National reference doses for common radiographic, fluoroscopic and dental X-ray examinations in the UK

An audit of patient radiation doses during interventional cardiology procedures in Uttarakhand, India, and establishment of local diagnostic reference levels

The objective of this study was to investigate patient radiation doses by a dose audit of three common interventional cardiology (IC) procedures: coronary angiography (CA), percutaneous transluminal coronary angioplasty (PTCA) and CA-PTCA procedures performed in IC centres in the Uttarakhand state of India, for the establishment of local diagnostic reference levels (DRLs) and the estimation of average effective dose (Eav) for these procedures. For each procedure, the values of kerma-area product (PKA), reference air kerma (Ka,r), fluoroscopy time (FT) and the number of cine images were recorded from 1233 CA, 458 PTCA and 736 CA-PTCA procedures performed over a 12-month period at 13 IC centres of the state. From the recorded dose data, 0.6%, 1.53% and 7.9% patients were identified to have exceeded the PKA trigger level of 500 Gy cm2 for possible skin injury for CA, PTCA and CA-PTCA procedures, respectively. The 3rd quartile of the distribution of the recorded PKA values for each type of procedure was calculated to estimate local DRL values. The estimated values of DRLs and Eav were 37, 153 and 224 Gy cm2, and 6.72, 23.97 and 34.79 mSv for CA, PTCA and CA-PTCA procedures, respectively. For about 77% of the surveyed centres, the recorded patient doses were in agreement with the international standards. The local DRLs proposed in this study may be used to achieve patient dose optimization during IC procedures and the obtained patient dose data may also be archived into national dose database for the establishment of national DRLs.

PyDAP: Automated dental OPG beam area measurement using python and raspberry Pi camera

INTRODUCTION

This study investigates if inexpensive computer hardware, open-source computer vision and a phosphor screen from disused CR (computed radiography) Cassette can be used to quantitatively assess beam shape and area.

MATERIALS AND METHODS

The phosphor screen was affixed to a Carestream CS 8100 dental OPG system and the camera was mounted above the X-ray tube. Videos were acquired of the green light emissions during the tomographic irradiation. Images of a chessboard pattern, attached to the detector were used to correct for camera angulation and provide image pixel size calibration. K-Means colour clustering was used to define beam area. The effect of light conditions on beam dimension measurement was also investigated. The beam width measurement from optimised methodology was compared with that determined from dose calibrated GAFChromicTM XR-SP2film.

RESULTS

Videos in dark conditions provided the most reproducible results. FW20M gained from initial sampling matched that obtained using the GAFChromicTM film within the errors of the measurements,6.41 ± 0.09 mm FW20M from this methodology,compared with FW20M (full width at 20 % of maximum) 6.4 ± 0.1 mm from film. The height and area were 126 ± 0.22 mm and 807 ± 11 mm2 respectively. The chess pattern imaging provided a robust means of perspective correction and pixel calibration. There is potential for this methodology to be employed using any digital camera, provided the camera acquisition settings remain constant, the sensor pixels are square, and the camera position is fixed.

CONCLUSION

The potential of this low-cost open-source method of beam area measurement using computer vision is thus proven.

National and local diagnostic reference levels for adult18F-FDG and CT in Jordanian PET/CT: findings and implications in practice

This study aims to report the findings of Jordanian national diagnostic reference level (NDRL) survey for fluorodeoxyglucose (18F-FDG) and local diagnostic reference level (LDRL) of computed tomography (CT) used for attenuation correction and anatomical localisation (AC-AL); and AC and diagnostic CT (AC-DX) within the context of whole-body WB and half-body HB adult oncology PET/CT scanning. Two-structured questionnaires were prepared to gather the necessary information: dosimetry data, patient demographics, equipment specification, and acquisition protocols for identified18F-FDG PET/CT procedures. The NDRL and achievable dose were reported based on the 75th and 50th percentiles for18F-FDG administered activity (AA), respectively. The LDRL was reported based on the 50th percentile for (CTDIvol) and (DLP). Data from 562 patients from four Jordanian PET/CT centres were collected. The survey revealed that Jordanian NDRL for AA (303 MBq) was within the acceptable range compared to the published-peer NDRL data (240-590 MBq). However, the18F-FDG AA varied across the participated PET/CT centres. The reported LDRL CTDIvoland DLP of CT used for (AC-AL) was 4.3 mGy and 459.3 mGy.cm for HB CT scan range, and 4.1 mGy and 659.9 mGy.cm for WB CT scans. The reported LDRL for CTDIvoland DLP for HB CT was higher when compared with the United Kingdom (3.2 mGy and 310 mGy.cm). Concurrently, in the context of WB CT, the reported values (i.e. CTDIvol and DLP) were also higher than both Kuwait (3.6 mGy and 659 mGy.cm) and Slovenia (3.6 mGy and 676 mGy.cm). The reported HB CT(AC-DX) was higher than Nordic, New Zealand and Swiss NDRLs and for WB (AC-DX) CT it was higher than Swiss NDRLs. This study reported the first Jordanian NDRL for18F-FDG and LDRL for HB and WB CT associated with18F-FDG PET/CT scans. This data is useful for Jordanian PET/CT centres to compare their LDRL to the suggested DRLs and utilise it in the process of optimising CT radiation doses.

Diagnostic Reference Levels of Radiographic and CT Examinations in Jordan: A Systematic Review

ABSTRACT

A comprehensive search was performed to examine the literature on diagnostic reference levels (DRL) for computed tomography (CT) and radiography examinations that are performed routinely in Jordan. EBSCO, Scopus, and Web of Science were used for the search. The acronym "DRL" and the additional phrase "dose reference levels" were used to search for articles in literature. Seven papers that reported DRL values for radiography and CT scans in Jordan were identified. One study reported DRLs for conventional radiography, two studies reported CT DRLs in pediatrics, and the remaining four studies provided DRL values for adult CT scans. The most popular techniques for determining the DRLs were the entrance surface dose, volume CT dose index (CTDIvol), and dose-length product (DLP) values. Variations in Jordanian DRL values were noted across both modalities. Lower radiation doses and less variation in DRL values may be achieved by educating and training radiographers to better understand dose reduction strategies. To limit dose variance and enable dosage comparison, CT DRLs must be standardized in accordance with the guidelines of the International Commission on Radiological Protection (ICRP).

Optimization of Radiation Protection in Pediatric Interventional Radiology in Latin America and the Caribbean: Development, Advancements, Challenges and Achievements of the OPRIPALC Program

This article presents the development, advancements, challenges and achievements of the "Optimization of Protection in Pediatric Interventional Radiology in Latin America and the Caribbean" (OPRIPALC) program. This international initiative is led by the World Health Organization, the Pan American Health Organization and the International Atomic Energy Agency. The main objectives of OPRIPALC are to foster a culture of radiological protection in pediatric interventions, enhance these procedures' quality, and define optimization strategies such as the use of diagnostic reference levels (DRLs). Currently, 33 centers from 12 countries participate actively in the program. Significant progress has been made towards the proposed objectives, overcoming the challenges posed by the COVID-19 pandemic. Through many virtual meetings for coordination, planning, training and follow-up, a comprehensive set of DRLs for both diagnostic and therapeutic procedures, categorized by weight and age, have been established and are in use. A consensus document on good practices is in the final stage of development. The program's continuation into at least a second phase is essential to address pending issues, including the integration of automatic dose management systems, the levels of occupational radiation doses, their correlation with pediatric patient doses, and strategies to reduce them.

