title: Quantitative evaluation of optical coherence tomography signal enhancement with gold nanoshells.
abstract: Nanoshell-enhanced optical coherence tomography (OCT) is a novel technique with the potential for molecular imaging and improved disease detection. However, optimization of this approach will require a quantitative understanding of the influence of nanoshell parameters on detected OCT signals. In this study, OCT was performed at 1310 nm in water and turbid tissue-simulating phantoms to which nanoshells were added. The effect of nanoshell concentration, core diameter, and shell thickness on signal enhancement was characterized. Experimental results indicated trends that were consistent with predicted optical properties-a monotonic increase in signal intensity and attenuation with increasing shell and core size. Threshold concentrations for a 2-dB OCT signal intensity gain were determined for several nanoshell geometries. For the most highly backscattering nanoshells tested-291-nm core diameter, 25-nm shell thickness-a concentration of 10(9) nanoshells/mL was needed to produce this signal increase. Based on these results, we discuss various practical considerations for optimizing nanoshell-enhanced OCT. Quantitative experimental data presented here will facilitate optimization of OCT-based diagnostics and may also be relevant to other reflectance-based approaches as well.
authors.affiliation: US Food and Drug Administration, Center for Devices and Radiological Health, Optical Diagnostics Laboratory, 12725 Twinbrook Parkway, HFZ-130, Rockville, Maryland 20852, USA. anant.agrawal@fda.hhs.gov
authors.forename: Anant
authors.initials: A
authors.lastname: Agrawal
authors.forename: Stanley
authors.initials: S
authors.lastname: Huang
authors.forename: Alex
authors.initials: A
authors.lastname: Wei Haw Lin
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Lee
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Barton
authors.forename: Rebekah A
authors.initials: RA
authors.lastname: Drezek
authors.forename: T Joshua
authors.initials: TJ
authors.lastname: Pfefer
mesh_terms: D003287:Contrast Media; D006046:Gold / Q000032:analysis*; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D049329:Nanostructures / Q000648:ultrastructure*; D010316:Particle Size; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000379:methods
chemical_list: D003287:Contrast Media; D006046:Gold