What is back projection in CT?

Backprojection. The standard method of reconstructing CT slices is backprojection. This involves “smearing back” the projection across the image at the angle it was acquired. By smearing back all of the projections, you reconstruct an image.

What is an advantage of filtered back projection compared with iterative reconstruction methods?

The major advantage of iterative reconstruction techniques is that they permit the emission and detection process to be accurately modelled. In contrast, the filtered back projection algorithm makes no allowance for the physics of emission including attenuation and scatter of the emitted photons.

What is iterative reconstruction technique?

Iterative reconstruction refers to an image reconstruction algorithm used in CT that begins with an image assumption, and compares it to real time measured values while making constant adjustments until the two are in agreement.

Why is filtered back projection used?

Filtered back projection is an analytic reconstruction algorithm designed to overcome the limitations of conventional back projection; it applies a convolution filter to remove blurring. It was, up until recently the primary method in cross-sectional imaging reconstruction.

What is back projection reconstruction?

Backprojection. The standard method of reconstructing CT slices is backprojection. This involves “smearing back” the projection across the image at the angle it was acquired. By smearing back all of the projections, you reconstruct an image.

How do you do a filtered back projection?

Video quote: The inverse operation of a forward projection. But instead of each detector getting the line integral of the object function now each point on the object domain receives.

What does the RAM Lak filter do?

Ram-Lak and Shepp-Logan filters are high pass filters which keeps the edges information in tact, whereas cosine, hamming and hann filters are band pass filters. They are used to smooth the image and remove extra edges from the …

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).