RT Contour — contouring trainer

RTContour · contouring trainer

◲ 3D Matcher ◱ 2D My results

Case No CT loaded

Add a contouring case

Upload a planning CT and its expert structure masks as NIfTI (.nii / .nii.gz). The case is saved to the shared dataset folder, so it appears in both the contouring trainer and the 3D matcher.

Case name

Reference — planning CT required

Treatment — CBCT/CT optional, enables the 3D matcher

Expert structure masks optional — you can contour them after loading

Name each file mask_Bladder.nii.gz style — the name becomes the structure label students choose.

Use a new case name. Existing CTs are protected; edit individual expert structures after loading the case.

Add an additional scan

Upload a de-identified MRI, CT or PET of the same patient. Use a 3D NIfTI file (.nii or .nii.gz) with spatial coordinates in millimetres. You can align it to the planning CT in the viewer.

Scan name

Scan type

Additional scan

I have checked that this scan belongs to the same patient as the planning CT. It is de-identified and permitted for shared teaching use.

Phone view · one plane at a time

100%

Crosshair

Slice -

Choose a case and load its CT, then load a structure from the side panel.

Axial

Coronal

Sagittal

Your teaching library

Build confidence.
One contour at a time.

Explore CT cases, practise an organ, and compare your contour with its teaching reference. Your submitted scores stay in My results.

View my progress

Choose a case and anatomy
Contour, score and compare
Repeat and track your progress

Score—/100

Dice · drawn slices—

CommonExtraMissing

Working…

Image fusionLoad a CT first

Load a planning CT to view additional scans.

Additional scan

Planning CT only

Image blend 50%

Planning CTAdditional scan

The blend shows the full available scan. A smaller MRI or PET only covers part of the CT; enlarging the alignment box cannot add scan coverage. Contours stay on the planning CT.

Find anatomy across cases

Anatomy Available reference

Find a structure across all available teaching cases.

Structures

Load a CT to choose a structure.

Structure to load

No structure loaded

Your shaded contour is scored as drawn. Use Close & fill if an outline needs filling.

Structure name

Expert editing changes the teaching reference for everyone. Review all slices before saving.

Pencil

Drawing mode

Smooth curves between points

Click around the boundary to draw a smooth curve. Click the first point or press Enter to close and fill. Backspace removes a point; Escape cancels.

Click the first boundary point on the scan.

Line smoothing

Softens hand jitter while drawing and on release. Small marks and stroke endpoints are preserved; Undo restores the entire stroke.

Adaptive - stay inside the tissue I start on

Tolerance ±150 HU

Close & fill the loop on release

Adaptive samples the density where you start drawing and paints only within ±tolerance of it. With Contiguous on (set in the Brush panel) it also stays inside the connected structure you started in, so a stroke begun in a rib fills that rib and stops at its cortex. Lower the tolerance if it bleeds; raise it if the structure is patchy.

Smart brush — add inside, erase outside

Green adds; red erases. The action stays fixed for each stroke. A blank slice paints normally. Hold Alt to add a separate region, or Shift to erase.

Fill closed brush loops (2D) Brush stroke smoothing

Smooths the path of your brush. Brush size and tissue limits still apply. Hold Shift to erase without smoothing.

2D 3D

Static Adaptive

Diameter 1.0 cm

Tolerance ±150 HU

Contiguous (2D) - confine to the structure I start in Reseed (2D) - re-lock when I move into new tissue

Opacity 0.70

Adaptive off - the brush paints everything under it.

A adaptive/static · 2 2D/3D · Shift erase · [ / ] size.
Tolerance is the density spread the tool accepts around your starting voxel. ±150 HU suits most organs; bone tolerates more, low-contrast soft tissue needs less.

Diameter 1.5 cm

Drag to remove. Holding Shift with the pencil or brush erases too, without switching tool.

Selected: From click

Tolerance ±250 HU

From click grows the region from the density you click, within ±tolerance. The named presets use fixed HU windows instead. The region is connected, so it stops at the structure boundary.

Drag across the image to measure.

Measurements are drawn on the image and listed here. They are display only and never form part of your contour or score.

Click anywhere to sample the density.

Use this to check a structure's density before switching to the adaptive brush - the value you read is what the tolerance is measured against.

Click or drag on any pane to move all three planes to that point.

Drawing is disabled while Navigate is active, so you cannot mark the contour by accident while finding your place.

Pan

Pan mode - drag repositions instead of drawing

Ctrl / Cmd + scroll to zoom · hold Space or right / middle mouse drag to pan · scroll or arrow keys to change slice.

Window / level

Level 40 HU

Width 400 HU

Displaying -160 to 240 HU

Contouring guidance

Load a structure to see anatomy notes, boundary definitions and common pitfalls.

Your result

—

Score / 100

—

Dice (drawn slices)

—

Slice coverage

—

95% Hausdorff

—

Volume vs expert

Score = 85% Dice on drawn slices + 15% reference slice coverage. Dice ranges from 0 (no overlap) to 1 (complete overlap).

Whole-volume Dice: —

Common — you and the expert

Extra — yours only

Missing — expert only

Expert Your contour

Show difference shading

✎

RT Contour

Log in to practise contouring. Your attempts are saved to your account so you can track progress over time.

Need an account? Register in the portal.

RT Contour · Teaching library

More anatomy.
More ways to practise.

Explore the available CT cases and choose a reference structure. Load one case at a time, with your full workspace ready for contouring.

Find a case or organ

Each case identifies its teaching reference. Compare Common, Extra and Missing regions after submission, then follow your scores for the same case and structure over time.