Ultrasound Physics Review | Multiple Echo Artifacts | Sonography Minutes

Sonography Minutes
21 Jul 202106:48
EducationalLearning
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TLDRThis educational video explores ultrasound physics, focusing on multiple echo artifacts. It explains how ultrasound machines make seven assumptions about sound waves, and when these assumptions fail, artifacts like reverberation, comet tail, ring down, mirror image, air, and speckle occur. The video delves into each type of artifact, describing their causes and appearances, and highlights the role of modern ultrasound technology in reducing speckle noise for clearer imaging.

Takeaways
  • 🌐 Ultrasound artifacts are echoes that do not correspond to actual structures and can be caused by the machine's assumptions about sound waves failing.
  • 🔍 An ultrasound machine makes seven assumptions about sound waves, including their straight-line travel, constant speed, and even attenuation in tissues.
  • 📐 Multiple echo artifacts occur when sound waves encounter structures and do not return directly to the transducer, causing scattering and false echoes.
  • 🔄 There are five categories of ultrasound artifacts: beam, multiple echo, velocity error, attenuation, and Doppler artifacts.
  • 💥 Multiple echo artifacts include reverberation, comet tail, ring down, mirror image, air artifact, and speckle.
  • 🏥 Reverberation is caused by sound waves bouncing between strong reflectors and the transducer, appearing as multiple parallel lines.
  • 🌠 Comet tail and ring down are types of reverberation artifacts, with comet tail caused by strong reflectors like needle tips and ring down by gas bubbles.
  • 🔍 Mirror image artifacts are created when sound waves bounce off strong reflectors, producing a duplicate structure that is not real.
  • 🌫 Air artifacts are seen as white hazy areas on ultrasound, which can be both helpful for tracking and a hindrance by obscuring anatomy.
  • 🖼️ Speckle is a noise artifact that gives the tissue a textured look, caused by echoes from other pulses interacting with scattering areas in the tissue.
  • 🛠️ Modern ultrasound machines often have speckle reduction imaging (SRI) to control the amount of speckle, making images smoother.
Q & A

  • What are ultrasound artifacts?

    -Ultrasound artifacts are reflections that do not correspond to actual structures, displaying incorrect size, shape, or brightness due to the failure of one or more assumptions made by the ultrasound machine about sound waves.

  • How many assumptions does an ultrasound machine make about sound waves?

    -An ultrasound machine makes seven assumptions about sound waves, including sound traveling in a straight line, encountering structures and returning directly to the transducer, traveling at a constant speed, arising only from within the main beam, the imaging plane being thin, time determining depth, and attenuating at an even rate in the tissue.

  • What are the five categories of ultrasound artifacts?

    -The five categories of ultrasound artifacts are ultrasound beam artifacts, multiple echo artifacts, velocity error artifacts, attenuation artifacts, and Doppler artifacts.

  • What is a multiple echo artifact?

    -A multiple echo artifact occurs when sound waves scatter in the tissue from strong reflectors, causing artifactual echoes due to the bouncing of sound between the reflectors.

  • What are the types of multiple echo artifacts mentioned in the script?

    -The types of multiple echo artifacts mentioned are reverberation, comet tail, ring down, mirror image, air artifact, and speckle.

  • How is reverberation caused in an ultrasound?

    -Reverberation is caused by one or more strong reflectors, such as a biopsy needle, causing sound waves to bounce back and forth between the reflector and the transducer or between two strong reflectors in the tissue.

  • What does the ultrasound appearance of reverberation look like?

    -The ultrasound appearance of reverberation is characterized by multiple parallel long echogenic horizontal lines located posterior to the strong reflector or reflectors.

  • How do comet tail and ring down artifacts differ from each other?

    -Comet tail is caused by a strong reflector and appears as multiple short parallel echogenic horizontal lines extending vertically, while ring down occurs as a sound wave encounters gas bubbles, causing vibrations that create a continuous sound wave directed back towards the transducer.

