Although many interventions involving radiation exposure have been replaced to endoscopic procedure in the gastrointestinal and hepatobiliary fields, there remains no alternative for enteroscopy and endoscopic retrograde cholangiopancreatography (ERCP), which requires the use of radiation. In this review, we discuss the radiation doses and protective measures of endoscopic procedures, especially for ERCP. For the patient radiation dose, the average dose area product for diagnostic ERCP was 14-26 Gy.cm², while it increased to as high as 67-89 Gy.cm² for therapeutic ERCP. The corresponding entrance skin doses for diagnostic and therapeutic ERCP were 90 and 250 mGy, respectively. The mean effective doses were 3- 6 mSv for diagnostic ERCP and 12-20 mSv for therapeutic ERCP. For the occupational radiation dose, the typical doses were 94 μGy and 75 μGy for the eye and neck, respectively. However, with an over-couch-type X-ray unit, the eye and neck doses reached as high as 550 and 450 μGy, with maximal doses of up to 2.8 and 2.4 mGy/procedure, respectively.A protective lead shield was effective for an over couch X-ray tube unit. It lowered scattered radiation by up to 89.1% in a phantom study. In actual measurements, the radiation exposure of the endoscopist closest to the unit was reduced to approximately 12%. In conclusion, there is a clear need for raising awareness among medical personnel involved endoscopic procedures to minimise radiation risks to both the patients and staff.

Endoscopic retrograde cholangiopancreatography (ERCP) is one of the most frequently used image-guided procedures in gastrointestinal endoscopy. Post-ERCP pancreatitis is an important concern, and prophylaxis, cannulation and other related technical procedures have been well documented by endoscopists. In addition, medical radiation exposure is of great concern in the general population because of its rapidly increasing frequency and its potential carcinogenic effects. International organizations and radiological societies have established diagnostic reference levels, which guide proper radiation use and serve as global standards for all procedures that use ionizing radiation. However, data on gastrointestinal fluoroscopic procedures are still lacking because the demand for these procedures has recently increased. In this review, we present the current status of quality indicators for ERCP and the methods for measuring radiation exposure in the clinical setting as the next quality indicator for ERCP. To reduce radiation exposure, knowledge of its adverse effects and the procedures for proper measurement and protection are essential. Additionally, further studies on the factors that affect radiation exposure, exposure management and diagnostic reference levels are necessary. Then, we can discuss how to manage medical radiation use in these complex fluoroscopic procedures. This knowledge will help us to protect not only patients but also endoscopists and medical staff in the fluoroscopy unit.

Endoscopic retrograde cholangiopancreatography (ERCP) is performed for various diseases. The aim of this study is to evaluate the difference of dose-area product (DAP) during the ERCP procedures according to location of the lesion. We performed a retrospective study of consecutive 217 therapeutic ERCP examinations performed between November 2014 and April 2015 at a tertiary care center. ERCP procedures divided into two groups according to location of the lesion identified on imaging: lesions in the common hepatic duct (CHD) or the common bile duct (CBD) and lesions in the hepatic hilum or the intrahepatic duct (IHD). The mean DAP of the hilum-IHD group (48.7 Gy cm2) was significantly higher than that of the CBD-CHD group (34.9 Gy cm2) (P = 0.003). Radiation exposure during ERCP was significantly different according to location of bile duct lesion.

The aim of this study was to assess the radiation burden imparted to patients from contrast-based X-ray fluoroscopy procedures in Tanzania. The effective doses (EDs) to patients from five contrast-based fluoroscopy procedures were obtained from four hospitals. The ED was estimated using the knowledge of the patient characteristics, patient-related exposure parameters, measurements of air kerma area product and PCXCM software. The median EDs for the barium swallow (BS), barium meal (BM), barium enema (BE), hysterosalpingography (HSG) and retrograde urethrography (RUG) were 0.50, 1.43, 2.83, 0.65 and 0.59 mSv, respectively. The median ED per hospital for the BS and BM procedures varied by factors of up to 9.9 and 4.2, respectively, while for the BE, HSG and RUG varied by factors of up to 2.3, 2.4 and 4.3, respectively. The overall differences between individual EDs across the four hospitals varied by factors of up to 53, 58.9 and 11.4 for the BS, BM and BE, respectively, while for the HSG and RUG differed by factors of up to 22 and 46.7, respectively. The mean EDs in this study were mostly lower than reported values from Spain, the UK, Ghana and Greece, while slightly higher than those reported from India. The observed wide variations of procedural protocols and patient doses within and across the hospitals; and the observed high patient doses in this study relative to those from the literature call for the need to standardize procedural protocols and optimize contrast-based fluoroscopy procedures.

