1,720,967 research outputs found
Anatomical variations of the trochlear notch angle: MRI analysis of 78 elbows
No full textBACKGROUND:
Little is known about the anatomical variations of the trochlear notch angle, nor do we know whether the cartilaginous layer modifies the trochlear bony contour. Our aim was to assess the variability of the bony and cartilaginous trochlear notch angles.
MATERIALS AND METHODS:
We assessed 78 healthy elbows (39 patients, 19 females and 20 males) with a mean age of 28 years (range 21-32). High-definition MRI coronal scans at the level of the flexion-extension axis were performed. The cartilage thickness, the notch angle, and trochlear width were calculated at the level of the deepest point of the trochlear sulcus, the edge of the lateral and medial ridge. Patient height was used as indirect measurement of humerus length. Pearson correlation and Student's t tests were performed.
RESULTS:
Mean cartilage thickness was 1.00 mm (range 0.62-1.83), with significant differences between the medial trochlear ridge and the other landmarks. The notch angle ranged from 124° to 156° (mean 142°) with no differences between the bony and cartilage layers. Trochlear width ranged from 1.57 to 2.75 cm (mean 2.24) and correlated with humerus length. No correlation emerged between the trochlear notch angle, trochlear width, or humerus length. The only significant difference between sexes was the width value, with a wider trochlea in males.
CONCLUSIONS:
The trochlear notch angle varies considerably, determining anatomical variations in trochlear shape which ranges from less concave to more concave types. Moreover, the cartilaginous layer does not modify this angle at the level examined. These findings may be relevant to anatomical implant design for distal humerus hemiarthroplasty
Contribution of cartilage to size and shape of radial head circumference: magnetic resonance imaging analysis of 78 elbows
No full textBackground: The aims of our study were to quantify cartilage thickness at the minimum and maximum diameters of the radial head circumference and to investigate its influence on the size and shape of the proximal radius. Methods: We analyzed high-definition magnetic resonance imaging scans of 78 healthy elbows in 19 men and 20 women, with a mean age of 28 (21-32) years. All measurements were estimated in the axial plane just distal to the fovea radialis. Maximum and minimum bone diameters, maximum and minimum total diameters (including cartilage thickness), and cartilage thickness were calculated. Cartilage thickness was measured at 4 different points: (1) at the articular side of the maximum diameter (point A), (2) at the nonarticular side of the maximum diameter (point B), (3) at the medial side of the minimum diameter (point C), and (4) at the lateral side of the minimum diameter (point D). Pearson correlation and t test were used for the statistical analysis. Results: Mean maximum and minimum bone diameters and maximum and minimum total diameters were 22.2, 21.5, 24.0, and 23.2 mm, respectively. All differences between diameters were statistically significant. Mean cartilage thickness at points A, C, and D was 1.7, 0.8, and 0.8 mm, respectively. No measurable cartilage thickness was found at point B. No significant correlation was found between bone diameters and cartilage thickness. Conclusions: Cartilage surface significantly increases and modifies the size and shape of the radial head. The observation that cartilage thickness varies between subjects and does not correlate with bone parameters suggests that the diameters of the radial head cannot be inferred from indirect measurements of dry bones or radiographs
The ulnar greater sigmoid notch "coverage angle": Bone and cartilage contribution. Magnetic resonance imaging anatomic study on 78 elbows
No full textBackground: To study the degree of coverage provided by the greater sigmoid notch (GSN) to the humeral trochlea, as well as the contribution of the olecranon and coronoid process cartilage tips to this angle, and its variations. Methods: We recruited 39 healthy volunteers, comprising 19 women and 20 men, with a mean age of 28 years (range, 21-32 years). High-definition magnetic resonance images were obtained for the right and left elbows. Four angles were measured on the sagittal plane passing through the coronoid and olecranon tips: angle A, identified by 2 lines from the trochlea center to the olecranon bone-cartilage junction and olecranon cartilage tip; angle B, identified by 2 lines from the trochlea center to the olecranon and coronoid bone-cartilage junction; angle C, identified by 2 lines from the trochlea center to the coronoid bone-cartilage junction and coronoid cartilage tip; and GSN coverage angle (GSN-ca), defined as the sum of angles A, B, and C. Pearson correlation tests, t tests, and intraclass correlation coefficients were used for statistical analyses. Results: The mean angle A, angle B, and angle C values were 6° (range, 2°-12°), 182° (range, 153°-204°), and 9° (range, 2°-16°), respectively. No correlations were found between these 3 angles. The mean GSN-ca was 198° (range, 167°-222°), and the GSN-ca was less than 180° in 8% of the cases. No significant differences emerged for side or gender or for total length of the ulna. Conclusion: The GSN showed significantly different shapes on the sagittal plane that we defined as closed type when the GSN-ca was greater than 180° (92%) and as open type when the GSA-ca was less than 180° (8%). The cartilage tip contribution varied and was not correlated with that of bone
Aortic valve stenosis. non-invasive preoperative evaluation using 64-slice CT angiography
No full textAIM: In patients affected by aortic valve stenosis (AS) it is mandatory to rule out coronary artery disease (CAD). The role of retrospectively ECG-gated 64-slice CT angiography (64-SCTA) was assessed in patients with AS referred for surgical valve replacement.