  • What is a mirror image artifact and how is it commonly seen?

    -A mirror image artifact is caused by sound waves bouncing off a strong reflector, creating a carbon copy structure that appears above, below, or to the side of the strong reflector. It is commonly seen with breast implants, where the implant shell is a strong reflector.

  • How does air appear on an ultrasound image and what artifacts can it cause?

    -Air appears as white hazy areas on the ultrasound image and can cause shadowing, reverberation, comet tail, and ring down artifacts posterior to the air. It can be both helpful, by leaving a white track showing the path of a biopsy needle, and a hindrance by obscuring anatomy or pathology.

  • What is speckle in an ultrasound image and how is it related to noise artifacts?

    -Speckle is the grainy or dot-like echoes on an ultrasound image that do not correspond to actual tissue or structures. It is a type of noise artifact caused by sound waves returning to the transducer and interacting with areas of scattering in the tissue, resulting in false echoes.

  • What is Speckle Reduction Imaging (SRI) and what does it do?

    -Speckle Reduction Imaging (SRI) is an ultrasound control that can either increase or decrease the amount of speckles seen on an ultrasound image, making the image appear smoother in texture.

Outlines
00:00
🌐 Understanding Ultrasound Artifacts

This paragraph delves into the world of ultrasound physics, focusing on the phenomenon of multiple echo artifacts. It explains that an echo artifact is a reflection that does not correspond to an actual structure and can manifest as missing or misplaced echoes with incorrect characteristics. The ultrasound machine operates on seven assumptions about sound waves, and when these assumptions fail, artifacts are produced. The paragraph categorizes artifacts into five types: beam artifacts, multiple echo artifacts, velocity error artifacts, attenuation artifacts, and Doppler artifacts. The main focus is on multiple echo artifacts, which occur when sound encounters a structure and reflects back to the transducer, often due to scattering from strong reflectors. The paragraph lists and describes various types of multiple echo artifacts, including reverberation, comet tail, ring down, mirror image, air artifact, and speckle, providing insights into their causes and appearances in ultrasound imaging.

05:02
🌌 Exploring Air and Speckle Artifacts in Ultrasound

The second paragraph continues the discussion on ultrasound artifacts, specifically addressing air and speckle artifacts. Air, found in the stomach, bowel, or introduced during an ultrasound-guided procedure, appears as white hazy areas on the ultrasound image and can cause shadowing, reverberation, comet tail, and ring down artifacts. While air can be helpful in tracking the path of a biopsy needle, it can also obscure anatomy and pathology. Speckle, described as the grainy or dot-like echoes on an ultrasound image, does not correspond to actual tissue or structures but gives the tissue its textured look. It is a type of noise artifact caused by echoes from sound waves returning to the transducer and interacting with areas of scattering. Modern ultrasound machines often have speckle reduction imaging (SRI) to control the amount of speckles seen, resulting in a smoother image texture. The paragraph ends with an invitation to stay tuned for more videos on ultrasound artifacts, encouraging viewers to like, comment, and subscribe for upcoming content.