Fluoroscopy during endoscopic retrograde cholangiopancreatography (ERCP) has a logarithmic relationship with radiation exposure, and carries a known risk of radiation exposure to patients and staff. Factors associated with prolonged fluoroscopy duration have not been well delineated.

To determine the specific patient, physician and procedural factors that affect fluoroscopy duration.

A retrospective analysis of 1071 ERCPs performed at two tertiary care referral hospitals over an 18-month period was conducted. Patient, physician and procedural variables were recorded at the time of the procedure.

The mean duration of 969 fluoroscopy procedures was 4.66 min (95% CI 4.38 to 4.93). Multivariable analysis showed that the specific patient factors associated with prolonged fluoroscopy duration included age and diagnosis (both P<0.0001). The endoscopist was found to play an important role in the duration of fluoroscopy (ie, all endoscopists studied had a mean fluoroscopy duration significantly different from the reference endoscopist). In addition, the following procedural variables were found to be significant: number of procedures, basket use, biopsies, papillotomy (all P<0.0001) and use of a tritome (P=0.004). Mean fluoroscopy duration (in minutes) with 95% CIs for different diagnoses were as follows: common bile duct stones (n=443) 5.12 (3.05 to 4.07); benign biliary strictures (n=135) 3.94 (3.26 to 4.63); malignant biliary strictures (n=124) 5.82 (4.80 to 6.85); chronic pancreatitis (n=49) 4.53 (3.44 to 5.63); bile leak (n=26) 3.67 (2.23 to 5.09); and ampullary mass (n=11) 3.88 (1.28 to 6.48). When no pathology was found (n=195), the mean fluoroscopy time was 3.56 min (95% CI 3.05 to 4.07). Comparison using t tests determined that the only two diagnoses for which fluoroscopy duration was significantly different from the reference diagnosis of 'no pathology found' were common bile duct stones (P<0.0001) and malignant strictures (P<0.0001).

Factors that significantly affected fluoroscopy duration included age, diagnosis, endoscopist, and the number and nature of procedures performed. Elderly patients with biliary stones or a malignant stricture were likely to require the longest duration of fluoroscopy. These identified variables may help endoscopists predict which procedures are associated with prolonged fluoroscopy duration so that appropriate precautions can be undertaken.

The aim of this study was to propose local diagnostic reference levels (DRL) for exposure to radiation during diagnostic procedures and neuroradiological interventions such as cerebral angiography and embolisation of cerebral aneurysms (intra-cranial aneurysms and arteriovenous malformations). Hospitals should adopt the national DRLs for use locally or establish their own DRLs based on local practice, if sufficient local data are available. For this purpose we studied a sample of 113 cerebral angiography procedures and 82 embolisations of cerebral aneurysms. The data recorded included the kerma-area product (KAP), the fluoroscopy time and the number of frames for each procedure: third quartiles from the total dosimetric databank were calculated and proposed as provisional local DRL. Since the complexity of a procedure must be taken into account when evaluating the radiation dose, in the case of embolisation of aneurysms (intra-cranial), in this initial phase we assessed whether the complexity of the embolisation procedure is related to the size of the aneurysm and/or its site. We, therefore, re-calculated the DRL for only intra-cranial aneurysms, leaving aside the arteriovenous malformations. Considering that the DRL calculated for all the therapeutic procedures are similar to those calculated considering only intra-cranial aneurysms, at the moment we propose, besides the DRL for cerebral angiography, a single DRL for all interventional procedures, even when the clinical pictures are very different. Local preliminary DRLs were proposed as follows: 180 Gy cm(2), 12 min and 317 frames for cerebral angiography and 487 Gy cm(2), 46 min and 717 frames for interventional procedures (intra-cranial aneurysms and arteriovenous malformations).

