Summary chart of resolution PDF

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Summary

a chart on the resolutions used in sonography ...

Description

MEDS12001 2018 WEEK 5 Resolution

RESOLUTION

DESCRIPTION

DETERMINED BY

RELATIONSHIP

Axial, also called: Longitudinal Range Depth

Ability to distinguish two structures in a path parallel to the sound beam Does not vary with distance Improves with transducer damping Always better than lateral resolution Diagnostic values: 0.05 to 0.5 mm

Transducer Medium

Equal to ½ SPL Directly related to the operating frequency Inversely related to the spatial pulse length and penetration depth Smaller is better

Contrast

Ability to differentiate between echoes of slightly different amplitude High contrast (High compression or Low Dynamic range) demonstrates fewer shades of gray Low contrast demonstrates more shades of gray.

Ultrasound system

Directly related to axial and lateral resolution

Elevation, also called: Z-axis Slice or section thickness

Thickness of the scanned tissue perpendicular to the scan plane

Transducer

Related to the beam width Thinner slice thicknesses produce better image quality

Lateral, also called: Angular Transverse Azimuthal

Ability to distinguish two structures in a path perpendicular to the sound beam Varies with distance Improves with focusing

Transducer

Equal to beam diameter Directly related to beam diameter, frequency, focusing, and distance

Spatial

Ability to see detail on the image Includes axial, elevational, and lateral resolution

Transducer

Directly related to the number of scan lines Indirectly related to temporal resolution

Temporal

Ability to precisely position moving structures Ability to separate two points in time

Frame rate

Directly related to the frame rate Indirectly related to the number of focal zones, imaging depth, and spatial resolution...