11 research outputs found

    Reducing the Number of Measurements in Liver Point Shear-Wave Elastography: Factors that Influence the Number and Reliability of Measurements in Assessment of Liver Fibrosis in Clinical Practice

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    PURPOSE: To identify the minimum number of measurements required for the noninvasive assessment of liver fibrosis by using point shear-wave elastography (pSWE) and determine whether the use of a reliability indicator such as interquartile range [IQR]–to-median ratio will affect diagnostic performance. MATERIALS AND METHODS: Ten liver shear-wave velocity (SWV) measurements by pSWE were obtained in 232 participants. Interclass correlation coefficients (ICC) between the median of the first two through the first nine measurements and all 10 measurements were calculated; the minimum number of measurements with ICC greater than 0.95 versus all 10 measurements was determined. The diagnostic performance of the minimum number of measurements and 10 measurements in identifying significant (Ishak stage, ≥3) and severe fibrosis or cirrhosis (Ishak stage, ≥5) was compared by using areas under the receiver operating characteristic curve. These were compared between measurements that demonstrated higher or lower reliability (IQR-to-median ratio of ≤ 30% and IQR-to-median ratio of > 30%, respectively). RESULTS: Compared with 10 measurements, a minimum of six SWV measurements was required. The overall area under the curve for diagnosing significant (areas under the receiver operating characteristic curve, 0.828 vs 0.839; P = .487) and severe fibrosis or cirrhosis (0.953 vs 0.969, respectively; P = .145) did not differ according to number of measurements (six vs 10); a median of six measurements resulted in only limited disagreement (nine of 232 [3.9%]) versus histologic evaluation. When using 10 measurements, higher reliability measurements showed a lower percentage of discordance between pSWE and significant fibrosis and severe fibrosis or cirrhosis (22 [14.7%] and three [2.0%] of 150 cases, respectively) compared with lower reliability measurements (26 [31.7%] and eight [9.8%] of 82 cases, respectively). Significant fibrosis was an independent predictor for lower reliability (hazard ratio, 2.22; P < .020). CONCLUSION: A limited number of SWV measurements (median six vs median 10) were required for the assessment of liver fibrosis by using pSWE. The number of measurements had less influence on the diagnostic accuracy compared with lower reliability measurements

    Prelude: the future of structural bamboo

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    Prelude demonstrates the possibilities for engineered bamboo in structural applications. Our pavilion is composed of a spiral pathway that cantilevers from the base and embodies the function of the Muziekgebouw through a lightweight design that mirrors a musical prelude in structure, concept and form. Inspired by Guastavino´s masonry vaults, the structure evokes the image of a spiral staircase originally constructed from thin tiles, transformed in a novel material with properties distinct from structural masonry. With a growing need for the development of sustainable materials, engineered bamboo combines the benefits of a natural fibre composite with the advantages of a laminated material. Highly renewable, large diameter bamboo used for structural applications is harvested every 4-5 years. Once harvested, the raw material can be processed into strips, which are then laminated into a board product. The processing reduces inherent geometric and mechanical variability of the natural material that currently limit the application of bamboo products. Currently promoted as a decorative material, Prelude is an example of the potential use of engineered bamboo beyond surface applications in architecture

    Evaluation of intratesticular lesions with strain elastography using strain ratio and color map visual grading: Differentiation of neoplastic and nonneoplastic lesions

