Parallax and Distortion in Fluoroscopy Units.

Area of Science:

• Medical Imaging
• Surgical Technology
• Radiology

Background:

• Parallax and distortion in fluoroscopy can lead to inaccurate intraoperative assessments and surgical decisions.
• Fluoroscopy is essential for real-time surgical guidance, making image accuracy critical.

Purpose of the Study:

• To determine the prevalence and patterns of parallax and distortion in large fluoroscopy units.
• To evaluate potential impacts on surgical accuracy in a level-1 trauma center setting.

Main Methods:

• Assessed two C-arm models: round image intensifiers and flat plate detectors (FPD).
• Utilized a grid, washer, and ball bearing to identify parallax and distortion patterns.
• Obtained anterior-posterior and lateral fluoroscopic views, controlling for external factors.

Main Results:

• 100% of evaluated fluoroscopy units displayed some degree of parallax and/or distortion.
• Observed sigmoidal, converging, and diverging distortion patterns.
• FPD units had less overall distortion, but 66% were off-axis.

Conclusions:

• All fluoroscopy units evaluated demonstrated parallax and distortion.
• While FPDs showed less distortion, off-axis imaging remains a concern.
• Understanding these limitations is crucial for musculoskeletal surgeons to enhance fluoroscopic accuracy and patient safety.