Low-dose imaging protocols in chest CT are important in the screening and surveillance of suspicious and indeterminate lung nodules. Techniques that maintain nodule detectability yet permit dose reduction, particularly for large body habitus, were investigated. The objective of this study was to determine the extent to which radiation dose can be minimized while maintaining diagnostic performance through knowledgeable selection of reconstruction techniques. A 320-slice volumetric CT scanner ͑Aquilion ONE™, Toshiba Medical Systems͒ was used to scan an anthropomorphic phantom at doses ranging from ϳ0.1 mGy up to that typical of low-dose CT ͑LDCT, ϳ5 mGy͒ and diagnostic CT ͑ϳ10 mGy͒. Radiation dose was measured via Farmer chamber and MOSFET dosimetry. The phantom presented simulated nodules of varying size and contrast within a heterogeneous background, and chest thickness was varied through addition of tissue-equivalent bolus about the chest. Detectability of a small solid lung nodule ͑3.2 mm diameter, Ϫ37 HU, typically the smallest nodule of clinical significance in screening and surveillance͒ was evaluated as a function of dose, patient size, reconstruction filter, and slice thickness by means of nine-alternative forcedchoice ͑9AFC͒ observer tests to quantify nodule detectability. For a given reconstruction filter, nodule detectability decreased sharply below a threshold dose level due to increased image noise, especially for large body size. However, nodule detectability could be maintained at lower doses through knowledgeable selection of ͑smoother͒ reconstruction filters. For large body habitus, optimal filter selection reduced the dose required for nodule detection by up to a factor of ϳ3 ͑from ϳ3.3 mGy for sharp filters to ϳ1.0 mGy for the optimal filter͒. The results indicate that radiation dose can be reduced below the current low-dose ͑5 mGy͒ and ultralow-dose ͑1 mGy͒ levels with knowledgeable selection of reconstruction parameters. Image noise, not spatial resolution, was found to be the limiting factor in detection of small lung nodules. Therefore, the use of smoother reconstruction filters may permit lower-dose protocols without trade-off in diagnostic performance.

Peripheral nerve transfer (PNT) to improve upper limb function following cervical spinal cord injury (SCI) involves the transfer of supralesional donor nerves under voluntary control to intralesional or sublesional lower motor neurons not under voluntary control. Appropriate selection of donor and recipient nerves and surgical timing affect functional outcomes. Although the gold standard of nerve selection is intraoperative nerve stimulation, preoperative electrodiagnostic (EDX) evaluation may help guide surgical planning. Currently there is no standardized preoperative EDX protocol. This study reviews the EDX workup preceding PNT surgery in cervical SCI and proposes an informed EDX protocol to assist with surgical planning. The PICO (Population, Intervention, Comparison, Outcome) framework was used to formulate relevant Medical Subject Headings (MeSH) terms and identify published cases of PNT in cervical SCI in Medline, Embase, CINAHL, and Emcare databases in the last 10 years. The EDX techniques evaluating putative donor nerves, recipient nerve branches, time sensitivity of nerve transfer and other electrophysiological parameters were summarized to guide creation of a preoperative EDX protocol. Needle electromyography (EMG) was the most commonly used EDX technique to identify healthy donor nerves. Although needle EMG has also been used on recipient nerves, compound muscle action potential amplitudes may provide a more accurate determination of recipient nerve health and time sensitivity for nerve transfer. Although there has been progress in presurgical EDX evaluation, EMG and nerve conduction study approaches are variable, and each has limitations in their utility for preoperative planning. There is need for standardization in the EDX evaluation preceding PNT surgery to assist with donor and recipient nerve selection, surgical timing and to optimize outcomes. Based on results of this review, herein we propose the PreSCIse (PRotocol for Electrodiagnosis in SCI Surgery of the upper Extremity) preoperative EDX panel to achieve said goals through an interdisciplinary and patient‐centered approach.

T raffic-related collisions comprise a significant proportion of preventable injury. In 2009 the World Health Organization ranked road traffic accidents the ninth leading cause of death, accounting for 1.21 million deaths and up to 50 million injuries per year. 1,2 Worldwide, nearly half of people who die in traffic collisions are vulnerable road users: pedestrians, cyclists and motorized 2-wheeler users. 2 In Canada, there were 199,337 road-traffic-related injuries and 2,889 fatalities in 2006; pedestrians comprised 13% and cyclists 3% of these deaths. 1 Though fatalities are fewer in developed countries and have decreased significantly over the last three decades, the physical, financial and psychosocial costs for the over 30,000 pedestrians and cyclists injured in Canada per year remain high. There is particular concern in large urban centres, where pedestrian and cyclist collisions may occur at higher rates due to increased vehicle and pedestrian traffic. Intersections are complex geographical entities with high potential for road traffic collisions; two thirds of Ontario cyclist-motorist collisions occur in intersections. 3,4 Preston and colleagues 5 found that 55% of accidents and 80% of fatal crashes in Minnesota occurred at stop-controlled intersections. Characteristics that increase the complexity of intersections include vehicle turning, pedestrian and traffic volumes, and built infrastructure, including number of lanes, presence of traffic-slowing methods (e.g., speed humps), roundabouts, bicycle lanes, paths or shared lanes, crosswalks, and transit stop usage. 6-8 Several studies have considered environmental, behavioural and socio-demographic risk factors for collisions in urban intersections. Environmental factors that increased collision risk included speed limits exceeding 50 km/h and lack of pedestrian signals. 9,10 Behavioural factors included alcohol intoxication, total driver violations, and lack of pedestrian supervision. 9,10 With respect to sociodemographic factors, injured pedestrians tend to be children and the elderly, predominantly male, Aboriginal, from low-income families or residing in neighbourhoods with low median home values. 9,10 Similar environmental, behavioural and demographic trends are expected for cyclists, but evidence is minimal in the literature to date.

No abstract