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Using the Plugin

The ConfUSIus sidebar contains four collapsible panels. Each panel operates independently and can be expanded or collapsed by clicking its header. For an in-app introduction, click Take a Tour in the sidebar header.

  • Data I/O — load and save fUSI files (NIfTI, Zarr, SCAN).
  • Video — load videos side-by-side, temporally synced with the fUSI acquisition.
  • Signals — plot voxel, point, or label-region signals in a bottom dock.
  • QC — compute DVARS, carpet, CV, tSNR for a selected layer.

Data I/O Panel

The Data I/O Panel handles both loading and saving fUSI files without leaving the viewer.

ConfUSIus Data I/O panel

Loading data

Click Browse to pick a file—it loads immediately on selection. Or paste a path directly in the text field and press Enter. Enable Load lazily beforehand to keep the array Dask-backed for large files. A progress bar animates during loading, and any error is reported in the napari notification bar.

Time overlay

When a loaded scan contains a time dimension, the current time coordinate is displayed as a text overlay in the bottom-left corner of the canvas. The value and units are read from the scan's coordinate metadata and update automatically as you scrub the time slider.

When multiple scans are open, the overlay reflects the currently selected layer. If zero or more than one layer is selected, it keeps following the previously selected one.

Saving data

  1. Select the layer to save from the Save layer dropdown.
  2. Optionally select a layer in the Coordinates from dropdown to borrow its physical coordinates and attributes. This is useful when saving a labels layer drawn on top of a fUSI image: selecting the image layer as the template preserves the full physical coordinate system. If the labels layer has fewer dimensions than the template (e.g. a 3D labels layer against a 4D image), the trailing spatial dimensions are used automatically.
  3. Type an output path or click Browse. The format is inferred from the extension: .nii / .nii.gz for NIfTI and .zarr for Zarr.
  4. Click Save. A notification confirms success.

Three save modes are applied automatically depending on what is available:

Mode When applied
Direct The layer was loaded via ConfUSIus (DataArray in metadata). Saved verbatim, all coordinates and attributes preserved.
Template A template layer is selected. Coordinates are borrowed from the template DataArray.
Reconstruct No template and no DataArray in metadata (e.g. a freshly drawn labels layer). Coordinates are reconstructed from the napari layer state (scale, translate, axis_labels).

Video Panel

The Video Panel loads one or more videos (.mp4, .mov, .avi) and overlays them beside a fUSI scan in a synchronized grid. Each video becomes its own napari Image layer whose time axis is locked to the reference scan, so scrubbing the time slider plays every video in lockstep with the fUSI recording.

Loading a video

  1. Pick the fUSI image layer to synchronize against in the Reference layer dropdown. The reference must have ConfUSIus coordinate metadata, so load it through the Data I/O Panel or the confusius CLI command.
  2. Insert a path or click Browse to pick a video file.
  3. Click Add video. The video appears as a new Image layer, grid mode is enabled with a single-row layout, and the viewer shows the reference scan and the video side by side.

Repeat to add more videos (each will get its own cell). All videos share the reference layer's axis labels, time index, and dimensionality; their spatial scale is chosen so the video height matches the fUSI height, with isotropic pixels and the frame centered on the scan.

Launch with a video from the CLI

Pass both a data file and --video to open them together:

confusius path/to/scan.nii.gz --video path/to/camera.mp4

ConfUSIus Video panel — playback

Playback

Option Description
Frame step Show every N-th frame of the video. Higher values skip frames for lighter playback of long or high-frame-rate recordings. The effective frame rate becomes fps / N. Changes apply to every loaded video.

Napari playback performance

Napari handles animations quite smoothly up to around 30 to 50 FPS (even higher depending on user hardware and operating system). Use Frame step to reduce the effective frame rate if playback is choppy or buffering.

The time scale of each video layer is frame_step / fps seconds, so the napari time slider and the time overlay continue to report physical seconds regardless of the chosen step.

Time axis is kept out of the displayed dims

The panel installs a guard that prevents napari from ever placing the time axis in the 2D display. If you reorder dimensions such that time would become a display dimension, the order is silently corrected.

