Age, degraded viewing environments, and the speed of accommodation

Subjects were 35 males in an accommodation experiment which utilized a subjective laser optometer. Seven different age groups, from average age 22-52, were measured on the time to change accommodation from a near to an infinity target. During the experiment, room illumination, time duration of reading at a near distance, and the distance of a near-reading task were varied. Results indicated that the time to accommodate from a near to infinity target varied as a function of age, room illumination, and the distance of the near-reading task. During ideal conditions, older subjects could accommodate nearly as quickly as the younger subjects; however, during degraded viewing conditions, the accommodation time for older subjects increased as much as tenfold. Time to accommodate to a distant target also increased solely as a function of time spent reading at a near distance, regardless of age. In accordance with previous reviews of aging and military pilots, it is suggested that the time to accommodate may be used as an objective measure of degraded vision as it relates to age.     

Milchige Flüssigkeit in der Brusthöhle

A chylothorax can occur as a rare complication of intensive care treatment and can lead to infection and thrombosis as well as to metabolic acidosis, electrolyte derangement and finally to respiratory insufficiency with potentially fatal outcome. In the following article the case of a 9-month-old female infant is described who died as a consequence of hypoxic brain damage after a 27-day period of intensive care treatment. The postmortem examination additionally showed a bilateral chylothorax mainly as a consequence of a traumatic iatrogenic injury in the context of bilateral positioning of central venous catheters (CVC).     

Assessment of myocardial viability using MRI during a constant infusion of Gd-DTPA: further studies at early and late periods of reperfusion.

It was previously shown in a canine model of ischemia/reperfusion injury that the partition coefficient of gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) (lambda) increases in infarcted tissue. That previous study used a non-magnetic resonance imaging (MRI) method to measure lambda and only investigated reperfusion times from 2 hr to 3 weeks. This study presents evidence suggesting that lambda starts to increase as early as 1 min after reperfusion of a 2 hr occlusion and continues to rise for up to 2 hr or more; lambda stays increased as late as 8 weeks, reaching peak values at 1-11 days and subsequently decreasing. It was also demonstrated that lambda can be accurately measured in vivo using a saturation recovery turbo fast low-angle shot (FLASH) sequence. The results of this study show that MRI during a constant infusion of Gd-DTPA has great potential for the non-invasive determination of myocardial viability as early as 1 min to as late as 8 weeks following reperfusion of acute myocardial infarction.     

Radiological clerkships as a critical curriculum component in radiology education

Objective

The aim of this research was to explore the perceived value of clinical clerkships in the radiology curriculum as well as the impact of radiology clerkship on students’ beliefs about the profession of radiology as a whole and as a career.

Methods

This study is a sequel to a previous survey in which student perceptions about radiology curriculum components were investigated. The present study focuses on a further analysis of a subsection in this study, based on 14 statements about radiology clerkship and two statements about radiology as a career.

Results

Perceived usefulness of the aspects of radiology clerkship as “radiology examination”, “skills development” and “diagnosis focus” were awarded the highest scores. The predict value of the subscale “radiology examination” on the level of performance was very high (adjusted R² = 0.19, p < .001).

Conclusion

Students expressed highly favorable evaluation of clerkship as a learning environment to learn to order and to interpret imaging studies as well as an unique possibility to attend various radiological examinations and to access to specific radiology software systems, as well as to get a better view on radiology and to improve image interpretation skills. This positive attitude towards clerkship is closely tied to students’ beliefs about the profession of radiology as a whole. These aspects of dedicated radiology clerkship are crucial for effective and high-quality education as well as for the choice of radiology as a career.     

Postmortem computed tomographic (PMCT) demonstration of fatal hemoptysis by pulmonary tuberculosis--radiological-pathological correlation in a case of rupture of Rasmussen's aneurysm

We report a case of fatal hemoptysis resulting from the rupture of a Rasmussen's aneurysm. Postmortem computed tomography (PMCT) clearly showed the air-fluid level within a tuberculous cavity and fluid-filled trachea. In this case, PMCT was useful as a screening tool to detect the cause of death as asphyxia from hemoptysis. It became a guideline for the following autopsy, as well as evidence to explain the importance of autopsy to the family.     

