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To estimate the incidence, timing and severity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) breakthrough infections in fully vaccinated healthcare personnel (HCP). In total, 6496 fully vaccinated HCP were analysed prospectively from 15th November 2021 to 17th April 2022. Full coronavirus disease 2019 (COVID-19) vaccination was defined as a complete primary vaccination series followed by a booster dose at least 6 months later. Overall, 1845 SARS-CoV-2 breakthrough infections occurred (28.4 episodes per 100 HCP), of which 1493 (80.9%) were COVID-19 cases and 352 (19.1%) were asymptomatic infections. Of the 1493 HCP with COVID-19, four were hospitalized for 3–6 days (hospitalization rate among HCP with COVID-19: 0.3%). No intubations or deaths occurred. SARS-CoV-2 breakthrough infections occurred at a mean of 16.2 weeks after the last vaccine dose. Multi-variable regression analyses showed that among the 1845 HCP with a breakthrough infection, the administration of a COVID-19 vaccine dose ≥16.2 weeks before the infection was associated with increased likelihood of developing COVID-19 rather than asymptomatic SARS-CoV-2 infection [odds ratio (OR) 1.58, 95% confidence interval (CI) 1.01–2.46; P =0.045] compared with administering a vaccine dose later. The likelihood of developing COVID-19 compared with asymptomatic infection increased by 7% weekly after the last COVID-19 vaccine dose (OR 1.07, 95% CI 1.03–1.11; P =0.001). SARS-CoV-2 breakthrough infections are common among fully (boosted) vaccinated HCP. However, full COVID-19 vaccination offered considerable protection against hospitalization. These findings may contribute to defining the optimal timing for booster vaccinations. More efficient COVID-19 vaccines that will also confer protection against SARS-CoV-2 infection are needed urgently. [ABSTRACT FROM AUTHOR]

The objective of this work is to introduce novel methodologies in specific parts of Field Development Plans (FDPs) by leveraging contemporary technological advancements, industry best practices, and accumulated knowledge. The proposed methodologies comprise volumetric analysis by conducting stochastic simulations within a Monte Carlo framework to evaluate the associated uncertainties and a piston-like CO 2 storage scheme (based on the material balance approach) aiming to enhance natural gas production and at the same time store CO 2 , mitigating climate change. Optimization of drilling operations based on appropriate material selection from commercial casing tables and assignment of a failure probability of casing configuration are also included. Another proposed methodology involves spatial risk analysis simulating accidental events based on the points of interest (POIs) and the distance from the event. Finally, a stochastic analysis of project economics is conducted showing uncertainties of cashflows throughout the economic life of the project and assessing the outcomes using various probabilistic performance metrics. The integration of these methodologies offers a robust framework for enhancing the effectiveness of FDPs and their applications, aligning with the evolving demands and complexities of the oil and gas sector. Such methodologies, rooted in mathematical tools aiming to quantify uncertainty in various ways, can increase production, potentially reducing costs through carbon tax incentives and benefit the environment. The applicability of the proposed methodology is demonstrated at the Frigg field, a natural gas reservoir situated in the Norwegian sector of the North Sea. Given its historical development in the 1970s and 1980s, the Frigg field serves as a rich repository of data and information for comparative analysis and fine-tuning of the proposed methodologies. The present study bridges the gap between theoretical advancements and practical applications, promoting innovation and efficiency within the oil and gas field development processes. • Monte Carlo simulations are tailored for cashflows and volumetrics. • Simulations of the injection of CO 2 for Enhanced Gas Recovery are presented. • In-house algorithm finds casing configuration with minimal cost ensuring integrity. • Kernel-based algorithm identifies spatial risk in accidents (e.g., explosions). • Cashflows include production start delay impacts, crucial for profitability metrics. [ABSTRACT FROM AUTHOR]

