Measurement of blood flow in tissue provides vital information for the diagnosis and therapeutic monitoring of various vascular diseases. A noncontact, camera-based, near-infrared speckle contrast diffuse correlation tomography (scDCT) technique has been recently developed for 3D imaging of blood flow index (αDB) distributions in deep tissues up to a centimeter. A limitation with the continuous-wave scDCT measurement of blood flow is the assumption of constant and homogenous tissue absorption coefficient (
Introduction: Tissue injuries are often associated with abnormal blood flow (BF). The ability to assess BF distributions in injured tissues enables objective evaluation of interventions and holds the potential to improve the acute management of these injuries on battlefield. Materials and Methods: We have developed a novel speckle contrast diffuse correlation tomography (scDCT) system for noncontact 3D imaging of tissue BF distributions. In scDCT, a galvo mirror was used to remotely project near-infrared point light to different source positions and an electron multiplying charge-coupled-device was used to detect boundary diffuse speckle contrasts. The normalized boundary data were then inserted into a modified Near-Infrared Fluorescence and Spectral Tomography program for 3D reconstructions of BF distributions. This article reports the first application of scDCT for noncontact 3D imaging of BF distributions in burn wounds. Results: Significant lower BF values were observed in the burned areas/volumes compared to surrounding normal tissues. Conclusions: The unique noncontact 3D imaging capability makes the scDCT applicable for intraoperative assessment of burns/wounds, without risk of infection and without interfering with sterility of the surgical field. The portable scDCT device holds the potential to be used by surgeons in combat surgical hospitals to improve the acute management of battlefield burn injuries.
more » « less- NSF-PAR ID:
- 10117996
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Military Medicine
- ISSN:
- 0026-4075
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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μ a ). The present study took the advantage of rapid, high-density, noncontact scDCT measurements of both light intensities and diffuse speckle contrast at multiple source-detector distances and developed two-step fitting algorithms for extracting bothμ a and αDB. The new algorithms were tested in tissue-simulating phantoms with known optical properties and human forearms. Measurement results were compared against established near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS) techniques. The accuracies of our new fitting algorithms with scDCT measurements in phantoms (up to 16% errors) and forearms (up to 23% errors) are comparable to relevant study results (up to 25% errors). Knowledge ofμ a not only improved the accuracy in calculating αDBbut also provided the potential for quantifying tissue blood oxygenation via spectral measurements. A multiple-wavelength scDCT system with new algorithms is currently developing to fit multi-wavelength and multi-distance data for 3D imaging of both blood flow and oxygenation distributions in deep tissues. -
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