Web Forms :: Adding An Image To Text On A LinkButton?

I am trying to combine text and an image on a LinkButton:

<asp:LinkButton ID="btnTest" runat="server" Text="Book">
<asp:Image ID="imgTest" runat="server" Height="8px" ImageUrl="~/DropDownArrow.png" Width="10px" />
</asp:LinkButton>

So far, this works.

However, if I change the text of the LinkButton in the code-behind, I lose the image.

btnTest.Text = "New book name"

I have tried removing the LinkButton's controls in the code-behind and recreating the image along with changing the text, but it still doesn't work. I get either the image or the text but not both.

btnTest.Controls.Clear()
Dim NewImage As New Image
With NewImage
.Height = Unit.Pixel(8)
.ImageUrl = "~/DropDownArrow.png"
.Width = Unit.Pixel(10)
End With
btnTest.Controls.Add(NewImage)
btnTest.Text = "New book name"

How can I change the text in the code-behind and still retain the image as well?