1,720,983 research outputs found
Diagnostic Accuracy of North America Expert Consensus Statement on Reporting CT Findings in Patients Suspected of Having COVID-19 Infection: An Italian Single-Center Experience
No full textPurpose: To evaluate the diagnostic accuracy of the four standardized categories for CT reporting proposed by the Radiological Society of North America (RSNA) to support a faster triage compared with real-time reverse-transcription polymerase chain reaction (RTPCR), which is the reference standard for suspected coronavirus disease 2019 (COVID-19), but has long reporting time (6–48 hours).
Materials and Methods: A retrospective analysis of 569 thin-section CT examinations performed for patients suspected of having COVID-19 from February 27 to March 27, 2020 (peak of infection in Italy) was conducted. The imaging pattern was classified according to the statement by the RSNA as “typical,” “indeterminate,” “atypical,” and “negative” and compared with RT-PCR for 460
patients. Interobserver variability in reporting between a senior and a junior radiologist was evaluated. Use of the vascular enlargement sign in indeterminate cases was also assessed.
Results: The diagnosis of COVID-19 was made in 45.9% (211/460) of patients. The “typical” pattern (n = 172) showed a sensitivity of 71.6%, a specificity of 91.6%, and a positive predictive value of 87.8% for COVID-19. The “atypical” (n = 67) and “negative” (n =123) pattern demonstrated a positive predictive value of 89.6% and 86.2% for non–COVID-19, respectively. The “indeterminate” (n
= 98) pattern was nonspecific, but vascular enlargement was most frequently found in patients with COVID-19 (86.1%; P , .001). Interobserver agreement was good for the “typical” and “negative” pattern and fair for “indeterminate” and “atypical” (k = 0.5; P =.002).
Conclusion: In an epidemic setting, the application of the four categories proposed by the RSNA provides a standardized diagnostic hypothesis, strongly linked to the RT-PCR results for the “typical,” “atypical,” and “negative” pattern. In the “indeterminate” pattern, the analysis of the vascular enlargement sign could facilitate the interpretation of imaging features
Tumor growth rate to assess therapy response to immune-based combinations for metastatic renal cell carcinoma
Get PDFBackground: Radiological response assessment is becoming challenging with novel immune-based combinations for metastatic renal cell carcinoma (mRCC). RECIST criteria appear not exhaustively adequate to capture the kinetics of treatment response, which is better reflected by tumor growth
rate (TGR). We explored TGR changes during first-line treatments and its association with clinical outcomes in mRCC.
Research design and methods: We retrospectively evaluated TGR in untreated patients undergoing pembrolizumab/axitinib (P/A) or tyrosine-kinase inhibitors (TKI). TGR was calculated at the first (TGR1, after 3 months) and the second (TGR2, after 6 months) evaluation, thus assessing the TGR2-TGR1 difference.
Results: Thirty-three patients were included (P/A n = 15, TKIs n = 18). Volumes firstly decreased more rapidly with TKIs, and then more slowly. Volumes initially remained stable with P/A, quickly decreasing until the second evaluation. TGR1 was related to progression-free survival (PFS; p = 0.023) and overall survival (p = 0.046) with P/A. TGR2 was correlated with PFS in all patients (p = 0.025). Patients with higher velocity volume reduction appeared to have improved survival benefits than patients with lower velocity considering both treatments, but especially with P/A.
Conclusion: Combining immunotherapy with TKIs has an important role in enhancing the rapidity of tumor shrinkage. A rapid disease volume reduction correlates with better OS and PFS
Do low-dose oral contraceptives have an effect on ovarian endometrioma diameter and endometriosis symptoms?
No full textAbstract
Purpose: To investigate the effect of a low-dose oral contraceptive containing drospirenone/ethinylestradiol 3 mg/20 μg on endometrioma mean diameter. Methods: Fifty women with sonographic diagnosis of ovarian endometrioma and at least 12 months of therapy with drospirenone/ethinylestradiol 3 mg/20 μg, without previous adnexal surgery, were selected for this retrospective study. Endometrioma mean diameter measured with transvaginal ultrasonography and endometriosis-associated symptoms evaluated by a visual analogue scale (VAS) score (0-10) were reported at therapy prescription (baseline) and after 6, 12 and 18 months of treatment. Main outcome measures were endometrioma mean diameters and endometriosis-associated symptoms variations during the follow-up; differences between cyclic and continuous regimen were also considered. Results: A significant reduction in endometrioma mean diameter was observed during the follow-up. The reductions of mean diameter versus baseline values were significantly higher in continuous users than in cyclic users at 6 and 18 months of follow-up. No new endometriomas occurred. The dysmenorrhea VAS score significantly decreased during the follow-up. Conclusions: Drospirenone/ethinylestradiol 3 mg/20 μg seems to be effective in reducing endometrioma mean diameter. The continuous regimen seems to be associated with a greater reduction than the cyclic one
Long-Term Outcomes of Balloon TACE for HCC: An European Multicentre Single-Arm Retrospective Study
Get PDFPurposeTo report response rates (using mRECIST), overall survival (OS), progression-free survival and local tumour recurrence-free survival (LRFS) of balloon-occluded transarterial chemoembolisation (bTACE) for hepatocellular carcinoma (HCC).Materials and MethodsPatients from five European centres treated with conventional or drug-eluting microsphere bTACE for HCC were included, and patients already lost to follow-up before 12 months were excluded. Possible factors contributing to LRFS and OS were evaluated with Cox proportional hazards models.ResultsSeventy-three patients were enrolled. The mean number of nodules per patient was 2.07(+/- 1.68), and the average maximum diameter of the nodules was 37 +/- 19.9 mm. The response of the target lesion at 6 months was complete response (CR) in 58.9%, partial response (PR) in 28.8%, stable disease (SD) in 6.8% and progressive disease (PD) in 5.5%. The median follow-up time was 31 months; at the last follow-up, target tumour response was CR in 49.3%, PR in 12.3%, SD in 5.5% and PD 32.9%. Overall response at the last follow-up was CR in 17.8%, PR in 9.6%, SD 2.7% and PD in 69.9% (for new lesions in 37% of patients). Median OS was not reached; mean overall survival was 50.0 months, while median LRFS was 31.0 months. At uni- and multivariable analysis, only tumour maximum diameter was related to LRFS (hazard ratio [HR] = 1.021; 95% CI 1.004-1.038, P = 0.015).ConclusionsbTACE demonstrated high efficacy for HCC, with a complete response in 58.9% of patients, a median local recurrence-free survival of 31.0 months and a mean overall survival of 50.0 months
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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