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Doppler OCT (DOCT)
In ultrasound, functional information can be acquired through various signal processing algorithms. These algorithms can also be employed in OCT imaging, which results in the ability to measure blood flow. This can provide a useful metric for the monitoring of cancer treatment and/or the diagnosis of other diseases. A number of modes such as color Doppler and power Doppler are achieved, while utilizing ultrasound Doppler algorithms. The achievement of Doppler detection consists of the decomposition of the detected OCT signal (S) into in-phase (I) and quadrature (Q) components.


 * $$ S = I + iQ \qquad \qquad \quad (5) $$

The intensity value at a given pixel in the structural image is calculated by


 * $$  = \frac {1} {MN} \sum_{m=1}^M \sum_{n=1}^N [I_{m,n}^{2} + Q_{m,n}^{2}] \quad (5) $$

where, $$ < > $$ denotes the average value, M represents the depth window length, N represents the lateral window length, m and n are the indices for the depth and lateral direction.

Both the structural OCT image and blood flow information in a number of modes can be displayed. One mode of blood flow information, known as color Doppler, is an estimate of the mean frequency shift of moving scatterers in the OCT signal. The evaluation of this shift can be calculated by the Kasai autocorrelation equation.