How is slice thickness calculated in CT?
With single-slice CT, the slice thickness is determined by the detector width – with mild slice broadening just based on the pitch of the helical scan. With MDCT, slices can be composed of a single detector thickness or multiple adjacent detectors.
What are the basic principles of CT?
CT uses ionizing radiation, or x-rays, coupled with an electronic detector array to record a pattern of densities and create an image of a “slice” or “cut” of tissue. The x-ray beam rotates around the object within the scanner such that multiple x-ray projections pass through the object (Fig 1).
What is the physics behind CT scan?
In the particular case of the CT, the emitter of x-rays rotates around the patient and the detector, placed in diametrically opposite side, picks up the image of a body section (beam and detector move in synchrony). Unlike x-ray radiography, the detectors of the CT scanner do not produce an image.
What are CT slices?
The term slice refers to the number of rows of detectors in the z-axis of a CT. For example, in an 8-slice CT, there are eight slices of data captured for each rotation of the gantry.
What is CT slice thickness?
Slice thickness and slice increment are central concepts that surround CT/MRI imaging. Slice thickness refers to the (often axial) resolution of the scan (2 mm in the illustration). Slice Increment refers to the movement of the table/scanner for scanning the next slice (varying from 1 mm to 4 mm in the illustration).
What is CT physics?
The term “computed tomography”, or CT, refers to a computerized x-ray imaging procedure in which a narrow beam of x-rays is aimed at a patient and quickly rotated around the body, producing signals that are processed by the machine’s computer to generate cross-sectional images—or “slices”—of the body.
What is CT attenuation?
PHYSICS OF CT The density of the tissue is in proportion to the attenuation of the x-rays which pass through. Tissues like air and water have little attenuation and are displayed as low densities (dark), whereas bone has high attenuation and is displayed as high density (bright) on CT.
What does slice mean in CT?
The term slice refers to the number of rows of detectors in the z-axis of a CT. For example, in an 8-slice CT, there are eight slices of data captured for each rotation of the gantry. The first CT scanners offered single slice CT (SSCT) images but now there are multiple-slice CT scanners (MSCT.)
