The potential for poplar and willow silvopastoral systems to mitigate nitrate leaching from intensive agriculture in New Zealand

In New Zealand, nitrate (NO₃⁻) leaching is a major environmental problem associated with intensive agriculture. Research suggests that plants with deeper roots and high evapotranspiration rates, such as poplars (Populus) and willows (Salix), may reduce NO3- leaching. In New Zealand, willows and poplars have largely been studied in relation to their soil conservation benefits, use as stock fodder, biomass production and phytoremediation of contaminated soil. This review compiles information on the use of poplars and willows in agricultural systems and explores their potential application to the management of NO₃⁻ leaching. Studies show reduced NO₃⁻ leaching under short rotation coppice willows. However, the establishment and harvesting phases are risk periods for NO₃⁻leaching where nitrogen application should be avoided. A case study has identified a potential for role of poplar and willow silvopastoral systems on intensively-managed irrigated farms of the Canterbury Plains. Height restrictions due to overhead irrigation, stock fodder value and the need to restrict light competition with pastures suggest Salix viminalis (with annual coppicing) is the most suitable species for integration into these farms. Further research is needed to quantify both the possible reduction in N losses and the additional on and off-farm benefits of poplar and willow silvopastoralism in the context of intensive farming in New Zealand

Visual grading characteristics and ordinal regression analysis during optimisation of CT head examinations

Objectives: To evaluate visual grading characteristics (VGC) and ordinal regression analysis during head CT optimisation as a potential alternative to visual grading assessment (VGA), traditionally employed to score anatomical visualisation.Methods: Patient images (n = 66) were obtained using current and optimised imaging protocols from two CT suites: a 16-slice scanner at the national Maltese centre for trauma and a 64-slice scanner in a private centre. Local resident radiologists (n = 6) performed VGA followed by VGC and ordinal regression analysis.Results: VGC alone indicated that optimised protocols had similar image quality as current protocols. Ordinal logistic regression analysis provided an in-depth evaluation, criterion by criterion allowing the selective implementation of the protocols. The local radiology review panel supported the implementation of optimised protocols for brain CT examinations (including trauma) in one centre, achieving radiation dose reductions ranging from 24 % to 36 %. In the second centre a 29 % reduction in radiation dose was achieved for follow-up cases.Conclusions: The combined use of VGC and ordinal logistic regression analysis led to clinical decisions being taken on the implementation of the optimised protocols. This improved method of image quality analysis provided the evidence to support imaging protocol optimisation, resulting in significant radiation dose savings.peer-reviewe

Breast screening attendance of Aboriginal and Torres Strait Islander women in the Northern Territory of Australia

Objective: To compare breast screening attendances of Indigenous and non-Indigenous women. Methods: A total of 4,093 BreastScreen cases were used including 857 self-identified Indigenous women. Chi-squared analysis compared data between Indigenous and non-Indigenous women. Logistic regression was used for groupings based on visits-to-screening frequency. Odds ratios and 95% confidence intervals were calculated for associations with low attendance. Results: Indigenous women were younger and had fewer visits to screening compared with non-Indigenous women. Non-English speaking was mainly associated with fewer visits for Indigenous women only (OR 1.9, 95%CI 1.3-2.9). Living remotely was associated with fewer visits for non-Indigenous women only (OR 1.3, 95%CI 1.1-1.5). Shared predictors were younger age (OR 12.3, 95%CI 8.1-18.8; and OR 11.5, 95%CI 9.6-13.7, respectively) and having no family history of breast cancer (OR 2.1, 95%CI 1.3-3.3; and OR 1.8, 95%CI 1.5-2.1, respectively). Conclusions: Factors associated with fewer visits to screening were similar for both groups of women, except for language which was significant only for Indigenous women, and remoteness which was significant only for non-Indigenous women. Implications for public health: Health communication in Indigenous languages may be key in encouraging participation and retaining Indigenous women in BreastScreen; improving access for remote-living non-Indigenous women should also be addressed

Book Reviews

Book Review

The pop-up research centre - Challenges and opportunities

Objectives: This article sets out to describe the concept of the “pop-up” research centre as a means to promote and develop radiography research locally, nationally and internationally, and to empower professional colleagues to set up similar initiatives in the future. Key findings: A detailed overview of the development and management of “pop-up” research is provided based on the experiences of the authors, including specific examples. Matters such as study design, approvals, equipment and software, environment, participant recruitment and management, research teams and activity costs are discussed. Quantifiable benefits of “pop-up” research such as resultant peer reviewed publications, development of researchers' skills and potential collaborations are described. A number of “soft skill” benefits are also apparent and include enhanced organisational profiles, team building and the development of leadership skills. Conclusions: “Pop-up” research centres are a valuable option for conducting research and offer the radiography profession an achievable mechanism to increase and enhance research activity. However, careful planning and execution are essential

Reducing dose for digital cranial radiography : The increased source to the image-receptor distance approach

This investigation proposes that an increased source to the image-receptor distance (SID) technique can be used to optimize occipital frontal and lateral cranial radiographs acquired with direct digital radiography. Although cranial radiography is not performed on a routine basis, it should nonetheless be optimized to keep the dose to the patient as low as reasonably achievable, particularly because it can form part of the facial bone and sinus series. Dose measurements were acquired at various SIDs, and image quality was assessed using visual grading analysis. Statistically significant reductions in the effective dose between 19.2% and 23.9% were obtained when the SID was increased from the standard 100 to 150 cm (P ≤.05), and visual grading analysis scores indicate that image quality remained diagnostically acceptable for both projections. This investigation concludes that increasing the SID effectively optimizes occipital frontal and lateral skull radiographs. Radiology departments must be advised of the benefits of this technique with the goal of introducing an updated reference SID of 150 cm into clinical practice.Peer reviewe

