PhD Thesis Defense: Yue Tang

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Meeting ID: 918 2206 5298
Passcode: 504771

"Intraoperative dynamic contrast-enhanced fluorescence imaging for navigating open orthopedic surgeries"

Abstract

Infection following trauma is one of the most prevalent and challenging complications faced by orthopedic surgeons. Inadequate tissue perfusion plays a critical role in this complication, as poorly perfused bone can be a nidus for bacterial biofilm formation and promote resistance to antibiotic treatments. Consequently, the management of open fractures and fracture-related infections relies on aggressive and thorough debridement to remove all poorly perfused bone. However, there is a lack of intraoperative imaging tools that can objectively assess bone perfusion and navigate the surgeries. To address this gap, this thesis focuses on developing an indocyanine green (ICG)-based dynamic contrast-enhanced fluorescence imaging (DCE-FI) to objectively measure bone perfusion during open orthopedic surgeries and guide surgical debridement of devitalized bone.

In terms of image processing, a novel approach was developed to eliminate motion artifacts and account for variations in manual ICG injection. To improve the accuracy of the perfusion assessment, an imaging platform incorporating a patient-specific arterial input function was developed and validated through simulation and patient studies. Analysis of data from 257 patients with varying degrees of bone damage demonstrated the following findings: 1) DCE-FI revealed trauma-induced perfusion changes that correlated with the severity of bone injury; 2) muscle perfusion quantified by DCE-FI was strongly associated with muscle necrosis; and 3) in patients with infections, areas of low perfusion (identified by reduced maximum fluorescence intensity and blood flow) were strong predictors of early re-infection within 3 months post-surgery. Additionally, we developed a portable compact fluorescence imaging system (cBPI) suitable for austere environments and forward operating units near battlefields. These findings demonstrate that DCE-FI has significant prognostic value in assessing bone damage and predicting surgical outcomes. It holds strong potential as an intraoperative tool for guiding real-time debridement decisions.

Thesis Committee

• Shudong Jiang (Chair)
• Jonathan Elliott
• Ida Leah Gitajn
• Kimberley Samkoe
• Kenneth Tichauer (Illinois Institute of Technology)

Contact

For more information, contact Thayer Registrar at thayer.registrar@dartmouth.edu.