Fundamental study on diagnostic reference level quantities for endoscopic retrograde cholangiopancreatography using a C-arm fluoroscopy system

The diagnostic reference level (DRL) is an effective tool for optimising protection in medical exposures to patients. However regarding air kerma at the patient entrance reference point (Ka,r), one of the DRL quantities for endoscopic retrograde cholangiopancreatography (ERCP), manufacturers use a variety of the International Electrotechnical Commission and their own specific definitions of the reference point. The research question for this study was whetherKa,ris appropriate as a DRL quantity for ERCP. The purpose of this study was to evaluate the difference betweenKa,rand air kerma incident on the patient's skin surface (Ka,e) at the different height of the patient couch for a C-arm system. Fluoroscopy and radiography were performed using a C-arm system (Ultimax-i, Canon Medical Systems, Japan) and a over-couch tube system (CUREVISTA Open, Fujifilm Healthcare, Japan).Ka,ewas measured by an ion chamber placed on the entrance surface of the phantom. Kerma-area product (PKA) andKa,rwere measured by a built-inPKAmeter and displayed on the fluoroscopy system.Ka,edecreased whileKa,rincreased as the patient couch moved away from the focal spot. The uncertainty of theKa,e/Ka,rratio due to the different height of the patient couch was estimated to be 75%-94%.Ka,rmay not accurately representKa,e.PKAwas a robust DRL quantity that was independent of the patient couch height. We cautioned against optimising patient doses in ERCP with DRLs set in terms ofKa,rwithout considering the patient couch height of the C-arm system. Therefore, we recommend thatKa,ris an inappropriate DRL quantity in ERCP using the C-arm system.

Establishment of institutional diagnostic reference level for coronary angiography procedures in Sri Lanka

Amongst many interventional procedures performed in a cardiac catheterisation laboratory, the coronary angiography (CAG) is the most frequently performed cardiac interventional procedure. A diagnostic reference level (DRL) is an effective tool to optimise the radiation exposure to patients and staff whilst maintaining the adequate diagnostic image quality. The aim of the study was to establish institutional DRLs for the CAG procedures performed at a selected private hospital in Colombo, Sri Lanka. A total of 325 CAG procedures were selected for this study from two C-arm machines. The institutional DRLs of cumulative dose length product (DAP) and fluoroscopic time for the CAG procedure were calculated. The established institutional DRL for accumulated DAP and fluoroscopic time are 10 610 mGycm2 and 2.31 min, respectively. As this study conducted at only one institute we recommend to develop national DRLs for mostly performing interventional procedures in Sri Lanka by considering all influencing factors to optimise the patient dose.

Effect of varying X-ray tube voltage and additional filtration on image quality and patient dose in digital radiography system

This study investigated the effect of varying x-ray tube voltage and additional filtration thicknesses on radiation dose and image quality in digital radiography system. The polymethylmethacrylate (PMMA) phantoms of different thicknesses simulating both the adult chest and abdomen and the pediatric patient's chest examinations were used. X-ray tube voltage range of 70-125 kVp was used for adult patient chest radiography, 70-100 kVp for adult patient abdominal radiography, and 50-70 kVp for pediatric 1-year-old chest examination. 0.1-0.3 mm Cu and 1.0 mm Al filters were used as additional filters. Patient doses were measured with an ionization chamber, considering the irradiation parameters recommended for radiographic examinations performed in radiology clinics in the EUR 16260 protocol. The Entrance Skin Dose (ESD) was calculated from the air kerma value measured at the entrance surface of the PMMA phantoms. Effective dose values were calculated by employing PCXMC 2.0 program. For image quality evaluations, CDRAD, LCD-4, Beam stop and Huttner test object used together with PMMA phantoms and Alderson RS-330 Lung/Chest phantom were used. Figure of Merit (FOM), which allows quantitative assessment in terms of image quality and patient dose, has been calculated. Based on the calculated FOM values were evaluated at the tube voltages and additional filter thicknesses recommended in the EUR 16260 protocol. Entrance Skin Dose and Inverse Image Quality Figure (IQF_inv) value obtained from contrast detail analysis decreased with increasing filter thickness and tube voltage. Decrease in ESD and IQF_inv with increasing tube voltage without additional filter was 56% and 21% for adult chest radiography, 69% and 39% for adult abdominal radiography and 34% and 6% for 1-year-old pediatric chest radiography. When calculated FOM values are examined, it can be recommended to use a 0.1 mm Cu filter at 90 kVp and a 0.1 mm Cu + 1.0 mm Al filter at 125 kVp for adult chest radiography. For adult abdominal radiography, 0.2 mm Cu filter at 70 and 80 kVp and 0.1 mm Cu filter at 90 and 100 kVp were found to be appropriate. It was determined that the appropriate additional filter at 70 kVp for 1-year-old chest radiography was 1.0 mm Al+0.1 mm Cu.

Entrance Skin Dose (ESD) and Bucky Table Induced Backscattered Dose (BTI-BSD) in Abdominal Radiography With nanoDot Optically Stimulated Luminescence Dosimeter (OSLD)

In radiography, inconsistencies in patients' measured entrance skin dose (ESD) exist. There is no published research on the bucky table induced backscattered radiation dose (BTI-BSD). Thus, we aimed to ascertain ESD, calculate the BTI-BSD in abdominal radiography with a nanoDot OSLD, and compare the ESD results with the published data. A Kyoto Kagaku PBU-50 phantom (Kyoto, Japan) in an antero-posterior supine position was exposed, selecting a protocol used for abdominal radiography. The central ray of x-ray beam was pointed at the surface of abdomen at the navel, where a nanoDot dosimeter was placed to measure ESD. For the BTI-BSD, exit dose (ED) was determined by placing a second dosimeter on the exact opposite side (backside) of the phantom from the dosimeter used to determine (ESD) with and without bucky table at identical exposure parameters. The BTI-BSD was calculated as the difference between ED with and without bucky table. The ESD, ED, and BTI-BSD were measured in milligray (mGy). ESD mean values with and without bucky table were 1.97 mGy and 1.84 mGy, whereas ED values were 0.062 mGy and 0.052 mGy, respectively. Results show 2-26% lower ESD values with nanoDot OSLD. The BTI-BSD mean value was found to be approximately 0.01 mGy. A local dose reference level (LDRL) can be established using ESD data to safeguard patients from unnecessary radiation. In addition, to minimize the risk of BTI-BSD in patients in radiography, the search for the use or fabrication of a new, lower atomic number material for the bucky table is suggested.

Characteristics of Cumulative Annual Radiation Exposure in Young Intensive Care Unit Survivors

OBJECTIVES

Patients admitted to the intensive care unit (ICU) are at high risk for hazardous medical radiation exposure. However, the cumulative annual radiation exposure in ICU survivors remains unknown.

METHODS

This was a single-center retrospective study of all critically ill adult patients admitted to the 64-bed adult medical ICU at a quaternary medical center. The study included patients aged 18 to 39 years admitted through the year 2013 (January 1, 2013-December 31, 2013) who survived their respective ICU admission.

