Patient's posteroanterior chest radiographs are routinely displayed at different sizes on PACS: Cause and prevalence.

OBJECTIVE: Sequential posteroanterior chest radiographs (CXRs) on any one patient are commonly displayed at different sizes on PACS monitors. The purpose of this study was to determine the cause of these differences, the percentage of radiographs affected, the relative change in magnification seen and if radiologists were aware of this display difference. METHODS: Differences in routine radiographer collimation pre-acquisition and image cropping (shuttering) post acquisition were noted. From three different hospitals, 300 posteroanterior (PA) erect CXRs with prior comparative studies were viewed side-by-side on a standard landscape display monitor. Variation in display size was calculated using the number of detector elements in the autofitted axis of the radiograph, when compared with the prior study. Correlation between patient gender and extent of magnification between images was recorded. Following this, a national survey was circulated to see if radiologists were aware of this phenomenon. RESULTS: Large variations in display size were noted. The mean extent of magnification between sequential PA chest radiographs was ±6.8% (range 0-21.6%). 98% of CXRs had some degree of variability in display size. There was no significant difference in the extent of variation in magnification based on age or gender. 86% of the radiologists who responded to the survey (n = 132) were unaware of any display size variability. CONCLUSION: Sequential DR acquired chest radiographs are routinely displayed with varying degrees of magnification on PACS monitors due to differences in radiographer practice and auto-fit display settings. Most radiologists surveyed were unaware of these differences and their causation.

Change from transrectal to transperineal ultrasound-guided prostate biopsy under local anaesthetic eliminates sepsis as a complication.

Transrectal ultrasound-guided (TRUS) biopsy of the prostate is associated with increased risk of post-procedural sepsis with associated morbidity, mortality, re-admission to hospital, and increased healthcare costs. In the study institution, active surveillance of post-procedural infection complications is performed by clinical nurse specialists for prostate cancer under the guidance of the infection prevention and control team. To protect hospital services for acute medical admissions related to the coronavirus disease 2019 (COVID-19) pandemic, TRUS biopsy services were reduced nationally, with exceptions only for those patients at high risk of prostate cancer. In the study institution, this change prompted a complete move to transperineal (TP) prostate biopsy performed in outpatients under local anaesthetic. TP biopsies eliminated the risk of post-procedural sepsis and, consequently, sepsis-related admission while maintaining a service for prostate cancer diagnosis during the COVID-19 pandemic.

Trade-offs between succulent and non-succulent epiphytes underlie variation in drought tolerance and avoidance.

Epiphyte communities comprise important components of many forest ecosystems in terms of biomass and diversity, but little is known regarding trade-offs that underlie diversity and structure in these communities or the impact that microclimate has on epiphyte trait allocation. We measured 22 functional traits in vascular epiphyte communities across six sites that span a microclimatic gradient in a tropical montane cloud forest region in Costa Rica. We quantified traits that relate to carbon and nitrogen allocation, gas exchange, water storage, and drought tolerance. Functional diversity was high in all but the lowest elevation site where drought likely limits the success of certain species with particular trait combinations. For most traits, variation was explained by relationships with other traits, rather than differences in microclimate across sites. Although there were significant differences in microclimate, epiphyte abundance, and diversity, we found substantial overlap in multivariate trait space across five of the sites. We found significant correlations between functional traits, many of which related to water storage (leaf water content, leaf thickness, hydrenchymal thickness), drought tolerance (turgor loss point), and carbon allocation (specific leaf area, leaf dry matter content). This suite of trait correlations suggests that the epiphyte community has evolved functional strategies along with a drought avoidance versus drought tolerance continuum where leaf succulence emerged as a pivotal overall trait.

Technique and protocols for cardiothoracic time-resolved contrast-enhanced magnetic resonance angiography sequences: a systematic review.

