What is interpolation in CT scan?
Interpolation. 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 are the reconstruction methods for CT imaging?
There are various algorithms used in CT image reconstruction, the following are some of the more common algorithms utilized in commercially available CT today.
- iterative algorithm without statistical modelling.
- iterative algorithm with statistical modelling.
- back projection.
- filtered back projection (convolution method)
What is a Sinogram CT?
A fistulogram is a medical test that uses fluoroscopy and contrast material to produce images of an abnormal passage within the body called a fistula. Similarly, a sinogram assesses an abnormal passage called a sinus that originates or ends in one opening, often on the skin.
What is a Sinogram image reconstruction?
Backprojection and filtered backprojection A sinogram acquired using projection imaging (forward projection) may be used to reconstruct an image of the original object through a process called backprojection. Information acquired at each projection angle is spread out along the path of that projection.
How is Sinogram formed?
The projection images are generated through a mathematical entity called the Radon Transform. This article is about the use of Radon Transforms to generate the Sinogram of an image. This is much harder than the Forward Problem, and involves the Inverse Radon Transform in its most basic form.
How does iterative reconstruction work?
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.
What is retrospective reconstruction in CT?
-Raw data from prospective reconstruction that is used to generate new images. …
What is iterative reconstruction in CT?
What is reconstruction interval in CT?
Reconstruction interval – the spacing between adjacent slices – is independent of slice thickness in helical CT. The z-position of any given slice is determined by which projection is used to start the slice. Remember that to reconstruct an entire slice, you need 180 (plus fan angle) degrees of projection data.
What is CT Matrix?
“A CT image is composed of a square image matrix that ranges in size from 256 X 256 to 1024 X 1024 picture elements or pixels. Since a CT section has a finite thickness, each pixel actually represents a small volume element, or voxel.
What is multiplanar reconstruction in CT?
Multiplanar reformation or reconstruction (MPR) involves the process of converting data from an imaging modality acquired in a certain plane, usually axial, into another plane 1.
How do you do a Sinogram?
All projection images are stacked and the 1D projections (or, simply, projections) that belong to the same slice (those between the vertical dotted lines) are grouped into a sinogram. This process is repeated for every slice. Therefore, there will be as many sinograms as slices.
Can a 3D MRI scan of the spine be done?
At present, there are several techniques for 3D MRI scan, but these are mostly used for brain imaging. Since the area of concern for spine is large, 3D image capturing of spine would be far more time consuming and noise prone due to any slightest movement of the subject during the long period of imaging.
What is linear interpolation in image processing?
In particular, linear interpolation algorithm is utilized to construct the 2D image surface by calculating the approximate value of a point between two consecutive layers in the spatial domain [9, 10]. This article has the main sections.
How do they reconstruct a 3D image from a 2D MRI?
They reconstruct a three-dimensional (3D) image of the spine from a sequence of 2D MRI slices along any one axis with reasonable slice gap. In order to preserve the image at the edges properly, they regenerate the 3D image by using a combination of bicubic and bilinear interpolation along the orthogonal axis.