13.07.2015 Views

Bush__The_Essential_Physics_for_Medical_Imaging - Biomedical ...

Bush__The_Essential_Physics_for_Medical_Imaging - Biomedical ...

Bush__The_Essential_Physics_for_Medical_Imaging - Biomedical ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

t IE«-f maxo~ __ Frequency(Velocity)FIGURE 16-50. A: Top graph: <strong>The</strong> spectral Doppler display is a plot of the Dopplershift frequency spectrum displayed vertically, versus time, displayed horizontally.<strong>The</strong> amplitude of the shift frequency is encoded as gray-scale variations. Bottomgraph: Two Doppler spectra are shown from the spectral display at two discretepoints in time, with amplitude (gray-scale variations) plotted versus frequency(velocity). A broad spectrum (bandwidth) represents turbulent flow, while a narrowspectrum represents laminar flow within the Doppler gate. B: Color Dopplerimage showing the active color area and the corresponding spectral Doppler display.<strong>The</strong> resistive index is calculated from the spectral display, and indicated onthe image as RI (also see Fig. 16-51).

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!