Performance characteristics of an interventional multispectral photoacoustic imaging system for guiding minimally invasive procedures.
Precise device guidance is important for interventional procedures in many different clinical fields including fetal medicine, regional anesthesia, interventional pain management, and interventional oncology. While ultrasound is widely used in clinical practice for real-time guidance, the image contrast that it provides can be insufficient for visualizing tissue structures such as blood vessels, nerves, and tumors. This study was centered on the development of a photoacoustic imaging system for interventional procedures that delivered excitation light in the ranges of 750 to 900 nm and 1150 to 1300 nm, with an optical fiber positioned in a needle cannula. Coregistered B-mode ultrasound images were obtained. The system, which was based on a commercial ultrasound imaging scanner, has an axial resolution in the vicinity of 100  μm and a submillimeter, depth-dependent lateral resolution. Using a tissue phantom and 800 nm excitation light, a simulated blood vessel could be visualized at a maximum distance of 15 mm from the needle tip. Spectroscopic contrast for hemoglobin and lipids was observed with ex vivo tissue samples, with photoacoustic signal maxima consistent with the respective optical absorption spectra. The potential for further optimization of the system is discussed.
University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom.
Wenfeng
W
Xia
University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom.
Daniil I
DI
Nikitichev
University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom.
Jean Martial
JM
Mari
University College Hospital, Department of Anaesthesia, Main Theatres, Maple Bridge Link Corridor, Podium 3, 235 Euston Road, London NW1 2BU, United Kingdom.
Simeon J
SJ
West
University College London, Institute for Women's Health, 86-96 Chenies Mews, London WC1E 6HX, United Kingdom.
Rosalind
R
Pratt
University College London, Institute for Women's Health, 86-96 Chenies Mews, London WC1E 6HX, United Kingdom.
Anna L
AL
David
University College London, Center for Medical Imaging Computing, Gower Street, London WC1E 6BT, United Kingdom.
Sebastien
S
Ourselin
University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom.
Paul C
PC
Beard
University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom.
Adrien E
AE
Desjardins
D054459:Elasticity Imaging Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation*; D057054:Molecular Imaging / Q000295:instrumentation*; D019047:Phantoms, Imaging; D061088:Photoacoustic Techniques / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000295:instrumentation*; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*