Biopolymers, such as silk fibroin, collagen, and chitosan, are promising candidates for a variety of applications that merge the fields of biomedical optics and biomaterials. Biocompatible silk fibroin, in particular, shows promise as a biomaterial, based on a number of attributes.[1] Silk fibroin is the strongest and toughest natural fiber known and is easily formed into robust films of thermodynamically stable beta-sheets of a controllable range of thicknesses (between tens of nanometers and hundreds of micrometers). [1][2][3] These films have excellent (ca. 95%) optical transparency across the visible range and can be easily characterized and biochemically functionalized because of the all-aqueous processing, broadening their overall value. It is possible to form such silk fibroin films, having intricate 2D or 3D nano-or micropatterns, through a softlithography-based simple casting technique. This technique enables the fabrication of (at least) sub-30 nm transverse features in silk fibroin films, when cast at ambient conditions from an aqueous silk solution. The elegance of this method is in its simplicity; the fabrication of such features is completed in the absence of additional harsh chemicals, salts, or high pressures that traditionally accompany most micro-and nanofabrication techniques. By employing this simple casting technique, high-quality films that contain a wide spectrum of nano-and micropatterns can be fabricated. These films are of great consequence for use in a variety of studies based in biomedical optics.In this Communication we report on a process developed for the construction of silk fibroin-based nano-and micropatterned films. This process includes the methods for producing ultrapure silk fibroin solution, the aqueous casting process for patterning silk fibroin films, and the characterization of the smallest transverse nanopatterns realized in silk fibroin films to date.Production of the silk fibroin solution begins with the purification of harvested Bombyx mori cocoons. Sericin, a water-soluble glycoprotein that binds fibroin filaments, is removed from the fibroin strands by boiling the cocoons in a 0.02 M aqueous solution of sodium carbonate for 45 min. [4] Upon completion of this step, the remaining fibroin bundle is rinsed thoroughly in Milli-Q water and allowed to dry overnight. The dry fibroin bundle is then dissolved in a 9.3 M aqueous solution of lithium bromide at 60 8C for 4 h. The lithium bromide salt is then extracted from the solution over the course of three days, through a water-based dialysis process. The resulting solution is extracted from the dialysis cassette (Slide-a-Lyzer, Pierce, molecular weight cut-off (MWCO) 3500) and remaining particulates are removed through centrifugation and syringe-based microfiltration (5 mm pore size, Millipore Inc, Bedford, MA). This process enables the production of 8-10% w/v silk fibroin solution of excellent quality and stability. The purification step is particularly important for the generation of high-quality optical films with maxim...

Contrast-enhanced mammography (CEM) is a developing modality used for the workup and management of breast cancer. Although diagnostic imaging modalities such as mammography and US have historically been the mainstays of initial breast cancer workup, recent advances in breast MRI have allowed better disease evaluation. However, MRI is not always readily available, can be time consuming, and is contraindicated in certain patients. CEM is an alternative to US and MRI, and it can be used to obtain contrast material-enhanced information and standard mammograms simultaneously. A CEM examination is shorter than that of MRI, and the modalities have similar rates of sensitivity to detect lesions. CEM also costs less than MRI. The authors evaluate clinical uses of CEM and discuss the literature supporting these indications. ©

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We demonstrate controllable structural color based on periodic nanopatterned 2D lattices in pure protein films of silk fibroin. We show here periodic lattices in silk fibroin films with feature sizes of hundreds of nanometers that exhibit different colors as a function of varying lattice spacing. Further, when varying the index of refraction contrast between the nanopatterned lattice and its surrounding environment by applying liquids on top of the lattices, colorimetric shifts are observed. The effect is characterized experimentally and theoretically and a simple example of glucose concentration sensing is presented. This is the first example of a functional sensor based on silk fibroin optics.

Free-standing silk films are useful materials to manufacture nanopatterned optical elements and to immobilize bio-dopants such as enzymes while maintaining their biological activity. These traits were combined by incorporating hemoglobin into free-standing silk diffraction gratings to fabricate chemically responsive optofluidic devices responsive to ambient gas conditions, constituting a simple oxygen sensor. This type of self-analyzing optical system is enabled by the unique ability to reproduce high-fidelity optical structures in silk while maintaining the activity of entrapped proteins such as hemoglobin. These bioactive optical devices offer a direct readout capability, adding utility into the bioresponsive material arena.