AIM: To review contrast medium administration protocols used for cardiothoracic applications of time-resolved, contrast-enhanced magnetic resonance angiography (MRA) sequences. MATERIALS AND METHODS: A systematic search of the literature (Medline/EMBASE) was performed to identify articles utilising time-resolved MRA sequences, focusing on type of sequence, adopted technical parameters, contrast agent (CA) issues, and acquisition workflow. Study design, year of publication, population, magnetic field strength, type, dose, and injection parameters of CA, as well as technical parameters of time-resolved MRA sequences were extracted. RESULTS: Of 117 retrieved articles, 16 matched the inclusion criteria. The study design was prospective in 9/16 (56%) articles, and study population ranged from 5 to 185 patients, for a total of 506 patients who underwent cardiothoracic time-resolved MRA. Magnetic field strength was 1.5 T in 13/16 (81%), and 3 T in 3/16 (19%) articles. The administered CA was gadobutrol (Gadovist) in 6/16 (37%) articles, gadopentetate dimeglumine (Magnevist) in 5/16 (31%), gadobenate dimeglumine (MultiHance) in 2/16 (13%), gadodiamide (Omniscan) in 2/16 (13%), gadofosveset trisodium (Ablavar, previously Vasovist) in 1/16 (6%). CA showed highly variable doses among studies: fixed amount or based on patient body weight (0.02-0.2 mmol/kg) and was injected with a flow rate ranging 1-5 ml/s. Sequences were TWIST in 13/16 (81%), TRICKS in 2/16 (13%), and CENTRA 1/16 articles (6%). CONCLUSION: Time-resolved MRA sequences were adopted in different clinical settings with a large spectrum of technical approaches, mostly in association with different CA dose, type, and injection method. Further studies in relation to specific clinical indications are warranted to provide a common standardised acquisition protocol.

Subtraction of time-resolved magnetic resonance angiography images improves visualization of the pulmonary veins and left atrium in adults with congenital heart disease: a novel post-processing technique.

To describe a novel time-resolved magnetic resonance angiography (TR-MRA) postprocessing technique using the time-resolved angiography with interleaved stochastic trajectories (TWIST) method to evaluate the pulmonary veins and left atrium in adults with congenital heart disease undergoing cardiac MRI. Institutional ethics committee approved the study. 21 consecutive adult patients (14 female, 7 male patients, mean age 28 years) with known congenital heart disease who underwent a cardiac MRI were included. Post-processing of the TR-MRA sequences created novel "subtracted" datasets. Two independent observers reviewed the conventional TWIST and novel subtracted TWIST data sets in source and maximum intensity projection (MIP) coronal reformats to assess visualization of the pulmonary veins and left atrium based on a 5-point scale. Quantitative signal to noise (SNR) comparison was performed. TR-MRA yielded diagnostic image data in 20/21 patients (95.2%). The novel "subtracted" TR-MRA technique improved visualization of the pulmonary veins and left atrium compared to the source TR-MRA sequence in 16/20 patients (mean scores 3.34 ± 0.69 vs. 2.92 ± 0.69, p < 0.008). Further improved visualization of the pulmonary veins and left atrium was observed in the subtracted MIP TWIST sequences compared to the MIP TWIST images (mean scores 4.43 ± 0.80 vs. 3.02 ± 0.87 vs., p < 0.001). No significant SNR difference between the source and novel subtracted group was observed (85.4 vs. 70.4, p = 0.57). Compared to source TR-MRA images, subtraction of TR-MRA images is a novel postprocessing technique that improves visualization of the pulmonary veins and left atrium in a substantial number of patients.

The role of 3D printing in preoperative planning for heart transplantation in complex congenital heart disease.

BACKGROUND: The presence of a structural cardiac defect in the setting of dextrocardia is extremely rare. Graspable models allow enhanced appreciation of aberrant structures and vascular relations, particularly in rare and complex cases. This is the first case report of the use of a replica of a patients' anatomy to plan the surgical strategy in the setting of dextrocardia. AIMS: We intend to demonstrate the benefit of three-dimensional printing to enhance preoperative planning in complex congenital heart disease undergoing heart transplantation. The anomalous structures encountered include situs inversus dextrocardia, transposition of the great vessels, a single atrium and a dilated double-outlet single right ventricle. METHODS: Computed Tomography acquisition was performed with the use of ECG multiphase gating technology and contrast enhancement. The structures of interest were segmented and the generated 3D mesh was exported as a stereolithographic (STL) file. The model was printed on a Z-Corp 250 binder jetting printer. Post processing techniques were used to enhance model strength. RESULTS: Pre-operative 3D visualisation of the patients' anatomy allowed for a more comprehensive surgical strategy to be planned, thus reducing the intra-operative duration and cross-clamp time which are recognised to correlate with reduced patient morbidity. CONCLUSION: The ongoing advances in medical image procurement and 3D processing software and printing technology will continue to enhance preoperative planning and thereby improve patient care. We demonstrate the pivotal role played by such technologies in advancing spatial comprehension of complex aberrant anatomy.

