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Low-dose high-resolution (1.25 mm) chest CT. HRCT is performed using a conventional CT scanner. However, imaging parameters are chosen so as to maximize spatial resolution: [1] a narrow slice width is used (usually 1–2 mm), a high spatial resolution image reconstruction algorithm is used, field of view is minimized, so as to minimize the size of each pixel, and other scan factors (e.g. focal ...
In 1996, results were published of a study of 1369 subjects screened in Japan that revealed that 73% of lung cancers that were missed by chest x-ray were detectable by CT scan. [19] Among the earliest United States-based clinical trials was the Early Lung Cancer Action Project (ELCAP), which published its results in 1999. [ 20 ]
In radiology, the tree-in-bud sign is a finding on a CT scan that indicates some degree of airway obstruction. [1] The tree-in-bud sign is a nonspecific imaging finding that implies impaction within bronchioles, the smallest airway passages in the lung.
Incidental findings are common in imaging. For instance, around 1 in every 3 cardiac MRIs result in an incidental finding. [2] Incidence is similar for chest CT scans (~30%). [2] As the use of medical imaging increases, the number of incidental findings also increases. [citation needed]
Ground-glass opacity is most often used to describe findings in high-resolution CT imaging of the thorax, although it is also used when describing chest radiographs. In CT, the term refers to one or multiple areas of increased attenuation (density) without concealment of the pulmonary vasculature .
Industrial computed tomography (CT) scanning is any computer-aided tomographic process, usually X-ray computed tomography, that uses irradiation to produce three-dimensional internal and external representations of a scanned object. Industrial CT scanning has been used in many areas of industry for internal inspection of components.
Tomographic systems have significant variability in their applications and geometries (locations of sources and detectors). This variability creates the need for very specific, tailored implementations of the processing and reconstruction algorithms. Thus, most CT manufacturers provide their own custom proprietary software.
In conventional CT machines, an X-ray tube and detector are physically rotated behind a circular shroud (see the image above right). An alternative, short lived design, known as electron beam tomography (EBT), used electromagnetic deflection of an electron beam within a very large conical X-ray tube and a stationary array of detectors to achieve very high temporal resolution, for imaging of ...