RESULTS

A total of 353 patients were included in the study. The median cumulative effective dose (CED) for the calendar year was 9.14 mSv (interquartile range, 1.74-27 mSv). In 11.6% of the patients (n = 41), CED was more than 50 mSv, while 5.1% of the patients (n = 18) exceeded annual CED of 100 mSv. Overall, radiation exposure from ICU-related imaging studies was lower than those from other medical settings (mean difference, -9.2 ± 83.6; P < 0.05). However, there was no statistically significant difference in exposure (ICU versus non-ICU) when restricting the analysis to patients with a CED of greater than 50 and greater than 100 mSv. Eighty-seven percent of the original cohort was alive at the end of the year.

CONCLUSIONS

Young ICU survivors are at risk for high annual radiation exposure from both ICU and non-ICU sources. A subset is exposed to hazardous annual radiation exposure in excess of 100 mSv.

Establishing diagnostic reference levels for pediatric fluoroscopic examinations in a tertiary hospital

BACKGROUND

Diagnostic reference levels (DRLs) identify unusually high patient radiation exposures and are required for dose optimisation. DRLs for pediatric fluoroscopic examinations are not widely determined in Australia.

OBJECTIVE

Our objectives were to establish DRLs for pediatric fluoroscopic examinations in a South Australian tertiary hospital and compare these to previously published data and to explore relationships between patient dose area product (DAP), age and fluoroscopy times.

MATERIALS AND METHODS

Dose data from 365 pediatric patients undergoing 5 fluoroscopic examinations were retrospectively collected for a 3-year period commencing January 2018 to develop local DRLs. Relationships between DAP, age and fluoroscopy time were explored using scatterplots, Spearman's correlation, and regression analyses.

RESULTS

Local DRLs were significantly lower than data published previously, possibly reflecting technological and procedural advancements. Each 1-year increase in patient age was associated with a 0.77 μGy·m² increase in DAP for barium meal and follow-through studies (95% confidence interval [CI]=0.055, 1.48) (P=0.04), and a 1.37 μGy·m² increase in DAP for barium swallow studies (95% CI=0.61, 2.12) (P<0.001). A low correlation was demonstrated between DAP and fluoroscopy time for micturating cystourethrography studies (r=0.35, 95% CI=0.15, 0.51, P<0.001) and barium meal and follow-through studies (r=0.37, 95% CI= -0.011, 0.65, P=0.05). Age and fluoroscopy time were not significantly related.

CONCLUSION

This study provides updated Australian pediatric fluoroscopic DRLs, with the intention of promoting a national database for benchmarking pediatric doses. The local DRLs can be used for dose comparisons and optimisation between facilities.

Diagnostic reference level for adult pelvic examination in several hospitals of Taif and Kharaj city, Saudi Arabia

The current study was aimed to estimate the entrance surface air kerma (ESAK, mGy) for adult patients undergoing conventional radiography of Anteroposterior pelvis examination, and finally to establish a local diagnostic reference level (DRL). A total of 500 patients were exposed to diagnostic radiation in four hospitals (coded A, B, C, and D) in Taif and Kharaj city, Saudi Arabia, with different X-ray equipment specifications. Patient demographic data like age (y), body mass index (BMI) in kg/m² as well as exposure factors and X-ray tube output were recorded. ESAK (mGy) was first calculated using the exposure data and tube output values, then the ESAK values were used to estimate entrance surface dose (ESD). The average BMI was 23.9 kg/m². The mean tube potential used in A, B, C, and D hospitals and the corresponding estimated ESD were found to be 74.2, 69.8, 73, 76,7 kVp, and 2.54, 2.64, 2.94, 3.03 mGy respectively. The correlation coefficient between ESAK and BMI was found to be 0.98. When compared to computed radiography (CR), the conventional X-ray digital radiography reduces the radiation exposure in pelvic imaging by a factor of 1.18. The third quartile of median proposed a lower than the DRL of the previous studies.

Establishing a diagnostic reference level of radiation dose in coronary angiography and intervention: A prospective evaluation

INTRODUCTION

Invasive Coronary Angiography (CAG) leads to significant radiation exposure to the patients. Guidelines suggest that a local landmark or Diagnostic Reference Level (DRL) for these procedures should be established for every region and country. This study attempts to create a DRL for a tertiary care hospital, acting as an interim DRL for the country/region.

METHODS

Radiation exposure data for all coronary procedures done at a tertiary care hospital between October 2016 to September 2018 were collected. Data was segregated into diagnostic Coronary Angiography (CAG) and single-vessel Percutaneous Intervention (PCI). The parameters collected include dose surface product (PKA), skin surface entry dose (KAR), and fluoroscopy time (FT). The 75th percentile of the PKA was used to define the DRL.

RESULTS

500 Patients were included in the CAG group, in which the Median KAR was 412.05 mGy, Median PKA was 2635.7 μGysqm, and median FT was 2.25 min. The DRL for coronary angiography was calculated as 3695.1 μGysqm. Two hundred fifty patients were in the PCI group, the Median KAR was 1649 mGy, Median PKA was 8822.1 μGysqm, the median FT being 8.2 min. The DRL for single-vessel coronary intervention was calculated as 11038 μGysqm.

CONCLUSION

This study establishes a benchmark for radiation dose for diagnostic coronary angiography and single-vessel coronary intervention at a tertiary care hospital in NCR. It establishes an interim DRL that can be used for future studies in other institutions in the region and country and to compare with other countries.

Occupational and patients effective radiation doses in dental imaging

Ionizing radiation exposure from medical applications is increasing annually worldwide. It was estimated that 325 million dental procedures were performed in the United States. Radiation exposure from dental radiography consists of intraoral, panoramic, and 3D imaging cone-beam computed tomography (CBCT) imaging. Recent studies reported an association between dental imaging procedures and increased cancer probability of brain and thyroid. Previous studies showed that some dental imaging practices exposed patients and staff to unnecessary radiation doses due to incorrect image acquisition and insufficient radiation protection measures. This study aims to (i) measure the occupational and patients doses during dental procedures and (ii) assess the current imaging techniques and radiation protection practices. Two hundred fourteen patients were evaluated for periapical, bitewing, cephalometric, occlusal, and panoramic procedures. Organ equivalent doses were quantified for the breast, eye lens, and thyroid gland during CBCT procedure. Occupational and ambient dose assessment were assessed using calibrated thermoluminescent dosimeters (TLD-100(LiF: Mg. Ti). Ambient doses were measure at different locations at the department using TLDs. Patients' radiation doses were quantified using kerma area product (PKA (mGy.cm) and the entrance surface air kerma (ESAK (mGy). Fixed tube voltage (65 kVp) and tube current-time product (7 mAs) were used. The overall mean, sd, and range of patients dose values during intraoral (mGy), panoramic and CBCT examinations were 4.6 ± 0.7 (1.4-7.1), 135 ± 45 (75.2-168.5), and 215 ± 165 (186-2115), respectively. The mean and range of the annual occupational doses (mSv) were 1.4 (0.6-3.7), which below the annual dose limits for radiation workers (20 mSv/y). The study showed that inadequate radiation protection for patients existed in terms of the use of the thyroid shield, the technologist's presence inside the room during radiation exposure. Patients' radiation doses were comparable with the international diagnostic reference level (DRL). Staff education and training in radiation protection aspects are highly recommended.

Diagnostic reference levels for fluoroscopically guided procedures in a South African tertiary hospital

BACKGROUND

The burgeoning usage and complexity of fluoroscopically guided procedures (FGPs) contribute to extended examination times and increased risk of adverse radiation effects. Diagnostic reference levels (DRLs) play a pivotal role in dose optimization. There are limited DRL data for FGPs in low- and middle-income countries (LMICs).