• TACE procedures delivered the highest doses, in terms of P KA and K a,r. • Peak skin doses were generally lower than the 2 Gy alarm threshold. • Procedure complexity can affect DRLs. • PSD can be safely predicted from total K a,r , depending on body region imaged. Institutional (local) Diagnostic Reference Levels for Cerebral Angiography (CA), Percutaneous Transhepatic Cholangiography (PTC), Transarterial Chemoembolization (TACE) and Percutaneous Transhepatic Biliary Drainage (PTBD) are reported in this study. Data for air kerma-area product (P KA), air kerma at the patient entrance reference point (K a,r), fluoroscopy time (FT) and number of images (NI) as well as estimates of Peak Skin Dose (PSD) were collected for 142 patients. Therapeutic procedure complexity was also evaluated, in an attempt to incorporate it into the DRL analysis. Local P KA DRL values were 70, 34, 189 and 54 Gy.cm2 for CA, PTC, TACE and PTBD respectively. The corresponding DRL values for K a,r were 494, 194, 1186 and 400 mGy, for FT they were 9.2, 14.2, 27.5 and 22.9 min, for the NI they were 844, 32, 602 and 13 and for PSD they were 254, 256, 1598 and 540 mGy respectively. P KA for medium complexity PTBD procedures was 2.5 times higher than for simple procedures. For TACE, the corresponding ratio was 1.6. PSD was estimated to be roughly 50% of recorded K a,r for procedures in the head/neck region and 10% higher than recorded K a,r for procedures in the body region. In only 5 cases the 2 Gy dose alarm threshold for skin deterministic effects was exceeded. Procedure complexity can differentiate DRLs in Interventional Radiology procedures. PSD could be deduced with reasonable accuracy from values of K a,r that are reported in every angiography system. [ABSTRACT FROM AUTHOR]

The aim of this systematic review was to explore the prognostic value of late gadolinium enhancement (LGE) in patients with aortic stenosis (AS). Myocardial fibrosis is a common feature of many cardiac diseases. Cardiac magnetic resonance (CMR) has the ability to noninvasively detect regional fibrosis by using the LGE technique. Several studies have explored whether LGE is associated with adverse outcome in patients with AS. Electronic databases were searched to identify studies investigating the ability of LGE to predict all-cause mortality in patients with AS. A random effects model meta-analysis was conducted. Heterogeneity was assessed with the I 2 statistic. Six studies comprising 1,151 patients met our inclusion criteria. LGE was present in 49.1% of patients with AS. In the pooled analysis, LGE was found to be a strong univariate predictor of all-cause mortality (pooled unadjusted odds ratio: 2.56; 95% confidence interval: 1.83 to 3.57; I 2 = 0%). Four of the included studies reported adjusted hazard ratios for mortality. LGE was independently associated with mortality, even after adjusting for baseline characteristics (pooled adjusted hazard ratio: 2.50; 95% confidence interval: 1.64 to 3.83; I 2 = 0%). Fibrosis on LGE-CMR is a powerful predictor of all-cause mortality in patients with AS and may serve as a novel marker for risk stratification. Future studies should explore whether LGE-CMR can also be used to optimize timing of AS-related interventions. [ABSTRACT FROM AUTHOR]

• A simplified extra low cost striatum phantom was constructed. • TEW scatter correction increases SBR values in 123I-FP-CIT imaging by 35–50% • SPECT radius of rotation strongly affects measured SBR values. • Appropriate correction factors can be applied to make SBR values radius independent. The high energy emissions of 123I and the suboptimal radius of rotation affect the semiquantitative measurements performed during 123I-FP-CIT tomographic imaging. An in-house extra low cost striatum phantom with brain and striatum compartments was constructed and was used to study the effects of Triple Energy Window scatter correction (TEW-SC) and radius of rotation on the Specific Binding Ratio (SBR) measurements. The phantom compartments were filled with radioactive 123I solutions with varying concentrations, in a series of experiments. Tomographic images were acquired at six different radii of rotation, with and without TEW-SC and the SBRs were calculated using appropriate regions of interest, as in clinical imaging. SBRs decreased with increasing radius of rotation in both non-SC and TEW-SC images, the decrease being more pronounced in the latter. The application of TEW-SC increases SBR values by 40% on average. A maximum %Recovery of 42.7% of the true SBR value was achieved in the non-SC images, which increased to 64.6% after TEW-SC. Appropriate correction factors (CF) were calculated in order to make the SBR values independent on the radius of rotation, which could be used to correct SBR values obtained from tomographic acquisitions with suboptimal radius of rotation. The use of appropriate CF can provide more consistent SBR values and a more meaningful comparison between SBRs calculated from images acquired at different radii of rotation. [ABSTRACT FROM AUTHOR]

