如何转储我的用户输入指定的单个dicom标签

Question

I am setting up a DICOM reader that I will be using to process CT scanner configurations. I am writing the application so that I can easily view DICOM either by dumping all tags or I would like to specify which tag I would like to look at. It is a C# console application using the fo-dicom library.

My problem is in my method definition I want to pass an argument in, I want the value of that argument to come from the user. Capture it through the console with a Console.Read().

I am able to dump all tags but can't seem to figure out just dumping the one.

        public static void DumpAllTags(string dicomFile)
        {
            try
            {
                Console.WriteLine($"Attempting to dump all tags from DICOM 
                file:{dicomFile}...");

                var file = DicomFile.Open(dicomFile);
                foreach (var tag in file.Dataset)
                {
                    Console.WriteLine($" {tag} 
                   '{file.Dataset.GetValueOrDefault(tag.Tag, 0, "")}'");
                }
            }
            catch (Exception e)
            {
                Console.WriteLine($"Error occured during DICOM file dump 
                operation -> {e.StackTrace}");
            }
        }

        public static void DumpSingleDicomTag(string dicomFile, string tag)
        {
            try
            {
                Console.WriteLine($"Attempting to dump {tag} from DICOM file: 
                {dicomFile}...");
                var file = DicomFile.Open(dicomFile);
                var dicomDataset = file.Dataset;
                var result = dicomDataset.Get<string>(DicomTag.tag);

                Console.WriteLine(result);


            }
            catch (Exception e)
            {
                Console.WriteLine($"Error occured during DICOM file dump 
                operation -> {e.StackTrace}");
            }
        }

When trying to pass the tag variable that is captured by the keyboard and apply it to the DicomTag method I get an error.

DicomTag does not contain a definition for 'tag'

Answer 1

Your code cannot compile because your variable tag is a string value and not a property of class DicomTag .

Generally spoken: in DICOM a tag is defined by two number: group and element. So if you are doing some kind of configration, then you should not store texts like "Patientname" but the numbers like "0010,0010".

So this code will work:

public static void DumpSingleDicomTag(string dicomFile, string tagNumber)
{
    var dataset = DicomFile.Open(dicomFile).Dataset;
    var tag = Dicom.DicomTag.Parse(tagNumber);
    var result = dataset.GetString(tag);
    Console.Writeline(result);
}

// calling it with
DumpSignleDicomTag(dicomFile, "0010,0010");

If you have some good reasons why you need to store the names of the tags and not the numbers, then you need to iterate the DicomDictionary, which may cost quite some time. There is a class DicomDictionary which holds a list of all defined DicomTags. This list is loadef from a resource file on demand, so when the class is first accessed. You then can iterate this whole list and find the first where the name matches:

using System.Linq;

public static void DumpSingleDicomTag(string dicomFile, string tagName)
{
    var dataset = DicomFile.Open(dicomFile).Dataset;

    var entry = Dicom.DicomDictionary.Default.FirstOrDefault(t => t.Keyword == tagName);
    var result = dataset.GetString(entry.Tag);

    Console.Writeline(result);
}

// calling it with
DumpSignleDicomTag(dicomFile, "PatientName");

But as I said, this code iterates the whole list of tags, which are currently about 4650 entries.

https://github.com/fo-dicom/fo-dicom/issues/942