PURPOSE

To determine local DRLs (LDRLs) for common FGPs in the South African (SA) context and compare these with published international data.

MATERIAL AND METHODS

A three-year, retrospective study of the 15 most frequently performed FGPs at a SA institution. For each procedure, the 50th and 75th percentiles of kerma area product (KAP), reference point air kerma (K_a,r), and fluoroscopy time data were derived. Published international FGP DRL data were collated and compared with the 75th percentiles of local institutional dosage parameters.

RESULTS

The commonest FGPs were aorto-bifemoral diagnostic angiography (n = 590), aorto-bifemoral interventional angiography (n = 287), nephrostomy (n = 265), and bronchial arterial embolization (BAE) (n = 208). Selective abdominal vessel interventional angiography (KAP = 170 Gy . cm²; K_a,r = 877 mGy) recorded the highest LDRL dosages; BAE was the longest procedure (LDRL = 38 min). Nephrostomies achieved the lowest LDRLs across all parameters (KAP = 10 Gy . cm²; K_a,r = 63 mGy, fluoroscopy time = 4.3 min). All Tygerberg Hospital LDRLs with comprehensive comparable data were within or below published ranges.

CONCLUSION

This study advances international radiation protection initiatives, addresses the paucity of LMIC DRL data, demonstrates broad alignment of Tygerberg Hospital FGP practice with international norms and highlights areas for optimization of institutional practice.

Patient-Based Dose Audit for Common Radiographic Examinations With Digital Radiology Systems: A Retrospective Cross-Sectional Study

This study aims to audit radiation doses of adult patients who underwent common diagnostic X-ray examinations and compare dose area product (DAP) values with the established International Diagnostic Reference Level (IDRLs). Retrospective cross-sectional records of 339-patients who underwent 699-radiographic examinations between October 2018 and March 2019 were obtained. Patient-related factors, exposure, and DAP data were recorded for the six most common examinations. The mean and 75th percentile of DAPs were recorded and compared to IDRLs values. The 75th percentiles of the locally measured DAPs were below IDRLs for all examinations except for lateral lumbar, AP, and lateral thoracic spine, in which DAP-75th-percentile exceeded all IDRLs by up to 40.7%, 2.8%, 365.5%, respectively. Considering the type of detector used, the mean of the locally measured DAPs significantly exceeded the UK DRLs for the lateral thoracic spine and lateral lumbar spine. Locally measured DAP values were below the IDRLs except for thoracic and lumbar spine projections, which significantly exceeded.

AN INTERVENTIONAL CARDIOLOGY INVESTIGATION: PATIENT EXPOSURE TO RADIATION AND INTER-OPERATOR VARIABILITY IN AN IRISH SETTING

AIM

To evaluate patient radiation exposure for Diagnostic Coronary Angiography (DCA) and Percutaneous Cardiac Intervention (PCI) performed by different operators.

METHODS AND RESULTS

Retrospective (n = 160) and prospective (n = 62) data for DCA (n = 179) and PCI (n = 43) examinations performed by interventional cardiologists (n = 3) using the same imaging equipment were reviewed. The operator with consistently low diagnostic reference levels (DRLs) was interviewed for their personal perceptions upon operator training. Retrospective Median [IQR] DAP was 18.8 [11.8-31.6] and 50.7 [35.3-85.6] Gy.cm2 for DCA and PCI, respectively. Prospective Median [IQR] DAP for DCA and PCI was 7.9 [5.2-10.6] and 15.9 [10.0-17.7] Gy.cm2, respectively. DRLs were within Irish and European DRLs; however, significant inter-operator variability (p < .001) was identified.

CONCLUSION

Radiation exposure in Interventional cardiology is highly operator dependent; further research is warranted in standardization of operator training with evolving technologies.

Assessment of radiation doses received by patients during endoscopic retrograde cholangiopancreatography according to disease location

OBJECTIVE

patients are exposed to ionizing radiation during endoscopic retrograde cholangiopancreatography (ERCP). Radiation dose depends on multiple factors. The goal of this study was to assess fluoroscopy time (FT), radiation doses and effective dose (ED) during ERCP according to the condition being treated.

MATERIALS AND METHODS

a descriptive study was performed of 369 consecutive ERCPs from January 2017 to June 2019. Patient demographic and procedure data were collected. FT, cumulative dose area product (DAP), fluoroscopy DAP, DA fluoroscopy, air kerma, and number of radiographs were assessed. ED was estimated using specific conversion factors.

RESULTS

the mean age was 73.34 years and 193 subjects were male. Mean FT was 4.56 ± 0.17 min, cumulative DAP was 2,056.73 ± 188.83 cGycm2, fluoroscopy DAP was 1,722.90 ± 82.26 cGycm2 and air kerma was 85.84 ± 4.93 mGy. The number of radiographs was 2.10 ± 0.07 and the mean ED was 5.34 ± 0.49 mSv. FT was significantly longer for choledocholithiasis (CL), proximal malignant biliary stricture (PMBS) and distal malignant biliary stricture (DMBS) versus others (OT). Cumulative DAP was higher for PMBS (p < 0.002). FT, cumulative DAP, fluoroscopy DAP and air kerma values were significantly higher for complicated CL as compared to simple CL. ED was higher for CL, DMBS and PMBS, but only significantly (p < 0.002) for PMBS.

CONCLUSIONS

FT for ERCP is variable and increases with exploration difficulty. Thus, it is longer in the case of PMBS, as well as with the amount of radiation received by the patients and ED.

ADULT CT EXAMINATIONS IN ALGERIA: TOWARDS UPDATING NATIONAL DIAGNOSTIC REFERENCE LEVELS

A pilot study has concerned the most frequent computed tomography examinations (CT). This represents the first results based on actual survey for diagnostic reference levels (DRLs) establishment in Algeria. A total number of 2540 patients underwent this survey that has included the recording of CT parameters, computed tomography dose index (CTDIvol) and dose-length product of the head, thorax, abdomen, abdomen-pelvis (AP), lumbar spine (LS) and thorax-abdomen-pelvis (TAP) performed on standard patients. The proposed DRLs are 71 mGy/1282 mGy.cm for head, 16 mGy/555 mGy.cm for thorax, 18 mGy/671 mGy.cm for abdomen, 21 mGy/950 mGy.cm for AP, 36 mGy/957 mGy.cm for LS and 18 mGy/994 mGy.cm for TAP. The rounded 75th percentile seems to be higher in some examinations compared to the literature. Our findings confirm the need to optimise our practice. These results provide a starting point for institutional evaluation of CT radiation doses.

PROPOSED NATIONAL DIAGNOSTIC REFERENCE LEVELS FOR STANDARD RADIOGRAPHIC X-RAY PROCEDURES IN SUDAN

This study aimed to calculate patient radiation doses for adults during the seven most commonly performed conventional X-ray procedures, and to propose national diagnostic reference levels (DRLs). A representative sample of patients from 29 hospitals was included. The entrance surface air kerma (ESAK) was calculated by measuring X-ray tube output and the corresponding technical and exposure factors for each patient. Third-quartile values of the mean ESAK distributions were proposed as DRL values. The DRLs in mGy were as follows: 0.6 for chest postero-anterior (PA), 3.5 for skull AP, 1.7 for skull lateral (LAT), 2.7 for abdominal, 2.6 for pelvic AP, 3.7 for lumbar spine AP and 8 for lumbar spine LAT. Compared with literature, the maximum percentages increase were in chest PA (329%) and skull AP (187%). Since the suggested DRL for chest PA was higher than literature values, dose optimization and a review of its value is recommended.

