1,721,010 research outputs found
Results of short-term follow-Up in BI-RADS 3 and 4a breast lesions with a histological diagnosis of fibroadenoma at percutaneous needle biopsy
No full text<b><i>Objective:</i></b> To evaluate the usefulness of short-term (6 months) follow-up in patients with Breast Imaging Report and Data System (BI-RADS) 3 and 4a lesions, after a diagnosis of fibroadenoma at an image-guided biopsy. <b><i>Patients and Methods:</i></b> The data of 318 women with 349 biopsy-proven fibroadenomas, a 6-month follow-up, and a follow-up of ≥ 24 months were retrospectively reviewed. Information on clinical history, lesion characteristics on ultrasound (US), mammography, and magnetic resonance imaging (MRI), BI-RADS classification, and follow-up was collected. The false-negative (FN) rate and the negative predictive value (NPV) for the biopsy were calculated. <b><i>Results:</i></b> 43 patients (13.5%) presented with a palpable nodule; 18 (5.7%) had a history of breast cancer. There were 334 lesions visible on US (95.7%), 57 on US and mammography (16.3%), and 15 on mammography only (4.3%); 37 lesions were first detected on MRI. All lesions were stable at 6 months. After an at least 1-year follow-up, 4 lesions changed their features and were excised. Histology showed 1 invasive lobular cancer, 1 ductal carcinoma in situ, 1 phyllodes tumor, and 1 papilloma. The FN rate of the needle biopsy was 1.1% and the NPV was 98.9%. <b><i>Conclusion:</i></b> For lesions initially described as BI-RADS 3 and 4a with a histological diagnosis of fibroadenoma after biopsy, short-term follow-up can be avoided.</jats:p
Breast Computed Tomography: Diagnostic Performance of the Maximum Intensity Projection Reformations as a Stand-Alone Method for the Detection and Characterization of Breast Findings
No full textObjectives: This study aimed to evaluate the diagnostic performance of the maximum intensity projection (MIP) reformations of breast computed tomography (B-CT) images as a stand-alone method for the detection and characterization of breast imaging findings. Materials and methods: A total of 160 women undergoing B-CT between August 2018 and December 2020 were retrospectively included; 80 patients with known breast imaging findings were matched with 80 patients without imaging findings according to age and amount of fibroglandular tissue (FGT). A total of 71 benign and 9 malignant lesions were included. Images were evaluated using 15-mm MIP in 3 planes by 2 radiologists with experience in B-CT. The presence of lesions and FGT were evaluated, using the BI-RADS classification. Interreader agreement and descriptive statistics were calculated. Results: The interreader agreement of the 2 readers for finding a lesion (benign or malignant) was 0.86 and for rating according to BI-RADS classification was 0.82. One of 9 cancers (11.1%) was missed by both readers due to dense breast tissue. BI-RADS 1 was correctly applied to 73 of 80 patients (91.3%) by reader 1 and to 74 of 80 patients (92.5%) by reader 2 without recognizable lesions. BI-RADS 2 or higher with a lesion in at least one of the breasts was correctly applied in 69 of 80 patients (86.3%) by both readers. For finding a malignant lesion, sensitivity was 88.9% (95% confidence interval [CI], 51.75%-99.72%) for both readers, and specificity was 99.3% (95% CI, 96.4%-100%) for reader 1 and 100% (95% CI, 97.20%-100.00%) for reader 2. Conclusions: Evaluation of B-CT images using the MIP reformations may help to reduce the reading time with high diagnostic performance and confidence
Is there a systematic bias of apparent diffusion coefficient (ADC) measurements of the breast if measured on different workstations? An inter- and intra-reader agreement study
No full textOBJECTIVES To evaluate the influence of post-processing systems, intra- and inter-reader agreement on the variability of apparent diffusion coefficient (ADC) measurements in breast lesions. METHODS Forty-one patients with 41 biopsy-proven breast lesions gave their informed consent and were included in this prospective IRB-approved study. Magnetic resonance imaging (MRI) examinations were performed at 1.5 T using an EPI-DWI sequence, with b-values of 0 and 1000 s/mm(2). Two radiologists (R1, R2) reviewed the images in separate sessions and measured the ADC for lesion, using MRI-workstation (S-WS), PACS-workstation (P-WS) and a commercial DICOM viewer (O-SW). Agreement was evaluated using the intraclass correlation coefficient (ICC), Bland-Altman plots and coefficient of variation (CV). RESULTS Thirty-one malignant, two high-risk and eight benign mass-like lesions were analysed. Intra-reader agreement was almost perfect (ICC-R1 = 0.974; ICC-R2 = 0.990) while inter-reader agreement was substantial (ICC from 0.615 to 0.682). Bland-Altman plots revealed a significant bias in ADC values measured between O-SW and S-WS (P = 0.025), no further systematic differences were identified. CV varied from 6.8 % to 7.9 %. CONCLUSION Post-processing systems may have a significant, although minor, impact on ADC measurements in breast lesions. While intra-reader agreement is high, the main source of ADC variability seems to be caused by inter-reader variation. KEY POINTS • ADC provides quantitative information on breast lesions independent from the system used. • ADC measurement using different workstations and software systems is generally reliable. • Systematic, but minor, differences may occur between different post-processing systems. • Inter-reader agreement of ADC measurements exceeded intra-reader agreement
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Liver involvement by multiple myeloma presenting as hypervascular focal lesions in a patient with chronic hepatitis B infection
No full textExtramedullary myeloma refers to the infiltration of neoplastic monoclonal plasma cells in either organs or soft tissues. The disease is clinically and radiologically underestimated compared with the autopsy findings and is usually associated with a more aggressive clinical course and poorer outcome. A minority of patients with extramedullary myeloma show hepatic involvement, usually in the form of diffuse parenchymal infiltration. When focal infiltration is present, variable imaging findings have been described both on CT scan and MRI. We report the case of a 63-year-old male with hepatitis B virus-related liver disease and biopsy-proven multiple myeloma involving the liver, manifesting as hypervascular focal liver lesions on MRI. A brief review of the literature is also proposed
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