21 research outputs found

    “Local Rank Differences” Image Feature Implemented on GPU

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    Abstract. A currently popular trend in object detection and pattern recognition is usage of statistical classifiers, namely AdaBoost and its modifications. The speed performance of these classifiers largely depends on the low level image features they are using: both on the amount of information the feature provides and the executional time of its evaluation. Local Rank Differences is an image feature that is alternative to commonly used haar wavelets. It is suitable for implementation in programmable (FPGA) or specialized (ASIC) hardware, but – as this paper shows – it performs very well on graphics hardware (GPU) as well. The paper discusses the LRD features and their properties, describes an experimental implementation of LRD in graphics hardware, presents its empirical performance measures compared to alternative approaches and suggests several notes on practical usage of LRD and proposes directions for future work.

    Evaluation of Transperineal Magnetic Resonance Imaging/Ultrasound-Fusion Biopsy Compared to Transrectal Systematic Biopsy in the Prediction of Tumour Aggressiveness in Patients with Previously Negative Biopsy

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    Objectives: We compared the transperineal MRI/ultrasoundfusion biopsy (fusPbx) to transrectal systematic biopsy (sys-Pbx) in patients with previously negative biopsy and investigated the prediction of tumour aggressiveness with regard to radical prostatectomy (RP) specimen. Material and Methods: A total of 710 patients underwent multiparametric magnetic resonance imaging (mpMRI), which was evaluated in accordance with Prostate Imaging Reporting and Data System (PI-RADS). The maximum PI-RADS (maxPI-RADS) was defined as the highest PI-RADS of all lesions detected in mpMRI. In case of proven prostate cancer (PCa) and performed RP, tumour grading of the biopsy specimen was compared to that of the RP. Significant PCa (csPCa) was defined according to Epstein criteria. Results: Overall, scPCa was detected in 40% of patients. The detection rate of scPCa was 33% for fusPbx and 25% for sysPbx alone (p < 0.005). Patients with a maxPI-RADS ≥3 and a prostate specific antigen (PSA)-density ≥0.2 ng/mL2 harboured more csPCa than those with a PSA-density < 0.2 ng/mL2 (41% [33/81] vs. 20% [48/248]; p < 0.001). Compared to the RP specimen (n = 140), the concordance of tumour grading was 48% (γ = 0.57), 36% (γ = 0.31) and 54% (γ = 0.6) in fusPbx, sysPbx and comPbx, respectively. Conclusions: The combination of fusPbx and sysPbx outperforms both biopsy modalities in patients with re-biopsy. Additionally, the PSA-density may represent a predictor for csPCa in patients with maxPI-RADS ≥3

    Implementing the local binary patterns with SIMD instructions of CPU

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    Usage of statistical classifiers, namely AdaBoost and its modifications, is very common in object detection and pattern recognition. Performance of such classifiers strongly depends on low level features they use. This paper presents an experimental implementation of the Local Binary Patterns (LBP) that uses SIMD instructions for acceleration. The experiments shows that the proposed implementation is about six times faster than the plain C implementation (i.e. with no special optimizations) and superior to optimized implementations of features with similar descriptive power

    Gpgpu implementation of the ”local rank differences” image feature

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    Abstract Usage of statistical classifiers, namely AdaBoost and its modifications, in object detectio

    An empirical study on hospital-based prevention of recurrent urinary stone disease in Germany

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    Purpose!#!Urinary stone disease is a common disease with a prevalence of 4.7% in Germany. The incidence increased over the last decades, and recurrence rates are up to 50% in the first 5 years after diagnosis. Adequate preventive measures can avoid up to 46% of stone recurrences. These numbers outline the importance of prevention. Especially among high-risk stone formers, specific diagnostics and measures are required. Published data indicate the divergence between the importance of prevention and its implementation in everyday clinical practice. This is the first survey among German urological departments highlighting medical care concerning the prevention of recurrent urinary stone disease, identifying challenges and providing recommendations for improvements.!##!Methods!#!Two hundred and seventy urological hospital departments in Germany were anonymously surveyed about measurements to prevent recurrent stone disease. The questionnaire comprised 23 items dealing with diagnostics, counselling, knowledge among doctors concerning preventive measures and difficulties in preventing recurrent urinary stone disease.!##!Results!#!Sixty-three urological departments (23.8%) answered the survey. The majority perform stone analysis at first and repeat events. Most patients with urinary stone disease receive general advice on preventive measures during their hospitalization. General recommendations focus on fluid intake and lifestyle changes. However, specific diets are infrequently recommended by inpatient urologists. Diagnostics to identify high-risk stone formers are mostly insufficient, and guideline-compliant urine tests are uncommon.!##!Conclusion!#!The quality of secondary prevention needs to improve considerably. The focus should be put on identifying high-risk stone formers and offering those patients specific counselling. Furthermore, general advice on dietary recommendations should be extended

    Role of Bacterial Surface Components in the Pathogenicity of <i>Proteus mirabilis</i> in a Murine Model of Catheter-Associated Urinary Tract Infection

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    Proteus mirabilis (PM) is a Gram-negative, rod-shaped bacterium that causes catheter-associated urinary tract infections (CAUTIs). The specific roles of bacterial surface components (BSCs) in PM pathogenicity and CAUTIs remain unknown. To address this knowledge gap, we utilized relevant in vitro adhesion/invasion models and a well-established murine model of CAUTI to assess the ability of wildtype (WT) and seven mutant strains (MSs) of PM with deficiencies in various genes encoding BSCs to undergo the infectious process (including adhesion to catheters) in both model systems. Overall, MSs adhesion to catheters and the different cell types tested was significantly reduced compared to WT, while no invasion of cells was evident at 24 h. In vivo, WT showed a greater number of planktonic (urine) bacteria, bacteria adherent to catheters, and bacteria adherent to/invading bladder tissue when compared to the MSs. Bacterial counts in urine for PMI3191 and waaE mutants were lower than that for WT and other MSs. The complementation of mutated BSC genes resulting in the biggest defects restored the invasion phenotype both in vitro and in vivo. BSCs play a critical role at various steps in the pathogenicity of PM including adhesion to indwelling medical devices and adhesion/invasion of urinary tissue in vivo
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