Calculate MD5 Hash with directory as string?

Imports System.Security.Cryptography
Imports System.Text
Imports System.IO

Public Function MD5FileHash(ByVal sFile As String) As String
    Dim MD5 As New MD5CryptoServiceProvider
    Dim Hash As Byte()
    Dim Result As String = ""
    Dim Tmp As String = ""

    Dim FN As New FileStream(sFile, FileMode.Open, FileAccess.Read, FileShare.Read, 8192)
    MD5.ComputeHash(FN)
    FN.Close()

    Hash = MD5.Hash
    Result = Strings.Replace(BitConverter.ToString(Hash), "-", ""
    Return Result
End Function