Ghost artifact cancellation using phased array processing.

In this article, a method for phased array combining is formulated which may be used to cancel ghosts caused by a variety of distortion mechanisms, including space variant distortions such as local flow or off-resonance. This method is based on a constrained optimization, which optimizes SNR subject to the constraint of nulling ghost artifacts at known locations. The resultant technique is similar to the method known as sensitivity encoding (SENSE) used for accelerated imaging; however, in this formulation it is applied to full field-of-view (FOV) images. The method is applied to multishot EPI with noninterleaved phase encode acquisition. A number of benefits, as compared to the conventional interleaved approach, are reduced distortion due to off-resonance, in-plane flow, and EPI delay misalignment, as well as eliminating the need for echo-shifting. Experimental results demonstrate the cancellation for both phantom as well as cardiac imaging examples.     

肝囊性包虫病的CT分型及其临床应用价值

目的：探讨肝囊性包虫病的CT分型及其临床应用价值。材料和方法：分析自2008年1～12月在我院行CT检查的包虫病患者85例,按照WHO标准化分型进行分型,分析其表现,评估其临床应用价值。结果：CT检出111个病灶,CL型16个病灶,CT表现为无壁的类圆形单房囊肿;CE1型15个病灶,CT表现为密度均匀的单房囊肿,并可显示囊壁;CE2型28个病灶,CT表现为多囊多分隔的子囊呈蜂窝征改变;CE3型6个病灶,CT表现为椭圆形单囊结构,内可见飘带状结构;CE4型10个病灶,CE5型36个病灶,CT表现为厚的钙化团块。结论：肝脏包虫病的CT分型有利于肝脏常见囊性疾病,如肝囊肿、肝脏脓肿和肝肿瘤等疾病的鉴别诊断和临床治疗。     

Splenogonadal fusion presenting as a testicular mass,a case report and literature review

Splenogonadal fusion is a rare, frequently misdiagnosed, congenital anomaly in which the splenic tissue is abnormally attached to the gonadal or mesonephric remnants. It is commonly found as an incidental finding at autopsy, during orchiopexy or hernia repair. However, it can present as a testicular mass or as an acute scrotal pathology such as testicular torsion or epididymoorchitis. It poses as a diagnostic challenge preoperatively and often leads to unnecessary orchiectomy.We present a case of a 15-year-old male who presented with a long-standing left testicular mass thought to be a testicular tumor. Resection of the lesion along with partial left orchiectomy was done and histopathologic evaluation revealed splenogonadal fusion.     

Interval cancer peer review in East Anglia: implications for monitoring doctors as well as the NHS breast screening programme

AIM: To devise a method for reviewing interval cancers that will both educate radiologists and facilitate improvement of breast screening practice. To evaluate different methods for case classification to find one that best serves this purpose. METHOD: The method of peer review and the means by which interval cancers are classified is described. The way in which cases are designated false-negative is an issue of acceptability for radiologists, and so three different methods are evaluated. Each is applied to the data set collected in this region over a 3-year period. RESULTS: For cases read by five readers, when a consensus method was used for classifying cases, the proportion of cases classified as false-negative was 14%. Using a method in which only one of the five readers had to classify a case as false-negative for it to be categorized as such, the proportion of false-negative cases rose to a maximum of 38%. The minimum proportion of cases that could be considered to be false-negative was 6% and was obtained when all five readers had to classify a case as false-negative for it to be so categorized. Consistent with its majority viewpoint, the consensus method gave results for proportions of total cases classified as false-negative which were similar to those given by methods in which cases are classified as false-negative if either three of five readers, or at least 60% of readers, classified it as such. CONCLUSION: For the peer review method to achieve its dual aims of educating radiologists and auditing performance, the participating radiologists must share ownership of the results and view the analysis as fair. The method used to classify interval cancers as false-negative will influence the number so classified. A consensus method has been found to give a result that is both fair and acceptable to our radiologist. Using this method 16% of all reviewed cases were classified as false-negative and 60% as true interval cancers. Britton, P. D. (2001). Clinical Radiology56, 44-49.     

