SPSiteDataQuery remove folders from result

I have a SPSiteDataQuery that returns me all the files but also the folders and I don't want the folders. How can I filter that?

            List<DocumentsRecentsItem> result;

            SPSiteDataQuery query = new SPSiteDataQuery{
                Lists = "<Lists ServerTemplate='101'/>",
                Query = "<OrderBy><FieldRef Name='Created'/></OrderBy>",
                Webs = "<Webs Scope='Recursive' />",
                ViewFields = "<FieldRef Name='Created'/><FieldRef Name='FileRef'/><FieldRef Name='Title' Nullable='TRUE'/><FieldRef Name='LinkFilename' Nullable='TRUE'/>",
                RowLimit = rowLimit
            };

            result = SPContext.Current.Web.GetSiteData(query).Rows.Cast<DataRow>().Select(row => new DocumentsRecentsItem(
                int.Parse(row["ID"] as string),
                (row["Title"] as string != "") ? row["Title"] as string : row["LinkFilename"] as string,
                row["FileRef"].ToString().Split('#')[1] as string
            )).ToList();

            return result;

Thanks