Evaluating the use of higher kVp and copper filtration as a dose optimisation tool in digital planar radiography.

INTRODUCTION: To identify the potential of beam hardening techniques, specifically the use of higher kilo voltage (kV) and copper (Cu) filtration, to optimise digital planar radiographic projections. The study assessed the suitability of such techniques in radiation dose reductions while maintaining diagnostic image quality for four common radiographic projections: antero-posterior (AP) abdomen, AP-knee, AP-lumbar spine, and lateral lumbar spine. METHODS: Anthropomorphic phantom radiographs were obtained at varying kVp (standard kVp, +10 kVp, and +20 kVp) and varying Cu filtration thickness (0 mm, 0.1 mm, and 0.2 mm Cu). The Dose Area Product (DAP), mAs and time (s) were recorded as an indication of the emitted radiation dose. Image quality was assessed objectively via Contrast-Noise-Ratio (CNR) calculations and subjectively via Visual Grading Analysis (VGA) performed by radiographers and radiologists. RESULTS: Optimised exposure protocols were established for the AP-abdomen (100 kVp with 0.2 mm Cu), AP-knee (85 kVp, and 0.1 mm Cu), AP-lumbar spine (110 kVp and 0.2 mm Cu), and lateral lumbar spine (110 kVp and 0.2 mm Cu). This strategy resulted in respective DAP reductions of 71.98%, 62.50%, 64.51% and 71.85%. While CNR values decreased as beam hardening techniques were applied, VGA demonstrated either a lack of statistical variation or improved image quality between the standard and the optimised exposure protocols. CONCLUSIONS: DAP reductions without compromising image quality can be achieved through beam hardening for the AP-abdomen, AP-knee, AP-lumbar spine, and lateral lumbar spine projections. IMPLICATIONS FOR PRACTICE: Beam hardening techniques should be considered as an optimisation strategy in medical imaging departments. Research into the applicability of this strategy for other radiographic projections is recommended.

Optimisation of the AP abdomen projection for larger patient body thicknesses.

INTRODUCTION: This study aims to identify optimal exposure parameters, delivering the lowest radiation dose while maintaining images of diagnostic quality for the antero-posterior (AP) abdomen x-ray projection in large patients with an AP abdominal diameter of >22.3 cm. METHODOLOGY: The study was composed of two phases. In phase 1, an anthropomorphic phantom (20 cm AP abdominal diameter) was repetitively radiographed while adding 3 layers (5 cm thick each) of fat onto the phantom reaching a maximum AP abdominal diameter of 35 cm. For every 5 cm thickness, images were taken at 10 kVp (kilovoltage peak) intervals, starting from 80 kVp as the standard protocol currently in use at the local medical imaging department, to 120 kVp in combination with the use of automatic exposure control (AEC). The dose area product (DAP), milliampere-second (mAs) delivered by the AEC, and measurements to calculate the signal to noise ratio (SNR) and contrast to noise ratio (CNR) were recorded. Phase 2 included image quality evaluation of the resultant images by radiographers and radiologists through absolute visual grading analysis (VGA). The resultant VGA scores were analysed using visual grading characteristics (VGC) curves. RESULTS: The optimal kVp setting for AP abdominal diameters at: 20 cm, 25 cm and 30 cm was found to be 110 kVp increased from 80 kVp as the standard protocol (with a 56.5% decrease in DAP and 76.2% in mAs, a 54.2% decrease in DAP and 76.2% decrease in mAs and a 29.2% decrease in DAP and 59.7% decrease in mAs, respectively). The optimal kVp setting for AP abdominal diameter at 35 cm was found to be 120 kVp increased from 80 kvp as the standard protocol (with a 50.7% decrease in DAP and 73.4% decrease in mAs). All this was achieved while maintaining images of diagnostic quality. CONCLUSION: Tailoring the exposure parameters for large patients in radiography of the abdomen results in a significant reductions in DAP which correlates to lower patient doses while still maintaining diagnostic image quality. IMPLICATIONS FOR CLINICAL PRACTICE: This research study and resultant parameters may help guide clinical departments to optimise AP abdomen radiographic exposures for large patients in the clinical setting.

An Investigation of Procedural Radiation Dose Level Awareness and Personal Training Experience in Communicating Ionizing Radiation Examinations Benefits and Risks to Patients in Two European Cardiac Centers.