Mindmap
Keywords
💡Ultrasound
Ultrasound refers to sound waves with frequencies higher than the upper audible limit of human hearing. In the context of the video, it is a medical imaging technique that uses high-frequency sound waves to create images of structures within the body. The video discusses the physics behind ultrasound and how it can produce artifacts due to the assumptions made by the ultrasound machine.
💡Echo
An echo in the video script refers to the reflection of sound waves that do not correspond to an actual structure. It is a fundamental concept in ultrasound imaging, where echoes are used to create images. However, incorrect echoes can lead to artifacts, which are errors in the ultrasound image that do not represent true anatomical structures.
💡Artifacts
Artifacts in the context of this video are errors or distortions in the ultrasound image that do not accurately represent the true anatomy or structures within the body. They occur due to the failure of one or more assumptions made by the ultrasound machine about the behavior of sound waves.
💡Assumptions
The ultrasound machine makes several assumptions about sound waves to function correctly. These include the straight-line travel of sound, constant speed of sound in tissues, and the imaging plane being thin, among others. The script explains that when these assumptions fail, artifacts are produced.
💡Multiple Echo Artifacts
Multiple echo artifacts are a type of ultrasound artifact that occurs when sound waves encounter a structure and reflect back multiple times, creating additional, incorrect echoes. The video script delves into various types of multiple echo artifacts, such as reverberation and comet tail, which affect the accuracy of ultrasound imaging.
💡Reverberation
Reverberation is a specific type of multiple echo artifact caused by sound waves bouncing back and forth between a strong reflector and the transducer. This results in multiple parallel lines of artifact inferior to the reflector, as mentioned in the script, and is often seen in the anterior portion of the cervix (CIS).
💡Comet Tail
Comet tail is another type of multiple echo artifact that occurs when a strong reflector, such as a needle tip or air calcifications, causes the sound wave to bounce between the transducer and the reflector, creating a series of short, parallel echogenic lines that extend vertically.
💡Ring Down
Ring down is a reverberation artifact that happens when a sound wave encounters gas bubbles, causing them to vibrate and produce a continuous sound wave directed back towards the transducer. This artifact appears similar to the comet tail but is distinguished by its cause and the context in which it appears.
💡Mirror Image
The mirror image artifact is created when sound waves bounce off a strong reflector, causing a duplicate or 'carbon copy' structure to appear on the ultrasound image. This is not a real structure but an artifact, often seen with breast implants where the implant shell acts as a strong reflector.
💡Air Artifact
Air artifact in ultrasound refers to the appearance of air pockets, such as those found in the stomach or bowel, or introduced during a procedure. It appears as white hazy areas on the image and can cause shadowing or other artifacts like reverberation or comet tail posterior to the air.
💡Speckle
Speckle in the context of ultrasound imaging is the grainy or dot-like appearance on the image that does not correspond to actual tissue or structures. It is a type of noise artifact caused by echoes from other ultrasound pulses interacting with areas of scattering in the tissue, creating a textured look on the image. Modern ultrasound machines often have speckle reduction imaging to minimize this effect.
Highlights

Ultrasound artifacts are reflections that do not correspond to actual structures and can display incorrect characteristics.

Ultrasound machines make seven assumptions about sound waves, and artifacts occur when these assumptions fail.

Sound travels at a constant speed in soft tissue, assumed to be 1540 meters per second.

There are five categories of ultrasound artifacts: beam, multiple echo, velocity error, attenuation, and doppler.

Multiple echo artifacts occur when sound encounters a structure and reflects back to the transducer.

Scattering in tissue from strong reflectors can cause artifactual echoes, leading to multiple echo artifacts.

Types of multiple echo artifacts include reverberation, comet tail, ring down, mirror image, air artifact, and speckle.

Reverberation is caused by sound waves bouncing between a strong reflector and the transducer.

Comet tail and ring down are types of reverberation artifacts caused by strong reflectors and gas bubbles, respectively.

Mirror image artifact is caused by sound waves bouncing off a strong reflector, creating a carbon copy structure.

Air artifact appears as white hazy areas on ultrasound and can be both helpful and hindering.

Speckle is a noise artifact that gives the ultrasound image its textured look, caused by echoes from scattering.

Speckle reduction imaging (SRI) is a control on modern ultrasound machines to reduce the grainy texture.

Differentiation between comet tail and ring down is based on the cause of the artifact, not ultrasound appearance.

Mirror image artifact is commonly seen with breast implants, where the implant shell acts as a strong reflector.

The appearance of reverberation is characterized by multiple parallel long echogenic horizontal lines.

Comet tail and ring down appear as short parallel echogenic horizontal lines, differing from reverberation's long lines.

Transcripts

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Ultrasound PhysicsMedical ImagingArtifactsEcho ReflectionsMultiple EchoesDiagnostic TechniquesUltrasound MachineHealthcare EducationMedical TechnologyImaging Artifacts