diff --git a/DicomGrep/MainWindow.xaml b/DicomGrep/MainWindow.xaml
index 650e000..535293e 100644
--- a/DicomGrep/MainWindow.xaml
+++ b/DicomGrep/MainWindow.xaml
@@ -7,11 +7,21 @@
         xmlns:vm="clr-namespace:DicomGrep.ViewModels"
         xmlns:enums="clr-namespace:DicomGrep.Enums"
         xmlns:i="http://schemas.microsoft.com/xaml/behaviors"
+        xmlns:coreEnum="clr-namespace:DicomGrepCore.Enums;assembly=DicomGrepCore"
         mc:Ignorable="d"
         Title="{Binding Version, StringFormat='Dicom Grep v{0}'}" Height="640" Width="960" MinWidth="300" MinHeight="200">
     <Window.DataContext>
         <vm:MainViewModel/>
     </Window.DataContext>
+    <Window.Resources>
+        <ObjectDataProvider x:Key="MatchPatternEnumSource"
+                            ObjectType="{x:Type coreEnum:MatchPatternEnum}"
+                            MethodName="GetValues">
+            <ObjectDataProvider.MethodParameters>
+                <x:Type TypeName="coreEnum:MatchPatternEnum" />
+            </ObjectDataProvider.MethodParameters>
+        </ObjectDataProvider>
+    </Window.Resources>
     <Grid>
         <Grid.RowDefinitions>
             <RowDefinition Height="Auto" MinHeight="16"/>
@@ -95,6 +105,7 @@
                     <StackPanel Margin="8,0,0,0">
                         <CheckBox Content="Case sensitive" IsChecked="{Binding CaseSensitive}"/>
                         <CheckBox Content="Whole word" IsChecked="{Binding WholeWord}"/>
+                        <ComboBox ItemsSource="{Binding Source={StaticResource MatchPatternEnumSource}}" SelectedItem="{Binding MatchPattern}"/>
                         <CheckBox Content="Include subfolders" IsChecked="{Binding IncludeSubfolders}"/>
                         <StackPanel Orientation="Horizontal">
                             <Label Content="Treads: "/>
diff --git a/DicomGrep/Services/ConfigurationService.cs b/DicomGrep/Services/ConfigurationService.cs
index 0dccf92..2c6f910 100644
--- a/DicomGrep/Services/ConfigurationService.cs
+++ b/DicomGrep/Services/ConfigurationService.cs
@@ -6,6 +6,7 @@
 using System.Text;
 using System.Text.Json;
 using DicomGrepCore.Entities;
+using DicomGrepCore.Enums;
 
 namespace DicomGrep.Services
 {
@@ -84,6 +85,7 @@ private static Configuration DefaultConfiguration()
                 SearchTag = "",
                 SearchText = "TREATMENT",
                 IncludeSubfolders = true,
+                MatchPattern = MatchPatternEnum.Normal,
                 SearchInResults = false,
                 SearchThreads = 1
             };
diff --git a/DicomGrep/ViewModels/MainViewModel.cs b/DicomGrep/ViewModels/MainViewModel.cs
index 9b32124..d18c565 100644
--- a/DicomGrep/ViewModels/MainViewModel.cs
+++ b/DicomGrep/ViewModels/MainViewModel.cs
@@ -17,6 +17,7 @@
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Input;
+using DicomGrepCore.Enums;
 
 namespace DicomGrep.ViewModels
 {
@@ -107,6 +108,14 @@ public bool WholeWord
             set { SetProperty(ref _wholeWord, value); }
         }
 
+        private MatchPatternEnum _matchPattern;
+
+        public MatchPatternEnum MatchPattern
+        {
+            get { return _matchPattern; }
+            set { SetProperty(ref _matchPattern, value); }
+        }
+
         private bool _includeSubfolders;
         public bool IncludeSubfolders
         {
@@ -227,7 +236,7 @@ public ICommand SopClassLookupCommand
         {
             get
             {
-                return _sopClassLookupCommand ?? (_sopClassLookupCommand = new RelayCommand<object>(_=> DoSopClassLookup()));
+                return _sopClassLookupCommand ?? (_sopClassLookupCommand = new RelayCommand<object>(_ => DoSopClassLookup()));
             }
         }
 
@@ -236,7 +245,7 @@ public ICommand DicomDictionaryLookupCommand
         {
             get
             {
-                return _dicomDictionaryLookupCommand ?? (_dicomDictionaryLookupCommand = new RelayCommand<object>(_=> DoDicomDictionaryLookup()));
+                return _dicomDictionaryLookupCommand ?? (_dicomDictionaryLookupCommand = new RelayCommand<object>(_ => DoDicomDictionaryLookup()));
             }
         }
 
