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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 ...
Contrast resolution or contrast-detail is an approach to describing the image quality in terms of both the image contrast and resolution. Contrast resolution is usually measured by generating a pattern from a test object that depicts how image contrast changes as the structures being imaged get smaller and closer together.
4DCT aims to visualise the temporal dynamics of a 3D sample with a sufficiently high temporal and spatial resolution. Successive time frames are typically obtained by sequential scanning, followed by independent reconstruction of each 3D dataset.
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 ...
This method provides high spatial resolution, but also requires long exposure times. An alternative approach is the retrieval of the differential phase by using Moiré fringes. These are created as a superposition of the self-image of G1 and the pattern of G2 by using gratings with the same periodicity and inclining G2 against G1 regarding to ...
Strengths: Micro-CT can have excellent spatial resolution, which can be up to 6 μm when combined with contrast agents. However, the radiation dose needed to achieve this resolution is lethal to small animals, and a 50 μm spatial resolution is a better representation of the limits of micro-CT.
With this lens, there are several potential advantages of using a PCD over using an EID in CT imaging. These include improved signal (and contrast) to noise ratio, reduced X-ray dose to the patient, improved spatial resolution and, through use of several energy bins, the ability to distinguish multiple contrast agents.
By contrast, the spatial resolution of flat-panel volume CT (rotational angiography using a C-Arm) can be much better than that of a multislice CT scanner, with resolution ranges between 200 and 300 μm in high-resolution mode, compared to up to 600μm for a multislice CT. [2] Contrast resolution, measured in hounsfield units (HU), is only ...