MAP PHYSICS LAB · ULTRASOUND

What can the scanner separate?

Explore axial, lateral and elevational resolution. Compare the actual targets with the echoes displayed in a simplified ultrasound image.

A 2D picture from a beam with thickness

The image displays depth and lateral position. Elevation is the third direction: through the thickness of the slice. Here, A and B share the same depth and lateral position, but lie in different planes.

Along the beam

Actual target positions

Target ATarget B

Simulated image

Relative echo contribution
Target A
Target B
100% means this target is centred in the slice. These are individual sensitivities, not shares of the total signal.

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Show explanation

Teaching model: equal point reflectors in a uniform medium (sound speed 1540 m/s). Smooth Gaussian echo responses illustrate overlap. The image is schematic, with fixed gain and no speckle, attenuation or interference. Beam width and slice thickness are local values at the target depth. Elevational slice thickness is the full width at half maximum of sensitivity (dashed limits in the slice view). Sensitivity fades gradually beyond those limits. In a real scanner, elevational thickness depends on transducer design and focus.