1,720,963 research outputs found
lomeprol versus iopamidol in tomography of thoracic contrast-enhanced computed and abdominal organs
No full textThe aim of this double-blind, parallel-group study was to compare the safety, tolerance, and elficacy ol iomeprol-350 (350
mgl/ml), iomeprol-400 (400 mgl/ml) and iopamidol-37O (370 mgl/ml) for use in contrast-enhanced body computed tomography
(CT). Following written informed consent, 120 adult inpatients of either sex requiring CT of thoracic or abdominal organs were
randomly assigned to receive iomeprol-350, iomeprol-400 or iopamidol-370. Pre- and post-contrast, all patients underwent clinical,
instrumental and laboratory investigation to assess the salety olthe test agents. Tolerance was assessed in terms of discomfort associated
with contrast injection. Two experienced radiologists independently and blindly graded the quality ol contrast enhancement
obtained with the different contrast solutions by means ola five-point ordinal scale as follows: 1, insufficient;2, sufficient;
3, good; 4, excellent; or E, excessive. Patients in the iomeprol groups needed lewer injections and a smaller volume of contrast
medium to obtain examinations of adequate diagnostic quality. Contrast enhancement was judged as excellent or good in about
90% ofthe study examinations, without significant differences between the three study groups. During contrast injection, heat and
pain sensations were minimal or absent in most cases. No serious adverse events occurred throughout the study. No significant
changes in clinical, instrumental or laboratory safety parameters were observed. In conclusion, iomeprol-4O0 and iomeprol-350
appear to be contrast solutions at least as sale, well tolerated and effective as iopamidol-370 when used as contrast agents lor body
CT
Destructive Spondyloarthropathy of the Cervical Spine in Long-Term Hemodialyzed patients: A Five Year Clinical Radiological Prospective Study.
No full textOBJECTIVE:
To describe the radiographic features and progression of cervical spine destructive spondyloarthropathy (DSA) in hemodialyzed patients, and to evaluate the relationship between this disease and patient characteristics, biochemical values, and hemodialysis duration.
DESIGN AND PATIENTS:
Standard radiographs, and lateral flexion and extension views of the cervical spine, were performed annually for 5 years in 31 hemodialyzed patients who were divided into three groups at the commencement of the study: those showing (I) DSA, (II) vertebral rim erosions (VRE) without DSA, and (III) absence of DSA and VRE. Magnetic resonance (MR) imaging and computed tomography (CT) were performed in seven and two patients respectively. The imaging features were evaluated for the presence and progression of spondyloarthropathy and correlated with clinical and biochemical variables. Statistical analysis was performed using one-way analysis of variance.
RESULTS:
The duration of hemodialysis appeared to be the main predictive factor (P=0.0003) for DSA, which was found in six patients (19%). DSA was found to correlate with higher levels of beta2-microglobulin (P<0.00001), parathyroid hormone (P<0.05), and alkaline phosphatase (P<0.05). Clinical symptoms were minimal. In two patients, MR imaging revealed changes mimicking spondylodiscitis. In another patient, CT of the craniocervical junction showed bone resorption due to a pseudotumor, and basilar invagination.
CONCLUSIONS:
DSA of the cervical spine is often clinically silent. Pathogenesis of DSA may be multifactorial but its progression is most influenced by the duration of hemodialysis. On MR imaging, DSA may mimic spondylodiscitis
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
The accuracy of voiding urosonography in detecting vesico-ureteral reflux: a summary of existing data.
No full textThe primary objective of this review was to assess the diagnostic accuracy of voiding urosonography (VUS) in detecting reflux (VUR). As a secondary objective, the reported technical suggestions and diagnostic mistakes were shown to improve the examination protocol and provide the most accurate results. Using a Medline Database search, the published articles comparing the grey-scale (GS) or colour-Doppler (CD) VUS with voiding cystourethrography (VCUG) as the gold standard were selected. Articles were excluded when data were not sufficient to construct 2x2 tables or when the gold standard was different from VCUG. For the analyses of diagnostic accuracy values, 95% confidence intervals were given. Agreements in the results of GSVUS and VCUG and in those of CDVUS and VCUG were determined by Kappa statistics. GSVUS and CDVUS were compared for diagnostic accuracy by the McNemar test. Results showed that the range of GSVUS sensitivity and specificity in detecting VUR was 69%-100% and 86%-97%, respectively. The agreement between GSVUS and VCUG diagnoses ranged from 90% to 97% (K score range 0.61-0.92; P<0.001). The range of CDVUS sensitivity and specificity in detecting VUR was 93%-100% and 86%-93%, respectively. The agreement between CDVUS and VCUG diagnoses ranged from 89% to 96% (K score range 0.77-0.91; P<0.001). One study comparing both VUS modalities with VCUG in the same group of patients, showed that the diagnostic accuracy of CDVUS was significantly higher than that of GSVUS (96% versus 90% of cases correctly classified; McNemar chi squared =4; P<0.05).
CONCLUSION:
the existing data indicate that false-negative voiding urosonographic diagnoses (8%-31%) and underestimated reflux grading cases using the same technique are related to anatomical conditions, patient cooperation and contrast medium administration. False-positive (3%-14%) and overestimated reflux grading cases using voiding urosonography could be correctly assessed cases. The intermittent nature of vesico-ureteral reflux is better detected by a technique employing a prolonged observation time, such as voiding urosonography. This might question the current role of voiding cystourethrography in the investigation of reflux
Adult medullary cystic disease of the kidney and pancreatic cystic disease: a new association.Scan J Urol Nephr 1999;33:422-424/IF=0.448
No full textA rare case of a woman with the adult form of medullary cystic disease associated with pancreatic cysts in pancreas divisum is described, which suggests that specific attention should be paid to computed tomography findings in the presence of pancreatic and renal cysts
Fallopian tube disease: The cobbblestone pattern as a radiographic sign
No full textPURPOSE: To identify radiographic signs of mucosal damage by comparing hysterosalpingography with salpingoscopy in a prospective study. MATERIALS AND METHODS: Forty-one candidates for laparoscopy underwent hysterosalpingography and peroperative salpingoscopy; at both, tubal patency was noted. Radiographic criteria for mucosal abnormality were rounded filling defects (ie, the cobblestone pattern) and the absence of longitudinal radiolucent bands in the ampullary tract. At salpingoscopy, tubal mucosa was categorized by means of inspection into five classes of fold pattern: classes I and II, normal; classes III-V, abnormal. Hysterosalpingographic and salpingoscopic results were compared by means of a two-by-two table and κ statistics. RESULTS: Seventy-four tubes were evaluated. At hysterosalpingography, 31 tubes were distally nonpatent. Of these, 26 showed a distal obstruction at salpingoscopy. None of the patent tubes at hysterosalpingography showed obstruction at salpingoscopy. The agreement between hysterosalpingography and salpingoscopy in detecting abnormal mucosal pattern was 89.2% (κ, 0.73; P < .001). The cobblestone pattern always corresponded to intraluminal adhesions at salpingoscopy. The absence of radiolucent bands corresponded to abnormal mucosa at salpingoscopy in four of six cases. The cobblestone pattern was found only in hydrosalpinges and never in patent tubes. Six normal patent tubes at hysterosalpingography showed intraluminal adhesions at salpingoscopy. CONCLUSION: Results indicate that the cobblestone pattern is an effective radiographic sign of intraluminal adhesions in hydrosalpinges and suggest that intraluminal disease in patent tubes might not always be excluded on normal hysterosalpingograms
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
- …