Fluoroscopy during ERCP has a linear relationship with radiation, carrying risk of exposure.

To determine patient, physician, and procedural factors affecting fluoroscopy duration.

Prospective analysis of ERCPs with evaluation of patient, physician, and procedural variables.

Two tertiary-care hospitals.

Consecutive patients undergoing ERCP.

ERCP.

Variables associated with prolonged fluoroscopy duration.

Mean fluoroscopy time (388 ERCPs) was 6.77 minutes (95% CI, 6.15-7.39). No patient factors were found to significantly affect fluoroscopy duration. Fluoroscopy duration was significantly lower for 2 endoscopists compared with the reference endoscopist (average of 4.16 minutes less; 95% CI, -5.48 to -2.48). Multivariable analysis identified variables associated with longer fluoroscopy duration; stent insertion (+3.11 minutes; 95% CI, 1.91-4.30), lithotripsy (+5.74 minutes; 95% CI, 0.931-10.5), needle-knife sphincterotomy (+4.44 minutes; 95% CI, 2.20-6.67), biopsies (+2.11 minutes; 95% CI, 0.025-4.18), use of a guidewire (+1.55 minutes; 95% CI, 0.025-3.07), additional guidewires (+5.61 minutes; 95% CI, 2.69-8.51), and balloon catheter (+4.27 minutes; 95% CI, 3.00-5.53). Mean fluoroscopy duration when a gastroenterology fellow was involved (n = 318) was 7.05 minutes (95% CI, 6.35-7.76) compared with 5.44 minutes (95% CI, 4.26-6.63) when no fellow present (n = 70) (P < .0451).

Only 2 centers; others may have different results. Not blinded; investigators may change their practice because fluoroscopy was duration studied. Irrelevance of measuring fluoroscopy duration because endoscopists using protection may not have increased radiation exposure.

In this prospective analysis, factors associated with fluoroscopy duration included endoscopists; stent insertion; lithotripsy; biopsies; use of a needle-knife, guidewire, and balloon catheter; and involvement of a gastroenterology fellow. These identified variables may help endoscopists predict which procedures are associated with prolonged fluoroscopy duration and may lead to appropriate precautions.

The purpose of the present work was to optimise the filtration and dose setting for double-contrast barium enema examinations using a Philips MultiDiagnost Eleva FD system. A phantom study was performed prior to a patient study. A CDRAD phantom was used in a study where copper and aluminium filtration, different detector doses and tube potentials were examined. The image quality was evaluated using the software CDRAD Analyser and the phantom dose was determined using the Monte Carlo-based software PCXMC. The original setting [100 % detector dose (660 nGy air kerma) and a total filtration of 3.5 mm Al, at 81 kVp] and two other settings identified by the phantom study (100 % detector dose and additional filtration of 1 mm Al and 0.2 mm Cu as well as 80 % detector dose and added filtration of 1 mm Al and 0.2 mm Cu) were included in the patient study. The patient study included 60 patients and up to 8 images from each patient. Six radiologists performed a visual grading characteristics study to evaluate the image quality. A four-step scale was used to judge the fulfillment of three image quality criteria. No overall statistical significant difference in image quality was found between the three settings (P > 0.05). The decrease in the effective dose for the settings in the patient study was 15 % when filtration was added and 34 % when both filtrations was added and detector dose was reduced. The study indicates that additional filtration of 1 mm Al and 0.2 mm Cu and a decrease in detector dose by 20 % from the original setting can be used in colon examinations with Philips MultiDiagnost Eleva FD to reduce the patient dose by 30 % without significantly affecting the image quality. For 20 exposures, this corresponds to a decrease in the effective dose from 1.6 to 1.1 mSv.