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    OBJECTIVE: To investigate the role of strain elastography using calculated strain ratio and visual elastography score in differentiating nonneoplastic, benign, and malignant neoplastic intratesticular lesions. MATERIALS AND METHODS: The study was approved by the hospital review board as a retrospective review of 86 patients examined with gray scale, color Doppler ultrasonography and strain elastography (visual elastography score and strain ratio). Sensitivity, specificity, and positive and negative likelihood ratio of color Doppler and stain elastography were documented. Receiver operator characteristic curves assessed the diagnostic accuracy of strain elastography to discriminate nonneoplastic, benign, and malignant neoplasms. Histology or follow-up ultrasonography determined lesion character. RESULTS: Thirty-one of 86 (36.0%) intratesticular malignant neoplasms, 17 of 86 (19.8%) benign neoplasms, and 38 of 86 (44.2%) nonneoplastic lesions were confirmed with histology (n\u2009=\u200952) or follow-up sonography (n\u2009=\u200934); 89.5% of intratesticular lesions were heterogeneous or hypoechoic on gray scale, with no difference between benign and malignant. Sensitivity, specificity, positive and negative likelihood ratio for nonneoplasm versus neoplasm were documented: color Doppler: 68.8%, 97.4%, 26.5, 0.32; visual elastography score: 81.3%, 57.9%, 1.93, 0.32; strain ratio: 68.8%, 81.6%, 3.73, 0.38. Neoplastic lesions showed a higher strain ratio than nonneoplastic lesions (P\u2009<\u2009.001), with strong correlation between median strain ratio and visual elastography score (Spearman's coefficient, 0.693; P\u2009<\u2009.001). Strain ratio is a significantly better assessment than visual elastography score for malignant lesions (P\u2009=\u2009.025). Logistic regression analysis revealed significant associations between size (P\u2009=\u2009.001), hypervascularity (P\u2009<\u2009.001), and malignancy. CONCLUSION: Higher strain ratio and visual elastography score are associated with neoplastic lesions and offer an alternative to assess tissue characteristics but do not improve the diagnostic accuracy when compared with the color Doppler pattern

    Sonographic imaging of extra-testicular focal lesions: comparison of grey-scale, colour Doppler and contrast-enhanced ultrasound

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    Extra-testicular lesions are usually benign but present with nonspecific grey-scale sonography findings. This study assesses conventional sonographic characteristics in the differentiation of extra-testicular tumoural from inflammatory lesions and whether contrast-enhanced ultrasound has a role. A retrospective database analysis was performed. All patients were examined by experienced sonographers employing standard techniques combining grey-scale, colour Doppler sonography and contrast-enhanced ultrasound. Features recorded were: clinical symptoms, size, location, echogenicity, colour Doppler sonography and contrast-enhanced ultrasound enhancement. Vascularity on colour Doppler sonography and contrast-enhanced ultrasound was graded and compared. The lesions were classified as tumoural or inflammatory. The Chi-square test was used to analyse the sonographic patterns and kappa coefficient to measure the agreement between colour Doppler sonography and contrast-enhanced ultrasound. A total of 30 lesions were reviewed (median diameter 12 mm, range 5-80 mm, median age 52 years, range 18-86 years), including 13/30 tumoural and 17/30 inflammatory lesions. Lesions were hypoechoic (n = 12), isoechoic (n = 6), hyperechoic (n = 2) or mixed (n = 10). Grey-scale characteristics of tumoural vs. inflammatory lesions differed significantly (P = 0.026). On colour Doppler sonography, lesions had no vessels (n = 16), 2-3 vessels (n = 10) and ≥4 vessels (n = 4). On contrast-enhanced ultrasound, lesions showed no vascularity (n = 17), perfusion similar to testis (n = 7) and higher (n = 6). All abscesses identified (n = 9) showed no vascularity on both colour Doppler sonography and contrast-enhanced ultrasound. There was good agreement between these techniques in evaluating vascularity (κ = 0.719) and no significant difference between colour Doppler sonography and contrast-enhanced ultrasound of tumoural vs. inflammatory lesions (P > 0.05). The grey-scale appearances of extra-testicular lesions are essential for characterisation. Colour Doppler sonography and contrast-enhanced ultrasound findings are not useful in that respect. Contrast-enhanced ultrasound is excellent in establishing absence of vascularity

    Common and uncommon features of focal splenic lesions on contrast-enhanced ultrasound: a pictorial review

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    <div><p>Abstract The characterization of focal splenic lesions by ultrasound can be quite challenging. The recent introduction of contrast-enhanced ultrasound (CEUS) has come to play a valuable role in the field of imaging splenic pathologies, offering the possibility of an ionizing radiation-free investigation. Because CEUS has been incorporated into everyday clinical practice, malignant diseases such as focal lymphomatous infiltration, metastatic deposits, benign cysts, traumatic fractures, and hemangiomas can now be accurately depicted and characterized without the need for further imaging. More specifically, splenic traumatic fractures do not require additional imaging by computed tomography (with ionizing radiation exposure) for follow-up, because splenic fractures and their complications are safely imaged with CEUS. In the new era of CEUS, more patients benefit from radiation-free investigation of splenic pathologies with high diagnostic accuracy.</p></div
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