@@ -254,7 +263,7 @@ public ICommand ExportCommand
         {
             get
             {
-                return _exportCommand ?? (_exportCommand = new RelayCommand<object>(_=> DoExport()));
+                return _exportCommand ?? (_exportCommand = new RelayCommand<object>(_ => DoExport()));
             }
         }
 
@@ -285,7 +294,7 @@ public MainViewModel()
             // dummy data for designer preview
             if (DesignerProperties.GetIsInDesignMode(new DependencyObject()))
             {
-                for (int i=1; i<=5; i++)
+                for (int i = 1; i <= 5; i++)
                 {
                     ResultDicomItem resultDicomItem1 = new ResultDicomItem(new DicomTag(0x0010, 0x0020), "John Doe", new byte[0]);
                     ResultDicomItem resultDicomItem2 = new ResultDicomItem(new DicomTag(0x0123, 0x99, "DicomGrep Creator"), "C533", new byte[0]);
@@ -320,6 +329,7 @@ public MainViewModel()
             SearchText = CurrentConfiguration.SearchCriteria.SearchText;
             CaseSensitive = CurrentConfiguration.SearchCriteria.CaseSensitive;
             WholeWord = CurrentConfiguration.SearchCriteria.WholeWord;
+            MatchPattern = CurrentConfiguration.SearchCriteria.MatchPattern;
             IncludeSubfolders = CurrentConfiguration.SearchCriteria.IncludeSubfolders;
             //SearchInResults = CurrentConfiguration.SearchCriteria.SearchInResults;
             SearchThreads = Math.Min(CurrentConfiguration.SearchCriteria.SearchThreads, Environment.ProcessorCount);
@@ -388,6 +398,7 @@ private void DoSearch(bool searchInResults = false)
                 SearchText = SearchText,
                 CaseSensitive = CaseSensitive,
                 WholeWord = WholeWord,
+                MatchPattern = MatchPattern,
                 IncludeSubfolders = IncludeSubfolders,
                 SearchInResults = searchInResults,  // from parameter
                 SearchThreads = SearchThreads
diff --git a/DicomGrepCore/Entities/SearchCriteria.cs b/DicomGrepCore/Entities/SearchCriteria.cs
index 5440ab4..bb831ac 100644
--- a/DicomGrepCore/Entities/SearchCriteria.cs
+++ b/DicomGrepCore/Entities/SearchCriteria.cs
@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using System.Text;
 using System.Text.Json.Serialization;
+using DicomGrepCore.Enums;
 
 namespace DicomGrepCore.Entities
 {
@@ -41,6 +42,7 @@ public string SearchTag
         public bool CaseSensitive { get; set; }
         public bool WholeWord { get; set; }
         public bool IncludeSubfolders { get; set; }
+        public MatchPatternEnum MatchPattern { get; set; }
 
         [JsonIgnore]
         public bool SearchInResults { get; set; }
diff --git a/DicomGrepCore/Enums/MatchPatternEnum.cs b/DicomGrepCore/Enums/MatchPatternEnum.cs
new file mode 100644
index 0000000..3ff15f1
--- /dev/null
+++ b/DicomGrepCore/Enums/MatchPatternEnum.cs
@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace DicomGrepCore.Enums
+{
+    public enum MatchPatternEnum
+    {
+        Normal,
+        Regex
+    }
+}
diff --git a/DicomGrepCore/Services/SearchService.cs b/DicomGrepCore/Services/SearchService.cs
index a543e10..26886d3 100644
--- a/DicomGrepCore/Services/SearchService.cs
+++ b/DicomGrepCore/Services/SearchService.cs
@@ -6,8 +6,10 @@
 using System.IO;
 using System.Linq;
 using System.Text;
+using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
+using DicomGrepCore.Enums;
 using FellowOakDicom;
 
 namespace DicomGrepCore.Services
@@ -48,7 +50,7 @@ public void Search(SearchCriteria criteria, CancellationTokenSource tokenSource)
             this.token = tokenSource.Token;
 
             searchedFileCount = 0;
-            
+
 
             if (criteria.SearchInResults)
             {
@@ -67,7 +69,7 @@ public void Search(SearchCriteria criteria, CancellationTokenSource tokenSource)
             matchFilenameList.Clear();
             matchFileCount = 0;
 