Establishing local diagnostic reference levels for mini C-arm use in upper limb surgery - A step towards national audit

AIMS

Under the Ionising Radiation Medical Exposure Regulations, hospitals using fluoroscopy and image intensifiers should monitor doses from exposures using ionising radiation. There is a need for national diagnostic reference levels to advise Orthopaedic and Plastic surgeons on safe screening times and radiation doses for patients having upper limb surgical procedures.

METHODS

Retrospective study of all patients who underwent upper limb surgical procedures requiring intra-operative mini C-arm image intensifier use at our hospital between 2013 and 2019. This included results from three machines in different rooms. Procedures were classified as closed and open procedures.

RESULTS

Information on a total of 2910 procedures over 6 years (June 2013 to June 2019) were obtained. 133 procedures with incomplete data and 4 cases of lower extremities were excluded. 1719 closed procedures had a median dose area product of 0.48 cGycm² and median screening time of 7 s, compared to 1054 open procedures, with a median dose area product of 1.88 cGycm² and median screening time of 28 s. National diagnostic reference levels are set at the third quartile and indicate the difference between good and poor practice. For diagnostic reference levels, we suggest a dose area product of 0.82 cGycm² and a screening time of 11 s for closed procedures and a dose area product of 3.07 cGycm² and screening time of 40 s for open procedures. Public Health England state that national diagnostic reference levels should be derived from multiple patients, radiology rooms and hospitals. Our data meets the first two criteria and is an initial step in establishing national diagnostic reference levels for upper limb mini C-arm use.

CONCLUSIONS

This large audit reports results, which, with further work across multiple hospital sites, should lead to establishing national diagnostic reference levels for mini C-arm fluoroscopy for upper limb Orthopaedic procedures.

Organ Doses from Chest Radiographs in Tuberculosis Patients in Canada and Their Uncertainties in Periods from 1930 to 1969

This paper describes a study to estimate absorbed doses to various organs from film-based chest radiographs and their uncertainties in the periods 1930 to 1948, 1949 to 1955, and 1956 to 1969. Estimated organ doses will be used in new analyses of risks of cancer and other diseases in tuberculosis patients in Canada who had chest fluoroscopic and radiographic examinations in those periods. In this paper, doses to lungs, female breast, active bone marrow, and heart from a single chest radiograph in adults and children of ages 1, 5, 10, and 15 y in the Canadian cohort and their uncertainties are estimated using (1) data on the tube voltage (kV), total filtration (mm Al), tube-current exposure-time product (mA s), and tube output (mR [mA s]) in each period; (2) assumptions about patient orientation, distance from the source to the skin of a patient, and film size; and (3) new calculations of sex- and age-specific organ dose conversion coefficients (organ doses per dose in air at skin entrance). Variations in estimated doses to each organ across the three periods are less than 20% in adults and up to about 30% at younger ages. Uncertainties in estimated organ doses are about a factor of 2 to 3 in adults and up to a factor of 4 at younger ages and are due mainly to uncertainties in the tube voltage and tube-current exposure-time product.

Radiation doses during cardiac catheterisation procedures in India: a multicentre study: Radiation dose study

AIMS

Established, evidence-based measures of radiation are required to minimise its hazards, while maintaining adequate image quality. The aim of this study is to evaluate radiation data and generate reference radiation levels for commonly performed coronary catheterisation procedures in India.

METHODS AND RESULTS

In this prospective, observational study, all procedures were performed in accordance with the established standards using Innova IGS 520/2100-IQ catheterisation laboratories. Demographic, procedural and radiation data were collected. Dose reference limits (DRL) were established as the 75th percentile of the total distribution. There were 2,906 coronary angiograms (CAG), 750 percutaneous coronary interventions (PCI) and 715 CAG+PCI. DRLs for dose area product were: 19.6 Gy·cm2 for CAG, 49.8 Gy·cm2 for PCI and 72.0 Gy·cm2 for CAG+PCI, respectively. Median cumulative air kerma levels were: 185 mGy for CAG, 533mGy for PCI, and 891 mGy for CAG+PCI. Male gender, higher BMI, combining CAG+PCI, fluoroscopy time, number of cine frames, and image acquisition settings were significant contributors to increased radiation dose.

CONCLUSIONS

This study established reference radiation dose levels for diagnostic and interventional coronary procedures in India, which were comparable to and in the lower range of international standards.

Assessment of Regional Pediatric Diagnostic Reference Levels for Panoramic Radiography Using Dose Area Product

AIM

The current work aims to calculate dose area product (DAP) and to determine regional diagnostic reference level (DRL) for pediatric panoramic radiography in Tamil Nadu.

MATERIALS AND METHODS

In this study, DAP was calculated after finding the product of air kerma on the detector side of scanner with the corresponding exposed area. The obtained DAP values were further analyzed, and DRL was calculated using Microsoft Excel. The study was carried out with routine pediatric exposure parameters.

RESULTS

The obtained mean, range, and third quartile values for pediatric panoramic radiography are found to be 65 mGycm2, 11-148 mGycm2, and 82 mGycm2, respectively. The proposed DRL is comparable with the other countries' DRL.

CONCLUSION

Based on the results of the present study, it was observed that there exists a wide difference in mean doses among the panoramic scanners. The variation in radiation doses between the clinics/hospitals and similar scanners suggests a large potential for optimization of panoramic procedures.

Radiation dose during fluoroscopically guided central venous access device insertion: retrospective observational study

INTRODUCTION

Central venous access devices (CVAD) are used to deliver intravenous therapy to the bloodstream. CVAD insertion is sometimes fluoroscopically guided and thus associated with radiation dose to both the patient and the staff members within the room. The objective of this study is to assess the radiation dose to the patient through a retrospective audit and directly measure the exposure to staff members in simulated procedures. A secondary objective is to evaluate the radiation exposure to the staff and patients when utilising fluoroscopic pulse rate of 7.5 pps and 4 pps.

MATERIAL AND METHODS

A retrospective audit of patients undergoing Permcath and Hickman line insertions was conducted. The patients were grouped by the pulse rate used for the duration of the study; 4 pulses per second (pps) (n=24) and 7.5 pps (n=33). A STEP OD-2 monitor and PMMA was used in a simulated environment to estimate the radiation exposure to locations that a Radiologist, Nurse and Radiographer would be standing during the procedures using the average procedure details collected in the retrospective audit. Measurements were conducted at heights to reflect a whole body estimate and an estimate to the lens of the eye.

RESULTS

The results show that the median dose area product (DAP) for CVAD insertion is 0.7Gy.cm² and 0.3Gy.cm² for procedures done at 7.5 pps and 4 pps, respectively. This corresponded to an effective dose of 0.22 mSv and 0.1 mSv. The radiologist, nurse and radiographer were exposed to a whole-body shielded dose of 0.36μSv, 0.1μSv and 0.05μSv when 7.5 pps was utilised and 0.13μSv, 0.03μSv and 0.02μSv when 4 pps was used. The exposure to the head of radiologist, nurse and radiographer was 2.1μSv, 1.4μSv, and 0.6μSv in the 7.5 pps studies and 0.7μSv, 0.5μSv, and 0.2μSv when 4pps was used.

