10 dose and image quality. The main objective was to recommend best practice with the lowest radiation exposure. Methods: Initially a literature review was performed investigating radiation doses in the area of paediatric IC. A prospective study was performed on 440 paediatric patients investigating radiation doses during paediatric IC in two specialised hospitals in the UK and Ireland. LDRL were calculated using data on 354 paediatric patients (0-17 years) from one hospital. A questionnaire was then distributed among all the clinical centres in the UK and Ireland investigating radiographic protocols used during IC. The results of the questionnaire informed experimental studies on anthropomorphic phantoms which investigated the different protocols and the corresponding effect on radiation dose and image quality. Results: The literature review highlighted both a scarcity of published research and great variation in paediatric IC radiation doses internationally. The prospective study identified wide variation in techniques and radiation dose between the two different hospitals performing the same IC procedures. One hospital routinely removed the anti-scatter (AS) grid during the IC examination for patients dd 10kg and reported doses up to 50% lower than the other hospital. LDRL were calculated by age and weight groupings. The questionnaire had a response rate of 79% and showed that although IC procedures share common techniques the radiographic protocol varied greatly from one hospital to another. The most common variation in practice is the use of the AS grid and frame rates used during digital acquisition. This was investigated further with the aid of experimental studies using paediatric anthropomorphic phantoms. The results showed that simple modifications can be made to the radiographic protocol during paediatric IC procedures which will give a dose reduction of 27.6% -50% without affecting image quality. The image quality studies showed little variation for the 5 cm phantom and 10cm phantom, however the larger sized 20cm phantom demonstrated a loss in image quality when the AS grid was removed. Discussion: It is apparent that confusion exists in the clinical departments about dose reduction strategies and what constitutes best practice. This can be attributed to the conflicting evidence in published literature. Radiographic projections used in paediatric IC need to be standardised to ensure the lower dose alternatives are used as often as possible. The proposed LDRL may be used as a clinical aid to alert staff they are approaching a threshold radiation dose. All IC departments should establish their own LDRL in line with international guidelines. In addition to this, regular clinical audit should be utilised to ensure clinical practice is in line with the established LDRL. Any procedure that continually exceeds the LDRL should trigger an investigation into practice. Conclusions: An international multicentre study needs to be initiated to collate sufficient data to establish DRL in paediatric IC and develop internationally recognised procedural guidelines. This will ensure that all departments adhere to best practice and that all possible dose reductions can be achieved. Removal of the AS grid should be practised for all patients ≤10kg, unless the lack of image quality deems it necessary. A lower frame rate should be used as often as possible during image acquisition consistent with good anatomical detail. 5. DOSE OPTIMIZING 5.1. Radiation justification - no to repeated examinations Presenter: Tora Hilde Westad Fjeld, Diakonhjemmet Hospital, Norway Authors: T. H. W. Fjeld, H. K. Andersen, K. Faraj Introduction: To avoid unjustified examinations the first question to be asked is: Has the examination already been done? Repeated examinations are evidently unjustified and can be avoided using CD import / export or electronic transfer between hospitals. We do have the tools, but unnecessary repeated examinations still occurs in most radiological departments. This study aims to increase awareness about radiation justification in general and in turn reduce number of repeated examinations. By doing this we aim to decrease collective radiation dose, improve patient flow, spare patient strain and optimise use of resources. We aim to motivate participants at the ISRRT to engage in this kind of optimization work. Yes to meaningful imaging - No to repeated examinations. Methods: Repeated examinations were reported as adverse events and the underlying causes identified. The occurrence of repeated examinations was monitored and the head of each department were informed bimonthly and asked to improve routines that was not work. Results: This study indicates that the main reasons for repeated examinations at our hospital are •previous images not included in patient transfer from other hospitals •suboptimal routines on obtaining previous images •double referrals due to poor communication between doctors •images are transferred, but the referring doctor is not able to locate them in PACS Through the workshops we learned that the level of knowledge about radiation justification among referrers was quite pour. 5.2. The shielding evaluation of radiation dose in an open door operating room during radiographic examinations Presenter: Weon-Keun Choi, Department of Diagnostic Radiology, Asan Medical Center, Korea Authors: Chang-Sun Lim, Ichiro Yamaguchi, Kwan-Seop Lee, Dong-Yun Ha Introduction: According to the the National Council on Radiation Protection and Measurements (NCRP) Report No.147, the shieding of radiation area should not exceed 0.1 mGy/week. We have to close door of operationg room during radiographic examinations on the principle of radiation protection. However, we should actually open door operating room for patient safety in the case of emergeny patients and pediatrics. Considering this situation, we need to evaluate radiation dose in the case of an open door operating room during radiographic examinations, and to find the ideal method for patient safety and reduce radiation dose. Methods: From January 2009 to March 2009, radiation dose was measured by attaching five glass dosimeters to the following four areas:(1) Where the operator is standing in front of the operating room shielding door including 1.5 mm Pb, (2) The inside of the operatoring room with an open door, (3) The rear of the operating room opened, and, (4) The background of where the glass dosimeters were kept. We used an electron gamma shower (EGS) program to evaluate shielding effects in the case of an open door operating room toward tube direction contrary to the existing door direction. Results/Conclusions: Dose rate in area 1 was higher (2.19 mGy/week) than NCRP Report No. 147 (0.1 mGy/week). Dose rate in area 2, 3 and 4 was 0.45 mGy/week, 0.028 mGy /week, and 0.033 mGy/week, respectively. Considering the effects of shielding door direction using the EGS program, an opened shielding door of the operating room facing to the tube direction during radiographic examinations is the ideal method for patient safety and reduction of radiation dose. 5.3. A Holistic Approach to Radiation Safety Presenter: Bart Leclou, Company RaySafe, Sweden Author: Leclou Introduction: One central aspect of radiation safety is the regular quality assurance and servicing of diagnostic x-ray equipment. Only when equipment complies with legal regulations, can it be assumed that it emits only the selected dose during diagnostic x-ray applications. The second central aspect is safety awareness among medical staff working with the equipment who are exposed to scattered radiation represents another important aspect affecting radiation safety. A third central aspect of radiation safety concerns the dose to the patient. When it comes to best practices in radiation safety for patients, some basic guidelines are widely referenced: Medical imaging examinations should only be performed if medically justified (Justification) and if so, patients should receive an optimal x-ray dose which is as low as reasonably achievable (ALARA) while maintaining sufficient image quality to meet the diagnostic need (Optimisation). Methods: Unfors RaySafe developed trough hardware and software solutions the tools to implement a holistic approach to radiation safety that targets the central aspects; equipment, staff and patient. Results: The developed solution indicates that a holistic approach improves the overall radiation safety therefore avoids unnecessary radiation exposure to patient and staff. 5.4. Statistics of patient doses in plain radiography and number of radiological examinations in Finland Presenter: Timo Helasvuo, STUK / Radiation and Nuclear Safety Authority in Finland Authors: Timo Helasvuo, Elina Hallinen Introduction: The Finnish Radiation and Nuclear Safety Authority in Finland (STUK) collected the number of radiological examinations classified
ISRRT | Book Of Abstracts
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