-            ParallelOptions options = new ParallelOptions 
+            ParallelOptions options = new ParallelOptions
             {
                 MaxDegreeOfParallelism = criteria.SearchThreads,
                 CancellationToken = this.token
@@ -147,7 +149,7 @@ private void SearchInDicomFile(string filePath)
                 OnLoadDicomFile?.Invoke(this, new OnLoadDicomFileEventArgs(filePath));
 
                 DicomFile dicomFile = DicomFile.Open(filePath, FileReadOption.ReadLargeOnDemand, 16 * 1024);
-                
+
                 IList<ResultDicomItem> resultDicomItems = null;
                 //new DicomDatasetWalker(dicomFile.Dataset).Walk(new DatasetWalker());
 
@@ -216,7 +218,7 @@ private IList<ResultDicomItem> CompareDicomTagAndValue(DicomDataset dataset, ref
                 else
                 {
                     // check the tag first
-                    if ( string.IsNullOrWhiteSpace(criteria.SearchTag) ||
+                    if (string.IsNullOrWhiteSpace(criteria.SearchTag) ||
                          CompareDicomTag(dicomItem.Tag, criteria.DicomSearchTag))
                     {
                         // skip binary VRs
@@ -245,8 +247,8 @@ private IList<ResultDicomItem> CompareDicomTagAndValue(DicomDataset dataset, ref
                                         valueString = Encoding.ASCII.GetString(bytes);
                                     }
                                 }
-                                
-                                if ( string.IsNullOrWhiteSpace(criteria.SearchText) || CompareString(valueString, criteria, false))
+
+                                if (string.IsNullOrWhiteSpace(criteria.SearchText) || CompareString(valueString, criteria, false))
                                 {
                                     //handle match
                                     if (resultDicomItems == null)
@@ -257,7 +259,7 @@ private IList<ResultDicomItem> CompareDicomTagAndValue(DicomDataset dataset, ref
                                     resultDicomItems.Add(new ResultDicomItem(element.Tag, valueString, rawValue));
 
                                     //Console.WriteLine($"match value: {dicomItem.ToString()}, {valueString}");
-                                    
+
                                 }
                             }
 
@@ -286,35 +288,60 @@ private bool CompareDicomTag(DicomTag dicomTag, DicomTag criteriaDicomTag)
             return criteriaDicomTag.Equals(dicomTag);
         }
 
-        private bool CompareString(string refString, SearchCriteria criteria, bool isDicomTag)
+        private bool CompareString(string refString, SearchCriteria _criteria, bool isDicomTag)
         {
             if (string.IsNullOrEmpty(refString))
             {
                 return false;
             }
 
-            return CompareString(refString, criteria.SearchText, criteria.CaseSensitive, criteria.WholeWord);
+            return CompareString(refString, _criteria.SearchText, _criteria.CaseSensitive, _criteria.WholeWord);
 
         }
 
         private bool CompareString(string refString, string testString, bool caseSensitive, bool wholeWord)
         {
-            if (wholeWord)
+            bool result = false;
+            switch (criteria.MatchPattern)
             {
-                if (caseSensitive)
-                    return refString.Equals(testString, StringComparison.InvariantCulture);
-                else
-                    return refString.Equals(testString, StringComparison.InvariantCultureIgnoreCase);
-            }
-            else
-            {
-                if (caseSensitive)
-                    return refString.CaseInsensitiveContains(testString, StringComparison.InvariantCulture);
-                else
-                    return refString.CaseInsensitiveContains(testString, StringComparison.InvariantCultureIgnoreCase);
+                default:
+                case MatchPatternEnum.Normal:
+                    if (wholeWord)
+                    {
+                        result = refString.Equals(testString, caseSensitive ? StringComparison.InvariantCulture : StringComparison.InvariantCultureIgnoreCase);
+                    }
+                    else
+                    {
+                        result = refString.CaseInsensitiveContains(testString, caseSensitive ? StringComparison.InvariantCulture : StringComparison.InvariantCultureIgnoreCase);
+                    }
+                    break;
+                case MatchPatternEnum.Regex:
+                    RegexOptions options = RegexOptions.Compiled;
+                    if (!caseSensitive)
+                    {
+                        options |= RegexOptions.IgnoreCase;
+                    }
+
+                    if (wholeWord)
+                    {
+                        // regex match start
+                        if (!testString.StartsWith('^'))
+                        {
+                            testString = "^" + testString;
+                        }
+
+                        // regex match end
+                        if (!testString.EndsWith('$'))
+                        {
+                            testString += "$";
+                        }
+                    }
+
+                    result = Regex.IsMatch(refString, testString, options);
+                    break;
             }
+            return result;
         }
 
-
     }
 }