SAIT DMST 202: Ultrasound Scanning Fundamentals (Week 1)

Evaluating Images: The Bowser Image and Core Goals

The "Bowser Image" serves as a structured target for identifying anatomical landmarks and adjusting imaging parameters during ultrasound examinations. This example is used throughout the "Evaluating Images" section to demonstrate various adjustable controls and their effects. Key adjustable controls referenced include Depth, Focus, Gain, Time-Gain Compensation (TGC), and Landmarks.

• Bowser Image Purpose: Portrayed as a structured target for identifying landmarks and for practicing the adjustment of imaging parameters.

• Parameter Adjustments: Variations across slides illustrate changes in labeling, notably for Depth and Focus adjustments. Gain is often described as darkening the image when increased. TGC (time-gain compensation) and Landmarks are highlighted as essential features to align with diagnostic goals.

• Alignment: Some slides emphasize the concept of aligning the Bowser image with the specific structures intended for visualization, often with comments about focusing attention (e.g., “Center of attention” guidance).

• Orientation Issues: Some slides show common issues like image inversion or other orientation problems (referencing Page 8/9 notes), stressing the importance of maintaining correct orientation and structural integrity in the image.

Core Goals for Image Evaluation

The primary goals during labs and real-time scanning are to: create a diagnostic image and actively evaluate sweeps before finalizing images.

Key foundational tasks include:

• Identifying and verifying anatomy and landmarks.

• Accurate annotation.

• Performing accurate measurements.

Optimization Criteria for Diagnostic Images

To achieve a high-quality diagnostic image, several parameters must be optimized:

• Depth

• Focus

• Overall Gain

• Time-Gain Compensation (TGCs)/Lateral Gain Compensation (LGCs)

• Frequency

• Sharp Borders

• True Axis of Organ

• Probe Orientation

Recommended Adjustment Sequence

There is a recommended sequence for parameter adjustments, often stated as "Always adjust in this order!" (Page 9):

1. Depth

2. Focus

3. Gain

4. TGCs/LGCs

5. Frequency

6. Borders/Signal

Detailed Criteria for Evaluating Images

1. Anatomy and Landmarks

• Are you displaying all required anatomy for each image/sweep?

• What specific anatomical structures are you missing?

• Are you utilizing the correct acoustic window? (Refer to SAIT, 2015 guidelines).

  • Example: Aorta window considerations often require specific tuning and landmark recognition, as indicated in SAIT materials.

2. Annotation

• Are you accurately stating the correct organ being imaged?

• Are you clearly indicating the correct side of the body (e.g., left/right)?

• Are you documenting the correct imaging plane (e.g., sagittal, transverse)? (Refer to SAIT, 2015 guidance).

3. Accurate Measurements

• Are you positioned in the correct plane to place calipers accurately?

• Are your measurements taken along the longest axis of the organ?

• Are your calipers precisely placed at the correct points? (Refer to SAIT, 2015 guidance).

4. Optimization Parameters

• Focus

  • Is the focal zone positioned at or below the area of interest?

  • Does the focus need to be adjusted anteriorly or posteriorly? (Refer to SAIT, 2015 guidance).

• Depth

  • Are you inadvertently cutting off any required anatomy posteriorly?

  • Do you have unnecessary space posterior to the organ, which could be optimized by reducing depth? (Refer to SAIT, 2015 guidance).

• TGC (Time-Gain Compensation)

  • Do you observe dark or light bands across any part of the organ or image?

  • Does the organ appear homogeneous in echotexture throughout?

  • Do you need to selectively lighten or darken the near, middle, or far field of the image? (Refer to SAIT, 2015 guidance).

• LGC (Logistics/Linear Gain Contrast) – Echo Only

  • Do you notice dark or light bands on the lateral aspects of the image? (Refer to SAIT, 2015 guidance, specifically for echocardiography).

• Overall Gains

  • Does the organ appear too bright or too dark overall?

  • Do you need to decrease gains (make darker) or increase gains (make brighter) to achieve optimal brightness? (Refer to SAIT, 2015 guidance).