CONCLUSION

The patient effective dose was estimated to be 0.1-0.22 mSv depending on the fluoroscopic pulse rate utilised during CVAD insertions. Additionally, The radiologist, nurse and radiographer whole body and lens exposure was estimated in a simulated setting. In all cases, there was a statistically significant dose reduction when the lower fluoroscopic pulse rate was used. Thus, where possible, consideration should be given to utilising a lower pulse rate during CVAD insertions to reduce the exposure to both staff and patients.

Local Diagnostic Reference Levels in Interventional Radiology

PURPOSE

Interventional cardiology procedures, during which live images are acquired, involve exposure to x-rays. The use of fluoroscopy can cause high radiation doses to patients and operators because of the prolonged duration of x-ray emission. For this reason, special attention and constant vigilance represent challenges for commissions and groups of experts in the field. The purpose of this study is to establish local diagnostic reference levels (DRLs) for these procedures, to improve radiological practice, and to optimize radiation doses.

METHODS

This work was carried out in two university hospitals and two private medical facilities in Rabat, the capital of Morocco, during the period 2017-2018. The study concerns 657 interventional cardiology procedures (457 coronary angiography [CA] and 200 percutaneous transluminal coronary angioplasty [PTCA]), performed by 11 cardiologists on different installations in 5 catheterization rooms. The data collected for each procedure were patient age, height and weight, dosimeter indicators in terms of dose area product (P_KA), total air kerma at the reference point (K_ar), fluoroscopy time (FT), and the number of frames, together with the primary beam parameters as kV and total mAs. The proposed DRLs were set from the 75th percentile of the P_KA and FT.

RESULTS

The mean of P_KA for CA and PTCA procedures were 29.2 Gy∗cm² and 70.4 Gy∗cm², respectively, the mean of fluoroscopy time were 4.0 min and 12.17 min for 334 and 685 frames, respectively. Results for the local DRLs were 37.3 and 87.1 Gy cm² for P_KA and 4.48 and 16.15 min for FT, corresponding to CA and PTCA procedures.

CONCLUSION

This work focuses on proposing local DRLs in Morocco for CA and PTCA procedures. The results show that the values found conform with those of international studies.

Dose assessment in dental cone-beam computed tomography: Comparison of optically stimulated luminescence dosimetry with Monte Carlo method

The variety of cone-beam computed tomography (CBCT) machines and their applications has rapidly increased in recent years, making the dose evaluation of individual devices an important issue. Patient doses from CBCT were assessed with two different methods: optically stimulated luminescence dosimeter (OSLD) measurements and Monte Carlo (MC) simulations, in four different examination modes. Based on an analysis of the measurement process and the obtained values, a recommendation is made regarding which method is more practical and efficient for acquiring the effective dose of CBCT. Twenty-two OSLDs were calibrated and equipped in human phantoms of head and neck organs. They were exposed to radiation from two CBCT units—CS9300 (Carestream Dental LLC, Atlanta, Georgia) and RAYSCAN α+ (Ray Co. Ltd, Hwaseong-si, Korea)—using two different examination modes. The dose recorded using the OSLDs was used to calculate the organ dose and the effective dose for each unit in each examination mode. These values were also calculated using MC software, PCXMC (STUK, Helsinki, Finland). The organ doses and effective doses obtained using both methods were compared for each examination mode of the individual units. The OSLD-measured effective dose value was higher than that obtained using the MC method for each examination mode, except the dual jaw mode of CS9300. The percent difference of the effective dose between the two methods ranged from 4.0% to 14.3%. The dose difference between the methods decreased as the field of view became smaller. The organ dose values varied according to the method, although the overall trend was similar for both methods. The organs showing high doses were mostly consistent for both methods. In this study, the effective dose obtained by OSLD measurements and MC simulations were compared, and both methods were described in detail. As a relatively efficient and easy-to-perform method, we cautiously suggest using MC simulations for dose evaluations in the future.

Variation of Pediatric Doses Undergoing Digital and Computed Radiography Examination in Addis Ababa, Ethiopia

BACKGROUND

Various researchers who carried out national and international surveys have reported wide variations in patient dose arising from specific X-ray examinations. Thus, assessment of radiation dose is an essential part in the optimization process. The aim of this study was to compare the entrance surface doses delivered to pediatric patients undergoing digital and computed radiography X-ray examination.

MATERIAL AND METHODS

A cross-sectional study was conducted on 389 pediatric X-ray projections less than 15 years of age on eight X-ray machines in Addis Ababa in February 2009 E.C. The tube output of the X-ray machines in air was measured using RaySafe XI dosimeters. Then, entrance surface dose was estimated for common x-ray examinations like chest, skull, extremities and pelvis using established relation between X-ray tube output and radiographic parameters. These data were analyzed statistically using computer (Excel and SPSS method).

RESULT

The third quartile estimated ESDs in mGy for both computed and digital radiography examinations of chest (AP) for age (0-1 year) were 0.24 and 0.15, (1-5 year) 0.3 and 0.16. For the age group (5-10 year), it was 1.97 and 0.26 and for the (10-15 year) group, 0.56 and 0.18 respectively. These values were higher than those of the United Nations Scientific Committee's on the Effects of Atomic Radiation's established dose reference levels (in mGy for age (0-1 year) 0.02, (1-5 year) 0.03, (5-10 year) 0.04, and (10-15 year) 0.05 respectively).

CONCLUSION

The wider dose variation between computed and digital radiography shows that there is a pressing need to minimize the detriment caused by unnecessary computed radiography.

Updated Australian diagnostic reference levels for adult CT

INTRODUCTION

In 2018, ARPANSA published updated national DRLs for adult CT, which were first published in 2012, and augmented the national DRL categories. This paper presents the updated national DRLs and describes the process by which they were produced.

METHODS

Examine patient survey data submitted to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) National Diagnostic Reference Level Service (NDRLS). Determine the quartiles of the distributions of median survey dose metrics with categorisation by procedure type. Engage a liaison panel representing the radiology professions to review procedure categories and recommend revised national DRLs. The revised NDRL procedure categories are: head (non-contrast brain (trauma/headache)), cervical spine (Non-contrast (trauma)), soft-tissue neck (post-contrast (oncology)), chest (post-contrast (oncology)), abdomen-pelvis (post-contrast (oncology)), kidney-ureter-bladder (non-contrast (suspected renal colic)), chest-abdomen-pelvis (post-contrast (oncology)) and lumbar spine (non-contrast (degenerative pain)).

RESULTS

The existing six procedure categories were revised and refined. Updated Australian national diagnostic reference levels for adult CT were recommended and endorsed for eight procedure categories: head (52 mGy/880 mGycm), cervical spine (23 mGy/470 mGycm),soft-tissue neck (17 mGy/450 mGycm), chest (10 mGy/390 mGycm), abdomen-pelvis (13 mGy/600 mGycm), kidney-ureter-bladder (13 mGy/600 mGycm), chest-abdomen-pelvis (11 mGy/940 mGycm) and lumbar spine (26 mGy/670 mGycm). The updated national DRLs are between 12 and 26% lower than the previous DRLs for dose-length product and between 13 and 63% lower for volume computed tomography dose index.