Multiple myeloma: a review of imaging features and radiological techniques.

The recently updated Durie/Salmon PLUS staging system published in 2006 highlights the many advances that have been made in the imaging of multiple myeloma, a common malignancy of plasma cells. In this article, we shall focus primarily on the more sensitive and specific whole-body imaging techniques, including whole-body computed tomography, whole-body magnetic resonance imaging, and positron emission computed tomography. We shall also discuss new and emerging imaging techniques and future developments in the radiological assessment of multiple myeloma.

Meticillin-resistant Staphylococcus aureus (MRSA) environmental contamination in a radiology department.

AIM: To explore the potential risk to patients and healthcare workers of acquiring meticillin-resistant Staphylococcus aureus (MRSA) in clinical and non-clinical areas within a radiology department. MATERIALS AND METHODS: High-risk sites in clinical and non-clinical areas within the Department of Radiology were identified and 125 environmental swabs were obtained by an infection control nurse specialist. Decontamination methods and protocols were reviewed and compared against international decontamination best practice. RESULTS: One of 125 samples was culture positive for MRSA. The positive sample was isolated from the surface of the bore of the magnetic resonance imaging (MRI) unit. A hypochlorite cleaning agent was applied using a long-handled brush to clean the bore of the MRI unit. A repeat environmental screen found the MRI unit to be culture negative for MRSA. CONCLUSION: This study has demonstrated that standard decontamination measures are adequate to prevent environmental contamination with MRSA in a radiology department. However, the MRI unit requires special attention because of its long bore and difficult access.

Managing animal disease risk in Australia: the impact of climate change.

Climate change is one of a number of factors that are likely to affect the future of Australian agriculture, animal production and animal health, particularly when associated with other factors such as environmental degradation, intensive animal production, an increasing human population, and expanding urbanisation. Notwithstanding the harshness and variability of Australia's climate, significant livestock industries have been developed, with the majority of products from such industries exported throughout the world. A critical factor in achieving market access has been an enviable animal health status, which is underpinned by first class animal health services with a strong legislative basis, well-trained staff, engagement of industry, effective surveillance, good scientific and laboratory support, effective emergency management procedures, a sound quarantine system, and strong political support. However, enhancements still need to be made to Australia's animal health system, for example: re-defining the science-policy interface; refining foresight, risk analysis, surveillance, diagnostics, and emergency management; improving approaches to education, training, technology transfer, communications and awareness; and engaging more with the international community in areas such as capacity building, the development of veterinary services, and disease response systems. A 'one health' approach will be adopted to bring together skills in the fields of animal, public, wildlife and environmental health. These initiatives, if managed correctly, will minimise the risks resulting from global warming and other factors predisposing to disease.

Meeting the requirements of importing countries: practice and policy for on-farm approaches to food safety.

In light of the increasing consumer demand for safe, high-quality food and recent public health concerns about food-borne illness, governments and agricultural industries are under pressure to provide comprehensive food safety policies and programmes consistent with international best practice. Countries that export food commodities derived from livestock must meet both the requirements of the importing country and domestic standards. It is internationally accepted that end-product quality control, and similar methods aimed at ensuring food safety, cannot adequately ensure the safety of the final product. To achieve an acceptable level of food safety, governments and the agricultural industry must work collaboratively to provide quality assurance systems, based on sound risk management principles, throughout the food supply chain. Quality assurance systems on livestock farms, as in other parts of the food supply chain, should address food safety using hazard analysis critical control point principles. These systems should target areas including biosecurity, disease monitoring and reporting, feedstuff safety, the safe use of agricultural and veterinary chemicals, the control of potential food-borne pathogens and traceability. They should also be supported by accredited training programmes, which award certification on completion, and auditing programmes to ensure that both local and internationally recognised guidelines and standards continue to be met. This paper discusses the development of policies for on-farm food safety measures and their practical implementation in the context of quality assurance programmes, using the Australian beef industry as a case study.

