Image overlay for CT-guided needle insertions

Gabor Fichtinger, Anton Deguet, Gregory Fischer, Iulian Iordachita, Emese Balogh, Ken Masamune, Russell H. Taylor, Laura M. Fayad, Michelle De Oliveira, S. James Zinreich

Research output: Contribution to journalArticlepeer-review


Objective: We present a 2D image overlay device to assist needle placement on computed tomography (CT) scanners. Materials and Methods: The system consists of a flat display and a semitransparent mirror mounted on the gantry. When the physician looks at the patient through the mirror, the CT image appears to be floating inside the body with correct size and position as if the physician had 2D 'X-ray vision'. The physician draws the optimal path on the CT image. The composite image is rendered on the display and thus reflected in the mirror. The reflected image is used to guide the physician in the procedure. In this article, we describe the design and various embodiments of the 2D image overlay system, followed by the results of phantom and cadaver experiments in multiple clinical applications. Results: Multiple skeletal targets were successfully accessed with one insertion attempt. Generally, successful access was recorded on liver targets when a clear path opened, but the number of attempts and accuracy showed variability because of occasional lack of access. Soft tissue deformation further reduced the accuracy and consistency in comparison to skeletal targets. Conclusion: The system demonstrated strong potential for reducing faulty needle insertion attempts, thereby reducing X-ray dose and patient discomfort.

Original languageEnglish (US)
Pages (from-to)241-255
Number of pages15
JournalComputer Aided Surgery
Issue number4
StatePublished - Jul 2005


  • Augmented reality
  • Computed tomography
  • Image guidance
  • Image overlay
  • Needle insertion

ASJC Scopus subject areas

  • Surgery
  • Radiology Nuclear Medicine and imaging


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