Get file "last saved by" property without changing it

I try to get the properties (owner) of a file with the line of code in PowerShell:

    $file = "\\networkshare\directory\file.doc"
    Get-ItemProperty -Path $file | Format-list -Property * -Force

It is easy to extract the owner, modified date, etc. But I want to extract the "last saved by' and 'revision number':

Update:

The following code seems to work. But every time I run the script it changes the value of "last saved by". How to prevent this and only read the property?

 $word = New-Object -Com Word.Application
$word.Visible = $false #to prevent the document you open to show
$doc = $word.Documents.Open("\\networkshare\directory\file.doc")

$binding = "System.Reflection.BindingFlags" -as [type]
Foreach($property in $doc.BuiltInDocumentProperties) {
   try {
      $pn = [System.__ComObject].invokemember("name",$binding::GetProperty,$null,$property,$null)
      if ($pn -eq "Last author") {
         $lastSaved = [System.__ComObject].invokemember("value",$binding::GetProperty,$null,$property,$null)
         echo "Last saved by: "$lastSaved      
      }        }
   catch { }
}

$doc.Close()
$word.Quit()

This happens because you are saving the document when you call $doc.Close()

Simply call Close with SaveChanges to false:

$doc.Close($false)

Your code (I also added the open in read only mode):

$word = New-Object -Com Word.Application
$word.Visible = $false #to prevent the document you open to show
$doc = $word.Documents.Open("\\networkshare\directory\file.doc", $false, $true) # open in read only mode

$binding = "System.Reflection.BindingFlags" -as [type]
Foreach($property in $doc.BuiltInDocumentProperties) {
   try {
      $pn = [System.__ComObject].invokemember("name",$binding::GetProperty,$null,$property,$null)
      if ($pn -eq "Last author") {
         $lastSaved = [System.__ComObject].invokemember("value",$binding::GetProperty,$null,$property,$null)
         echo "Last saved by: "$lastSaved      
      }        }
   catch { }
}

$doc.Close($false) 
$word.Quit()