A new software scheme for scatter correction based on a simple radiographic scattering model

In common radiography, image contrast is often limited due mainly to scattered x-rays and noise, decreasing the quantitative usefulness of x-ray images. Several scatter reduction methods based on software correction schemes have been extensively investigated in an attempt to overcome these difficulties, most of which are based on measurement, mathematical-physical modeling, or a combination of both. However, those methods require special equipment, system geometry, and extra manual work to measure scatter characteristics. In this study, we investigated a new software scheme for scatter correction based on a simple radiographic scattering model where the intensity of the scattered x-rays was directly estimated from a single x-ray image using a weighted l¹-norm contextual regularization framework. We implemented the proposed algorithm and performed a systematic simulation and experiment to demonstrate its viability. We also conducted some clinical image studies using patient's image data of breast and L-spine to verify the clinical effectiveness of the proposed scheme. Our results indicate that the degradation of image characteristics by scattered x-rays and noise was effectively recovered by using the proposed software scheme, thus improving radiographic visibility considerably. Graphical abstract The schematic illustrations of scatter suppression methods by using a an antiscatter grid and b a scatter estimation algorithm.

Report from the 19th annual Western Canadian Gastrointestinal Cancer Consensus Conference; Winnipeg, Manitoba; 29-30 September 2017

The 19th annual Western Canadian Gastrointestinal Cancer Consensus Conference (wcgccc) was held in Winnipeg, Manitoba, 29-30 September 2017. The wcgccc is an interactive multidisciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer.

Oncology education for Canadian internal medicine residents: the value of participating in a medical oncology elective rotation

Background

Despite the high incidence and burden of cancer in Canadians, medical oncology (mo) rotations are not mandatory in most Canadian internal medicine (im) residency training programs.

Methods

All im residents scheduled for a mo rotation at 4 Canadian teaching cancer centres between 1 January 2013 and 31 December 2015 were invited to complete an online survey before and after their rotation. The survey was designed to evaluate perceptions of oncology, comfort in managing cancer patients, and basic oncology knowledge.

Results

The survey was completed by 68 im residents pre-rotation and by 48 (71%) post-rotation. Cancer-related learning was acquired mostly from mo physicians in clinic (35%). Self-directed learning, didactic teaching, and resident or fellow teaching accounted for 31%, 26%, and 10% respectively of learning acquisition. Comfort level in dealing with cancer patients and patients at end of life improved to 4.0/5 from 3.2/5 (p < 0.001) and to 4.0/5 from 3.6/5 (p = 0.003) respectively. Mean knowledge assessment score improved to 83% post-rotation from 76% pre-rotation (p = 0.003), with the greatest increase observed in general knowledge of common malignancies. The 3 topics ranked as most important to learn during a mo rotation were oncologic emergencies, common complications of treatment, and approach to diagnosis of cancer.

Conclusions

A rotation in mo improves the perceptions of im residents about oncology and their comfort level in dealing with cancer patients and patients at end of life. Overall cancer knowledge is also improved. Given those benefits, im residency programs should encourage most of their residents to complete a mo rotation.

Reduced partitioning of plastic strain for strong and yet ductile precipitate-strengthened alloys

When a material that contains precipitates is deformed, the precipitates and the matrix may strain plastically by different amounts causing stresses to build up at the precipitate-matrix interfaces. If premature failure is to be avoided, it is therefore essential to reduce the difference in the plastic strain between the two phases. Here, we conduct nanoscale digital image correlation to measure a new variable that quantifies this plastic strain difference and show how its value can be used to estimate the associated interfacial stresses, which are found to be approximately three times greater in an Fe-Ni2AlTi steel than in the more ductile Ni-based superalloy CMSX-4®. It is then demonstrated that decreasing these stresses significantly improves the ability of the Fe-Ni2AlTi microstructure to deform under tensile loads without loss in strength.

Association between dietary carbohydrate quality and the prevalence of obesity and hypertension

BACKGROUND

Dietary carbohydrate quality may play an important role in disease development. We evaluated the association between carbohydrate quality index (CQI) and the prevalence of obesity and metabolic disorders among adults in South Korea.

METHODS

We analysed 12 027 adults aged 19-64 years from the fifth Korea National Health and Nutrition Examination Survey (KNHANES). CQI was based on four criteria: crude fibre intake, dietary glycaemic index (DGI), whole grains/total grains ratio and solid carbohydrates/total carbohydrates ratio.

RESULTS

Participants with a lower CQI were younger, had a lower income and were more likely to be smokers and to drink alcohol. The highest quintile CQI group showed the lowest DGI and the lowest consumption of liquid carbohydrates and refined grains, as well as the highest consumption of solid carbohydrates, crude fibre and whole grains (P < 0.05). A higher CQI was negatively associated with the prevalence of obesity (odds ratio = 0.83; 95% confidence interval = 0.69-0.99) and hypertension (odds ratio = 0.78; 95% confidence interval = 0.61-0.99) but was not associated with other metabolic disorders.

