Ultrasonography | USG | The Principles of Ultrasound Imaging | Clinical application of USG | Biology

Summary

This video, hosted by The Nerd Medic on 'Animated Biology with Arpan,' explains the basics of ultrasonography (USG). It describes how USG uses high-energy sound waves to visualize internal tissues and organs. The process involves ultrasound probes with piezoelectric crystals that generate and receive sound waves to create real-time images. Different probes are used for various applications, and USG is commonly used during pregnancy and for detecting conditions like neural tube defects. The video also covers specialized ultrasound techniques like Doppler ultrasound and elastography for vascular and tissue imaging.

Takeaways

• 🔊 Ultrasonography (USG) is a non-invasive technique using high-frequency sound waves to visualize internal tissues and organs.
• 📏 The frequency range used in ultrasonography is beyond human hearing and measured in megahertz.
• ⚡ Ultrasonography involves an ultrasound machine and probes containing piezoelectric crystals, which generate sound waves when supplied with electricity.
• 🔄 These sound waves reflect back from tissues, and the returning mechanical vibrations are converted into electrical patterns to create images.
• 🧪 Tissues with different densities in the body reflect sound waves differently, helping to identify structures based on their density.
• 💻 The software analyzes the electrical signals to produce an image known as an ultrasonograph, representing tissue size, shape, and structure.
• 🛑 Air can interfere with ultrasound imaging, so gel is applied to remove air bubbles and avoid image distortions called artifacts.
• 💧 Liquids appear dark (hypoechoic) on ultrasound, while solid tissues like bones appear white (hyperechoic). Air-filled organs like lungs are not suitable for ultrasound.
• 👶 USG is commonly used during pregnancy to detect developmental defects, such as neural tube defects like spina bifida.
• 🩸 Special types of ultrasound, like Doppler ultrasound, assess blood flow in vessels, and elastography measures tissue consistency using color mapping.

Q & A

What is ultrasonography (USG)?

Ultrasonography, commonly known as USG, is a non-invasive imaging technique that uses high-energy sound waves to visualize tissues and organs inside the body in real time.

How does ultrasonography work?

Ultrasonography works by using an ultrasound machine and probes containing piezoelectric crystals. When supplied with electricity, these crystals generate mechanical vibrations that produce sound waves. The sound waves are reflected back from tissues of different densities and are converted into electrical patterns, which are analyzed by a computer to produce an image.

What is the frequency range of ultrasonic waves used in ultrasonography?

The frequency of ultrasonic waves used in ultrasonography lies beyond human hearing capacity and is measured in megahertz.

Why is gel applied during an ultrasonography procedure?

Gel is applied to the body surface during ultrasonography to eliminate air bubbles between the probe and the skin, which can cause image distortions known as artifacts.

What types of probes are used in ultrasonography?

Different types of probes used in ultrasonography include curvilinear, linear, and phased array probes. Each type of probe has specific applications depending on the area being examined.

How are tissues differentiated in USG images?

Tissues are differentiated in USG images based on their density. Solid tissues like bone appear white (hyperechoic) because they reflect more sound waves, while fluid-filled tissues, like amniotic fluid, appear dark (hypoechoic).

Why is ultrasonography not suitable for imaging organs filled with air?

Ultrasonography is not suitable for imaging air-filled organs, such as the lungs, because air disrupts the transmission of sound waves, making it difficult to produce clear images.

Is ultrasonography safe, and does it involve radiation?

Yes, ultrasonography is safe as it does not use any radiation, reducing the risk associated with radiation exposure. It is commonly used during pregnancy for this reason.

What is Doppler ultrasound, and what is it used for?

Doppler ultrasound is a type of ultrasonography that uses the Doppler effect to visualize the velocity and direction of blood flow in vessels. It is used to detect vascular conditions like varicose veins.

What is elastography, and how does it differ from standard ultrasonography?

Elastography is a type of ultrasound imaging that uses colors to represent the consistency of tissues. It provides additional information on tissue stiffness, which helps in diagnosing conditions that standard ultrasonography may not detect.