• Weight-adjusted administered activity can yield weight independent count density. • The same activity escalation formula can be used for males and females. • Radiopharmaceutical residual syringe activity must be compensated for. Nuclear medicine myocardial perfusion imaging (MPI) in obese patients requires the administration of higher amounts of radioactivity, to compensate for the loss of photons due to the increased attenuation and scatter. The aim of the present study was to investigate whether an administered activity escalation protocol, proposed to yield the same effective dose irrespective of patient's weight, can also lead to images of comparable count density for all patients. 184 pharmacologically induced stress 99m-Tc MIBI and 99m-Tc tetrofosmin SPECT MPI examinations (123 males, 61 females) were included in this study. Body weight, BMI and chest circumference were collected for each patient. The administered activity was adjusted to body weight according to the IAEA protocol. Detector count rate (DCR) from the projection images and normal myocardial count rate (MCR) from the appropriately segmented reconstructed images, with and without attenuation correction, were recorded. No statistically significant correlation was found between DCR and any anthropometric parameter. A weak correlation was observed between MCR and BMI and between MCR and chest circumference for male patients only, but even these correlations were eliminated after the application of attenuation correction. The anthropometric parameter that generally correlates more strongly with DCR/MBq and MCR/MBq was body weight for men and chest circumference for women. The IAEA activity escalation protocol used in this study leads to comparable image count densities, irrespective of body weight, for both men and women. [ABSTRACT FROM AUTHOR]

The purpose of this review article is to explore a new paradigm on healthcare assessment and intervention practices for students with learning, physical and/or sensory disabilities. The perspective presented here is regarded as patient centric and relies on ICTs, in order to address evidence–based treatment and care, meeting every individual’s health profile, with regard to his or her needs, preferences, goals and culture. Patient-centric ICTs based approach has an impact on healthcare systems, introducing a multi-disciplinary care planning that overcomes individual, professional and organizational barriers, reduces anxiety and establishes better understanding with the student at the center. Generally, results show the impact of the interoperability of healthcare information between patients’ healthcare record and information systems which facilitate healthcare systems to be lifesaving if available at the time of medical examination. When medical treatment is combined with ICTs based methods and applications such as Serious Games, Mobile Assistive Technologies applications, Telehealth Systems and Virtual Training, patients with learning, physical and/or sensory disabilities can benefit from a cost-effective and flexible network model while having their customized needs fully examined and resolved. The articles presented within this review demonstrate that ICTs based patient-centeredness for students with learning, physical and/or sensory disabilities is associated with better (functional) outcomes leading to quality of life and inclusion, improved quality of care, fewer problem behaviors, higher levels of health-related autonomy and greater patient satisfaction. [ABSTRACT FROM AUTHOR]

• Dose-optimized exposure protocols preserved or, in some cases, improved image quality. • Low-contrast detectability exhibited a strong dependence on kV/mAs settings. • Optimized head protocol resulted in a 48 % decrease in lens dose for both eyes. • Head-PA view reduced eye lens doses by about 98.5 % compared to AP view. In contemporary radiotherapy, patient positioning accuracy relies on kV imaging. This study aims at optimizing planar kV image acquisition protocols regarding patient dose without degrading image quality. An image quality test-object was placed in-between PMMA plates, suitably arranged to model head or pelvis. Constructed phantoms were imaged using default protocols, the resultant image quality was assessed and the corresponding radiation dose was measured. The process was repeated using numerous kV/mAs combinations to identify those acquisition settings providing images at lower dose than the default protocols but without deterioration in image quality. Default and dose-optimized protocols were then tested on an anthropomorphic phantom and on 51 patients during two successive treatment sessions. Image quality was independently assessed by two readers. Organ and effective doses were estimated using a Monte Carlo simulation software. Low-contrast detectability exhibited a stronger dependence on kV/mAs settings, compared to high-contrast resolution. Dose-optimized protocols resulted in significant dose reductions (anteroposterior-head 48.0 %, lateral-head 30.0 %, anteroposterior-pelvis 28.4 %, lateral-pelvis 27.0 %) compared to the default ones, without compromising image quality. Optimized protocols decreased effective doses by 54 % and 29.6 % in head and pelvic acquisitions, respectively. Regarding image quality, anthropomorphic and patient images acquired using the dose-optimized protocols were subjectively evaluated equivalent to those obtained with the corresponding default settings, indicating that the proposed protocols may be routinely used. Given the potentially large number of radiotherapy fractions and the pertinent image acquisitions, dose-optimized protocols could significantly reduce patient dose associated with planar imaging without compromising positioning accuracy. [ABSTRACT FROM AUTHOR]

