What is filtered back projection in nuclear medicine?
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 does a ramp filter do?
1. Filtering to Reduce the Star Artifact. 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).
What is spect used for?
The most common uses of SPECT are to help diagnose or monitor brain disorders, heart problems and bone disorders.
What is back projection algorithm?
Background: The back-projection algorithm is the most common method for the reconstruction of circular-scanning-based photoacoustic tomography (CSPAT) due to its simplicity, computational efficiency, and robustness.
What does a nuclear scan show?
By measuring the behavior of the radionuclide in the body during a nuclear scan, the healthcare provider can assess and diagnose various conditions, such as tumors, infections, hematomas, organ enlargement, or cysts. A nuclear scan may also be used to assess organ function and blood circulation.
What is nuclear imaging used for?
Nuclear imaging is used primarily to diagnose or treat illnesses. Conditions diagnosed by nuclear medicine imaging include: Blood disorders. Thyroid disease, including hypothyroidism.
How to filter the projections with a ramp filter?
A well-known approach to filter the projections with a ramp filter is to calculate the linear convolution. If the support of the projections has a length N, only the central Nsamples of the filtered projection are needed in backprojection. This requires that the minimal length of the convolution kernel be 2N-1.
What is filtered back projection?
Dr Yuranga Weerakkody â—‰ and Ferb Maligs et al. 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 crossectional image reconstruction.
Which Butterworth filter should be used for the reconstruction of projections?
] suggested the use of a Butterworth filter with an order of 7 and a cut-off frequency of 0.55 Nq, for the reconstruction of the projection data. According to Groshar et al. (1997) [ 26
What is the filtered backprojection algorithm?
The filtered backprojection (FBP) algorithm has been serving as the driving engine in tomographic image reconstruction for many decades [1–4]. This algorithm consists of ramp filtering and backprojeciton procedures. Ramp filtering can be implemented as convolution in the spatial domain or multiplication in the Fourier domain.