A transducer that produces a beam with a very wide slice thickness, which problem is most likely?

• A. Increased near field reverberations
• B. Increased side lobes
• C. Partial volume artifact
• D. Decreased penetration

Answer: (C)

A wide slice thickness reduces elevational resolution, causing partial volume averaging. The ultrasound beam in the elevational direction samples a thicker volume of tissue, so echoes from different tissues within that volume are averaged together. The machine assumes a single tissue type within each voxel, which blurs boundaries and can misrepresent small or thin structures. This is why a partial volume artifact is the most likely problem when the beam has a very wide thickness.

Other issues listed aren’t primarily caused by slice thickness. Near-field reverberations come from strong reflections very close to the transducer, side lobes are off-axis energy from beamforming, and decreased penetration relates to frequency and tissue attenuation, not the elevational thickness of the beam.