As far as i am aware as a 2005 user, it is not possible to load a image directly into the message box function. You could however, create a custom message box, something along the lines of
Button Click
CODE
img = Image.FromFile("c:\Myfile\Images\myimage.bmp")
msgbox(img, msg)
Then try writing a sub named custom message box ... along the lines of
CODE
public sub msgbox(byval img as image, byval msg as string)
Dim frm As New Form
Dim pbx As New PictureBox
Dim lbl Text As New Label
Dim btn As New Button
With frm
.MinimizeBox =
.MaximizeBox =
.Width =
.Height =
.AutoSize =
End With
frm.ShowDialog()
end sub
Obviously the values need filling in, there an example, and use the same With...EndWith for each of the others, pbx, lbl, btn to customise them as needed, just explore the options, there the same as you get using a control you can see

Hope this helps!