• Medical Physics educators contribute to the education of healthcare professions. • Updated mission and vision statements for the role. • Suggested best practices for teaching non-physics healthcare professionals. • Stepwise process for curriculum development. • Research based summary recommendations. Although Medical Physics educators have historically contributed to the education of the non-physics healthcare professions, their role was not studied in a systematic manner. In 2009, EFOMP set up a group to research the issue. In their first paper, the group carried out an extensive literature review regarding physics teaching for the non-physics healthcare professions. Their second paper reported the results of a pan-European survey of physics curricula delivered to the healthcare professions and a Strengths-Weaknesses-Opportunities-Threats (SWOT) audit of the role. The group's third paper presented a strategic development model for the role, based on the SWOT data. A comprehensive curriculum development model was subsequently published, whilst plans were laid to develop the present policy statement. This policy statement presents mission and vision statements for Medical Physicists teaching non-physics users of medical devices and physical agents, best practices for teaching non-physics healthcare professionals, a stepwise process for curriculum development (content, method of delivery and assessment), and summary recommendations based on the aforementioned research studies. [ABSTRACT FROM AUTHOR]

Abstract: We aimed to investigate the effect of metal ions on the semen of males of child fathering age with metal-on-metal (MM) total hip arthroplasty (THA). Semen was collected form 11 patients with MM THA and 5 control of comparable age. Cobalt and chromiun concentrations were measured in both the seminal plasma and in the blood of patients. Results showed that cobalt level was higher in the seminal plasma of MM THA patients (2.89 μg/L) compared to control patients (1.12 μg/L) (P = .011). The ejaculate volume, the sperm density, the total sperm count, the pH, and the percentage of cells with normal morphology were in the range of the World Health Organization criteria for fertile population. [Copyright &y& Elsevier]

Abstract: To assess the impact of I-123 ioflupane single photon emission computed tomography (SPECT) imaging on classifying patients with striatal dopaminergic deficits. Sixty-one patients with an initial diagnosis of parkinsonism or uncertain tremor disorder were screened and followed-up for one year. All patients were re-examined by two neurologists at our centre and were classified as having neurodegenerative or non-neurodegenerative disorders. Patients underwent I-123 ioflupane SPECT imaging. SPECT studies were blindly evaluated and classified as normal or abnormal (indicative of neurodegenerative disorders). The overall agreement of the SPECT imaging results with the initial classification was 65.6% (kappa=0.229, p =0.074) but was 90.2% (kappa=0.782, p <0.001) with the classification of the neurologists at our centre. I-123 ioflupane SPECT imaging is a valuable method in the evaluation of patients presenting clinically with uncertain parkinsonian syndromes or for whom diagnostic doubt exists. [Copyright &y& Elsevier]