Gene variants predisposing to SIDS: current knowledge

Genetic risk factors play a role in sudden unexpected infant death; either as a cause of death, such as in cases with medium-chain acyl-coenzyme A dehydrogenase deficiency and cardiac arrest due to long QT syndrome, or as predisposing factors for sudden infant death syndrome (SIDS). Most likely genetic predisposition to SIDS represent a polygenic inheritance pattern leading to sudden death when combined with other risk factors, such as a vulnerable developmental stage of the central nervous system and/or the immune system, in addition to environmental risk factors, such as a common cold or prone sleeping position. Genes involved in the regulation of the immune system, cardiac function, the serotonergic network and brain function and development have so far emerged as the most important with respect to SIDS. The purpose of the present paper is to survey current knowledge on SIDS and possible genetic contributions.     

Water-proton nuclear magnetic relaxation in heterogeneous systems: hydrated lysozyme results.

Spin-lattice relaxation rates of water protons in hydrated immobilized lysozyme are measured as a function of magnetic field strength. The dependence of water relaxation versus hydration is presented from 35 to 55% by weight water content. The water-proton relaxation is directly coupled to that of the protein and the coupling exists in the absence of chemical exchange. A model is applied where relaxation within the two proton phases is coupled through a dipolar cross-relaxation mechanism as well as chemical exchange. The observed amplitudes of the water-proton relaxation profiles scale with the ratio of protein to water protons as well as the protein-proton relaxation rate. The field dependence of the protein-proton spin-lattice relaxation is presented in the presence of D2O where a cross-relaxation coupling is absent. The coupled relaxation model accounts well for the NMR relaxation data as a function of magnetic field strength which is similar to measurements on other heterogeneous systems such as tissues.     

An introduction to disaster: some considerations of a psychological nature

This paper provides a review of the literature dealing with the psychological reactions of individuals and groups to disaster. The paper was intended for use by a broad readership and serves both as an introduction to the field as well as a resource document for workers already engaged in disaster planning and training. Characteristic stages of human response to disaster situations are discussed as well as the specific immediate reactions of individuals and groups. Phenomena such as "scapegoating," long-term reactions, reactions of rescue and relief personnel, psychological first aid, and disaster planning, are among the other topics examined.     

The Early Influence and Effects of the Coronavirus Disease 2019 (COVID-19) Pandemic on Resident Education and Adaptations

The novel coronavirus disease 2019 (COVID-19) has had a major impact on the education of trainees in the radiology environment. The precipitous drop in patient volumes and sequestering of faculty and trainees to maintain social distancing affects experiential learning. The shift of nearly all teaching settings to a virtual environment has been challenging but may also allow more interaction during teaching sessions than traditional readout sessions or didactic lectures. Faculty development is key in ensuring competence and confidence in this new environment. Recruitment of trainees using a virtual platform will require communication of opportunities as well as the culture of the department and institution as well as the community. Delay of the board examinations has caused angst as well as disruption of the timing of clinical rotations but may ultimately result in a shift of how the examinations are administered. The exceptional disruption of the COVID-19 pandemic allows us to reconsider how the educational aspects of imaging can emerge as improved in the years to come.     

Computed tomographic features of afferent loop syndrome: pictorial essay.

ALS, a rare condition, is often difficult to diagnose clinically but has a characteristic CT appearance as a U-shaped, fluid-filled tubular structure crossing the midline between the abdominal aorta and the superior mesenteric artery. Radiologists should be familiar with this rare entity, as awareness of its pathognomonic CT features will aid in establishing the correct diagnosis as well as in offering a tentative etiology as a guide for treatment.     

