Quiz Quality Control and Data
Management
Describe Multiplayer reformation - Answer-(MPR) describes the process of displaying CT images in a
different orientation from the one used in the original reconstruction process. MPR images may be
constructed in the coronal , sagittal or any other two dimensional plane. MPR images are typically
formed from a vertical stack of contiguous, helically acquired axial CT image
Which of the following types of image noise can be most easily reduced by the CT technologist -
Answer-quantum noise
The quantum or statistical noise of a CT image can be reduced by increasing the number of x ray
photons absorbed by the detectors for each voxel of tissue. This can be accomplished with increases in
technique (mAs) and with increases in the pixel and voxel dimensions
Describe surface rendering - Answer-Computer programs are capable of constructing 3D models of
anatomy with several different types of rendering techniques. A surface rendered 3D model provides
excellent surface anatomy while maintaining the normal crossectional anatomy appearance of the
volume inside the model
, The smallest object that can be resolved if a reconstruction FOV of 24 cm and a 512 x 512 matrix are
used is ______ mm. - Answer-0.47mm x 0.47mm
If a reconstruction FOV of 32 cm and a 512 x 512 matrix are used, the pixel size is __________ mm. -
Answer-0.625mm x 0.625mm
what can be changed retrospectively - Answer-The slice thickness from an MDCT helical scan
What value for pitch would stretch the x ray helix the most - Answer-1.5
A set of images is reconstructed with a 150 mm reconstruction FOV. Keeping all other parameters
constant, a second set of images is reconstructed with a 300 mm reconstruction FOV, and then
magnified so that the anatomical structures in the first and second set appear the same size. Which of
the following statements is FALSE? - Answer-1. the resolution of the second set of images is better than
the first set
2. the apparent noise in the second set of images is more pronounced than the first set
3. the patient dose of the first set of images is higher than the second set
What will result in an increased voxel size - Answer-increased slice thickness
What determinants of CT image quality is responsible for how grainy or speckled a CT image appears -
Answer-noise
What Does not occur when reconstruction FOV is decreased - Answer-pixel size is increased
what occurs when reconstruction FOV is decreased - Answer-1. spatial resolution is increased
2. noise in the image increases
Management
Describe Multiplayer reformation - Answer-(MPR) describes the process of displaying CT images in a
different orientation from the one used in the original reconstruction process. MPR images may be
constructed in the coronal , sagittal or any other two dimensional plane. MPR images are typically
formed from a vertical stack of contiguous, helically acquired axial CT image
Which of the following types of image noise can be most easily reduced by the CT technologist -
Answer-quantum noise
The quantum or statistical noise of a CT image can be reduced by increasing the number of x ray
photons absorbed by the detectors for each voxel of tissue. This can be accomplished with increases in
technique (mAs) and with increases in the pixel and voxel dimensions
Describe surface rendering - Answer-Computer programs are capable of constructing 3D models of
anatomy with several different types of rendering techniques. A surface rendered 3D model provides
excellent surface anatomy while maintaining the normal crossectional anatomy appearance of the
volume inside the model
, The smallest object that can be resolved if a reconstruction FOV of 24 cm and a 512 x 512 matrix are
used is ______ mm. - Answer-0.47mm x 0.47mm
If a reconstruction FOV of 32 cm and a 512 x 512 matrix are used, the pixel size is __________ mm. -
Answer-0.625mm x 0.625mm
what can be changed retrospectively - Answer-The slice thickness from an MDCT helical scan
What value for pitch would stretch the x ray helix the most - Answer-1.5
A set of images is reconstructed with a 150 mm reconstruction FOV. Keeping all other parameters
constant, a second set of images is reconstructed with a 300 mm reconstruction FOV, and then
magnified so that the anatomical structures in the first and second set appear the same size. Which of
the following statements is FALSE? - Answer-1. the resolution of the second set of images is better than
the first set
2. the apparent noise in the second set of images is more pronounced than the first set
3. the patient dose of the first set of images is higher than the second set
What will result in an increased voxel size - Answer-increased slice thickness
What determinants of CT image quality is responsible for how grainy or speckled a CT image appears -
Answer-noise
What Does not occur when reconstruction FOV is decreased - Answer-pixel size is increased
what occurs when reconstruction FOV is decreased - Answer-1. spatial resolution is increased
2. noise in the image increases
