Powershell, DataTable, ExecuteReader, zero rows returned by a query

I use the following PowerShell function to run an arbitrary SQL query against an SQL Server instance, then return whatever data is there:

Function ExecSQLReader([string] $sqlText) {
    $cn = New-Object System.Data.SqlClient.SqlConnection
    $cn.ConnectionString = "Data Source={0};Initial Catalog={1};Integrated Security=SSPI;" -f $fc.server,$fc.database
    $cn.Open()
    $cmd = $cn.CreateCommand()
    $cmd.CommandText = $sqlText
    $cmd.CommandTimeout = 60
    $resTable = New-Object("System.Data.DataTable")
    try {
        $result = $cmd.ExecuteReader()
        $resTable.Load($result)
        $result.Close()
        $cn.Close()
    } catch {
        "=======ERROR in ExecSQLReader========" | DoLog
        "Message: {0}" -f $_.Exception.Message | DoLog
        "SQL: {0}" -f $sqlText | DoLog
       "=======/ERROR in ExecSQLReader=======" | DoLog
    }
    return($resTable)
}

The function works fine when there is data returned by the query.

However, the function does not return any column-related info when there is no data returned by the query.

I need to know column names / types / order etc even if there is no data rows.

I can see that the returned value is different based on resulting record count (which makes things even more complicated):

• an empty result for 0 records
• a [DataRow] object for a single record
• a Collection of [DataRow] objects for more than 1 record

So, the question is: how to make sure that the returned object is always of a "System.Data.DataTable" type?

Or, at least, how to make sure that columns-related information (names, types, order) is always available in function results, regardless of the number of rows returned by the query?

Any hints?