Velocity Analysis¶
Velocity analysis estimates blood flow velocity from line scan kymographs using a Radon-transform-based method.
Later documentation may refer to this workflow simply as velocity analysis, but the implemented analysis is specifically designed for line scan kymograph data.
Input data¶
Velocity analysis expects image data organized as a line scan kymograph. The ROI should cover the region of the kymograph used to estimate flow velocity.
Detection parameters¶
Detection parameters define the scientific behavior of the analysis. For velocity analysis, the primary parameter controls the width of each Radon analysis window.
Velocity Detection Parameters¶
| name | display_name | type | default | choices | unit | editable | visible | methods | description |
|---|---|---|---|---|---|---|---|---|---|
| window_width | Window Width | int | 64 | (16, 64, 128) | True | True | Number of time samples per Radon analysis window. |
Results¶
Velocity analysis stores summary values in the AcqImage JSON sidecar and writes tabular output to a CSV file.
For a source file named my_file.tif, velocity analysis saves:
my_file.tif.json
my_file.tif.radon_velocity.csv
The JSON sidecar includes the detection parameters and summary values for each analyzed ROI. Typical summary values include:
velocity_meanvelocity_medianvelocity_cvnum_windows
The CSV file stores per-window tabular velocity results.
Programmatic use¶
Velocity analysis can be run from the GUI or from Python code using the same acqstore backend.
See the Velocity Analysis API.