pt 1. Ultrasound Examination Training and Techniques

Macro movement:
Movements of more than 1 cm, including:

• Sweep motion: A broad motion used to cover large areas when locating structures. Ideal for initial assessments.

• Slide motion: Involves moving the transducer slightly while maintaining contact with the skin, useful for tracking anatomy as it progresses in a linear fashion.

• Fan or rock motion (angle change > 15 degrees): This technique allows for better visualization by angling the transducer to capture different perspectives, particularly useful in complex anatomical areas.

Micro movement:
Movements of less than 1 cm, including:

• Small adjustments in the probe position: Critical for fine-tuning the image and ensuring optimal visualization of structures.

• Angle change < 15 degrees: Necessary for enhance image clarity and detail without causing excessive motion artifacts.

Sonographer Skills Required

• Manual Dexterity: Critical for manipulating equipment accurately. This skill includes the ability to perform precise movements with the transducer for quality imaging.

• Hand-Eye Coordination: Essential for translating 2D images into 3D perspectives with accuracy.

• Knowledge Base:

  • Anatomy: Familiarity with human body structures and their locations assists in obtaining diagnostic images.

  • Physiology: Understanding bodily functions supports in interpreting ultrasound images.

  • Pathology: Awareness of common diseases helps in identifying abnormalities.

  • Instrumentation: Knowledge of ultrasound machine function and settings enhances imaging outcomes.

  • Artifact Recognition: Ability to distinguish between real structures and imaging artifacts.

  • Transducer Characteristics: Knowledge of different transducer types and their appropriate applications is essential.

Importance of Training and Practice

• Clinical Training: Essential for producing high-quality images through guided learning.

• Hands-on experience with imaging equipment in a controlled environment (laboratory settings) is vital for skill development.

• Use of anatomic mannequins for practice to simulate real-life conditions without patient involvement.

• Observation:

  • Students should receive the practical experience of scanning other students to understand equipment response and patient comfort.

Patient Preparation for Ultrasound

• Fasting:
  Recommended 8-hour fasting to reduce interference from gas and ensure gallbladder distension, which aids in clearer imaging of the biliary system.

• Patient Positioning: Initial exam performed in supine position with flexibility for additional positions to optimize ultrasound quality:

  • Oblique: Helps visualize organ positioning and structures.

  • Lateral decubitus: Useful for imaging certain organ systems, providing gravity assistance for better views.

  • Prone: Rarely used, primarily reserved for specific organs like the gallbladder.

  • Upright positions: Occasionally employed for certain conditions, helping to identify stones or gallbladder issues.

Equipment Familiarity

• Know all ultrasound system controls: Understanding of gain, depth, frequency settings, and image modes (2D, M-Mode) for optimal imaging.

• Understand transducer types:

  • Curved Array: Large field of view, used for general abdominal evaluation due to its versatility.

  • Linear Array: Offers high-quality images for superficial structures (7.5 - 11 MHz), best suited for vascular/musculoskeletal imaging.

  • Phased Array: Useful for scanning intercostal spaces; ideal for cardiac imaging because of its small footprint.

Documentation and Communication

• Accurate documentation of ultrasound exams is crucial for maintaining patient records and facilitating future medical care.

• Results must be communicated promptly between the performing and ordering physicians to ensure timely patient management.

• Written or electronic orders should clearly indicate examination purposes and provide pertinent clinical information relevant to the case.

Scanning Techniques and Protocols

• Adopt standardized protocols from organizations like:

  • American Institute of Ultrasound in Medicine (AIUM)

  • American College of Radiology (ACR)

  • American Society of Echocardiography (ASE)

  • Society for Vascular Ultrasound (SVU)

• Importance of understanding and adhering to established protocols for consistent imaging standards.

Key Actions in Scanning

• Sweep Motion: Locate and assess areas of interest with large wrist movements to cover broader anatomical regions.

• Slide Motion: Used for longitudinal tracking of anatomical structures, crucial for detailed imaging.

• Rock Motion: Involves small, precise movements for visualizing small structures, enhancing visual detail.

• Rotation: Changing orientation from transverse to longitudinal views allows for comprehensive assessments of structures.

• Compression: Evaluating structures like veins or bowel by applying gentle pressure can help in visualizing blood flow or assessing organ size.

General Considerations

• Control of patient breathing during scans enhances image quality and minimizes motion artifacts.

• Communication with the patient about procedure specifics and ensuring they understand what to expect should be handled professionally.

• Maintain confidentiality and discuss cases only with qualified personnel to uphold patient privacy and trust.