What is attenuation in ultrasound?

What is attenuation in ultrasound?

The amplitude and intensity of ultrasound waves decrease as they travel through tissue, a phenomenon known as attenuation. Given a fixed propagation distance, attenuation affects high frequency ultrasound waves to a greater degree than lower frequency waves.

Which of the following are the display modes of ultrasound?

These are:

• A-mode: A-mode is the simplest type of ultrasound.
• B-mode: In B-mode ultrasound, a linear array of transducers simultaneously scans a plane through the body that can be viewed as a two-dimensional image on screen.
• M-mode: M stands for motion.

What does Isoechoic mean in ultrasound?

Isoechoic – Tissue or structures which produces an echo of the same strength as that of the surrounding structures or tissues, making it difficult to isolate.

What appears hyperechoic on ultrasound?

Hyperechoic: Increased density of sound waves compared to surrounding structures. Examples include bone and fat calcifications.

What is resolution in ultrasound?

Axial resolution Axial (also called longitudinal) resolution is the minimum distance that can be differentiated between two reflectors located parallel to the direction of ultrasound beam. Mathematically, it is equal to half the spatial pulse length. Axial resolution is high when the spatial pulse length is short.

What is ultrasound display mode?

Ultrasonic Systems. The two most commonly used ultrasonic imaging modalities in ophthalmology are termed A-mode and B-mode. Each presents anatomic information in a distinctive display format. A-mode refers to a graphic display of echo amplitude as a function of distance along one line of sight, or vector (Figure 2.1).

What is hyperechoic?

‌Hyperechoic. This term means “lots of echoes.” These areas bounce back many sound waves. They appear as light gray on the ultrasound. Hyperechoic masses are not as dense as hypoechoic ones are. They may contain air, fat, or fluid.

What does Isoechogenic mean?

(ī″sō-ĕ-kō′ĭk) Producing ultrasound echoes equal to those of neighboring or of normal tissues.

What is long axis ultrasound?

Needle placement with ultrasound guidance can be performed using either a short-axis (out-of-plane) or a long-axis (in-plane) approach to visualize the needle as it is advanced toward the desired target.

What is ultrasound Slideshare?

Ultrasound imaging, also called sonography, involves exposing part of the body to high- frequency sound waves to produce pictures of the inside of the body. • Ultrasound examinations do not use ionizing radiation (as used in x-rays).

What is the definition of the term ultrasound?

INTRODUCTION Ultrasound is the term that describes the sound signal wave’s pulse frequencies above the domain of real human hearing, and their publishing (propagation) in a medium.

How is Doppler ultrasound used in the medical field?

Medical Doppler ultrasound is usually utilized in the clinical adjusting to evaluate and estimate blood flow in both the major (large) and the minor (tiny) vessels of the body. The normal and abnormal sign waveforms can be shown by spectral Doppler technique.

What causes strong echoes in an ultrasound image?

The strength of the echoes throughout the image can be varied by changing the power output from the system. Strong echoes that delineated the boundary of organs and that are caused by the difference between the acoustic eimpedance of the two adjacent structures.

Which is the highest frequency that ultrasound can be heard?

Definition of Ultrasound. Sound travels as a mechanical longitudinal wave in which back-and-forth particle motion is parallel to the direction of wave travel. Ultrasound is high-frequency sound and refers to mechanical vibrations above 20 kHz. Human ears can hear sounds with frequencies between 20 Hz and 20 kHz.