Signals Panel

The Signals Panel plots signals extracted from image layers along any non-spatial dimension (time, lag, feature, etc.). The plot appears in a bottom dock that is created the first time you click Show Signal Plot.

Choosing a data source

Pick one of three source modes in the Source group:

Mouse
Hold Shift and move the mouse over the canvas. The plot updates live with the single-voxel signal at the cursor position.

ConfUSIus Signals panel — hover mode

Points
Select a Points layer from the dropdown (or click + to create one). Each point is plotted as a separate line colored by its face color. Add or remove points in napari and the plot updates automatically.

ConfUSIus Signals panel — points mode

Labels
Select a Labels layer from the dropdown (or click + to create one). The mean signal is extracted for each distinct non-zero label and plotted as a separate line, colored by the label's color in the napari colormap. This is useful for quickly comparing region-averaged signals after painting ROIs with napari's brush tool.

ConfUSIus Signals panel — labels mode

In Points and Labels modes, the Reference dropdown selects which image layer to extract signals from. It defaults to All image layers, which plots each layer as a separate line (distinguished by line style).

Axis parameters

Option Description
x-axis Choose which non-spatial dimension to plot on the horizontal axis. Defaults to time when available, otherwise the first non-spatial dimension.
y min / y max Manual limits for the vertical axis (disabled while autoscale is on).
Autoscale y-axis When enabled, the vertical axis rescales to fit the data automatically. Disabling it captures the current limits so you can fine-tune them.

Display options

Option Description
Show grid Show or hide the background grid.
Show x-axis cursor Draw a vertical line on the plot that follows the napari dimension slider for the selected x-axis dimension.
Z-score signal Normalize each signal to zero mean and unit variance before plotting. The y-axis label changes from "Intensity" to "Z-score".

Click to navigate

Left-click anywhere on the signal plot to jump the napari viewer to the corresponding time slice. Clicks are ignored while a zoom or pan tool is active in the plot toolbar.

Managing signals

Click Manage Signals to open a floating dialog where you can customize both live signals (from the current source mode) and imported signals:

  • Rename: Double-click a signal's name to edit it.
  • Recolor: Click the color swatch to pick a new color. Changes are synced back to the napari layer (point face color or label colormap).
  • Show / Hide: Toggle individual signal visibility with the checkbox.

Importing and exporting signals

Import
In the Manage Signals dialog, click Import to load signals from a CSV or TSV file. The file must contain a column whose header matches the current x-axis dimension name (e.g. time) plus one or more numeric value columns. Each value column becomes a separate signal overlaid on the plot.
Export
Click the Export button in the plot toolbar to export all currently plotted signals—both live and imported—to a CSV or TSV file.

QC Panel

The QC Panel computes quality control metrics for a selected image layer.

ConfUSIus QC panel

Select a layer from the Layer dropdown, check the metrics you want, and click Compute.

Temporal metrics are rendered as plots in the bottom dock (the same dock used by the Signals Panel, in separate tabs). Computed plots are cached and survive dock closure: closing and reopening the bottom dock restores the last computed result.

DVARS
Plots the standardized temporal derivative of variance over time. A vertical cursor follows the napari time slider. See DVARS for interpretation.
Carpet plot
Displays the full voxel time series as a 2D raster (time × voxels). See Carpet Plot for interpretation.

Click to navigate

Left-click anywhere on a temporal metric plot (DVARS or carpet) to jump the napari viewer to the corresponding time slice. Clicks are ignored while a zoom or pan tool is active in the plot toolbar.

Spatial map metrics are added as new image layers in the napari layer list, with correct physical scale and origin preserved.

CV
Coefficient of variation map.
tSNR
Temporal signal-to-noise ratio map.

Prefer CV over tSNR for fUSI power Doppler data

tSNR is misleading for power Doppler: low-signal regions such as gel layers and shadow zones behind the skull can appear bright. CV correctly highlights regions with high temporal variability. See the Quality Control guide for a full explanation.