If inside query

Hi, I have a query that I have to return Title only if it exists, if it doens't exist I have to get LinkFilename. How do I do that pls?

            result = SPContext.Current.Web.GetSiteData(query).Rows.Cast<DataRow>().Select(row => new DocumentsRecentsItem(
                int.Parse(row["ID"] as string),
                row["Title"] as string,   >>>>>>>>>>>> HERE IF "TITLE" IS EMPTY IT TAKES "LINKFILENAME"
                row["FileRef"] as string
            )).ToList();