• Frequency

  • Is the detail within the structure optimal for diagnostic purposes?

  • Is the area of interest deep or superficial, influencing the optimal frequency selection? (Refer to SAIT, 2015 guidance).

• True Axis of Organ

  • Does any organ appear foreshortened?

  • Are your measurements smaller than the average expected size for the organ?

  • Do any areas of the organ look oblong in shape when they should not?

  • If the organ is tubular, does it accurately appear tubular? (Refer to SAIT, 2015 guidance).

• Sharp Borders

  • Can you clearly visualize the edges of the organ?

  • Do you need to move to a new acoustic window?

  • Should you apply more or less pressure with the probe?

  • Have you tried a different breathing technique or patient position to improve border definition? (Refer to SAIT, 2015 guidance).

• Probe Orientation

  • Where is the marker on your probe positioned relative to the image display?

  • Is your image inverted? (Refer to SAIT, 2015 guidance).

Practical Takeaways for Imaging

• Throughout all course work and laboratory sessions, there is a strong imperative to actively seek a diagnostic image and to thoroughly evaluate sweeps before capturing final images.

• Consistent evaluation order and vigilance towards image orientation issues (e.g., image inversion, probe orientation) are critical for accurate diagnoses.

Ergonomics (WRMSD) – Work-Related Musculoskeletal Disorder

WRMSD Overview

• Also referred to as Repetitive Strain Injury (RSI).

• The most common injury among Sonographers.

• Estimated prevalence: 80\%-90\% of sonographers have experienced pain.

Causes (Risk Factors) of WRMSD

• Force

• Repetition / Workload

• Awkward Postures

• Contact Pressure

Areas Most Affected by WRMSD

• Shoulders

• Neck

• Lower back

• Elbow

• Wrist

Symptoms of WRMSD

• Pain, dull ache

• Inflammation, swelling

• Deterioration of tendons and ligaments

• Burning/tingling sensations

• Clumsiness, weakness

• Loss of sensation / numbness

• Visual eye strain, headache

Recommendations to Reduce WRMSD Risk

• Vary Scan Types: Avoid scheduling two intensive scans back-to-back; vary the types of scans performed per shift.

• Ergonomic Adjustments: Complete all ergonomic equipment adjustments prior to and during the examination.

• Stretching: Perform stretches prior to and after the examination. Stretching/strengthening equipment is often available in the lab.

• Patient Setup: Position patients as close as possible to the sonographer to reduce reaching and potential injuries.

• Equipment Setup:

  • Stretcher Height: Adjust the stretcher so the bed surface is just below the sonographer’s elbow height. Adjust for both sitting and standing positions, and as the patient's position changes.

  • Support: Utilize foot support, chair rings, and foot stools as needed.

  • Machine & Monitor Positioning: Bring the ultrasound machine close and lock it in position. Adjust the console height to keep elbows at approximately a 90^{\circ} angle. Position the monitor at eye level or slightly below to reduce neck extension.

• Posture Guidelines:

  • Maintain relaxed shoulders and an upright posture; keep arms close to the body.

  • Abduction of the arm should be no more than 30^{\circ} to prevent reduced blood flow and fatigue.

  • Keep the head and trunk upright.

  • Maintain elbows at approximately a \sim90^{\circ} angle; avoid resting wrists on the console.

• Transducer Grip & Pressure:

  • Minimize transducer grip strength; avoid “white-knuckling.”

  • Apply pressure using the whole arm, not just the wrist.

  • Utilize a C-shaped grip.

Ergonomic Tools Available at SAIT

• Anti-fatigue mat

• Foot stool

• Cable brace

• Stretching poster

• Strengthening tools bin

• Probe Grip (Echo): Specific ergonomic tools and devices like Therabands, rubber bands, tubing, therapy putty, hand grips, hand exercisers, and soft balls for strengthening (e.g., Theraband FlexBar, web hand exerciser, power web, hand exerciser options).

Sonographer Checklist (Pre-scan, During scan, Post-scan)

• Pre-scan:

  • Perform stretches.

  • Ensure patient proximity to reduce reach.

  • Adjust chair/bed height.

