Lateral resolution (mm) equals which of the following?

Lateral resolution (mm) equals which of the following?

• A. Pulse Duration (mm)
• B. Beam Diameter (mm)
• C. Wavelength (mm)
• D. Acoustic Impedance (mm)

Answer: (B)

Lateral resolution is about how well two structures that lie side by side can be distinguished. It is determined by how wide the ultrasound beam is in the lateral direction at the point of interest. That width, the beam diameter, sets the smallest separation you can resolve side-to-side, so the lateral resolution in millimeters essentially equals the beam diameter at that depth. Narrower beams (achieved with focusing or array design) give better lateral resolution. Pulse duration and wavelength influence how long a pulse extends along the beam (axial resolution), not how wide the beam is to separate side-by-side structures. Acoustic impedance affects how much sound is reflected at tissue interfaces, not how finely you can distinguish two lateral targets.

Lateral resolution is about how well two structures that lie side by side can be distinguished. It is determined by how wide the ultrasound beam is in the lateral direction at the point of interest. That width, the beam diameter, sets the smallest separation you can resolve side-to-side, so the lateral resolution in millimeters essentially equals the beam diameter at that depth. Narrower beams (achieved with focusing or array design) give better lateral resolution.

Pulse duration and wavelength influence how long a pulse extends along the beam (axial resolution), not how wide the beam is to separate side-by-side structures. Acoustic impedance affects how much sound is reflected at tissue interfaces, not how finely you can distinguish two lateral targets.