What is a CT kernel?

The kernel, also known as a convolution algorithm, refers to the process used to modify the frequency contents of projection data prior to back projection during image reconstruction in a CT scanner ¹. This process corrects the image by reducing blurring ¹.

What is a CT projection?

CT makes use of filtered back projection reconstruction techniques, whereby each projection is convolved with a “filter”, and then back projected. When this procedure is performed for all 1000 or so projections, it is possible to achieve a perfect reconstruction of the scanned object.

How are CT images formed?

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 image reconstruction?

Image reconstruction in CT is a mathematical process that generates tomographic images from X-ray projection data acquired at many different angles around the patient. Image reconstruction has fundamental impacts on image quality and therefore on radiation dose.

What is a tomographic image?

1 Introduction. ¯ Tomography is a non-invasive imaging technique allowing for the visualization of the internal structures of an. object without the superposition of over- and under-lying structures that usually plagues conventional projection images.

What is CT interpolation?

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 controls slice thickness in CT scanning?

In MSCT, however, slice thickness is determined by detector configuration and not x-ray beam collimation. For example, the 4 slices in Figure 2A are each 5 mm thick because they are acquired by 5-mm detectors (formed by linking four 1.25-mm detector elements).

What is spacing in CT scan?

What is volumetric pixel spacing? For CT or MRI modalities, a series of 2D image “slices” constitute a 3D volume. Pixel spacing values indicate the real-world size or scale of each pixel in the 3D slice stack.

What is the CT number of water?

CT number = 1000 × ( μ − μ water ) / μ water. (1) The unit for CT numbers is Hounsfield units (HU); from the definition, water is zero HU and air is − 1000 HU .

What is interval in CT?

Slice Interval

This is the distance between the centre of two adjacent slices, and it ultimately determines the number of images in a series. You can select one of three slice interval settings: 1) Contiguous: Interval = Thickness. So where one slice ends, the next one starts. 2) Non-Contiguous: Interval > Thickness.

What does slice mean in Connecticut?

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 a 16-slice CT scanner?

The 16-Slice CT Scanner captures multiple images of a patient’s anatomy in a matter of seconds and presents information 3-dimensionally. This means the images of the body are now taken much faster, therefore reducing the examination time and increasing your comfort.

What is slice in DICOM?

Slice ordering (SO) is set in a protocol for MR scan and the information is saved in DICOM image header. For example, Sagittal (R)ight >> (L)eft, Coronal (A)nterior >> (P)osterior, Transverse (F)oot >> (H)ead.