Diagnosis of pulmonary emboli and image quality at CT pulmonary angiography: influence of imaging direction with multidetector CT.

AIM: To determine whether there was a significant difference in the prevalence of emboli detected when patients underwent computed tomography pulmonary angiography (CTPA) in a craniocaudal direction versus a caudocranial direction. MATERIALS AND METHODS: This was a prospective study of 203 consecutive patients attending for CTPA for suspected pulmonary embolus. Imaging was performed on a multisection Siemens Volume Zoom CT machine, with bolus tracking centred on the main pulmonary artery after intravenous administration of contrast at 3 ml/s. Patients were examined in a single breath-hold, from the top of the aortic arch to the highest point of the diaphragm, in a randomly assigned cranio-caudal (group A), or caudo-cranial (group B) direction. Images were reviewed on a workstation in a cranio-caudal direction jointly by two radiologists unaware of the original imaging direction. The presence, number and position of arterial emboli were noted, and a subjective assessment of overall image quality and opacification of upper and lower lobe vessels (grade 1, 2, 3, or 4) was made. RESULTS: Emboli were detected in 46 patients. There was no significant difference in the prevalence of emboli detected in the two groups [group A craniocaudal direction n=22, group B caudocranial direction n=24 (p=0.76)]. Imaging direction did not significantly influence overall image quality (p=0.07), however, there was a significantly greater proportion of patients in group A with grade 1 opacification of the upper lobe arteries (p=0.02). CONCLUSION: Imaging direction does not significantly influence the diagnosis of pulmonary emboli but it does significantly improve the upper lobe pulmonary arterial enhancement with fewer non-diagnostic images, and on that basis we recommend that craniocaudal direction be used for CTPA studies.

MR imaging of traumatic spinal injuries.

Plain films form the initial evaluation in all cases of spinal trauma. In cases of indeterminate or incomplete plain radiographs, further evaluation should be performed by multiplanar computed tomography (CT) and/or magnetic resonance imaging (MRI). Rapid triage is important to distinguish surgical and nonsurgical cases, as this has implications in terms of relief of cord compression and long-term prognosis. CT is unparalleled in its capacity to demonstrate bony abnormalities. MRI is the modality of choice in the evaluation of soft tissue injuries, in particular where there is a suspicion of ligamentous or intervertebral disc injury and spinal cord injury. MRI has the ability to distinguish between spinal cord edema and hemorrhage, which has important prognostic significance.

Transrectal ultrasound-guided biopsy of the prostate gland: value of 12 versus 6 cores.

We investigated the effect on prostate carcinoma detection of 12 versus 6 core biopsies at transrectal ultrasound (TRUS), when all biopsies are taken from the lateral peripheral zone. This was a prospective study of 202 consecutive men, ages 51 to 81 years, referred for TRUS-guided biopsy of the prostate gland. All patients had prostate serum antigen levels higher than 4.0 ng/mL and/or abnormal digital rectal examination. In each case three biopsies were taken from the peripheral zones of the right and left lobes of the prostate. Biopsies were taken at the apex, midway between the apex and the base, and at the base. A second set of biopsies was taken from the same regions and analyzed separately. In total, twelve biopsies were taken. Note was subsequently made of additional carcinoma diagnosis increase in Gleason grade, and new diagnoses of carcinoma in the opposite side of the gland diagnosed on the second set of biopsies alone. Seventy-eight of the 202 men (38.6%) had prostatic carcinoma diagnosed on TRUS-guided biopsy. Of these 78 patients, six were diagnosed with malignancy based on the second set of biopsies alone, a 2.9% increase in the 202 patients, representing an increased yield of 8.3% (95% confidence interval, 5.3-28.6%). In nine cases (12.5%; 95% confidence interval, 6.2-22.9%), the Gleason tumor grade was increased on the second set of sextant biopsies; in an additional nine cases, carcinoma was detected in the opposite side of the gland. There were two complications (1%). A 12- versus six-core biopsy strategy for TRUS-guided biopsy of the prostate gland improves detection and histologic grading of prostate carcinoma. The added benefit of additional biopsies was lower in this series than in some prior studies using extensive biopsy protocols.