  • Ensure monitor/console are accessible and at proper height.

• During Scan:

  • Maintain head-over-neck-over-shoulders alignment.

  • Sit/stand with proper posture.

  • Keep arm/elbow tucked close to the body.

  • Maintain a neutral wrist position.

  • Use a C-shaped grip on the transducer.

  • Ensure feet/legs are supported.

  • Shift weight evenly if standing.

• Post-scan:

  • Perform stretches.

  • Monitor for any unusual symptoms of pain or discomfort.

Sonographer Stretches (Illustrated Sets)

(Note: Always consult a physician before starting any exercise program. Sound Ergonomics is not liable for injuries from program use.)

A wide range of exercises targets shoulders, scapular stabilization, neck, and upper back muscles. Some exercises use tubing or bands with progression from 5 to 30 repetitions per day. Illustrated sets typically include:

• Shoulder Elevation Stretch: 3 repetitions, about 5 times per day; relax shoulders, elevate toward ears and slowly lower.

• Corner Stretch (Pectoral/Chest): Lean into a corner with arms at shoulder level; maintain a straight back; hold the stretch; avoid arching; keep head/trunk level.

• Shoulder Horizontal Adduction Stretch

• Cervical-Thoracic-Scapular Flexion Stretch: Standing, clasped hands around elbows; retract cervical spine; bend forward; elbows dangling toward floor; reach for the floor.

• Levator Scapula Stretch: Place hand on head; gently stretch neck; alternate sides; hold for about 8 seconds each side.

• Cervical Spine-Neck Retraction

• Scapular Protraction Strengthening and other cervical spine stretches.

• Various combinations of arm/shoulder stretches with guidance on hold times and repetition counts.

• Examples include: shoulder external/internal rotation, scapular protraction, shoulder abduction, shoulder horizontal abduction/adduction, shoulder extension strength, etc.

Postural and Setup Reminders (Summary)

• Keep the patient close; adjust bed height to maintain a comfortable reach.

• Monitor and console should be at an accessible height; avoid neck extension.

• Maintain a neutral spine; avoid extreme shoulder abduction; keep elbows near the body.

Instrument Tips

• Reduce transducer grip strength; use whole-arm pressure; avoid pinching or squeezing the probe.

• Maintain a relaxed shoulder and neck; ensure natural breathing and comfort during scanning.

Cautions and References

• The materials include vendor-specific links and images. Always ensure you follow SAIT guidelines for ergonomics and do not rely on external sources without proper evaluation.

• Additional notes from the slides sometimes include placeholders or image references that illustrate demonstrations. While not essential to memorize verbatim, they indicate visual examples used in training.

• Copyright and publication notices emphasize intellectual property protection and contact information for SAIT.

Practical Takeaways for Exam Preparation

• Be able to list and explain the core criteria for evaluating ultrasound images: anatomy/landmarks, annotation, measurements, and optimization (depth, focus, gain, TGC, frequency, borders, axis, orientation).

• Understand common pitfalls: wrong window, missing anatomy, incorrect annotation, inappropriate caliper placement, foreshortening, and inverted images.

• Recognize the sequence for image adjustments: Depth, then Focus, then Gain, then TGCs/LGCs, then Frequency, then border sharpness and orientation.

• Be familiar with WRMSD concepts, common affected areas, typical symptoms, and high-level ergonomic recommendations (varied scans, breaks, stretches, proper setup).

• Memorize the basic posture and transducer grip guidelines (90-degree elbows, neutral wrists, C-shaped grip, whole-arm pressure).

• Know common stretching and strengthening exercises categories and purpose (shoulders, neck, upper back, scapular stabilizers, wrists, etc.).

• Remember practical setup tips: keep equipment close, monitor at eye level, chair height, bed height near elbow level, and patient proximity to reduce reaching.

Summary Emphasis for Exams

• Diagnostic image quality hinges on correct anatomy, proper labeling, accurate measurements, and well-tuned imaging parameters.

• Ergonomics is essential to long-term safety and career sustainability; adopt proactive posture, equipment setup, and a regular stretch/strength program.