Compare slice thickness CT/US/MRI

COMPARISONS BETWEEN THE MODALITIES – IS THIS SUFFICIENT

Compare slice thickness CT/US/MRI

Slice thickness in CT

·  Single detector arrays

o Slice thickness determined by physical collimation of incident beam

o Increase gap=increase slice thickness

o Collimator width smaller than detector width

·  multiple detector arrays

o slice thickness determined by DETECTOR width

o slice thickness can be changed via binning of detectors

o Collimator width always wider than single detector width

Slice thickness in Ultrasound

·  Elevational resolution

·  Dimension of beam perpendicular to image plane

·  Depends on transducer element height 

·  Depends on image depth-best resolution @ focal point 

Slice thickness in MRI

Determined by

·   Band width of RF pulse

·  Gradient strength across FOV

o Narrow BW = thin slice -Broad BW = thick slice

o Low gradient = thick slice

o high gradient =thin slice