Methylsulfonylmethane observed by in vivo proton magnetic resonance spectroscopy in a 5-year-old child with developmental disorder: effects of dietary supplementation

Proton magnetic resonance spectroscopy (MRS) revealed a distinct resonance at 3.15 ppm in the brain of a 5-year-old male diagnosed with autism. The resonance assignment is attributable to ingestion of methylsulfonylmethane (MSM) as a dietary supplement. Glucosamine with MSM is marketed as a source of dietary sulfur and treatment of joint pain. Recognition of this chemical on brain proton MRS as an exogenous compound is necessary to avoid confusion as a pathologic metabolite of pediatric metabolic disease.     

Generation of dose calculation data tables using cubic spline interpolation

In order to calculate treatment machine settings for a teletherapy machine (e.g., time or monitor units), tables are usually used for variables such as output factor, TMR, percent depth dose. The tables are often generated from data collected at a few points. A linear interpolation is usually used to generate values between the measured points. This can introduce errors as great as 2% between the calculated and actual data points. Using a mathematical software package a computer can generate smooth, accurate curves that agree with measured values to within a few tenths of a percent. This method is not an averaging type of procedure by which a certain function is chosen and parameters are adjusted to force the function to fit the data as closely as possible, but rather is a procedure that fits curves exactly through the measured data points.     

一种高效敏感的神经束路追踪方法

为寻找一种高效敏感的神经通路追踪方法。采用结合了霍乱毒素亚单位Ｂ的辣根过氧化物酶（ＣＢ ＨＲＰ）作为示踪剂，用钨酸钠作为四氨基联苯胺（ＴＭＢ）显色剂的稳定剂，顺行追踪视神经纤维向下丘脑前区的投射；逆行追踪舌下神经纤维在延髓背侧的分布。结果发现视神经纤维投射到视交叉上核背内侧；舌下神经纤维在延髓背侧的舌下神经纤维核分部区显示神经元胞体和轴突结构清晰。提示用霍乱毒素亚单位Ｂ与辣根过氧化物酶结合（ＣＢ ＨＲＰ）作为示踪剂，以钨酸钠作为四氨基联苯胺显色剂的稳定剂的方法是一种高效敏感的神经束路追踪方法。     

Controlling the Smoking Epidemic: Report of the WHO Expert Committee on Smoking Control

Summary

The experimental design consisting of a partial tolerance dose followed by a top-up dose, is used as a method of comparing the effects of different radiations and irradiation schedules in vivo. It complements the usual approach of giving multiple equal fractions of a single radiation type to obtain an iso-effect, as it enables low doses per fraction to be studied without the need to use a large number of fractions or a long overall time. For normal tissues in animals, the effect of X-ray doses as low as 0·1 Gy per fraction can be detected when given as 20–40 fractions followed by a top-up dose of neutrons. In order to minimize variations in the effect of the top-up dose, neutrons are used as a top-up radiation in preference to X-rays.

The methods of implementing this approach are explained in detail. Analysis of the data is described, with emphasis on the Linear Quadratic model of radiation dose-fractionation. However, it is not necessary to adopt this or any particular mathematical model in order to intercompare directly the effects of different radiations or irradiation schedules using the top-up approach. Such models nevertheless simplify the design of top-up experiments. Whilst any type of radiation can in principle be used as the top-up, this is given optimally as a dose of fast neutrons split into two fractions.     

Financial implications of serving as team physician

Time is the greatest negative financial burden that you accept as a sports medicine physician, because the only way to produce revenue as a physician is with your time. This cost measured in time of doing business as a team physician can be high. Unless being a team physician is very rewarding to you through personal satisfaction or the other intangible indirect benefits associated with the role, being a team physician may not be a good financial decision for you as a person and a physician, or for your practice and your family.