Which artifact is NOT a cause of filling in an anechoic structure such as a cyst?

Which artifact is NOT a cause of filling in an anechoic structure such as a cyst?

• A. Partial volume artifact
• B. Ghosting artifact
• C. Slice thickness artifact
• D. Section thickness artifact

Answer: (B)

The idea is that anechoic structures can appear to fill with echoes when echoes from surrounding tissues are included in the same imaging element or display. Partial volume artifact happens when a single voxel contains both fluid and adjacent tissue, so the echoes from the walls or surrounding structures are averaged into the voxel and show up as internal echoes within the cyst. Slice thickness artifact and section thickness artifact arise from the finite thickness of the ultrasound beam and the imaging plane; echoes from walls, septations, or nearby structures that lie within the slice contribute to the image and can make the lumen look partially echogenic. Ghosting, however, is a motion- or display-related duplication of structures rather than true internal echoes filling the lumen. It creates a faint or repeated image rather than actual echogenic material inside the cyst. So ghosting does not cause filling of an anechoic structure.

The idea is that anechoic structures can appear to fill with echoes when echoes from surrounding tissues are included in the same imaging element or display. Partial volume artifact happens when a single voxel contains both fluid and adjacent tissue, so the echoes from the walls or surrounding structures are averaged into the voxel and show up as internal echoes within the cyst. Slice thickness artifact and section thickness artifact arise from the finite thickness of the ultrasound beam and the imaging plane; echoes from walls, septations, or nearby structures that lie within the slice contribute to the image and can make the lumen look partially echogenic. Ghosting, however, is a motion- or display-related duplication of structures rather than true internal echoes filling the lumen. It creates a faint or repeated image rather than actual echogenic material inside the cyst. So ghosting does not cause filling of an anechoic structure.