If your images are stored as resources you can use the following to query their names

Code:
Private Sub Button1_Click( _
    ByVal sender As System.Object, _
    ByVal e As System.EventArgs) _
Handles Button1.Click

    Dim MyProperties As System.Reflection.PropertyInfo() =
        GetType(My.Resources.Resources).GetProperties(System.Reflection.BindingFlags.NonPublic Or
                                                      System.Reflection.BindingFlags.Instance Or
                                                      System.Reflection.BindingFlags.Static)

    Dim BitMaps = (From T In MyProperties Where T.PropertyType Is GetType(Bitmap)).ToList
    For Each bm In BitMaps
        Console.WriteLine(bm.Name)
    Next

End Sub