Ct Registry Ch2 Pt2

Front 1

A ________________ is applied to the raw data during image reconstruction. This process is called ________________.

Back 1

reconstruction filter

convolution

Front 2

What are the two reconstruction filters and what does each do?

Back 2

2 types: sharp & smooth

sharp - improves edges

smooth - minimizes grainy appearance or noise

Front 3

True or False - With 1500 projections, the back projection reconstruction would closely resemble the original object.

Back 3

False, back projection(on its own) can never provide enough data to closely resemble the original object

Front 4

Sharp reconstruction filters are often used for visualizing ________________. Smooth reconstruction filters are often used for visualizing ________________.

Back 4

musculoskeletal detail

soft tissue contrast

Front 5

Sharp recon filters are also beneficial for ________________.

Smooth recon filters are also beneficial for ________________.

Back 5

high contrast regions

low contrast regions

Front 6

If back projection was applied to the raw data without convolution, the tissues in the resulting image would have ________________ and would be ________________.

Back 6

blurry edges

grainy or noisy

Front 7

What is cone beam artifact?

Back 7

When a CT tube's cone beam and the structures at the periphery of the image are not properly reconstructed with filtered back projection. Has a "spoke" or "star-like" appearance.

Front 8

To prevent cone beam artifact when using a cone beam, ________________ must be used during final CT image reconstruction.

Back 8

cone beam reconstruction

Front 9

________________ requires the raw data, which is lost once that portion of the raw data storage device is overwritten.

Back 9

retrospective reconstruction

Front 10

The raw data of scan is retained on the ________________.

Back 10

raw data storage device on the host computer

Front 11

On ________________ scanners, a retrospective reconstruction is commonly used to modify the reconstructed slice thickness.

Back 11

MDCT

Front 12

________________ allows for the reconstruction of images in planes that would otherwise be difficult or impossible to acquire with CT.

Back 12

multi-planar reconstruction

Front 13

Multi-planar reconstruction requires ________________. The ________________ is not utilized.

Back 13

image data

raw data

Front 14

Slices with no gaps in them are called ________________.

Back 14

contiguous

Front 15

Using ________________ in the initial data set improves the quality of the reconstructed images.

Back 15

overlapped slices

Front 16

What does 3D SSD stand for?

Back 16

3D Shaded Surface display

Front 17

In 3D SSD, you can set the threshold value equal to the ________________ of the tissue on which we want the surface rendering, so tissues with other ________________ are ignored.

Back 17

CT number

CT numbers

Front 18

3D SSD is better at extracting ________________ than at distinguishing fat, muscles, and other soft tissues.

Back 18

bony surfaces and skin surfaces

Front 19

Volume rendering can incorporate information from the entire image data set, rather than just a surface, into the post-processed images, enabling visualization of ________________.

Back 19

structures above and below the surface

Front 20

VR uses ________________ or pixel volume for its display.

Back 20

voxels