PURPOSE: Cardiac interventional practitioners need to be appropriately informed regarding radiation dose quantities and risks. Communicating benefit-risk information to patients requires attention as specified in Basic Safety Standards Directive 2013/59/Eurotom. This study investigated the awareness of procedural radiation dose levels and the impact of personal training experience in communicating ionizing radiation benefit-risks to patients. METHODOLOGY: A questionnaire, consisting of 28 questions, was distributed directly to adult and pediatric interventional cardiology specialists at specialized cardiovascular imaging centers in Dublin, Ireland and Milan, Italy. RESULTS: A total of 18 interventional cardiologists (senior registrar to consultant grades with between 2 y to over 21 y experience in cardiac imaging) participated. The majority of participants (n = 17) stated that parents of pediatric and adult patients should be informed of the potential benefits and risk. All participants indicated they had radiation safety training; however, 50% had not received training in radiation examination benefit-risk communication. Despite this, 77.8% (n = 14) participants indicated a high confidence level in successfully explaining risks and/or benefits of cardiac imaging procedures. When asked to estimate effective dose (ED) values for common cardiac imaging procedures less than 50% identified appropriate dose ranges. All participants underestimated procedural dose values based on recent European data. 50% (n = 9) participants answered all questions correctly for a number of true or false radiation risk statements. CONCLUSION: Benefit-risk communication training deficits and inaccurate understanding of radiation dose levels was identified. Further research and training to support clinicians using radiation on a daily basis is required.

Benefit-risk communication in paediatric imaging: What do referring physicians, radiographers and radiologists think, say and do?

INTRODUCTION: To assess how referrers and practitioners disclose benefit-risk information about medical imaging examinations to paediatric patients and their parents/guardians; to gauge their confidence in doing so; and to seek their opinion about who is responsible for disclosing such information. METHODS: This study followed on from a previously published study, with a questionnaire distributed in staggered phases to 146 radiographers, 22 radiology practitioners, 55 emergency physicians and 43 paediatricians at a primary paediatric referral centre in Malta. The questionnaire sought details about referrers' and practitioners' practice of disclosing benefit-risk information, as well as their opinion about their confidence and responsibility to do so. RESULTS: An overall response rate of 63.2% (168/266) was achieved. Most referrers and practitioners would generally explain the purpose of the imaging examination, with fewer providing benefit-risk information. The content and the approach adopted to communicate benefit-risk information varied, at times considerably. While 75% (123/164) felt that the responsibility to provide benefit-risk information was a shared one between referrers and practitioners, only 32.1% (53/165) reported a high level of confidence in their own ability to do so. CONCLUSIONS: Our findings highlight potential knowledge and skills gaps amongst local referrers and practitioners. This needs addressing so as to ensure that paediatric patients and their parents/guardians are provided with adequate, reassuring and consistent information. Additionally, we recommend that local referrers and practitioners come together and develop a consensus document that can offer guidance on how to go about discussing the benefits and risks of paediatric imaging examinations.

Mammographic image reject rate analysis and cause - A National Maltese Study.

Mammography is used as a first-line investigation in the detection of breast cancer and imaging is required to be of optimal quality and achieved without adverse effects on the health of individuals. Repeated images come at a cost in terms of radiation dose, discomfort to clients and unnecessary financial burdens. No studies investigating mammography quality in Malta had been previously undertaken. Hence, this research aimed to investigate whether mammography is being performed at an acceptable level, through the investigation of reject rates. Quantitative methodology was used to collect data from eight participating mammography units, which were utilising screen film (SFM), computed radiography (CR) and direct digital mammography (DDM). Data relating to the total number of images performed, rejects and causes was prospectively collected over two weeks, resulting in a sample of 2291 images. All units were also asked to answer a questionnaire which provided other data that could be used for analysis. The national mammography reject rate was found to be 2.62%; within the 3% acceptable range. Individual rates' analysis revealed unacceptably high or low reject rates in some units. Positioning was the main reject cause. No significant difference in rejection was found between different types of mammography units or radiographers' experience. Alternatively, radiographers' qualifications, employment conditions and use of rejection criteria were proven to affect reject rates. Whilst on a national level, images are being rejected at an acceptable rate, individual units revealed suboptimal rates; at the cost of extra radiation, added discomfort and financial burden.