Near-infrared fluorescence imaging
Near-infrared fluorescence (NIRF) imaging is an emerging technology that uses light in the NIR region, typically between 700-900 nm, for deep tissue imaging (Aswathy et al., 2010). This “optical window” offers several centimeters of tissue penetration with minimal autofluorescence interference that is inherent to biological tissues (Frangioni, 2003). Moreover, this technique possesses high sensitivity, less scatter,
Monitoring and Evaluation of Biomaterials and their Performance in vivo. http://dx.doi.org/10.1016/B978-0-08-100603-0.00003-1
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and high optical contrast, all of which are obvious advantageous for the noninvasive real-time imaging of deep tissues in vivo (Frangioni, 2003). To this end, numerous fluorescent imaging probes have been designed and developed, and they are commercially available for clinical applications such as vascular mapping, cancer imaging, medical diagnostics, and image-guided surgery (Frangioni, 2003; Kobayashi et al., 2010; Gibbs, 2012). In addition, NIRF imaging offers three-dimensional (3-D) image reconstruction, whose spatial resolution can be augmented with higher resolution modalities such as magnetic resonance imaging (MRI) and X-ray computed tomography (CT) through multimodal imaging (Talanov et al., 2006; Guo et al., 2010). Furthermore, as this imaging modality is compatible with existing fluorescence imaging instrumentations, it is cost-effective and requires minimal infrastructural investment or regulatory compliance. Due to the aforementioned considerations, NIRF imaging has been exploited for noninvasive real-time imaging of aseptic inflammation around implanted devices and can be classified into the following three groups.