What is limited angle tomography?

Limited Angle Tomography (LAT) is an X-ray imaging technique for generating a stack of cross-sectional images based on a limited number of two-dimensional projections.

What is backprojection algorithm?

The backprojection is the action to assign the filtered data value uniformly along the line, along which a line integral was performed, in a manner of line-by-line and view-by-view. Another popular image reconstruction technique uses iterative algorithms, in which the image is pixelized [6–10].

What is algorithm in CT scan?

The reconstruction kernel, also referred to as “filter” or “algorithm” by some CT vendors, is one of the most important parameters that affect the image quality. Generally speaking, there is a tradeoff between spatial resolution and noise for each kernel.

What is sinogram image?

In CT and SPECT imaging, a sinogram is generated by rotating detectors around a patient, and storing the detected projection profiles at each angle in the sinogram, as depicted in the gif above.

What is simple backprojection?

Simple Backprojection In 2D acquisition, activity in a given line of response (LOR) in a sinogram is the sum of all activities detected by a detector pair along the line through the depth of the object. The principle of backprojection is employed to reconstruct the images from these acquired LORs.

What does pitch mean in CT?

Pitch = Distance table travels during one revolution / Slice thickness or beam collimation. When the distance the table travels during one revolution of the x-ray tube equals the slice thickness or beam collimation, the pitch ratio is 1:1. A pitch of 1 results in the best image quality.

What is sinogram test?

A sinogram is a similar procedure done to assess a sinus, an abnormal passage or cavity that originates or ends in one opening, often on the skin. Contrast material is used to help fill the track and determine what parts of your body are involved.

What is interpolation in CT?

Interpolation is a mathematical process used to smooth, enlarge or average images that are being displayed with more pixels than that for which they were originally reconstructed.

What is a ramp filter?

Ramp Filter. The ramp filter is a high pass filter that does not permit low frequencies that cause blurring to appear in the image. In frequency domain, its mathematical function is given by (1).