Abstract: The lip is estimated to be the most frequent location for carcinoma of the oral cavity. It occurs more frequently in men, especially those with a history of exposure to sunlight. Despite the usually effective management, regional and occasionally distant metastases do occur, especially in advanced stages. In this retrospective analysis of patients with labial carcinoma presenting with distant bone metastases in 1995–2003, the extremely limited number of patients did not allow for multivariate data analysis. From a cohort of 415 patients presenting with lip lesions, 186 cases were diagnosed as carcinoma and managed accordingly. Four patients (2.14%) showed distant bone metastases, one with concurrent axillary node metastasis. Patient demographics, tumour characteristics, case management and survival were evaluated. The distant metastasis patients were of clinical stages II–IV; initial management was wide local excision with reconstruction for all cases, with one undergoing concurrent neck dissection and one adjuvant radiotherapy. Time for distant bone metastasis was 9–21 months, subsequent survival 3–14 months and overall survival 13–35 months. Distant metastases from labial carcinoma are rare, not exceeding 2%. Metastasis to bone and axillary lymph nodes is exceptionally rare and can be attributed to either inadequate initial management or aggressive tumour behaviour. [Copyright &y& Elsevier]

Summary: Introduction: There is still no consensus on the need for routine removal of titanium miniplates in the maxillofacial skeleton. The purpose of this 4-year prospective study was to evaluate the reasons for removal of titanium miniplates (“2.0mm”) following maxillofacial trauma. Material and methods: Records of 280 patients were evaluated concerning the number of plates inserted, the site of plating, the number of patients in whom plates were removed, the site of removal and the reasons for which removal of plates was indicated. Results: In the 280 patients with facial trauma, 599 miniplates were used during this period. Thirty-seven miniplates were removed from 27 of these patients. The main causes for removal were infection and exposure of the plate in the oral cavity, patients’ request and/or the plates being palpable. The nasofrontal region, the area around the anterior wall of the antrum and the body of the mandible proved to be the commonest regions where plate removal was required. Conclusion: The number of miniplates removed was small but not insignificant. There is no evidence from this study to support advice for the routine removal of titanium miniplates from the maxillofacial skeleton. [Copyright &y& Elsevier]

Biochars produced from various organic waste feedstocks have lately been utilized as adsorbents for the decontamination of antibiotics-contaminated environmental matrices. The aims of the present study were a) the assessment of the adsorption capacity of three distinct derived biochars [biosolids (BDΒ), cattle manure (MDB) and spent coffee grounds (SCGDB)], applied either at a low (1 g L−1) or high (10 g L−1) dose on seven antibiotics (tetracycline, TET; erythromycin, ERY; clarithromycin, CLA; ampicillin, AMP; ofloxacin, OFL; sulfamethoxazole, SMX; trimethoprim, TMP) spiked as mixture in environmentally relevant concentration (100 μg L−1) of an aqueous solution (8.27 < pH < 10.48), and b) the understanding of the relative adsorption mechanisms. Batch sorption experiments showed that all biochars applied at the low dose efficiently removed more than 70%, reaching even 100%, of TET, ERY, CLA, whereas MDB also removed AMP. Biochars applied at the high dose (10 g L−1) exhibited enhanced adsorption capacity, resulting in the quick (within 5 min of incubation) and complete removal of TET, ERY, CLA, as well as increased removal (>85%) of AMP and TMP. However, the studied biochars failed to remove OFL and SMX. The adsorption results were best fitted to the Freundlich model with the sole exception of SMX. The main responsible mechanisms for the adsorption of antibiotics included surface complexation, H-bonding, π-π electron-donor-acceptor (EDA) interactions, pore-filling effects or the simultaneous occurrence of several of these mechanisms. Overall, the results highlighted the potential utilization of BDB, MDB and SCGDB for the decontamination of antibiotics-contaminated water bodies, while promoting the circular economy strategy. [Display omitted] • Biochar produced can effectively decontaminate antibiotics-contaminated solutions. • The removal efficiency is greatly depended on the pH value of the medium. • Biochars applied at the high dose (10 g L−1) exhibited enhanced adsorption capacity. • The adsorption results were best fitted to the Freundlich model. [ABSTRACT FROM AUTHOR]

P023 - Expression of RANK-c in ER-/HER2+ breast cancer cells affect aggressiveness through altering the NF- B equilibrium. [Extracted from the article]

