Dose overlay

Show an RT Dose as a colour wash and isodose lines over the CT or MR in 3D MPR.

Browser: available nowmacOS app: 1.4.0 or newer

When the loaded study holds an RT Dose, 3D MPR shows a Dose overlay bar under the series header.

• Dose overlay picks the RT Dose to show. None removes it.
• Opacity sets how strongly the colours cover the images, from 0% to 100%.
• The colour scale runs from blue to red. The number on the left is the lowest dose that gets colour, the number on the right is the maximum dose, both in the RT Dose’s own unit (Gy, or relative).
• Isodose lines draws lines at 95%, 80%, 50% and 20% of the maximum dose on each plane. Each line has the colour the wash gives that dose, and the legend next to the box lists each level in percent and in Gy. The lines are on by default. Clear the box to hide them. They do not depend on the opacity, so you can set the opacity to 0% and keep only the lines.

The lines are worked out from the dose on the plane you are looking at. They move with the plane when you scroll, rotate it with the crosshair handles, or change the slab projection.

The dose values are the stored values multiplied by Dose Grid Scaling (3004,000E). Doses below 10% of the maximum get no colour, so the low-dose spread does not hide the anatomy.

The dose is shown only when the RT Dose and the image series share one Frame of Reference UID (0020,0052). Otherwise the bar shows why it was refused and draws nothing: dcmage does not register one series to another, so a dose from a different frame of reference would land in the wrong place. Each refusal is written to the audit log.

The overlay goes away when you leave MPR or pick another series in the series header. The colour wash and the lines are shown on screen only and are never written into a DICOM file. Export Frame Image and Print copy the colour wash, but not the isodose lines.