The COVID-19 pandemic disrupted breast cancer screening and diagnostic imaging in the United States. We sought to evaluate how medical facilities prioritized breast imaging services during periods of reduced capacity or upon re-opening after closures. In fall 2020, we surveyed 77 breast imaging facilities within the Breast Cancer Surveillance Consortium in the United States. The survey ascertained the pandemic's impact on clinical practices during March–September 2020. Nearly all facilities (97%) reported closing or operating at reduced capacity at some point during this period. All facilities were open by August 2020, though 14% were still operating at reduced capacity in September 2020. During periods of re-opening or reduced capacity, 93% of facilities reported prioritizing diagnostic breast imaging over breast cancer screening. For diagnostic imaging, facilities prioritized based on rescheduling canceled appointments (89%), specific indication for diagnostic imaging (89%), patient demand (84%), individual characteristics and risk factors (77%), and time since last imaging examination (72%). For screening mammography, facilities prioritized based on rescheduled cancelations (96%), patient demand (83%), individual characteristics and risk factors (73%), and time since last mammogram (71%). For biopsy services, more than 90% of facilities reported prioritization based on rescheduling of canceled exams, patient demand, patient characteristics and risk factors and level of suspicion on imaging. The observed patterns from this large and geographically diverse sample of facilities in the United States indicate that multiple factors were commonly used to prioritize breast imaging services during periods of reduced capacity.

Although much attention has been paid to the reduction of disparities in health care within the United States, these issues continue to exist. Such efforts include increased focus on patient centeredness and cultural responsivity. These concepts are based on the recognition that diverse, marginalized, and vulnerable patients may possess different physical, psychologic, or social characteristics that contribute to their diversity and susceptibility. Such patients may face numerous obstacles and barriers when seeking medical care, including financial constraints, difficulties with communication, a limited understanding of how to navigate the health care system, and not feeling welcomed, respected, or safe. It is essential that the radiologist and members of the radiology care team understand and embrace patients' unique characteristics to provide effective and appropriate care to all patients. This article illustrates the spectrum of knowledge that benefits radiologists and members of the radiology care team when interacting with and providing care for the growing pool of diverse, marginalized, and vulnerable patients. © RSNA, 2018 • Abbreviations: LEP = limited English proficiency, LGBTQ = lesbian, gay, bisexual, transgender, or queer, PTSD = posttraumatic stress disorder

BackgroundEstablished mammography screening performance metrics use the initial screening mammography assessment because they were developed for radiologist performance auditing, yet these metrics are frequently used to inform health policy and screening decision making. The authors have developed new performance metrics based on the final assessment that consider the entire screening episode, including diagnostic workup.MethodsThe authors used data from 2,512,577 screening episodes during 2005‐2017 at 146 facilities in the United States participating in the Breast Cancer Surveillance Consortium. Screening performance metrics based on the final assessment of the screening episode were compared with conventional metrics defined with the initial assessment. Results were also stratified by breast density and breast cancer risk.ResultsThe cancer detection rates were similar for the final assessment (4.1 per 1000; 95% confidence interval [CI], 3.8‐4.3 per 1000) and the initial assessment (4.1 per 1000; 95% CI, 3.9‐4.3 per 1000). The interval cancer rate was 12% higher when it was based on the final assessment (0.77 per 1000; 95% CI, 0.71‐0.83 per 1000) versus the initial assessment (0.69 per 1000; 95% CI, 0.64‐0.74 per 1000), and this resulted in a modest difference in sensitivity (84.1% [95% CI, 83.0%‐85.1%] vs 85.7% [95% CI, 84.8%‐86.6%], respectively). Absolute differences in the interval cancer rate between final and initial assessments increased with breast density and breast cancer risk (eg, a difference of 0.29 per 1000 for women with extremely dense breasts and a 5‐year risk >2.49%).ConclusionsEstablished screening performance metrics underestimate the interval cancer rate of a mammography screening episode, particularly for women with dense breasts or an elevated breast cancer risk. Women, clinicians, policymakers, and researchers should use final‐assessment performance metrics to support informed screening decisions.