Abstract: INTRODUCTION: Perianal extra-mammary Paget''s disease is a rare skin disorder of unknown aetiology, which is frequently associated with malignancy. This case report draws attention to this rare condition and comments upon its diagnosis and treatment. PRESENTATION OF CASE: A 64-year-old otherwise fit man, presented to us in 2006 with one-year-long history of perianal irritation. On examination there was an erythematous discoid skin lesion in the right perianal area. The lesion was excised with wide margins and the defect closed with a local transposition flap. Histology confirmed extra-mammary Paget''s disease (EMPD) with a focus of invasion showing a well-differentiated mucinous adenocarcinoma. Adjuvant therapy was not advised. On follow-up in 2011, a small irregular skin lesion, well away from the previous excision site was noted on the left perianal area. Biopsies from this lesion confirmed EMPD with no focus of invasion. Once again wide local excision with closure using local transposition flap was undertaken. Long term follow up has been advised. DISCUSSION: The optimal treatment for Perianal Paget''s disease (PPD) remains controversial. Surgery is the commonest modality used with wide local excision being the treatment of choice for resectable disease. We report herein a short review of various therapies reported so far in the management of this rare disorder. CONCLUSION: A thorough initial evaluation and long-term follow-up is essential to identify recurrence and the development of other related malignancies. [Copyright &y& Elsevier]

Background and Purpose: Acute vertigo (sense of motion) can be the sole manifestation of a posterior circulation stroke, and often gets missed in the emergency department (ED). The studies for evaluation of central vertigo have focused on physical exam findings, which require expertise and may not be suitable for rapid triage by a nurse in ED or by paramedics.Methods: This cross sectional study included retrospective chart review of patients 18 years of age and older who presented to the Adult ED with acute dizziness or vertigo during the calendar year 2017. All the patients with a diagnosis of central or peripheral vertigo were included in the final analysis. Sensitivity, specificity, Likelihood Ratio of positive result (LR (+)) and Likelihood Ratio of negative result (LR (-)) for central and peripheral vertigo were calculated for risk factors, symptoms and physical examination features. Chi-squared test and univariate logistic regression were used to evaluate statistical correlation and to calculate the prevalence odds ratio (POR).Results: Two hundred and forty nine out of 505 (49.3%) patients presenting with dizziness had vertigo. Of these, 14 had central vertigo and 163 had peripheral vertigo. Statistically significant variables were: constant symptoms of vertigo (p 0.000- POR 8.7, 95% confidence interval (CI) 2.3-33.1), no change in symptoms with head movement (p 0.000- POR 10.2, 95% CI 3.0-35.4), dysmetria (p 0.000- POR 56.8, 95% CI 5.8-557.1), and unsteady gait (p 0.000- POR 13.3, 95% CI 3.3-54.3). The sensitivity and specificity to detect central vertigo were 100% and 66.4% respectively if the patient had either unsteady gait, constant symptoms, or no change in symptoms with head movement, [VAIN triad (Vertigo- Ataxia, Incessant, or Non-positional)].Conclusions: We suggest that triage with VAIN triad can be used to design prospective studies to develop a triage algorithm for the detection of central vertigo in the ED. [ABSTRACT FROM AUTHOR]

Abstract: Insertion of a grass awn in the parotid duct and migration through the duct into the gland caused suppurative parotitis. This is an extremely rare condition, with few such cases reported in literature. As it happened here, under a quite common infection, such as suppurative parotitis is, an unexpected cause triggering inflammation was underlying. In an era of modern, expensive and sophisticated diagnostic methods, it is meticulous clinical examination and inspection of details that can give answers to such problems. [Copyright &y& Elsevier]

