Attenuation refers to the reduction in the intensity of the ultrasound beam as it travels through tissue. Higher frequency ultrasound beams experience more attenuation because they are absorbed and scattered more than lower frequency beams. This is due to the fact that higher frequency waves have shorter wavelengths and interact more with the small particles in tissues, causing greater energy loss.
Reference: ARDMS Sonography Principles and Instrumentation, Chapter on Ultrasound Physics and Instrumentation.

Compression in ultrasound imaging adjusts the range of grayscale displayed, affecting the contrast resolution.
This function allows sonographers to enhance the differentiation between structures of varying echogenicities.
By modifying the contrast resolution, sonographers can better visualize subtle differences in tissue composition and improve the diagnostic quality of the images.
Increasing contrast resolution is particularly important in differentiating between fluid-filled cysts and solid masses. Reference:
ARDMS Sonography Principles and Instrumentation guidelines on image processing and contrast resolution.

In the given image of a tissue-mimicking phantom, Option B (yellow box) is used to evaluate axial resolution. Axial resolution refers to the ability of the ultrasound system to distinguish between two structures that are close to each other along the path of the ultrasound beam (i.e., parallel to the beam). The targets in Option B are typically aligned in such a way to test the system's capacity to differentiate between structures that are situated closely together along the beam's axis. Reference:
ARDMS Sonography Principles and Instrumentation guidelines
"Sonography: Principles and Instruments" by Joan P. Baker and Marveen Craig

Write magnification, or pre-processing zoom, involves rescanning the region of interest (ROI) with more scan lines, thus acquiring new data for that specific area. This process increases the spatial resolution of the image in the magnified area because it gathers more detailed data by adjusting the scan parameters, resulting in improved image quality. This is different from read magnification (post-processing zoom), which simply enlarges the existing image data without increasing resolution.
Reference:
ARDMS Sonography Principles & Instrumentation Guidelines
Hedrick WR, Hykes DL, Starchman DE. Ultrasound Physics and Instrumentation. 4th ed. Philadelphia, PA: Elsevier Saunders; 2005.

The frame rate in ultrasound imaging is influenced by several factors, including the number of focal zones. Each focal zone requires additional transmission and reception cycles, thus decreasing the frame rate. By decreasing the number of focal zones, the system requires fewer cycles per frame, which increases the frame rate. This enhances the temporal resolution, making it easier to capture fast-moving structures in real-time imaging.
Reference:
ARDMS Sonography Principles & Instrumentation Guidelines
Hagen-Ansert SL. Textbook of Diagnostic Ultrasonography. 8th ed. St. Louis, MO: Mosby; 2017.