Methods to assess sensitivity of optical coherence tomography systems

Abstract

Measuring the sensitivity of an optical coherence tomography (OCT) system determines the minimum sample reflectivity it can detect and provides a figure of merit for system optimization and comparison. The published literature lacks a detailed description of OCT sensitivity measurement procedures. Here we describe a commonly-used measurement method and introduce two new phantom-based methods, which also offer a means to directly visualize low reflectivity conditions relevant to biological tissue. We provide quantitative results for the three methods from different OCT system configurations and discuss the methods' advantages and disadvantages.

Trans-retinal cellular imaging with multimodal adaptive optics

“…The fast acquisition speed is achieved by reading out the central 1024 pixels of the spectrometer in 8-tap, 10-bit camera mode (limited by the NI framegrabber). The measured spectrometer sensitivity and roll-off were 83 dB and −9.9 dB/mm (−7.7 dB/mm up to 1 mm depth), following the method reported by Agrawal [ 40 ]. The SLO channel is not active in ‘fast scan’ mode.…”

Two dimensional non-scanning transform-free spatial-domain optical coherence tomography

“…Figure 4(b) shows the processed one-dimensional intensity distribution indicated with the dashed line in Fig. 4(a) from which the signal-to-noise ratio (SNR) can be estimated to be [25] SNR = 20 log I samp σ bg = 20 log 1904 11.47 = 44.40 dB.…”

“…The incident power on the reflection mirror was estimated to be about 0.01 mW. When the effect of the NDF is taken into account, the maximum available SNR of the system can be estimated to achieve 120.65 dB [25]. Therefore, the sensitivity of the system can be further improved when a camera with higher dynamic range is used.…”

Optimal stimulation frequency for vibrational optical coherence elastography

“…It is commonly based on imaging techniques, such as ultrasound-based elastography [4] and magnetic resonance elastography [5]; they have been widely studied and applied for the diagnosis and evaluation of the treatment responses in many diseases, for example, breast cancer [6], cardiology [7] and liver fibrosis staging [8]. Optical coherence elastography (OCE) stands out with the inherited advantages from optical coherence tomography (OCT), with high resolution in micrometre scale [10] and high sensitivity above 90 dB [11]. Optical coherence elastography (OCE) stands out with the inherited advantages from optical coherence tomography (OCT), with high resolution in micrometre scale [10] and high sensitivity above 90 dB [11].…”

“…However, the resolution of ultrasound imaging and MRI systems is relatively low, that limits the application of early tumour detection with a size of 100 μm [9]. Optical coherence elastography (OCE) stands out with the inherited advantages from optical coherence tomography (OCT), with high resolution in micrometre scale [10] and high sensitivity above 90 dB [11]. OCT also offers high displacement sensitivity with the capability to detect deformation in nanometre scale, phase sensitive OCT (PhS-OCT) built by Wang et al [12] could detect deformation in 10 nm; common path Fourier domain OCT established achieved a displacement sensitivity of 0.34 nm [13].…”