V.D. Vincely, M. Dickerson, C.L. Bayer
LumaWave,
United States
Keywords: spectral photoacoustic imaging, deep tissue oximetry, handheld
Summary:
Photoacoustic imaging (PAI) is a rapidly emerging technology allowing real-time mapping of oxygenation using traditional ultrasound hardware. Compared to purely optical modalities, this hybrid approach allows local assessments of tissue hypoxia deep within the body demonstrating clinical utility in various applications including oncology, dermatology, pediatrics, obstetrics and wound care. Traditional PAI systems rely on bulky and expensive solid-state lasers, limiting clinical translation. Alternative miniature sources such as light emitting diodes (LED) have been demonstrated for PAI, albeit at significantly reduced imaging depths (< 5 mm). In this work, an integrated array of pulse laser diodes emitting at the second near infrared window combined with detection electronics sensitive for low-frequency signals were employed. This allowed mapping of in vivo renal oxygenation up to a depth of 3.85 cm under multiple layers of porcine tissue. For the first time, this work demonstrates the feasibility of performing deep tissue oxygenation mapping using a highly portable PAI system.