Standard Operating Procedure: Diagnostic Ultrasound Examination

This Standard Operating Procedure (SOP) outlines the mandatory clinical and technical steps required to perform a diagnostic ultrasound examination. The objective of this protocol is to ensure patient safety, maintain diagnostic image quality, ensure infection control, and optimize workflow efficiency. All sonographers and ultrasound technicians must adhere to these guidelines to ensure consistency across clinical operations and to minimize the risk of repetitive strain or equipment damage.

1. Pre-Examination Protocol

• Patient Verification: Verify the patient’s identity using at least two identifiers (full name and DOB) against the clinical requisition.
• Requisition Review: Confirm the specific exam ordered, clinical indications, and history (e.g., prior surgeries, previous imaging).
• Environment Preparation: Ensure the examination room is clean, the ultrasound machine is powered on, and the appropriate transducer is connected.
• Infection Control: Wash hands thoroughly and ensure the transducer is disinfected according to facility protocols (High-Level Disinfection/HLD).

2. Patient Interaction and Positioning

• Introduction: Greet the patient, explain the procedure in simple terms, and obtain verbal consent.
• Privacy: Ensure the patient is properly draped to maintain modesty throughout the scan.
• Ergonomic Positioning: Position the patient for optimal acoustic windows while ensuring the sonographer maintains neutral posture to prevent musculoskeletal injury.
• Instruction: Instruct the patient regarding breath-holding techniques or position changes (e.g., LLD, RLD, or upright) as required by the specific protocol.

3. Imaging and Data Acquisition

• Gel Application: Apply a sufficient amount of acoustic coupling gel to the transducer or patient skin; avoid excess gel that causes equipment fouling.
• System Optimization: Adjust gain, depth, focus, and frequency (TGC) to achieve an optimal image.
• Protocol Adherence: Execute the facility-specific scan protocol (e.g., standard abdominal, pelvic, or vascular survey).
• Image Archiving: Ensure all standard anatomical views are captured, labeled correctly, and sent to the Picture Archiving and Communication System (PACS).
• Measurement Accuracy: Record all mandatory measurements with precision, ensuring calipers are placed accurately on the borders of the structure.

4. Post-Examination and Documentation

• Cleanup: Assist the patient in removing gel; provide privacy for re-dressing.
• Documentation: Complete the sonographer’s worksheet or technical impression notes accurately within the Electronic Health Record (EHR).
• Equipment Maintenance: Wipe down the transducer with facility-approved wipes and return the machine to the docking station for charging.
• Reporting: Notify the supervising radiologist of any critical findings immediately per the facility’s "Critical Result" policy.

Pro Tips & Pitfalls

• Pro Tip: Always utilize the "Patient Information" (PI) screen to enter data before scanning to ensure images are correctly indexed in PACS.
• Pro Tip: Adjust your chair height to keep your forearm parallel to the floor; do not reach across the patient.
• Pitfall (Artifacts): Do not misidentify reverberation or mirror-image artifacts as pathology. If unsure, change the angle of incidence.
• Pitfall (Infection Control): Never skip the transducer cleaning protocol between patients, even if the probe appears clean.
• Pitfall (Ergonomics): Avoid "scanning with your wrist." Use your whole arm and shoulder to reduce the risk of Carpal Tunnel Syndrome.

Frequently Asked Questions (FAQ)

Q: What should I do if the patient is unable to follow breath-hold instructions? A: Use a "free-breathing" technique and utilize the "Cine" loop capture function to select the clearest frames from a series of images rather than trying to capture a single static frame during an inconsistent breath-hold.

Q: How often should the ultrasound gel bottles be refilled? A: To prevent bacterial colonization, ultrasound gel should never be "topped off." The bottle should be completely emptied and cleaned/disinfected before being refilled or replaced with a new factory-sealed container.

Q: If an image looks grainy or dark, what is the first setting I should adjust? A: First, check your "Depth." Often, reducing the depth increases the frame rate and allows for better focus. If depth is correct, adjust the "Gain" or "Time Gain Compensation" (TGC) sliders to balance the image brightness.