Thyroid remnant ablation with radioiodine is a well-established treatment for patients with Differentiated Thyroid Carcinoma (DTC) following thyroidectomy. After 3–4 days of hospitalization, these patients return home, presenting a possible radiation hazard to their family members. This work aims at estimating the radiation burden to the cohabitants of DTC patients treated with radioiodine, after hospital release. 724 patients (183/541 men/women) suffering from DTC were treated with radioiodine activities ranging from 1850 to 9250MBq. Thyroid Hormone Withdrawal (THW) was applied in 305 patients (42.1%), whereas 419 (57.9%) patients were prepared with recombinant human TSH (rhTSH). Radioiodine T eff was calculated from dose rate measurements at 1 and 2 m from the patients, performed at regular time intervals throughout their hospitalization. All patients were discharged 3–4 days post-treatment and were provided with written and oral instructions about radiation protection precautions. Patients were grouped according to their family status and radiation doses to their cohabitants were estimated based on appropriate exposure scenarios. Mean radioiodine T eff was 15.3 h (range 1.9–37.5 h). T eff in the rhTSH group was lower than the THW group (14.5 h and 17.1 h respectively, p〈0.05). Mean absorbed doses to all family members were estimated to be well below the corresponding dose constraints. Maximum dose to any child was slightly above 0.5 mSv, whereas maximum dose to any non-relative co-traveller was <0.2 mSv. Provided necessary precautions are followed, radiation burden to the family members of DTC patients treated with radioiodine following thyroidectomy can be kept lower than the corresponding dose constraints. [ABSTRACT FROM AUTHOR]

Computed Tomography (CT) has been an invaluable tool in medical diagnosis, but its increasing use has been also responsible for a significant increase in population radiation exposure. Iterative reconstruction algorithms have been recently introduced in clinical practice, in an attempt to decrease CT radiation dose. The purpose of this work was to investigate quantitatively the relationship between image quality and dose in CT and to establish the effectiveness of ASIR in reducing radiation dose, without compromising image quality. A CT image quality phantom was scanned in a 64-slice GE Optima CT660 scanner, using a typical head acquisition protocol with mA modulation, at 8 different Noise Index levels, corresponding to a CTDI vol range of 18.7–91.2 mGy. Scanned data were used to reconstruct 5 mm slices, using (a) only FBP and (b) FBP blended with 3 ASIR levels (20%–40%–60%). Mean CT number, image noise (SD) and CNR were measured in appropriately selected slices in all reconstructed images by three different observers. A reduction in image noise by 35–55% for the same radiation dose was observed in the ASIR reconstructed images compared to FBP, whereas images with similar noise levels could be produced using ASIR with 55–75% less dose compared to FBP. Similarly, ASIR with at least 40% blending, was found to increase CNR by 20–45% compared to FBP at the same radiation dose, and could produce images with comparable CNR with 20–60% less dose compared to FBP. ASIR can be very effective in reducing the radiation dose in CT, while preserving image quality. [ABSTRACT FROM AUTHOR]

Ping-pong gaze (PPG) is a rare eye movement abnormality consisting of conjugate smooth rhythmical horizontal eye deviations between the 2 extreme positions. PPG is encountered in cases of severe bilateral hemispheric or posterior fossa brain damage with intact brain stem and more rarely during drug toxicity. In this brief video case report, we present a 91-year-old woman with PPG after sustaining bilateral hemispheric ischemic stroke. We also present the neuroanatomic substrates of PPG along with its main saccadic variant, and we coin the hypothesis that PPG actually represents the paralysis of eye saccades. [ABSTRACT FROM AUTHOR]

The problem of determining the steady state pressure field for single and multi-well configurations with non-trivial wellbore boundary conditions is considered in this work as an integral equation problem. The aquifer, where the well configuration resides, is assumed to have different vertical and horizontal intrinsic permeabilities and it is bounded above and below by impermeable geological settings. The solutions of the integral equation, known as density functions, are studied from two points of view. First, the singular behavior of the density function is investigated by studying the singular part of the kernel of the integral equation; on this basis the density function is suitably expressed in terms of a non-singular counterpart, the reduced density function, for which a polynomial approximation is formulated and constructed numerically. The convergence of the approximation is studied with respect to the order of the polynomial and shown to be adequately fast. Second, the density functions for large depth to radius ratio and/or large horizontal to vertical permeability ratio exhibit similarity. The density functions depend on the parameters of the single-well problem through a single similarity parameter c . For large values of c , corresponding to the physical limits just mentioned, the density functions are reduced to essentially a single function, modulo a factor ( log c ) - 1 . This property simplifies considerably the analysis of all the large c cases. Considering the case of two wells, as an illustrative example, we also show that the properties of the single well case are also exhibited by the multi-well density functions. [ABSTRACT FROM AUTHOR]