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Contrast CT, or contrast-enhanced computed tomography (CECT), is X-ray computed tomography (CT) using radiocontrast. Radiocontrasts for X-ray CT are generally iodine-based types . [ 1 ] This is useful to highlight structures such as blood vessels that otherwise would be difficult to delineate from their surroundings.
Contrast agents are sometimes used in CT scans of the chest to accentuate or enhance the differences in radiopacity between vascularized and less vascularized structures, but a standard chest CT scan is usually non-contrasted (i.e. "plain") and relies on different algorithms to produce various series of digitalized images known as view or "window".
As with any test that screens for disease, the risks of full-body CT scans need to be weighed against the benefit of identifying a treatable disease at an early stage. [6] An alternative to a full-body CT scan may be Magnetic resonance imaging (MRI) scans. MRI scans are generally more expensive than CT but do not expose the patient to ionizing ...
Dual source CT is an advanced scanner with a two X-ray tube detector system, unlike conventional single tube systems. [15] [16] These two detector systems are mounted on a single gantry at 90° in the same plane. [17] Dual Source CT scanners allow fast scanning with higher temporal resolution by acquiring a full CT slice in only half a rotation.
State of the art modern CT scanners with a scan rate of up to 320 mm/s can acquire all the images within a 1-second X-ray exposure, avoiding the problems of respiratory motion, cardiac motion and contrast draining from the pulmonary circulation during the study. Even though the actual scan may be completed in 1 second or less, considerable ...
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 ...
Ground-glass opacity (GGO) is a finding seen on chest x-ray (radiograph) or computed tomography (CT) imaging of the lungs. It is typically defined as an area of hazy opacification (x-ray) or increased attenuation (CT) due to air displacement by fluid, airway collapse, fibrosis , or a neoplastic process . [ 1 ]
4DCT has started to be used for diagnostic radiology procedures, for example looking at joint problems, the cardiac cycle and parathyroid washout of contrast.Downsides of 4DCT for diagnostic purposes include large and complex datasets, and increased radiation dose to the patient.