CONCLUSIONS

Australian national DRLs for adult CT have been reviewed and revised. The revised national DRLs are lower, better reflecting current practice among imaging facilities in Australia. The revised Australian national DRLs are similar to those in other developed countries.

Measuring the dose-width product and proposing the local diagnostic reference level in panoramic dental radiography: a multi-center study from Iran

OBJECTIVE

Although radiation exposure associated with dental radiography is relatively low, patient exposure must be kept practically low. Therefore, it is necessary for each country to establish its own diagnostic reference levels (DRLs) suitable for its equipment and practice. In the present study, dose-width product (DWP) values for panoramic dental radiography were measured and a local DRL was established.

METHODS

Five panoramic devices from five radiology clinics of Kashan, Iran were selected to measure the DWP values of panoramic dental radiography. To investigate the DWP values, the parameters of each patient's exposure (e.g., tube voltage, tube current, and exposure time) at these five radiology clinics were extracted. Then, the dose value received by each patient was measured based on a CT pencil chamber. Finally, the overall median DWP values for the patients with small, medium, and large sizes were obtained, and these values were considered as the local DRLs for panoramic dental radiography.

RESULTS

A total of 99 adult patients were included in the present study. The findings demonstrated that the median and third-quartile DWP values for these five radiology clinics ranged from 42.3 to 94.3 and 49.7 to 142.8 mGy mm, respectively. The local DRL values, which were established as the overall median DWP values, were 43.4, 52.0, and 80.3 mGy  mm for the adults with small, medium, and large sizes, respectively.

CONCLUSION

The local DRL proposed in this study for the adult with standard/medium size was lower than those proposed by other reports and seemed acceptable for panoramic radiography in Kashan, Iran.

Distribution of radiation exposure in patients with partially stable and unstable pelvic ring fractures: first-time use of highly accurate assessment by Monte Carlo calculations

PURPOSE

Radiological examinations including X-ray and CT play a critical role in the assessment and treatment of trauma patients. The ionizing radiation used is known to be carcinogenic. However, little is known about the total radiation exposure in trauma patients. The objective of this study was to accurately estimate radiation exposure of patients with severe pelvic ring fractures.

METHODS

In this retrospective dynamic cohort study, adult patients with partially stable and unstable pelvic ring fractures were included. For each patient, data concerning demography and injury characteristics were collected. Subsequently, the total effective radiation dose due to all trauma-related X-rays and CT scans during initial assessment, treatment and follow-up was calculated using Monte Carlo software.

RESULTS

A total of 114 patients were included. The median total effective dose was 49.7 millisievert (mSv). 57 patients (50.0%) received more than 50 mSv and 13 patients (11.4%) received more than 100 mSv. 62.4% of the total effective dose was received within the 24 h after admission. The median total effective dose for survivors (n = 95) was 52.0 mSv. Polytrauma patients received a significantly higher total effective dose than non-polytrauma patients.

CONCLUSIONS

This study showed that a substantial number of patients with partially stable and unstable pelvic ring fractures have an increased cancer risk due to trauma-related medical imaging. Physicians should be aware of the amount of radiation their patients are exposed to, and minimize imaging related increase of cancer risks during initial assessment, treatment and follow-up.

CONTEMPORARY RADIATION DOSES IN INTERVENTIONAL CARDIOLOGY: A NATIONWIDE STUDY OF PATIENT DOSES IN FINLAND

The amount of interventional procedures such as percutaneous coronary intervention (PCI), transcatheter aortic valve implantation (TAVI), pacemaker implantation (PI) and ablations has increased within the previous decade. Simultaneously, novel fluoroscopy mainframes enable lower radiation doses for patients and operators. Therefore, there is a need to update the existing diagnostic reference levels (DRLs) and propose new ones for common or recently introduced procedures. We sought to assess patient radiation doses in interventional cardiology in a large sample from seven hospitals across Finland between 2014 and 2016. Data were used to set updated national DRLs for coronary angiographies (kerma-air product (KAP) 30 Gycm2) and PCIs (KAP 75 cm2), and novel levels for PIs (KAP 3.5 Gycm2), atrial fibrillation ablation procedures (KAP 25 Gycm2) and TAVI (KAP 90 Gycm2). Tentative KAP values were set for implantations of cardiac resynchronization therapy devices (CRT, KAP 22 Gycm2), electrophysiological treatment of atrioventricular nodal re-entry tachycardia (6 Gycm2) and atrial flutter procedures (KAP 16 Gycm2). The values for TAVI and CRT device implantation are published for the first time on national level. Dose from image acquisition (cine) constitutes the major part of the total dose in coronary and atrial fibrillation ablation procedures. For TAVI, patient weight is a good predictor of patient dose.

A MULTICENTRE SURVEY OF LOCAL DIAGNOSTIC REFERENCE LEVELS AND ACHIEVABLE DOSE FOR CORONARY ANGIOGRAPHY AND PERCUTANEOUS TRANSLUMINAL CORONARY INTERVENTION PROCEDURES IN KOREA

Interventional cardiology procedures can involve relatively high radiation doses compared to general radiography. During coronary angiography (CAG) and percutaneous transluminal coronary intervention (PCI), the same area is exposed to radiation for a long period. In this study, radiation exposure data of 1071 examinations in Korean hospitals were collected, and the achievable dose (AD) and diagnostic reference levels (DRLs) in actual medical practice for two types of interventional cardiology procedures in Korea were established. In CAG, 75th percentile DRLs and AD of the total kerma-area product were 47.0 and 33.1 Gy·cm 2, respectively. In PCI, those values were 171.3 and 102.6 Gy·cm2, respectively. This is the first study to introduce the DRLs for cardiovascular interventional procedures in Korea. These results will help optimise the interventional cardiology procedures for Korean cardiac centres.

NATIONAL DIAGNOSTIC REFERENCE LEVELS AND ACHIEVABLE DOSES FOR 13 ADULT CT PROTOCOLS AND A PAEDIATRIC HEAD CT PROTOCOL: NATIONAL SURVEY OF KOREAN HOSPITALS

To develop a second set of diagnostic reference levels (DRLs) and achievable doses (ADs) for 13 adult computed tomography (CT) protocols and a paediatric head CT protocol in Korea. A survey of 13,625 CT examinations was performed based on 13 adult CT protocols and a paediatric non-contrast brain CT protocol using 369 CT systems, with patients grouped according to age. Most CT protocols in this survey had DRLs similar to those reported in other countries. However, chest and abdomen-pelvic CT had lower DRLs than those reported in the first Korean national survey and those from other countries. Paediatric non-contrast brain CT in each age group, with the exception of the 11-15-year age group, had lower DRLs than those reported in other countries. The DRLs presented here are similar to (or lower than for some protocols) those reported in the first Korean national survey and those from other countries.

Radiation exposure of patients during mini C-arm use: an audit in 2032 procedures

This study aimed to audit large quantities of mini C-arm data used in hand and wrist surgery and to analyse what effect the type and anatomical location of procedures had on screening time and dose area product. Of a total of 2032 procedures, the median screening time was 11 seconds and median dose area product was 0.75 cGycm². The third quartile value for screening time was 23 seconds and dose area product was 1.62 cGycm². The median screening time for closed procedures was 7 seconds and the dose area product was 0.57 cGycm². The median screening time for open surgery was 23 seconds with a median dose area product of 1.45 cGycm². The data for steroid injection procedures were similar to those of the closed procedures, with a median screening time of 7 seconds and dose area product of 0.45 cGycm². We found no significant differences in the screening time or dose area product between procedures on the wrist and forearm compared with the hand and digits. Level of evidence: III.