Risk of pulmonary embolism after negative MDCT pulmonary angiography findings.

OBJECTIVE: The purpose of our study was to determine the risk of pulmonary embolism in patients who have negative MDCT pulmonary angiography findings. SUBJECTS AND METHODS: In this prospective study, one hundred two consecutive patients with suspected pulmonary embolism underwent MDCT pulmonary angiography. Scans were reviewed jointly by two observers and findings recorded by consensus. Observers noted whether pulmonary embolism or other disease was present. No pulmonary embolism was seen in 85 patients (52 men and 33 women; age range, 20-94 years; mean age, 60 years) who were followed up for a mean of 9 months (range, 4-13 months) for evidence of subsequent pulmonary embolism. RESULTS: One patient had a diagnosis of pulmonary embolism made within 3 weeks of undergoing CT pulmonary angiography. MDCT pulmonary angiography showed additional potentially significant findings in 76% of patients; 47% of these findings were not suspected on chest radiography. CONCLUSION: The risk of pulmonary embolism at a mean of 9 months after negative MDCT pulmonary angiography findings is 1%. In our study of patients without pulmonary embolism, MDCT pulmonary angiography revealed other causes for individual patients' signs or symptoms in most cases.

Quality assurance and meat inspection in Australia.

The aim of meat inspection in Australia is to contribute to the production of safe and wholesome food, comply with the requirements of importing countries, and support national animal health objectives. An analysis of the role of quality assurance (QA) in the meat inspection systems at federally inspected establishments shows that the position of Australia as a leading meat exporter is aided by a co-regulatory, QA-based approach to meat inspection, which is equally applicable to all species at slaughter. Technical developments in meat inspection at the national and international level during the 1990s led to significant enhancements in QA systems. Quality assurance is implemented through nationally uniform documented systems, which are designed to achieve consistent standards of meat safety. These systems are complemented by hazard analysis critical control point-based QA programmes which meet the quality-standards of the International Organization for Standardization. Quality assurance programmes aim for a 'whole of chain' approach, so that the system is implemented 'from the paddock to the plate', or from pre-harvest through to post-harvest, i.e., from on-farm practices to the refrigeration, storage and transportation stages. The QA elements of meat inspection employed in production systems in Australia have significantly contributed to the consistent achievement of meat safety objectives that are appropriate to contemporary risks.

Transjugular liver biopsy: assessment of safety and efficacy of the Quick-Core biopsy needle.

BACKGROUND: We assessed the safety and efficacy of transjugular liver biopsy with the Quick-Core biopsy needle. METHODS: Fifty consecutive patients with liver failure and contraindications to percutaneous liver biopsy were referred for transjugular liver biopsy. Eighteen (36%) patients had thrombocytopenia (platelet range = 44-92/microL, mean = 66/microL), 31 (62%) patients had elevated prothrombin times (international normalized ratio range = 1.3-3, mean = 1.6), and 19 (38%) patients had ascites. The Cook Quick-Core biopsy needle was used. RESULTS: Average procedure time was 30 min. Transjugular access to the hepatic veins was successful in 49 of 50 cases. A transfemoral approach was used in one patient. Tissue specimens were satisfactory for histologic diagnosis in all cases. Established cirrhosis was present in 37 (74%) patients. The mean number of cores was 2.2 (range = 1-3). The mean number of portal triads per core was 10.4 (range = 6-20). There were no procedure-related complications. CONCLUSION: Transjugular liver biopsy with the Quick-Core biopsy needle is safe and effective in patients in whom the percutaneous route is contraindicated by coagulopathy or ascites.