CONCLUSIONS

These results suggest that the quality of carbohydrates consumed is associated with the risk of obesity and hypertension. However, the cross-sectional design does not preclude reverse causality.

Successful targeting of the NRG1 pathway indicates novel treatment strategy for metastatic cancer

Background

NRG1 fusion-positive lung cancers have emerged as potentially actionable events in lung cancer, but clinical support is currently limited and no evidence of efficacy of this approach in cancers beyond lung has been shown.

Patients and methods

Here, we describe two patients with advanced cancers refractory to standard therapies. Patient 1 had lung adenocarcinoma and patient 2 cholangiocarcinoma. Whole-genome and transcriptome sequencing were carried out for these cases with select findings validated by fluorescence in situ hybridization.

Results

Both tumors were found to be positive for NRG1 gene fusions. In patient 1, an SDC4-NRG1 gene fusion was detected, similar gene fusions having been described in lung cancers previously. In patient 2, a novel ATP1B1-NRG1 gene fusion was detected. Cholangiocarcinoma is not a disease type in which NRG1 fusions had been described previously. Integrative genome analysis was used to assess the potential functional significance of the detected genomic events including the gene fusions, prioritizing therapeutic strategies targeting the HER-family of growth factor receptors. Both patients were treated with the pan HER-family kinase inhibitor afatinib and both displayed significant and durable response to treatment. Upon progression sites of disease were sequenced. The lack of obvious genomic events to describe the disease progression indicated that broad transcriptomic or epigenetic mechanisms could be attributed to the lack of prolonged response to afatinib.

Conclusion

These observations lend further support to the use of pan HER-tyrosine kinase inhibitors for the treatment of NRG1 fusion-positive in both cancers of lung and hepatocellular origin and indicate more broadly that cancers found to be NRG1 fusion-positive may benefit from such a clinical approach regardless of their site of origin.

Clinical trial information

Personalized Oncogenomics (POG) Program of British Columbia: Utilization of Genomic Analysis to Better Understand Tumour Heterogeneity and Evolution (NCT02155621).

Association of high-dose postoperative opioids with recurrence risk in esophageal squamous cell carcinoma: reinterpreting ERAS protocols for long-term oncologic surgery outcomes

Esophageal squamous cell carcinoma (ESCC) is associated with a poor prognosis and high postoperative recurrence rate. Although postoperative opioid use has been associated with cancer recurrence, its relevance in ESCC has not been determined. Therefore, this study investigated whether high-dose postoperative opioid use was associated with recurrence risk in patients with ESCC. For this retrospective analysis, the medical records of patients who were diagnosed with ESCC and who underwent surgery between January 2006 and December 2010 in the National Cancer Center, Korea were evaluated. Total opioid administration over a 10-day period, from during surgery to postoperative day 9, was calculated. A cutoff value was determined using receiver operating characteristic curve analysis, and patients were classified into the high-use and low-use groups. The primary and secondary outcomes of the study were freedom from recurrence and overall survival, respectively. After propensity score matching, the effect of opioid use on freedom from recurrence and overall survival was evaluated using the Kaplan-Meier method. The final analysis set included 258 patients. The cumulative opioid dose cutoff point was 1783.5 mg of oral morphine. High-dose postoperative opioid use was a significant factor affecting recurrence (Hazard ratio [HR], 2.162; 95% confidence interval [CI], 1.583-2.954; P < 0.0001). In contrast, postoperative opioid use was not associated with death (HR, 1.274; 95% CI, 0.922-1.761; P = 0.1422). In patients with ESCC, compared with low-dose opioid use, high-dose intraoperative and postoperative opioid use was significantly associated with an increased risk of recurrence. However, opioid dosage did not affect overall survival.

Adequate interval for the monitoring of vital signs during endotracheal intubation

Background

In the perioperative period, it may be inappropriate to monitor vital signs during endotracheal intubation using the same interval as during a hemodynamically stable period. The aim of the present study was to determine whether it is appropriate to use the same intervals used during the endotracheal intubation and stable periods to monitor vital signs of patients under general anesthesia.

Methods

The mean arterial pressure (MAP) and heart rate (HR) were continuously measured during endotracheal intubation (15 min after intubation) and hemodynamically stable (15 min before skin incision) periods in 24 general anesthesia patients. Data was considered “unrecognized” when continuously measured values were 30% more or less than the monitored value measured at 5- or 2.5-min intervals. The incidence of unrecognized data during endotracheal intubation was compared to that during the hemodynamically stable period.