Strategies for dose reduction with specific clinical indications during computed tomography

Increasing integration of computed tomography (CT) into routine patient care has escalated concerns regarding associated radiation exposure. Specific patient cohorts, particularly those with cystic fibrosis (CF) and Crohn's disease, have repeat exposures and thus have an increased risk of high lifetime cumulative effective dose exposures. Thoracic CT is the gold standard imaging method in the diagnosis, assessment and management of pulmonary disease. In the setting of CF, CT demonstrates increased sensitivity compared with pulmonary function tests and chest radiography. Furthermore, in specific cases of Crohn's disease, CT demonstrates diagnostic superiority over magnetic resonance imaging (MRI) for radiological evaluation. Low dose CT protocols have proven beneficial in the evaluation of CF, Crohn's disease and renal calculi, and in the follow up of testicular cancer patients. For individuals with chronic conditions warranting frequent radiological follow up, the focus must continue to be the incorporation of appropriate CT use into patient care. This is of particular importance for the paediatric population who are most susceptible to potential radiation induced malignancy. CT technological developments continue to focus on radiation dose optimisation. This article aims to highlight these advancements, which prioritise the acquisition of diagnostically satisfactory images with the least amount of radiation possible

The effect of breast shielding outside the field of view on breast entrance surface dose in axial X-ray examinations: a phantom study

PURPOSEThe purpose of this study was to evaluate the effect of outside-field-of-view (FOV) lead shielding on the entrance surface dose (ESD) of the breast on an anthropomorphic X-ray phantom for a variety of axial skeleton X-ray examinations.METHODSUsing an anthropomorphic phantom and radiation dosimeter, the ESD of the breast was measured with and without outside-FOV shielding in anterior-posterior (AP) abdomen, AP cervical spine, occipitomental 30° (OM30) facial bones, AP lumbar spine, and lateral lumbar spine radiography. The effect of several exposure parameters, including a low milliampere-seconds technique, grid use, automatic exposure control use, wraparound lead (WAL) use, trolley use, and X-ray table use, on the ESD of the breast with and without outside-FOV shielding was investigated. The mean ESD (μSv) and standard deviation for each radiographic protocol were calculated. A one-tailed Student’s t-test was carried out to evaluate whether ESD to the breast was reduced with the use of outside-FOV shielding.RESULTSA total of 920 breast ESD measurements were recorded across the different protocol parameters. The largest decrease in mean ESD of the breast with outside-FOV shielding was 0.002 μSv (P = 0.084), recorded in the AP abdomen on the table with a grid, OM30 on the table with a grid, OM30 standard protocol on the trolley, and OM30 on the trolley with WAL protocols. This decrease was found to be statistically non-significant.CONCLUSIONThis study found no significant decrease in the ESD of the breast with the use of outside-FOV shielding for the AP abdomen, AP cervical spine, OM30 facial bones, AP lumbar spine, or lateral lumbar spine radiography across a range of protocols

A comparison of performances of consultant surgeons, NCHDs and medical students in a modified HPAT examination.

Following the implementation of the Fottrell report, entry to medical school in Ireland has undergone significant change. Medical school studentship is now awarded based on a combination of points obtained from the final examination of Irish secondary schools (the leaving certificate) combined with HPAT scores (Health Professions Admissions Test). The HPAT is designed to test a candidate\u27s knowledge in several different fields including problem solving skills, logical and non verbal reasoning. A sample HPAT was administered to a test group composed of consultant surgeons, non consultant hospital doctors, and medical students. Statistical analysis was performed and no significant difference was found between the performances of the groups. This is surprising as it was expected that groups with greater experience at medical problem solving would have translated to higher scores. This exposes a flaw within the HPAT system and a potential weakness in the process of doctor selection

Analysis of motion during the breast clamping phase of mammography

Objectives: To measure paddle motion during the clamping phase of a breast phantom for a range of machine/paddle combinations. Methods: A deformable breast phantom was used to simulate a female breast. Twelve mammography machines from three manufacturers with twenty two flexible and twenty fixed paddles were evaluated. Vertical motion at the paddle was measured using two calibrated linear potentiometers. For each paddle, the motion in millimeters was recorded every 0.5 seconds for 40 seconds while the phantom was compressed with 80 N. Independent t-tests were used to determine differences in paddle motion between flexible and fixed, small and large, GE Senographe Essential and Hologic Selenia Dimensions paddles. Paddle tilt in the medial-lateral plane for each machine/paddle combination was calculated. Results: All machine/paddle combinations demonstrate highest levels of motion during the first 10s of the clamping phase. Least motion is 0.17±0.05 mm/10s (n=20) and the most is 0.51±0.15 mm/10s (n=80). There is a statistical difference in paddle motion between fixed and flexible (p<0.001), GE Senographe Essential and Hologic Selenia Dimensions paddles (p<0.001). Paddle tilt in the medial-lateral plane is independent of time and varied from 0.04° to 0.69°. Conclusions: All machine/paddle combinations exhibited motion and tilting and the extent varied with machine and paddle sizes and types. Advances in knowledge: This research suggests that image blurring will likely be clinically insignificant 4 seconds or more after the clamping phase commences