The aim of this study was to measure patient and staff doses simultaneously for some complex x-ray examinations. Measurements of dose-area product (DAP) and entrance skin dose (ESD) were carried out in a sample of 107 adult patients who underwent different x-ray examinations such as double contrast barium enema (DCBE), single contrast barium enema (SCBE), barium swallow, endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC), and various orthopaedic surgical procedures. Dose measurements were made separately for each projection, and DAP, thermoluminescent dosimetry (TLD), film dosimetry and tube output measurement techniques were used. Staff doses were measured simultaneously with patient doses for these examinations, with the exception of barium procedures. The measured mean DAP values were found to be 8.33, 90.24, 79.96 Gy cm(2) for barium swallow, SCBE and DCBE procedures with the fluoroscopy times of 3.1, 4.43 and 5.86 min, respectively. The calculated mean DAP was 26.33 Gy cm(2) for diagnostic and 89.76 Gy cm(2) therapeutic ERCP examinations with the average fluoroscopy times of 1.9 and 5.06 min respectively. Similarly, the calculated mean DAP was 97.53 Gy cm(2) with a corresponding fluoroscopy time of 6.1 min for PTC studies. The calculated mean entrance skin dose (ESD) was 172 mGy for the orthopaedic surgical studies. Maximum skin doses were measured as 324, 891, 1218, 750, 819 and 1397 mGy for barium swallow, SCBE, DCBE, ERCP, PTC and orthopaedic surgical procedures, respectively. The high number of radiographs taken during barium enema examinations, and the high x-ray outputs of the fluoroscopic units used in ERCP, were the main reasons for high doses, and some corrective actions were immediately taken.

The purpose of this study was to measure the effective dose during abdominal three-dimensional imaging obtained with an angiography unit with a digital flat-panel system on a phantom and to determine dose-area product (DAP)-to-effective dose conversion factors. DAPs and effective doses were evaluated for 163-cm-tall human-shaped phantoms with estimated body weights of 54, 64, and 77 kg, and the effective doses were 2.1, 3.2, and 4.2 mSv, respectively. The DAP-to-effective dose conversion factors were 0.28-0.29 mSv x Gy(-1) x cm(-2). In conclusion, the DAPs were useful for estimating the effective dose during abdominal three-dimensional angiographic imaging.

The purpose of our study was to compare organ and effective doses for small-bowel follow-through (SBFT) and abdominopelvic MDCT in adults with Crohn's disease, to retrospectively evaluate the number of radiographic examinations performed for Crohn's disease indications, and to identify those patients undergoing serial examinations to better delineate the use of radiology in the diagnosis and clinical management of Crohn's disease.

Using an anthropomorphic phantom and metal-oxide semiconductor field-effect transistor (MOSFET) dosimeters, specific organ doses were measured for 5 minutes of continuous fluoroscopy (kVp, 120; mA, 0.6) of each of the following: right lower quadrant, central abdomen, and pelvis. Effective doses were determined based on International Commission on Radiological Protection (ICRP) 60 weighting factors. Organ and effective doses were determined for abdominal and pelvic 16-MDCT: detector configuration, 16 x 0.625 mm; pitch, 1.75; 17.5 mm per rotation; rotation time, 0.5 second; 140 kVp; 340 mA. Electronic records were reviewed to determine the number of patients imaged for Crohn's disease indications and the number of studies per patient.

The highest fluoroscopic organ doses were as follows: in the right lower quadrant, right kidney (0.78 cGy) and marrow (0.66 cGy); in the central abdomen, kidneys (1.5 and 1.6 cGy) and marrow (0.76 cGy); and in the pelvis, marrow (0.67-0.95 cGy). Effective doses for the right lower quadrant, central abdomen, and pelvis were 1.37, 2.02, and 3.83 mSv, respectively. For MDCT, the highest organ doses were to the liver (2.95-3.33 cGy). The effective dose for abdominopelvic MDCT was 16.1 mSv. Three hundred seventy-three patients underwent imaging for Crohn's disease. The average number of SBFT and CT examinations was 1.8 and 2.3, respectively. Thirty-four (9%) of 373 patients underwent more than five CT examinations and 11 (3%) had more than 10.