Result

There were significantly more unrecognized MAP data measured at 5-min intervals during endotracheal intubation than during the hemodynamically stable period (p value <0.05). However, there was no difference in the incidence of unrecognized MAP data at 2.5 min intervals or HR data at 5 or 2.5 min intervals between during the endotracheal intubation and hemodynamically stable periods.

Conclusion

A 5-min interval throughout the operation period was not appropriate for monitoring vital signs. Therefore, , a 2.5-min interval is recommended for monitoring the MAP during endotracheal intubation.

Control of interior surface materials for speech privacy in high-speed train cabins

The effect of interior materials with various absorption coefficients on speech privacy was investigated in a 1:10 scale model of one high-speed train cabin geometry. The speech transmission index (STI) and privacy distance (r_P ) were measured in the train cabin to quantify speech privacy. Measurement cases were selected for the ceiling, sidewall, and front and back walls and were classified as high-, medium- and low-absorption coefficient cases. Interior materials with high absorption coefficients yielded a low r_P , and the ceiling had the largest impact on both the STI and r_P among the interior elements. Combinations of the three cases were measured, and the maximum reduction in r_P by the absorptive surfaces was 2.4 m, which exceeds the space between two rows of chairs in the high-speed train. Additionally, the contribution of the interior elements to speech privacy was analyzed using recorded impulse responses and a multiple regression model for r_P using the equivalent absorption area. The analysis confirmed that the ceiling was the most important interior element for improving speech privacy. These results can be used to find the relative decrease in r_P in the acoustic design of interior materials to improve speech privacy in train cabins.

Mixing with applications to inertial-confinement-fusion implosions

Approximate one-dimensional (1D) as well as 2D and 3D simulations are playing an important supporting role in the design and analysis of future experiments at National Ignition Facility. This paper is mainly concerned with 1D simulations, used extensively in design and optimization. We couple a 1D buoyancy-drag mix model for the mixing zone edges with a 1D inertial confinement fusion simulation code. This analysis predicts that National Ignition Campaign (NIC) designs are located close to a performance cliff, so modeling errors, design features (fill tube and tent) and additional, unmodeled instabilities could lead to significant levels of mix. The performance cliff we identify is associated with multimode plastic ablator (CH) mix into the hot-spot deuterium and tritium (DT). The buoyancy-drag mix model is mode number independent and selects implicitly a range of maximum growth modes. Our main conclusion is that single effect instabilities are predicted not to lead to hot-spot mix, while combined mode mixing effects are predicted to affect hot-spot thermodynamics and possibly hot-spot mix. Combined with the stagnation Rayleigh-Taylor instability, we find the potential for mix effects in combination with the ice-to-gas DT boundary, numerical effects of Eulerian species CH concentration diffusion, and ablation-driven instabilities. With the help of a convenient package of plasma transport parameters developed here, we give an approximate determination of these quantities in the regime relevant to the NIC experiments, while ruling out a variety of mix possibilities. Plasma transport parameters affect the 1D buoyancy-drag mix model primarily through its phenomenological drag coefficient as well as the 1D hydro model to which the buoyancy-drag equation is coupled.

Chemically induced topological zero mode at graphene armchair edges

The electronic and magnetic properties of chemically modified graphene armchair edges are studied using a combination of tight-binding calculations, first-principles modelling, and low temperature scanning tunneling microscopy (STM) experiments. The atomically resolved STM images of the hydrogen etched graphitic edges suggest the presence of localized states at the Fermi level for certain armchair edges. We demonstrate theoretically that the topological zero-energy edge mode may emerge at armchair boundaries with asymmetrical chemical termination of the two outermost atoms in the unit cell. We particularly focus our attention on armchair edges terminated by various combinations of the hydrogen (H, H₂) and methylene (CH₂) groups. The inclusion of the spin component in our calculations reveals the appearance of π-electron-based magnetism at the armchair edges under consideration.

A study of the dietary intakes by the pre-pregnancy body mass index in pregnant women

The authors analyzed the difference in weight gain and nutrition, according to the BMI before pregnancy. They divided 91 subjects into BMI group I (normal weight) and BMI group 2 (overweight) before pregnancy. In general, the BMI before pregnancy did not influence weight gain but, in the BMI group 2, the intakes of all of cholesterol, total fatty acids, vitamin B 12, iron, and copper were significantly higher. Neither group exhibited sufficient intake of vitamin B 1, vitamin B2, niacin, vitamin B6, folic acid, calcium, magnesium, iron, or zinc. Pre-pregnancy weight management and nutrition during pregnancy is very important.

Report from the 17th Annual Western Canadian Gastrointestinal Cancer Consensus Conference; Edmonton, Alberta; 11-12 September 2015

The 17th annual Western Canadian Gastrointestinal Cancer Consensus Conference (wcgccc) was held in Edmonton, Alberta, 11-12 September 2015. The wcgccc is an interactive multidisciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of gastric cancer.