52 research outputs found

    Ground-Water Availability in the Atlantic Coastal Plain Aquifers of North and South Carolina

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    2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio

    Comparison of magnetic resonance imaging-based and conventional measurements for proton beam therapy of uveal melanoma

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    Objective: Conventionally, ocular proton therapy (PT) is planned using measurements obtained by an ophthalmologist using ultrasound, fundoscopy, biometry, and intraoperative assessments. Owing to the recent advances in magnetic resonance imaging (MRI) of uveal melanoma (UM), it is possible to acquire high-resolution 3-dimensional images of the eye, providing the opportunity to incorporate MRI in ocular PT planning. In this study, we described how these measurements can be obtained using MRI, compared the MRI-based measurements with conventional ophthalmic measurements, and identified potential pitfalls for both modalities. Design: Cross-sectional study. Subjects: Data from 23 consecutive patients with UM treated with PT were retrospectively evaluated. Methods: Magnetic resonance imaging-based measurements of axial length, tumor height and basal diameter, and marker-tumor distances were compared with the conventional ophthalmic measurements, and discrepancies were evaluated in a multidisciplinary setting. Main Outcome Measures: Tumor prominence and basal diameters on MRI and ultrasound, axial length on MRI and biometry, tumor-marker distances on MRI and measured intraoperatively. Results: The mean absolute differences of the tumor height and basal diameter measurements between ultrasound and MRI were 0.57 mm and 1.44 mm, respectively. Larger absolute differences in height and basal diameter were observed when the full tumor extent was not visible on ultrasound (0.92 mm and 1.67 mm, respectively) compared with when the full tumor extent was visible (0.44 mm and 1.15 mm, respectively). When the full tumor was not visible on ultrasound, MRI was considered more reliable. Tumor-marker distances measured using MRI and intraoperative techniques differed Biological, physical and clinical aspects of cancer treatment with ionising radiatio

    MR-based follow-up after brachytherapy and proton beam therapy in uveal melanoma

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    PurposeMRI is increasingly used in the diagnosis and therapy planning of uveal melanoma (UM). In this prospective cohort study, we assessed the radiological characteristics, in terms of anatomical and functional imaging, of UM after ruthenium-106 plaque brachytherapy or proton beam therapy (PBT) and compared them to conventional ultrasound.MethodsTwenty-six UM patients were evaluated before and 3, 6 and 12 months after brachytherapy (n = 13) or PBT (n = 13). Tumour prominences were compared between ultrasound and MRI. On diffusion-weighted imaging, the apparent diffusion value (ADC), and on perfusion-weighted imaging (PWI), the time-intensity curves (TIC), relative peak intensity and outflow percentages were determined. Values were compared between treatments and with baseline.ResultsPre-treatment prominences were comparable between MRI and ultrasound (mean absolute difference 0.51 mm, p = 0.46), but larger differences were observed post-treatment (e.g. 3 months: 0.9 mm (p = 0.02)). Pre-treatment PWI metrics were comparable between treatment groups. After treatment, brachytherapy patients showed favourable changes on PWI (e.g. 67% outflow reduction at 3 months, p < 0.01). After PBT, significant perfusion changes were observed at a later timepoint (e.g. 38% outflow reduction at 6 months, p = 0.01). No consistent ADC changes were observed after either treatment, e.g. a 0.11 x 10(-3)mm(2)/s increase 12 months after treatment (p = 0.15).ConclusionMR-based follow-up is valuable for PBT-treated patients as favourable perfusion changes, including a reduction in outflow, can be detected before a reduction in size is apparent on ultrasound. For brachytherapy, a follow-up MRI is of less value as already 3 months post-treatment a significant size reduction can be measured on ultrasound.Biological, physical and clinical aspects of cancer treatment with ionising radiatio

    The association between frailty and MRI features of cerebral small vessel disease

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    Frailty is a common syndrome in older individuals that is associated with poor cognitive outcome. The underlying brain correlates of frailty are unclear. The aim of this study was to investigate the association between frailty and MRI features of cerebral small vessel disease in a group of non-demented older individuals. We included 170 participants who were classified as frail (n = 30), pre-frail (n = 85) or non-frail (n = 55). The association of frailty and white matter hyperintensity volume and shape features, lacunar infarcts and cerebral perfusion was investigated by regression analyses adjusted for age and sex. Frail and pre-frail participants were older, more often female and showed higher white matter hyperintensity volume (0.69 [95%-CI 0.08 to 1.31], p = 0.03 respectively 0.43 [95%-CI: 0.04 to 0.82], p = 0.03) compared to non-frail participants. Frail participants showed a non-significant trend, and pre-frail participants showed a more complex shape of white matter hyperintensities (concavity index: 0.04 [95%-CI: 0.03 to 0.08], p = 0.03; fractal dimensions: 0.07 [95%-CI: 0.00 to 0.15], p = 0.05) compared to non-frail participants. No between group differences were found in gray matter perfusion or in the presence of lacunar infarcts. In conclusion, increased white matter hyperintensity volume and a more complex white matter hyperintensity shape may be structural brain correlates of the frailty phenotype.Ophthalmic researc

    Groundwater Quality in the Upper Santa Cruz Basin, Arizona, 1998

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    Water-resources investigations report 00-4117. Ill. (some col.), col. maps. Includes bibliographical references

    Crystal structure of trialuminium trihydroxo disilicate, Al 3

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    Virtual Spaces and How to Embrace #Blackgirlmagic in the Classroom

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    Dominant narratives of black girls and woman as they are presented in media often construct less than desirable images of what it means to be both black and female in today’s society. #Blackgirlmagic draws upon the need to explain the ways in which black excellence intersects with social justice. The virtual space of #blackgirlmagic provides a space where black girls and women can be recognized positively on the global stage of various social media platforms. By acknowledging critical media literary (CML) as a useful tool to examine the complex lives of black girls and women, careful attention can be drawn to the absence of positive portrayals in media. We will use CML as a framework to look in-depth at social media movements aiming to dismantle projections of black girls and women as less than admirable. The cultural, economic, political, and social presumptions of #blackgirlmagic inform other social media campaigns (i.e. #Blacklivesmatter, #Sayhername, etc.) ring true to the necessity to project positive images of black girls and women in a global society that would otherwise objectify and invisiblize the black and brown female body, mind, and spirit. The dynamic nature of the intersection of gender and race through the power of social media— which possesses the unique ability to self-regulate— calls for communities with implicit and/or immediate needs to collaborate and effectively resolve the fragmentation that occurs between realities and misrepresentations of black women through popularized media sources. Educators can bring these critical conversation into the classroom, not only to expose students to the counter-narrative of black girls and women, but also to critique the overarching institutions that make movements such as these a necessity in today’s society. Cultivating meaningful conversations about the use of virtual spaces to empower marginalized groups while simultaneously acknowledging the need to support the endeavors of all young people creates a learning community aimed to define “difference” and celebrate everyone. #Blackgirlmagic reclaims attention to pressing issues and deserving causes; thus, it serves as a solution begin to correct the flawed dominant narrative

    Rapid MR imaging of ocular movement for radiotherapy planning

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    Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas
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