Diagnostic reference levels for paediatric CT in Jordan

This study aimed to investigate the current status of Diagnostic Reference Levels (DRLs) in paediatric CT across Jordan. The dose data for four main CT examinations (brain, chest, abdominopelvic, and chest, abdomen and pelvis (CAP)) in hospitals and imaging centres (n = 4) were measured. The volume CT dose index (CTDIvol) and Dose Length Product (DLP) values were compared within the different hospitals and age groups (<1 year, 1-4 years, 5-10 years and 11-18 years). DRLs in Jordan were compared to international DRLs. The paediatric population consisted of 1818 children; 61.4% of them were male. There were significant variations between the DRLs for each CT scanner with an up to four-fold difference in dose between hospitals. There were apparent significant differences between Jordan and other countries with the DLPs in Jordan being relatively high. However, for CTDIvol, the values in Jordan were close to those of other countries. This study confirmed variations in the CTDIvol and DLP values of paediatric CT scans in Jordan. These variations were attributed to the different protocols and equipment used. There is a need to optimise paediatric CT examinations doses in Jordan.

Intraoperative Computed Tomography Versus Fluoroscopy for Ventriculoperitoneal Shunt Placement

OBJECTIVE

Catheter malposition represents one of the major causes of ventriculoperitoneal (VP) shunt dysfunction. The usefulness of intraoperative fluoroscopy using skull landmarks has already been proved to decrease catheter malposition and surgical revision rates. After introducing intraoperative computed tomography (iCT) in our department, our objective was to evaluate the accuracy of this imaging modality to decrease cranial catheter misplacement compared with intraoperative fluoroscopy.

METHODS

In our retrospective analysis of 152 patients, catheter placement was evaluated by iCT (n = 48) and biplane fluoroscopy (n = 57). A control group (n = 47) had no intraoperative imaging. Outcome measures included accuracy of ventricular catheter position, revision surgeries, and clinical outcomes.

RESULTS

Ventricular catheter placement was accurate in 24/48 patients with iCT and 45/57 patients with fluoroscopy (P = 0.002) versus 23/47 patients in the control group. Sensitivity and positive predictive value for estimating optimal catheter position with iCT were 100% and 54%. The specificity and negative predictive value were 50% and 100%. After intraoperative revision, 4 catheters remained malpositioned in the iCT group, whereas the fluoroscopy group had none (P = 0.03); 2 of these 4 catheters were revised postoperatively.

CONCLUSIONS

Fluoroscopy may be the method of choice to intraoperatively assess ventricular catheter positioning. In our experience, iCT shows a tendency to be more time consuming and, in the beginning, was not associated with a steeper learning curve. Another consideration was the significant higher radiation exposure per patient. iCT did not improve the accuracy of catheter placement and did not decrease early revisions for VP placement patients.

Simple preoperative radiation safety interventions significantly lower radiation doses during central venous line placement in children

PURPOSE

The purpose of this study was to reduce radiation exposure during pediatric central venous line (CVL) placement by implementing a radiation safety process including a radiation safety briefing and a job-instruction model with a preradiation time-out.

METHODS

We reviewed records of all patients under 21 who underwent CVL placement in the operating room covering 22 months before the intervention through 10 months after 2013-2016. The intervention consisted of a radiation safety briefing by the surgeon to the intraoperative staff before each case and a radiation safety time-out. We measured and analyzed the dose area product (DAP), total radiation time pre- and postintervention, and the use of postprocedural chest radiograph.

RESULTS

100 patients with valid DAP measurements were identified for analysis (59 preintervention, 41 postintervention). Following implementation of the radiation safety process, there was a 79% decrease in median DAP (61.4 vs 13.1 rad*cm², P < 0.001) and a 73% decrease in the median radiation time (28 vs 7.6 s, P < 0.001). Additionally, there was a significant reduction in use of confirmatory CXR (95% vs 15%, P < 0.01).

CONCLUSION

A preoperative radiation safety briefing and a radiation safety time-out supported by a job-instruction model were effective in significantly lowering the absorbed doses of radiation in children undergoing CVL insertion.

TYPE OF STUDY

Case-control study.

LEVEL OF EVIDENCE

Level III.

DIAGNOSTIC REFERENCE LEVELS FOR CARDIAC CT ANGIOGRAPHY IN AUSTRALIA

This study aims to assess patient radiation dose from cardiac computed tomography angiography (CCTA) with the aim of proposing a national diagnostic reference levels (NDRLs) for CCTA procedures in Australia. A questionnaire was used to retrospectively gather baseline information related to CCTA scanning and patient parameters in CT centres across the country. The 75th percentile of both volumetric CT dose index (CTDIvol) and dose length-product (DLP) was used as DRL values for CCTA. A DRL for CT calcium scoring test was also determined. NDRLs were compared with international published data. Data sets of 338 patients from nine CT centres were used for analysis. The CCTA DRL for the CTDIvol and the DLP were 22 mGy and 268 mGy cm, respectively. The CT calcium scoring test DRL for DLP was 137 mGy cm. The DRL values for CCTA in Australia have been recommended for the first time. DRLs are lower than those in most published studies due to the implementation of dose-saving technologies such as prospective ECG-gated mode and iterative reconstruction algorithms. Considerable variations remain in patient doses between hospitals for the most frequently used CCTA protocols, indicating the potential for DRLs to prompt dose optimisation strategies in CT facilities.

Fluoroscopically guided wide-bore thoracostomy tube placement: Description of the technique and comparison to blind placement

OBJECTIVE

To describe and compare fluoroscopic guidance for placement of wide-bore thoracostomy tubes (FGTT) to traditional, blind placement of thoracostomy tubes (BPTT).

STUDY DESIGN

Prospective clinical trial.

ANIMALS

Twenty client-owned dogs.

METHODS

Dogs requiring medical management of pleural effusion received a BPTT, whereas dogs undergoing postoperative management of pneumothorax and/or pleural fluid after lateral thoracotomy received an FGTT. Time of placement, accuracy of positioning, radiation exposure, and complications were compared between groups.

RESULTS

Initial placement of BPTT took a mean of 168 seconds (range, 89-197), whereas adequate placement was radiographically confirmed at 20 minutes and 38 seconds (range, 7 minutes and 57 seconds to 39 min). Initial placement of FGTT took a mean time of 108 seconds (range, 50-341, P = .17), and adequate placement was confirmed at 125 seconds (range, 50-341, P < .001). Major errors in placement requiring removal and replacement occurred in 2 dogs for BPTT and in none for FGTT. Procedural complications did not differ between groups, and no postoperative complication occurred within the first 12 hours after placement. Radiation entrance surface dose was lower in the BPTT group (P = .004), but stochastic radiation doses did not differ.

CONCLUSION

Fluoroscopic guidance of wide-bore thoracostomy tubes accelerated the time to accurate tube placement and alleviated the requirement for removal and replacement in this population. Although use of fluoroscopy increased radiation entrance surface dose, the dose was not clinically significant.

CLINICAL SIGNIFICANCE

Fluoroscopic guidance of wide-bore thoracostomy tubes should be considered as an alternative to traditional, blind placement.