Ultrasound System Operation
📌 Ultrasound imaging relies on a transducer (probe) sending sound waves into the body and processing the returning echoes to create black and white cross-sectional images.
🔊 The transducer uses piezoelectric elements that vibrate when excited by an electric current, generating pressure waves that travel at approximately 1,540 m/s through human tissue.
⬆️ Shallow structures reflect sound waves first and appear at the top of the image, while deeper structures take longer to return and appear at the bottom.

Sound Wave Interactions and Image Quality
💥 The primary source of sound wave attenuation in soft tissue is absorption, where acoustic energy converts to heat, weakening the signal for deeper structures.
⚖️ Time Gain Compensation (TGC), or gain, is used to brighten deeper structures to counteract signal attenuation and improve visibility.
🦴 Reflection occurs at boundaries between different media (e.g., tissue and bone); strong reflectors like bone create an acoustic shadow.
🌫️ Scatter, caused by non-homogeneous surfaces, results in speckle, giving the ultrasound image its characteristic grainy appearance.

Acoustic Coupling and Frequency Physics
🧴 Proper acoustic coupling using gel is necessary because ultrasound is reflected by air; trapped air causes shadowing.
🎵 Human audible sound ranges from 16 to 20,000 Hertz (Hz); ultrasound exceeds 20 kHz.
🔬 Typical ultrasound imaging frequency ranges between 1 and 20 MHz; higher frequencies yield better resolution for shallow structures, while lower frequencies offer better penetration for deeper anatomy.

Key Points & Insights
➡️ For optimal imaging, select the transducer with the right frequency corresponding to the anatomy being examined.
➡️ Deeper structures are often difficult to visualize because the signal attenuates (weakens) due to absorption.
➡️ Reflection by solid structures or air can prevent imaging behind those areas.

📸 Video summarized with SummaryTube.com on Jan 10, 2026, 14:25 UTC