Multislice Computed Tomography || 100% Accurate Solutions.
SSCT was invented to do the following correct answers Overcome the problems imposed by
conventional CT. Provide shorter scan times.Improve three-dimensional (3D) imaging
Slice-by-Slice CT Limitations correct answers Longer examination times because of the
interscan delay.Omitted anatomy due to inconsistent patient respiration referred to as slice-to-
slice misregistration.Inaccurate generation of 3D or reformatted images producing stairstep
artifacts.Few slices with maximum contrast enhancement
Requirements for Volume Scanning correct answers Continuously rotating scanner based on
slip-ring technology.Continuous couch movement.Increase in loadability of the x-ray tube,
capable of delivering at least 200 mA per revolution continuously throughout the time it takes to
scan the volume of tissue.Increased cooling capacity of the x-ray tube.Spiral/helical weighting
algorithmMass memory buffer to store the vast amount of data collected
SSCT Data Acquisition Problems correct answers No defined slice, and thus localization of a
particular slice is difficult.Data collected in nonplanar geometry.Effective slice thickness
increases .Projection data inconsistencies resulting in streak artifacts
These problems can be solved through a special postprocessing technique called interpolation.
Two steps needed to eliminate artifacts in SSCT correct answers Calculation (using
interpolation) of a planar data set from the tissue volume data set for every image.Reconstruction
of images using the filtered back-projection algorithm
Linear Interpolation (LI) Algorithm correct answers 360-degree LI algorithm180-degree LI
algorithm
360-Degree LI Algorithm correct answers Planar slice is interpolated by use of data points
measured 360 degrees apartAlgorithm broadens the slice sensitivity profile (SSP) degrading
image quality
180-Degree LI Algorithm correct answers Calculates a second spiral from the measured
spiral/helical data offset by 180 degreesImproves slice sensitivity profile (SSP) enhancing image
quality
Limitations of SSCT correct answers As pitch increases, image quality decreases and artifacts
increase.Limited volume coverage speed, which is necessary in CT angiography and 3D
postprocessing techniques.Based on a single row of detectors.Poor geometric efficiency.Unable
to meet the needs of time-critical clinical examinations such as multiphase organ dynamic
studies
Collimation of Single-Slice CT correct answers Designed to ensure a constant beam widthWidth
of precollimator defines the slice thickness8-mm collimation width falling on a one-dimension
detector array produces an 8-mm slice thickness
SSCT was invented to do the following correct answers Overcome the problems imposed by
conventional CT. Provide shorter scan times.Improve three-dimensional (3D) imaging
Slice-by-Slice CT Limitations correct answers Longer examination times because of the
interscan delay.Omitted anatomy due to inconsistent patient respiration referred to as slice-to-
slice misregistration.Inaccurate generation of 3D or reformatted images producing stairstep
artifacts.Few slices with maximum contrast enhancement
Requirements for Volume Scanning correct answers Continuously rotating scanner based on
slip-ring technology.Continuous couch movement.Increase in loadability of the x-ray tube,
capable of delivering at least 200 mA per revolution continuously throughout the time it takes to
scan the volume of tissue.Increased cooling capacity of the x-ray tube.Spiral/helical weighting
algorithmMass memory buffer to store the vast amount of data collected
SSCT Data Acquisition Problems correct answers No defined slice, and thus localization of a
particular slice is difficult.Data collected in nonplanar geometry.Effective slice thickness
increases .Projection data inconsistencies resulting in streak artifacts
These problems can be solved through a special postprocessing technique called interpolation.
Two steps needed to eliminate artifacts in SSCT correct answers Calculation (using
interpolation) of a planar data set from the tissue volume data set for every image.Reconstruction
of images using the filtered back-projection algorithm
Linear Interpolation (LI) Algorithm correct answers 360-degree LI algorithm180-degree LI
algorithm
360-Degree LI Algorithm correct answers Planar slice is interpolated by use of data points
measured 360 degrees apartAlgorithm broadens the slice sensitivity profile (SSP) degrading
image quality
180-Degree LI Algorithm correct answers Calculates a second spiral from the measured
spiral/helical data offset by 180 degreesImproves slice sensitivity profile (SSP) enhancing image
quality
Limitations of SSCT correct answers As pitch increases, image quality decreases and artifacts
increase.Limited volume coverage speed, which is necessary in CT angiography and 3D
postprocessing techniques.Based on a single row of detectors.Poor geometric efficiency.Unable
to meet the needs of time-critical clinical examinations such as multiphase organ dynamic
studies
Collimation of Single-Slice CT correct answers Designed to ensure a constant beam widthWidth
of precollimator defines the slice thickness8-mm collimation width falling on a one-dimension
detector array produces an 8-mm slice thickness
