Ultrasound frequency and resolution — FRCA Primary MCQ

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HardPhysics and Clinical MeasurementUltrasound frequency and resolutionFRCA Primary

Which ultrasound property most directly determines axial resolution?

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Correct answer: E — Spatial pulse length of the transmitted ultrasound pulse

The best answer is “Spatial pulse length of the transmitted ultrasound pulse”. Axial resolution is the ability to distinguish reflectors along the beam axis and equals one half of spatial pulse length. Beam width chiefly influences lateral resolution, while attenuation, impedance and Doppler shift determine different aspects of image formation.

Reference: RCoA, Primary FRCA Syllabus: https://rcoa.ac.uk/sites/default/files/documents/2026-01/Primary-FRCA-Syllabus.pdf