16 research outputs found

    Analysis of motion during the breast clamping phase of mammography

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    Objectives: To measure paddle motion during the clamping phase of a breast phantom for a range of machine/paddle combinations. Methods: A deformable breast phantom was used to simulate a female breast. Twelve mammography machines from three manufacturers with twenty two flexible and twenty fixed paddles were evaluated. Vertical motion at the paddle was measured using two calibrated linear potentiometers. For each paddle, the motion in millimeters was recorded every 0.5 seconds for 40 seconds while the phantom was compressed with 80 N. Independent t-tests were used to determine differences in paddle motion between flexible and fixed, small and large, GE Senographe Essential and Hologic Selenia Dimensions paddles. Paddle tilt in the medial-lateral plane for each machine/paddle combination was calculated. Results: All machine/paddle combinations demonstrate highest levels of motion during the first 10s of the clamping phase. Least motion is 0.17±0.05 mm/10s (n=20) and the most is 0.51±0.15 mm/10s (n=80). There is a statistical difference in paddle motion between fixed and flexible (p<0.001), GE Senographe Essential and Hologic Selenia Dimensions paddles (p<0.001). Paddle tilt in the medial-lateral plane is independent of time and varied from 0.04° to 0.69°. Conclusions: All machine/paddle combinations exhibited motion and tilting and the extent varied with machine and paddle sizes and types. Advances in knowledge: This research suggests that image blurring will likely be clinically insignificant 4 seconds or more after the clamping phase commences

    Blurred digital mammography images : an analysis of technical recall and observer detection performance

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    Background: Blurred images in Full Field Digital Mammography (FFDM) are a problem in the UK Breast Screening Programme. Technical recalls may be due to blurring not being seen on lower resolution monitors used for review. Objectives: This study assesses the visual detection of blurring on a 2.3 megapixel (MP) monitor and a 5 MP report grade monitor and proposes an observer standard for the visual detection of blurring on a 5 MP reporting grade monitor. Method: Twenty-eight observers assessed 120 images for blurring; 20 had no blurring present whilst 100 had blurring imposed through mathematical simulation at 0.2, 0.4, 0.6, 0.8 and 1.0 mm levels of motion. Technical recall rate for both monitors and angular size at each level of motion were calculated. Chi-squared (X2) tests were used to test whether significant differences in blurring detection existed between 2.3 and 5 MP monitors. Results: The technical recall rate for 2.3 and 5 MP monitors are 20.3 % and 9.1% respectively. Angular size for 0.2 to 1 mm motion varied from 55 to 275 arc seconds. The minimum amount of motion for visual detection of blurring in this study is 0.4 mm. For 0.2 mm simulated motion, there was no significant difference X2 (1, N=1095) =1.61, p=0.20) in blurring detection between the 2.3 and 5 MP monitors. Conclusion: According to this study monitors equal or below 2.3 MP are not suitable for technical review of FFDM images for the detection of blur. Advances in knowledge: This research proposes the first observer standard for the visual detection of blurring. Key words: Simulated motion; technical recall; monitor resolution; observer standard; blurring detectio

    Mimics of Duplication Cysts: Intraperitoneal Nodules in a 14-Year-Old Boy

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    Hemangiomas are the most common primary hepatic tumors, but there are few reports of their occurrence elsewhere in the abdomen. The concurrent existence of multiple fibrous nodules of the omentum, mesentery, and porta hepatis, along with a gastric hemangioma, in a child raises the question of syndromic association. Our search of the English literature revealed only rare mentions of hemangiomas involving the stomach and mesentery or omentum. These lesions have attracted clinical attention by symptoms of obstruction, gastrointestinal bleeding, intussusception, infection, perforation, or vague abdominal pain. Although some tumors exist unnoticed for many decades and are identified only incidentally, others present emergently and require immediate surgical attention. We report the case of a 14-year-old boy who presented with symptoms similar to those for appendicitis or duplication cyst, who was found to have a torsed gastric hemangioma and multiple benign fibrous nodules in the abdomen. The presence of multiple vascular or fibrous lesions is associated with genetic syndromes that can have lifelong and reproductive repercussions; so it is imperative that these tumors be recognized by diagnosticians

