1,721,001 research outputs found
Metastasi pancreatica solitaria da carcinoma renale: Descrizione di 1 caso simulante tumore neuroendocrino [Solitary pancreatic metastasis from renal cell carcinoma. A case report]
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MRI evaluation of myometrial invasion by endometrial carcinoma. Comparison between fast-spin-echo T2W and coronal FMPSPGR Gadolinium-dota-enhanced sequences
No full textPurpose. The depth of myometrial invasion by endometrial carcinoma strongly affects the incidence of metastasis to regional nodes and influences the surgical strategies. The aim of this paper is to compare the results of FSE T2-w and Gadolinium-enhanced FMPSGR MR sequences in assessing the depth of myometrial invasion by endometrial cancer. Materials and methods. Forty-five women with histopathologically-proven endometrial carcinoma underwent preoperative MRI. Axial SE T1w, axial, sagittal and para-coronal FSE T2w and para-coronal Gadolinium-enhanced FMPSGR sequences were performed using a high field strength magnet (1.5T). Within one month of MR all patients underwent hysterectomy, and anatomical evaluation of the surgical specimen was done sectioning the uterus along the short axis. Based upon the results of the histological evaluation the results of the FSE T2w and Gadolinium-enhanced sequences were compared and the statistical difference between the results obtained was statistically evaluated. Results. The histological evaluation showed intramucosal neoplasm in 1 patients, myometrial infiltration less than 50% in 31 patients, myometrial infiltration more than 50% in 12 patients and transmural cancer in 1 patient. Statistical evaluation showed that the FSE T2w sequence had a global sensitivity and specificity of 80.6% and 87.6%, respectively, with a mean Negative Predictive Value of 92.6% and a mean Positive Predictive Value of 86%. Gadolinium-enhanced FMPSPGR sequence had a global sensitivity and specificity of 90.6% and 93.3%, respectively, with a mean Negative Predictive Value of 96,3% and a mean Positive Predictive Value of 88%. The staging accuracy (chi(2) test) on FMPSPGR images (95%) was higher than that on FSE T2w images (78%). Conclusions. In our experience Gadolinium-enhanced dynamic sequences increase the accuracy of MR imaging in diagnosing the depth of myometrial invasion. In particular they improve the visualisation of the inner myometrium, the so called subendometrial enhancing zone, whose disruption or changes are essential for diagnosing myometrial invasion. The major diagnostic advantages of the enhanced sequences were found in postmenopausal women, where visualisation of the junctional zone may be difficult in the T2w sequences. We believe that Gadolinium-enhanced dynamic sequences should be used whenever the diagnosis is unclear at FSE T2w sequences
Gadolinium-enhanced MRI with dynamic evaluation in diagnosing the local recurrence of rectal cancer
No full textBackground: At early stages, the diagnosis of local recurrence of rectal cancer is often difficult and magnetic resonance imaging (MRI) is currently considered the most accurate method for diagnosing recurrence. We evaluated the role of unhenhanced and gadolinium-enhanced MRI for the diagnosis of local recurrence of rectal cancer. Methods: Thirty-six patients, suspected of having a pelvic recurrence of rectal cancer, were evaluated by a high field strength MRI unit. Unenhanced spin-echo T1- and T2-weighted sequences and gadolinium-enhanced dynamic fast multiplanar spoiled gradient recalled sequences were performed in all patients. The dynamic images were re-elaborated with semiquantitative postprocessing by plotting intensity-time curves and calculating the percentage of signal increase at the end of the first postcontrast dynamic sequence. The pelvic lesions were classified as recurrent or not recurrent by applying the following diagnostic criteria: (a) morphology and signal intensity of the lesion in unenhanced sequences and (b) percentage of enhancement in dynamic enhanced sequences. Diagnosis was confirmed by computed tomography-guided needle biopsy (12 patients), surgery (four patients), clinical and imaging follow-up (20 patients). Results: The diagnosis was local recurrence in 15 patients and noncancerous lesions in 21 patients. Unenhanced MRI had 80% sensitivity and 86% specificity. Analysis of the percentage of enhancement showed 87% sensitivity and 100% specificity. Conclusion: In agreement with the literature, our results showed a high sensitivity and specificity for dynamic MRI. This technique thus can be considered an important adjunct to unenhanced MRI, especially in selected cases in which unenhanced MRI cannot rule out local recurrences. However, these results must be validated by further investigations
Radiological screening programs for women at high risk of developing breast cancer
No full textThe aim of this review is to identify the evidence for the surveillance of women at high risk of breast cancer with the different modalities. The definition of high risk refers to the subpopulation of women with a family history of breast cancer, including both those with and without identified genetic mutations. The following topic has been evaluated: clinical breast examination (CBE), mammography, ultrasound and MRI accuracy of detecting breast cancer among women at high risk. The search was limited to full reports published in English and published between 1996 and March, 2010. We found consistent evidence that adding MRI provides a highly sensitive screening strategy (sensitivity range: 93-100%) compared to mammography alone (32-86%) or mammography plus ultrasound +/- CBE (26-93%). Three studies that compared MRI plus mammography versus mammography alone showed the sensitivity of MRI plus mammography as 93% (95% CI 86-100%) and the incremental sensitivity of MRI as 60%. Incremental sensitivity of MRI was lower when added to mammography plus ultrasound (43%) or to the combination of mammography, ultrasound plus CBE. Estimates of screening specificity with MRI were less consistent but suggested a 3-5-fold higher risk of patient recall for investigation of false positive results. No studies assessed whether adding MRI reduces patient mortality, interval or advanced breast cancer rates, even if we found strong evidence that MRI leads to the detection of earlier stage disease. This review suggests that a surveillance strategy would be accurate and effective in improving health outcomes for women at high risk of breast cancer, but randomized studies should be considered for a better evaluation of these topics. © 2012 Bentham Science Publishers
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
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