Search results for "resolution."
showing 10 items of 1825 documents
Requirements on resolution of digital imaging equipment in the cardiac catheterization laboratory.
1988
We evaluated the requirements on spatial resolution of digital imaging equipment in the cardiac catheterization laboratory. Fifty cinefilms of the heart as the biological object and one film of a lead-ladder-pattern as an objective test were used. The patient films were examined for the visibility of the left ventricular angiogram, coronary arterial tree, coronary artery lesions, branching of septal arteries and the number of septal arteries. All films were viewed three times: with a 625 line TV-system, with a 1249 line TV-system and with a cineprojector. It was found that two application areas with different demands on the spatial and temporal resolution can be distinguished: 1) low spatia…
Technical development in cardiac CT: current standards and future improvements—a narrative review
2020
Non-invasive depiction of coronary arteries has been a great challenge for imaging specialists since the introduction of computed tomography (CT). Technological development together with improvements in spatial, temporal, and contrast resolution, progressively allowed implementation of the current clinical role of the CT assessment of coronary arteries. Several technological evolutions including hardware and software solutions of CT scanners have been developed to improve spatial and temporal resolution. The main challenges of cardiac computed tomography (CCT) are currently plaque characterization, functional assessment of stenosis and radiation dose reduction. In this review, we will discu…
Use of leukocyte and platelet-rich fibrin (L-PRF) in periodontally accelerated osteogenic orthodontics (PAOO): clinical effects on edema and pain
2015
Background Demand for shorter treatment time is common in orthodontic patients. Periodontally Accelerated Osteogenic Orthodontics (PAOO) is a somewhat new surgical procedure which allows faster tooth movement via combining orthodontic forces with corticotomy and grafting of alveolar bone plates. Leukocyte and Platelet-Rich Fibrin (L-PRF) possess hard- and soft-tissue healing properties. Further, evidence of pain-inhibitory and anti-inflammatory potential is growing. Therefore, this study explores the feasibility, intra- and post-operative effects of using L-PRF in PAOO in terms of post-operative pain, inflammation, infection and post-orthodontic stability. Material and methods A pilot prosp…
Differences Between Conventional Anorectal Manometry and High Resolution/High Definition Anorectal Manometry
2020
The book provides a comprehensive overview of high-resolution and high-definition anorectal manometry (HRAM/HDAM), showing the possible benefits of a wider use of these techniques in clinical practice, as well as their limitations. Although these techniques provide fresh insights into anorectal function and offer a new perspective on the pathophysiologic mechanisms of many defecation disturbances, there is a need to clarify whether their use has beneficial effects on clinical management compared to conventional manometry. There is still a considerable way to go to gain the clinical diffusion of esophageal HRM, which has become the gold standard in studying esophageal motility. Indeed, many …
Performing, Analyzing, and Interpreting HRAM and HDAM Recordings
2020
Anorectal manometry is one of the most widely performed tests for the assessment of anal sphincter function and anorectal coordination. Nowadays high resolution (HRAM) and high definition anorectal manometry (HDAM) are available, instead of the water-perfused system. The ability to visualize the anorectum as a dynamic structure during test maneuvers should intuitively allow for a better appreciation of the normal physiology and hopefully enhance our understanding of the pathophysiology of defecatory dysfunctions. Even if the anorectal manometry protocols can vary by centers, the procedure must include an assessment of rectoanal pressure and anal canal length at rest, cough reflex test, rect…
Systematic review of the diagnosis of gastric premalignant conditions and neoplasia with high-resolution endoscopic technologies
2013
Aim. The aim of the article is to systematically review the current evidence on the diagnostic use of narrow band imaging (NBI), flexible spectral imaging color enhancement (FICE) and endoscopic image enhancement technology i-scan endoscopies for gastric precancerous and cancerous lesions. Materials and methods. Original manuscripts were searched in PubMed until October 2012. Pertinent data were collected and pooled diagnostic accuracy measures were estimated when possible. Results. In total, 38 studies were evaluated. Thirty-one studies were included for NBI and 7 studies for FICE assessment in this systematic review. No article was found meeting inclusion criteria for i-scan endoscopy. Th…
The value of high resolution CT in the diagnosis of meniscal lesions of the knee
1991
We report on 50 patients who had meniscal pathology and were given computed tomographic (CT) scans. Our diagnostic accuracy was approximately 92%. We believe that CT is a good method of screening these patients prior to using a much more expensive method, such as magnetic resonance imaging or diagnostic arthroscopy.
Diffuse reflectance and fluorescence multispectral imaging system for assessment of skin
2014
The diffuse reflectance multispectral imaging technique has been used for distant mapping of in vivo skin chromophores (hemoglobin and melanin). The fluorescence multispectral imaging is not so common for skin applications due to complicity of data acquisition and processing, but could provide additional information about skin fluorophores. Both techniques are compatible, and could be combined into a multimodal solution. The multispectral imaging system Nuance based on liquid crystal tunable filters was adapted for diffuse reflectance and fluorescence spectral imaging of in vivo skin. Uniform illumination was achieved by LED ring light. Combination of four LEDs (warm white, 770 nm, 830 nm a…
Automatic scanning of large tissue areas in neurosurgery using optical coherence tomography
2012
Background With its high spatial and temporal resolution, optical coherence tomography (OCT) is an ideal modality for intra-operative imaging. One possible application is to detect tumour invaded tissue in neurosurgery, e.g. during complete resection of glioblastoma. Ideally, the whole resection cavity is scanned. However, OCT is limited to a small field of view (FOV) and scanning perpendicular to the tissue surface. Methods We present a new method to use OCT for scanning of the resection cavity during neurosurgical resection of brain tumours. The main challenges are creating a map of the cavity, scanning perpendicular to the surface and merging the three-dimensional (3D) data for intra-ope…
High Resolution CT Angiography in Detection of an Aneurysm of the Vein of Galen as a Source of Intracranial Haemorrhage in a Newborn.
2011
Cerebral haemorrhage is a rare condition in infants and carries a known poor prognosis. Common causes of spontaneous haemorrhage include various vascular venous lesions due to incomplete hydrovenous maturation, among them Galen vein aneurysm may be a very rare cause of cerebral haemorrhage. This report emphasizes the role of multidector CT with high resolution CT angiography in a newborn with cerebral hemorrhage caused by Galen vein aneurysm rupture. MDCT with high resolution CT angiography helps to differentiate the cause of haemorrhage, and to address the appropriate treatment.