    Financing Reparative Climate Infrastructures: Capital Switching, Repair and Decommodification

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    Despite geographical critiques of the financialisation of climate governance, the realities of deteriorating environmental conditions, entrenched market logics, and the concentration of capital in the hands of financiers demand new strategies to contend with climate finance. We envision routes to better futures by surveying “financialised” responses to climate catastrophe that might be harnessed towards more reparative and decommodified ends. We combine ideas of “repair” and “capital switching” to evaluate financial tools for “reparative climate infrastructures” in five cases centred on energy, land, and water in the United States, Australia, Indonesia, and Brazil. Through these cases, we identify three key themes—governance, scale, and the state—that illuminate the socioecological, material, and political dimensions of reparative capital switching. The cases are each hopeful and cautionary. Together they offer a window into the contested terrain of climate finance in the present and highlight the need for critical attention to its strategic possibilities

    Robust Phagocyte Recruitment Controls the Opportunistic Fungal Pathogen Mucor circinelloides in Innate Granulomas In Vivo

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    Mucormycosis is an emerging fungal infection with extremely high mortality rates in patients with defects in their innate immune response, specifically in functions mediated through phagocytes. However, we currently have a limited understanding of the molecular and cellular interactions between these innate immune effectors and mucormycete spores during the early immune response. Here, the early events of innate immune recruitment in response to infection by Mucor circinelloides spores are modeled by a combined in silico modeling approach and real-time in vivo microscopy. Phagocytes are rapidly recruited to the site of infection in a zebrafish larval model of mucormycosis. This robust early recruitment protects from disease onset in vivo. In silico analysis identified that protection is dependent on the number of phagocytes at the infection site, but not the speed of recruitment. The mathematical model highlights the role of proinflammatory signals for phagocyte recruitment and the importance of inhibition of spore germination for protection from active fungal disease. These in silico data are supported by an in vivo lack of fungal spore killing and lack of reactive oxygen burst, which together result in latent fungal infection. During this latent stage of infection, spores are controlled in innate granulomas in vivo. Disease can be reactivated by immunosuppression. Together, these data represent the first in vivo real-time analysis of innate granuloma formation during the early stages of a fungal infection. The results highlight a potential latent stage during mucormycosis that should urgently be considered for clinical management of patients

    A dominant mutation in RPE65 identified by whole-exome sequencing causes retinitis pigmentosa with choroidal involvement

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    Linkage testing using Affymetrix 6.0 SNP Arrays mapped the disease locus in TCD-G, an Irish family with autosomal dominant retinitis pigmentosa (adRP), to an 8.8 Mb region on 1p31. Of 50 known genes in the region, 11 candidates, including RPE65 and PDE4B, were sequenced using di-deoxy capillary electrophoresis. Simultaneously, a subset of family members was analyzed using Agilent SureSelect All Exome capture, followed by sequencing on an Illumina GAIIx platform. Candidate gene and exome sequencing resulted in the identification of an Asp477Gly mutation in exon 13 of the RPE65 gene tracking with the disease in TCD-G. All coding exons of genes not sequenced to sufficient depth by next generation sequencing were sequenced by di-deoxy sequencing. No other potential disease-causing variants were found to segregate with disease in TCD-G. The Asp477Gly mutation was not present in Irish controls, but was found in a second Irish family provisionally diagnosed with choroideremia, bringing the combined maximum two-point LOD score to 5.3. Mutations in RPE65 are a known cause of recessive Leber congenital amaurosis (LCA) and recessive RP, but no dominant mutations have been reported. Protein modeling suggests that the Asp477Gly mutation may destabilize protein folding, and mutant RPE65 protein migrates marginally faster on SDS-PAGE, compared with wild type. Gene therapy for LCA patients with RPE65 mutations has shown great promise, raising the possibility of related therapies for dominant-acting mutations in this gene
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