AesManaged.IV Property

using (Aes aes = new AesManaged())
{
    Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes(decryptPassWordBox.Password, Encoding.UTF8.GetBytes(PasswordSalt));
    aes.Key = deriveBytes.GetBytes(128 / 8);
    // Get the initialization vector from the encrypted stream
    aes.IV = ReadByteArray(isoStoreStream);
    CryptoStream cs = new CryptoStream(isoStoreStream, aes.CreateDecryptor(), CryptoStreamMode.Read);
    StreamReader reader = new StreamReader(cs, Encoding.Unicode);
    try
    {
        string retval = reader.ReadToEnd();
        reader.Dispose();
        cs.Dispose();
        return retval;
    }
    catch (Exception e)
    {
        return e.ToString();
    }

}