Ultrasound Physics and Instrumentation (MRD535)

Transducer selection is crucial for optimizing image quality and obtaining the most relevant information from the target area. Choosing the appropriate transducer ensures proper penetration depth, resolution, and frequency for the specific anatomical structure being imaged.

Image orientation is fundamental for accurate interpretation of ultrasound scans. It ensures anatomical structures are correctly positioned and displayed to facilitate proper diagnosis and communication between healthcare professionals.

Ultrasonic scanning limitations include acoustic shadowing, acoustic enhancement, and difficulties in imaging structures with poor acoustic transmission. These limitations can affect image clarity and require careful understanding and interpretation by the sonographer.

<p>Ultrasound physics principles govern the generation, propagation, reflection, and absorption of sound waves in biological tissues. These principles determine how images are formed and interpreted, providing insights into the composition and structure of tissues within the body.</p> Signup and view all the answers

<p>Ultrasound accessories include probes, gels, and Doppler systems. Probes are responsible for transmitting and receiving sound waves, while gels facilitate sound wave transmission. Doppler systems measure blood flow velocities, providing valuable information about vascular health.</p> Signup and view all the answers

<p>Vascular and Breast Examinations.</p> Signup and view all the answers

<p>Linear transducers are high frequency and used for small parts and superficial tissues, whereas curvilinear transducers are low frequency and used for deep examinations, such as the abdomen and OB/GYN.</p> Signup and view all the answers

<p>A phase array uses a phased array of piezoelectric crystals for its arrangement. It is used for deep examinations, like with the abdomen and cardiac structures.</p> Signup and view all the answers

<p>Endocavitary transducers allow for internal examinations. They are middle frequency, providing good resolution for examinations of the prostate and female reproductive organs.</p> Signup and view all the answers

<p>The marking on the transducer should be pointing towards the patient's head.</p> Signup and view all the answers

<p>The superior direction represents the patient's head in longitudinal imaging.</p> Signup and view all the answers

<p>In a transverse image, the patient's right is displayed on the right side of the image, and the patient's left is displayed on the left side of the image.</p> Signup and view all the answers

<p>Echogenicity refers to the ability of tissues and structures to reflect or transmit ultrasound waves.</p> Signup and view all the answers

<p>A hyperechoic structure produces stronger echoes, resulting in a lighter color on the ultrasound image.</p> Signup and view all the answers

<p>An anechoic structure appears completely black on the ultrasound image, meaning there are no internal echoes. This is commonly seen with fluid-filled structures, such as cysts.</p> Signup and view all the answers

<p>Homogenous refers to a uniform shade of gray throughout the organ, indicating a mostly normal tissue appearance. Heterogenous implies non-uniform shades of gray within the organ, suggesting abnormal tissue or changes within.</p> Signup and view all the answers

<p>Ultrasound cannot accurately diagnose intestinal issues because they are often obscured by the presence of gas or air, which interfere with the ultrasound waves' ability to penetrate and provide clear images.</p> Signup and view all the answers

<p>Bone's high density and reflective nature makes it difficult to visualize using ultrasound, as the waves are either partially reflected or scattered, preventing clear images of structures behind the bone.</p> Signup and view all the answers

<p>Excess adipose tissue in overweight or obese individuals leads to increased tissue depth. This forces ultrasound waves to travel through a greater distance, making it difficult for them to reach and image deeper structures clearly.</p> Signup and view all the answers

<p>Air molecules are more spread out than those in denser media, limiting ultrasound waves' ability to propagate. This results in rapid energy dissipation, leading to weaker and less clear images of structures behind the air.</p> Signup and view all the answers

<p>Isoechoic means that a specific structure has similar echo characteristics to another structure on the ultrasound screen. For example, a benign thyroid nodule might be described as isoechoic to the surrounding thyroid tissue.</p> Signup and view all the answers

<p>Adipose tissue attenuates (absorbs and scatters) ultrasound waves more than lean tissue, leading to reduced energy and weaker echoes, making it harder to obtain clear images.</p> Signup and view all the answers

<p>Fat has different acoustic properties than muscle or organs, leading to poor transmission of sound waves between tissues with varying densities, resulting in image artifacts.</p> Signup and view all the answers

<p>The curved transducer surface and potential air gaps between the transducer and skin can make it difficult to achieve consistent contact, resulting in image degradation due to shadows and artifacts.</p> Signup and view all the answers

<p>They eliminate air gaps between the transducer and skin, reduce attenuation, and help visualize superficial lesions by bringing them into the transducer focal zone.</p> Signup and view all the answers

<p>An anechoic structure is a structure that appears black on the ultrasound image, meaning it doesn't reflect sound waves back to the transducer.</p> Signup and view all the answers

<p>They provide a cushioning effect, reducing pressure from the transducer on the skin, especially in sensitive areas, leading to a more comfortable experience for the patient.</p> Signup and view all the answers

<p>Stand-off pads improve image quality by eliminating air gaps between the transducer and the skin, thereby reducing shadows and artifacts, and achieving better acoustic coupling for clearer images.</p> Signup and view all the answers

<p>By creating a gap between the transducer and the skin, stand-off pads bring the superficially placed lesions into the transducer's focal zone, allowing for better image resolution and clarity.</p> Signup and view all the answers

The process of choosing the appropriate transducer for ultrasound imaging based on factors like frequency and application.

The arrangement of the ultrasound image as viewed on the screen, typically providing a standard perspective for interpretation.

Factors that restrict the quality or accuracy of ultrasound imaging, such as patient anatomy or equipment constraints.

Fundamental concepts that govern how ultrasound waves are emitted, reflected, and used to create images of body structures.

The method used to capture and store ultrasound images for analysis and diagnosis.

Has a linear arrangement of piezoelectric crystals; high frequency and rectangular beam shape.

Features a curvilinear arrangement of piezoelectric crystals; low frequency and convex beam shape.

Uses a phased array of piezoelectric crystals; low frequency for detailed internal imaging.

Used for internal examinations; has middle frequency and good resolution.

The transducer is marked towards the patient's head in a longitudinal orientation.

The transducer points to the side, indicating patient's left and right in transverse orientation.

The ability to reflect or transmit ultrasound waves.

Orientation where anterior is at the top and posterior at the bottom; left/right oriented to patient.

Tissues that generate greater echoes, appearing lighter on ultrasound.

Tissues producing weaker echoes, appearing darker than surrounding areas.

No internal echoes are emitted, displaying a completely black appearance.

Structures giving off similar echoes to each other on ultrasound.

Uniform grey shade throughout an organ, typically normal appearance.

Nonuniform shades of grey throughout the organ, usually abnormal.

Increased depth of tissue in obese individuals impacts ultrasound image quality.

In ultrasound, it can lower image resolution.

Reduction of wave energy by adipose tissue, affecting echo clarity.

Fat's acoustic properties hinder ultrasound wave passage between tissues.

Flexible materials placed between transducer and skin to improve ultrasound transmission.

Better contact with stand-off pads reduces artifacts in ultrasound images.

Stand-off pads allow better contact in difficult scanning areas.

Stand-off pads provide cushioning, reducing pressure on sensitive skin.