Organ and effective doses are up to five times higher with MDCT than with SBFT. Crohn's disease is more frequently imaged with CT. For a subset of patients who undergo numerous CT examinations, efforts should be made to minimize the number of CT examinations, decrease the CT dose, or consider MR enterography.

The effective dose (E) was created to provide a dose quantity that was related to the probability of health detriment due to stochastic effects from exposure to low doses of ionizing radiation. E is derived from the weighted sum of doses to tissues that are known to be sensitive to radiation and so can only be derived by calculation. The tissue weighting factors are derived from the extrapolation of epidemiological evidence. E was intended for use in radiation protection, but has found wide application in evaluation of doses for medical exposures involving only parts of the body. More reliance is often placed on E values and risk estimates based on E than the evidence on which it is based can justify. In this paper, the uncertainties in the estimated values of E for a reference patient and the associated risk coefficients are reviewed in order to provide an indication of how much reliance can be placed on E as an indicator of risk for patients. The relative uncertainty in estimated values of E for medical exposures for a reference patient is seen to be about +/-40%. The estimated risk of cancer may be a factor of three higher or lower when applied to a reference patient, and will be more variable when applied to an individual. A set of recommendations relating to the use of E and description of risk for medical exposures is proposed.

Measures should be used to limit radiation exposure of the staff and patients during ERCP.

To determine whether "time-limited fluoroscopy" reduces radiation exposure and fluoroscopy time (FT) compared with continuous fluoroscopy.

Prospective randomized trial.

Tertiary academic medical center.

Consecutive adult patients presenting for ERCP.

Subjects were randomized into 2 fluoroscopy setting groups: (1) time-limited, where x-ray exposure is limited to 3 seconds each time the foot-operated switch is depressed; (2) continuous, where x-ray exposure continues for as long as the switch is depressed.

FT, patient, and procedure-related data were recorded. Radiation dosimetry badges were used to estimate cumulative exposure.

Ninety-nine procedures were performed in the time-limited group and 100 by using continuous fluoroscopy. The mean FT for time-limited fluoroscopy was 284.4 seconds (95% confidence interval [CI] 247.1-321.6) and for continuous fluoroscopy was 314 seconds (95% CI 265.6-362.4; P=.34). Longer FT was associated with moderate or difficult cannulation (P=.008), lithotripsy (P<.001), stent placement (P=.007), sphincterotomy (P<.001), and longer overall procedure length (P<0.001). After controlling for confounding factors and interactions with a multiple linear regression model, time-limited fluoroscopy was associated with a 16.4% lower FT (P=.029). The average radiation dose was not amenable to multivariate analysis, and, therefore, no significant difference between groups was found.

Endoscopists were not blinded to the study group assignments.

FT and radiation exposure are dependent upon numerous patient-, operator-, and procedure-related factors. This study found that, after controlling for the impact of confounding factors, time-limited fluoroscopy significantly decreases FTs.

A nationwide survey was launched to investigate the use of fluoroscopy and establish national reference levels (RL) for dose-intensive procedures. The 2-year investigation covered five radiology and nine cardiology departments in public hospitals and private clinics, and focused on 12 examination types: 6 diagnostic and 6 interventional. A total of 1,000 examinations was registered. Information including the fluoroscopy time (T), the number of frames (N) and the dose-area product (DAP) was provided. The data set was used to establish the distributions of T, N and the DAP and the associated RL values. The examinations were pooled to improve the statistics. A wide variation in dose and image quality in fixed geometry was observed. As an example, the skin dose rate for abdominal examinations varied in the range of 10 to 45 mGy/min for comparable image quality. A wide variability was found for several types of examinations, mainly complex ones. DAP RLs of 210, 125, 80, 240, 440 and 110 Gy cm2 were established for lower limb and iliac angiography, cerebral angiography, coronary angiography, biliary drainage and stenting, cerebral embolization and PTCA, respectively. The RL values established are compared to the data published in the literature.