1,720,966 research outputs found
An Improved Method for Hepato-Renal Ratio Assessment: a Feasibility Study
No full textHepato-Renal Ratio (HRR) is a method for the quantitative assessment of liver steatosis based on the processing of ultrasound images. Its reliability has been validated in literature through biopsy and 1H magnetic resonance spectroscopy.This paper describes a new method for ROI segmentation and HRR assessment, designed to minimize both inter-observer and inter-scan variability
Freehand Liver Volumetry by Using an Electromagnetic Pen Tablet: Accuracy, Precision, and Rapidity
No full textThe purpose of this study is to assess the accuracy, precision, and rapidity of liver volumes calculated by using a freehand electromagnetic pen tablet contourtracing method as compared with the volumes calculated by using the standard optical mouse contourtracing method. The imaging data used as input for accuracy and precision testing were computed by software developed in our institution. This computer software can generate models of solid organs and allows both standard mouse-based and electromagnetic pen-driven segmentation (number of data sets, n = 70). The images used as input for rapidity testing was partly computed by modeling software (n = 70) and partly selected from contrast-enhanced computed tomography (CT) examinations (n = 12). Mean volumes and time required to perform the segmentation, along with standard deviation and range values with both techniques, were calculated. Student's t test was used to assess significance regarding mean volumes and time calculated by using both segmentation techniques on phantom and CT data sets. P value was also calculated. The mean volume difference was significantly lower with the use of the freehand electromagnetic pen as compared with the optical mouse (0.2% vs. 1.8%; P < .001). The mean segmentation time per patient was significantly shorter with the use of the freehand electromagnetic pen contourtracing method (354.5 vs. 499.1 s on phantoms; 457.4 vs. 610.0 s on CT images; P < .001). Freehand electromagnetic pen-based volumetric technique represents a technologic advancement over manual mouse-based contourtracing because of the superior statistical accuracy and sensibly shorter time required. Further studies focused on intra- and interobserver variability of the technique need to be performed before its introduction in clinical application
Proper use of common image file formats in handling radiological images.
No full textThis paper highlights the differences among the most common file formats used for storing digital radiological images. It promotes the proper use of these formats to guarantee easy manipulation in handling the most typical practical applications in daily radiological practice. The authors provide a simple yet
exhaustive introduction to the concept of "file format" and describe the algorithms and main features of the most common formats (BMP, JPEG, GIF, DICOM, TIF, PNG) and Portable Network Graphics (PNG).The different formats are compared
in terms of dimension, quality, portability and with reference to the following specific needs: electronic communications, publication on the World Wide Web, presentation of electronic posters, video presentations for teaching and manuscript publishing. We also illustrate how to handle the various formats with the programmes supplied with standard software installations.The large number of digital applications of image file formats calls for a simplification in daily radiological practice. We recommend the use of JPEG and PNG for electronic communications; PNG and GIF for publication on the worldwide web; JPEG and PNG for electronic poster presentations; DICOM, PNG and JPEG for teaching presentations; TIF and PNG for printing on paper
Accuratezza della stadiazione TNM mediante imaging dei tumori neuroendocrini funzionanti e non funzionanti del pancreas
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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
Defecography: a practical approach
No full textThe purpose of this pictorial essay is to describe the main morpho-functional imaging features, physiological and pathological, of the recto-anal region and pelvic floor as depicted with conventional video defecography. Defecography has dramatically improved our knowledge of dysfunctions of evacuation. The most frequent indications and related disorders are presented from a database of more than 2500 examinations conducted in two radiology departments over a period of 15 years. Imaging features of the common recto-anal and pelvic flor disorders are described: rectal prolapse, rectocele, intussusception, descending pelvic floor syndrome, puborectalis muscle syndrome, enterocele, and sigmoidocele. Conventional video defecography still represents the gold standard examination for the identification and staging of morphological and functional disorders of the recto-anal region and pelvic floor in evacuation dysfunctions
The diagnostic contribution of CT volumetric rendering techniques in routine practice
No full textComputed tomography (CT) volumetric rendering techniques such as maximum intensity projection (MIP), minimum intensity projection (MinIP), shaded surface display (SSD), volume rendering (VR), and virtual endoscopy (VE) provide added diagnostic capabilities. The diagnostic value of such reconstruction techniques is well documented in literature. These techniques permit the exploration of fine anatomical detail that would be difficult to evaluate using axial reconstructions alone. Although these techniques are now widely available, many radiologists are either unfamiliar with them or do not fully utilize their potential in daily clinical practice. This paper is intended to provide an overview of the most common CT volumetric rendering techniques and their practical use in everyday diagnostics
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