METHODS: Forty-two patients with AS underwent ECG-gated 64-SCTA of thoracic aorta, including the heart and coronary arteries, before surgical valve replacement. Images were evaluated by two independent readers and compared with surgical findings in terms of aortic valve calcification grading, valvular morphology, aortic valve annulus and sino-tubular junction diameters, and valvular area planimetry. Quantitative evaluation of cusps opening was also performed. Finally, the presence of CAD, thoracic aortic aneurysm and left ventricle hypertrophy were assessed.
RESULTS: Visualization of the aortic valve without motion artefacts was possible in 38 patients (90.5%). Valvular morphology was correctly assessed in all cases (100%). 64-SCTA correctly determined aortic valve calcification grading and the aortic valve annulus and sinotubular junction diameters in 100% of cases. The aortic valve planimetric area was assessed in 38 cases (90.5%). Ascending aortic aneurysms requiring surgical replacement were detected in 12 patients (28.6%). Significant left ventricle hypertrophy was found in 30 patients (71%).
CONCLUSION: Preoperative evaluation of patients undergoing surgical replacement for AS with 64-SCTA is feasible. 64-SCTA can rule out CAD and evaluate the status of the aortic valve and thoracic aorta in the same examination, obtaining relevant information for surgical planning
Sterile abscesses complicating monoclonal gammopathy of undetermined significance.
No full textA 47-year-old man presented with cough, fever and chest pain. A chest CT scan showed multiple nodules with air cavities in some, and IgGj monoclonal gammopathy of undetermined significance (MGUS) was detected. Blood, sputum and bronchoalveolar lavage cultures were negative for common and acid-fast bacteria or fungi. Antineutrophil cytoplasmic antibodies were negative. Empirical broad-spectrum antibiotic therapy was unsuccessful, while steroid therapy (prednisone 50 mg? d) was followed by rapid clinical and radiological improvement. After steroid withdrawal fever recurred and novel pulmonary nodules developed. An open lung biopsy revealed abscesses with acute and chronic inflammatory areas containing neutrophlis and eosinophils, surrounded by giant epitheloid cells and interstitial fibrosis (Fig. 1A). As steroid therapy was resumed, fever disappeared and nodules regressed. The patient remained well on maintenance steroid therapy for 6 months, but shortly after treatment withdrawal fever relapsed and multiple lung, mesenteric, hepatic and splenic abscesses developed (Fig. 1B). As a predominantly eosinophilic abscess was revealed by liver biopsy, visceral larva migrans was suspected and albendazole was given without success. Based on the absence of microorganisms in the lesions, the failure of antimicrobial therapy, and the efficacy of steroid therapy we diagnosed an ‘aseptic abscesses syndrome,’ a rare condition commonly associated with chronic inflammatory bowel disease or MGU
CT angiography and magnetic resonance angiography findings after surgical and interventional radiology treatment of peripheral arterial obstructive disease
No full textIn the last years, technical innovations in the field of CT angiography (CTA) and magnetic resonance angiography (MRA) have allowed accurate and highly detailed evaluation of peripheral vascular pathologies. This has dramatically changed the diagnostic approach in treatment planning of peripheral arterial obstructive disease and also enabling early identification of treatment failure or treatment-related complications after surgical or endovascular procedures. Although Doppler Ultrasound is the first-line imaging modality during follow-up after treatment, its role is currently diminishing in importance mostly because of the proliferation of high-end CT and MR scanners capable of fast, reproducible, and highly reliable vascular imaging. The aim of this study is to review the various surgical and endovascular procedures for peripheral arterial obstructive disease and to provide CTA and MRA samples of common and uncommon complications related to treatmen
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
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