WPF Image / Rendering Event

Question

I am using an Image control to display documents:

<Image x:Name="cImage" SnapsToDevicePixels="True" ... />

Because it takes about half a second to display the image on the screen I first display a preview with:

RenderOptions.SetBitmapScalingMode(cImage, BitmapScalingMode.NearestNeighbor);
cImage.Source=...;

Then I set a timer to change the mode to HighQuality.

Is there an event that WPF fires when it has finished rendering that I could use instead of the timer?