11 to those made to adult and child patients in Finland in 2011. In 2011, approximately 3.6 million x-ray examinations were made in Finland this number does not include dental x-ray examinations taken in dentist’s offices. Earlier, the number of x-ray examinations has been investigated in 1984, 1995, 2000, 2005, and in 2008. Slightly more than 650 000 ultrasound examinations and 261 000 MRI examinations were reported in 2011. So the total number of medical imaging, excluding the dental examinations, go up to near 4.6 million examinations done. STUK conduct patient equivalent dose measurements for plain radiography during every inspection. Inspections are done for all new x-ray units and for older x-ray units every five years. A water + PMMA -phantom corresponding an average patient of about 75 kg is used in the measurements or a standard 4,5 cm thick PMMA -phantom for measurements in mammography. Measurements of ESD are made for Thorax PA and Lumbar spine AP projections and ESD and MGD/AGD for CC projection in mammography using the parameters used for real patients. Sample size since 2010 is approximately 290 x-ray units and 90 mammography units. Various statistics can be drawn from this data (for example the development of patient doses (at least since 1998), dispersion of patient doses, use of additional filtration and its effect on patient dose, use of different sensor techniques and their effect on patient dose etc.). Methods: The collecting of the number of x-ray examinations was based on the statute of the Ministry of Social Affairs and Health on the medical use of radiation. Results: In 2011, in proportion to the Finnish population about 677 x-ray examinations per 1000 inhabitants were performed. Dental examinations are excluded from this number. The patient doses (ESD) have been dropping quite consistently and the average doses are to drop even further in the future, since DR technology will become more common. In mammography, despite the linear drop in ESD, the average MGD has stayed fairly constant in the past few years. 5.5. Knowledge, attitudes and practices of medical radiation workers on radiation optimization, African perspective Presenter: Stephen Bule, Makerere University Kampala, Uganda Author: Stephen Bule, Msc. College of Health Science, school of medicine, radiology dept . Makerere University Introduction: Although ionizing radiation is widely used to diagnose some pathology, the relevant hazards are also known to be as an important limitation of its application. It is believed that the awareness of ionizing radiation dose values is one of the main stages in patient's radiation protection which always refer to optimizing for better health. The purpose of this study has been to investigate the level of radiation workers' (Radiographers, Imaging Technologists and radiologists) knowledge, attitudes and practices about radiation doses received by patients in radiological investigations. Methods: Using questionnaire the most commonly requested radiological investigations were listed. 158 radiation workers in several hospitals were asked to identify the average dose of radiation received by patients when they undergo a posterior-anterior hand. Conclusions: The results indicated that only 56% of radiation worker know the units of radiation absorb dose measurement units. Most of them could not correctly estimate the amount of radiation dose received by patients in a routine radiography of hand and majority of them underestimated the radiation dose of other radiological investigations. Despite passing medical physics course during training, it seems that most of medical radiation workers did not have enough knowledge about the amount of radiation. 5.6. Relationship between dose optimization and compression level of digital pediatric chest images acquired by computed radiography Presenter: Akintade Dare, Bayero University Kano, Nigeria Authors: #Akintade Dare1, M. C. Okeji2, E. O. Balogun3 and A. Y. Abdulkadir1. 1Department of Medical Radiography, Bayero University Kano, Nigeria, 2University of Nigeria, Enugu campus, Nigeria & 3National Orthopedic Hospital, Lagos, Nigeria Introduction: The purpose of digital medical image compression is to reduce the size of the image with the goal of decreasing transmission time and reducing storage space. There are two types of image data compression; lossless or reversible compression and lossy or irreversible compression. While in the former, no information is lost when the image is decompressed or reconstructed; in the latter, there is loss of some information, when the image is decompressed. There is growing evidence that lossy compression can be applied without significantly affecting the diagnostic quality of the images. However it is not well known if lossy compression will affect the diagnostic image quality of pediatric chest images. On the other hand, chest radiographic examinations in pediatric patients should be performed using the lowest possible radiation exposure. Therefore, optimization of image quality and radiation dose in chest radiography has become an important area of research over the last decade. We hypothesize that reducing the patient dose in pediatric chest examination should not compromise the image quality when compressing at 50% level using JPEG wavelet algorithm. The goal of this study was to evaluate the relationship between dose optimization in pediatric chest radiological examinations using computed radiography (CR) and the compression level using JPEG wavelet algorithm. Our specific objectives were to: (1) establish the optimum compression level above which the diagnostic image quality of digital pediatric chest image begins to be affected and (2) determine the effect of patient dose on achievable optimum compression of digital pediatric chest image. Methods: Pediatric chest X-rays at different doses were done. Each image was subjected to 3 different compression levels. Ranked scores for visibility of details were used as measure of diagnostic image quality in each dose for the 3 compression levels. Results: Data analysis using SPSS 17.0 for windows indicate that reducing the patient dose in pediatric chest examination does not compromise the image quality when compressing at 50% level using JPEG wavelet algorithm. Reducing dose in pediatric chest X-ray from 6 mAs to 4 mAs does and compressing at 50% level corresponding to 1:109 compression ratio does not compromise the image quality. Storage space and transmission time for pediatric chest image can be greatly reduced when patient dose is reduced. 5.7. The reducing radiation doses cheaper Presenter: Francesc Xavier Ramon, Insiut de diagnostic per la imatge Tarragona, Hospital Joan XXIII, Spain Authors: Francesc X. Ramon, Alvaro Labata, Francisc Peralbo Introduction: Many companies spend a lot of money to get methods to reduce the radiation dose, but the best and cheapest modulator is the radiographer. The computed tomography image is acquired with many projections and multiple linear attenuation coefficients. In order to obtain multiple linear attenuation coefficients, we can increase the radiation technique (mA) or we can acquire data more slowly. By adjusting the parameters of data acquisition, we achieve dose reduction of 40% without losing image quality. Methods: Our purpose was to reduce the value of CTDI in abdominal CT studies done in our hospital where we have a CT Philips Brilliance with 40 channels. To achieve this, we have made the study more slowly, decreasing pitch. This more linear attenuation co Results: When we compared our studies we did previously with the studies we present, we have seen that we have managed to reduce by 45% the value of CTDI obtaining an image with low noise and optimum quality for radiological diagnosis. 5.8. Indication-based Diagnostic Reference Levels for Adult and Pediatric CT-examinations in Finland Presenter: Atte Lajunen, STUK - Radiation and Nuclear Safety Authority, Finland Authors: H. Järvinen, STUK - Radiation and Nuclear Safety Authority; M. Kortesniemi, HUS Medical Imaging Center; E. Lantto, HUS Medical Imaging Center; R. Seuri, HUS Medical Imaging Center Introduction: A diagnostic reference level (DRL) is a predefined dose level, which should not be exceeded in an examination that is conducted appropriately on an average-sized patient. In Finland, the DRLs for most common examinations are given by Radiation and Nuclear Safety Authority (STUK). Currently there are no DRLs for pediatric CTexaminations and the previous DRLs for CT-examinations for adults were issued in 2007 and they covered only examinations conducted on a particular body region. Since the image quality requirements, and thus the dose needed, vary between different indications, there has been a call for indication-based DRLs for CT. The DRLs for adult CT-examinations are based on a dose survey done in 2012. Doses for different examinations were reported from 57 different CT units out of the approximately 100 units that are in use in Finland. Doses were collected from examinations
ISRRT | Book Of Abstracts
To see the actual publication please follow the link above