annual exposure for a surgeon performing 100 hip arthroscopies per year are DDE 8.75 mrem (0.0875 mSv), LDE 8.75 mrem (0.0875 mSv), and SDE 8.43 mrem (0.0842 mSv).
Hip arthroscopy & hip preservation procedures are being performed with increasing frequency annually. Fluoroscopic guidance is recommended for safe entrance into the central compartment and during various parts of the procedures. Radiation exposure to the surgeon, staff, and patient is a valid concern. The IRCP sets recommended annual safety thresholds for occupational radiation exposure. Current annual safety thresholds are 50,000 mrem (500 mSv) to the hands, 50,000 mrem (500 mSv) to the skin, hands & feet, 15,000 mrem (150 mSv) to the eye, and 30,000 mrem (300 mSv) to the thyroid of healthcare workers. Our study shows surgeon radiation exposure below the annual safety thresholds recommended by the IRCP for 100 cases per year. For surgeons performing more than 100 hip arthroscopic procedures annually, the exposure will be higher. Appropriate safety equipment such as lead aprons, thyroid shields, and leaded glasses are still recommended, especially for high volume hip arthroscopists.
PMCID: PMC4901706
25.  Coronary CTA using scout-based automated tube potential and current selection algorithm, with breast displacement results in lower radiation exposure in females compared to males 
To evaluate the effect of automatic tube potential selection and automatic exposure control combined with female breast displacement during coronary computed tomography angiography (CCTA) on radiation exposure in women versus men of the same body size.
Materials and methods
Consecutive clinical exams between January 2012 and July 2013 at an academic medical center were retrospectively analyzed. All examinations were performed using ECG-gating, automated tube potential, and tube current selection algorithm (APS-AEC) with breast displacement in females. Cohorts were stratified by sex and standard World Health Organization body mass index (BMI) ranges. CT dose index volume (CTDIvol), dose length product (DLP) median effective dose (ED), and size specific dose estimate (SSDE) were recorded. Univariable and multivariable regression analyses were performed to evaluate the effect of gender on radiation exposure per BMI.
A total of 726 exams were included, 343 (47%) were females; mean BMI was similar by gender (28.6±6.9 kg/m2 females vs. 29.2±6.3 kg/m2 males; P=0.168). Median ED was 2.3 mSv (1.4-5.2) for females and 3.6 (2.5-5.9) for males (P<0.001). Females were exposed to less radiation by a difference in median ED of –1.3 mSv, CTDIvol –4.1 mGy, and SSDE –6.8 mGy (all P<0.001). After adjusting for BMI, patient characteristics, and gating mode, females exposure was lower by a median ED of –0.7 mSv, CTDIvol –2.3 mGy, and SSDE –3.15 mGy, respectively (all P<0.01).
Conclusions: We observed a difference in radiation exposure to patients undergoing CCTA with the combined use of AEC-APS and breast displacement in female patients as compared to their BMI-matched male counterparts, with female patients receiving one third less exposure.
PMCID: PMC4278037  PMID: 25610804
Coronary computed tomography angiography (CCTA); female; breast displacement; radiation exposure

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