Compreender o conteúdo do arquivo DICOM é essencial para o desenvolvimento da imagem médica, resolução de problemas e garantia de qualidade. Este tutorial mostra-lhe como construir um visualizador de metadados de DIKOM abrangente em C# que extrai e exibe informações do paciente, detalhes de estudo e parâmetros técnicos de imagem.

O que é o DICOM Metadata?

Os arquivos DICOM contêm dois componentes principais: dados de pixel (a imagem real) e metadados (informação sobre a imagem).

  • ** Demografia do paciente**: Nome, ID, data de nascimento, sexo
  • Informação de estudo: data, hora, descrição, referência médico
  • ** Detalhes da série**: Modalidade, parte do corpo, protocolo de imagem
  • Parâmetros de imagem: Dimensões, espaço de pixel, configurações de janela/nivel
  • Informação de equipamento: fabricante, modelo, versão de software

Um visualizador de metadados ajuda os desenvolvedores a inspecionar esses atributos para debugging, validação e análise de dados.

Extracção de metadados básicos

Comece com a extração de atributos DICOM comuns:

using Aspose.Medical.Dicom;

public class DicomMetadataViewer
{
    public DicomMetadata ExtractMetadata(string filePath)
    {
        DicomFile dicomFile = DicomFile.Open(filePath);
        var dataset = dicomFile.Dataset;
        
        return new DicomMetadata
        {
            // Patient Information
            PatientName = dataset.GetString(DicomTag.PatientName),
            PatientID = dataset.GetString(DicomTag.PatientID),
            PatientBirthDate = dataset.GetString(DicomTag.PatientBirthDate),
            PatientSex = dataset.GetString(DicomTag.PatientSex),
            PatientAge = dataset.GetString(DicomTag.PatientAge),
            
            // Study Information
            StudyInstanceUID = dataset.GetString(DicomTag.StudyInstanceUID),
            StudyDate = dataset.GetString(DicomTag.StudyDate),
            StudyTime = dataset.GetString(DicomTag.StudyTime),
            StudyDescription = dataset.GetString(DicomTag.StudyDescription),
            AccessionNumber = dataset.GetString(DicomTag.AccessionNumber),
            ReferringPhysician = dataset.GetString(DicomTag.ReferringPhysicianName),
            
            // Series Information
            SeriesInstanceUID = dataset.GetString(DicomTag.SeriesInstanceUID),
            Modality = dataset.GetString(DicomTag.Modality),
            SeriesDescription = dataset.GetString(DicomTag.SeriesDescription),
            SeriesNumber = dataset.GetString(DicomTag.SeriesNumber),
            BodyPartExamined = dataset.GetString(DicomTag.BodyPartExamined),
            
            // Image Information
            SOPInstanceUID = dataset.GetString(DicomTag.SOPInstanceUID),
            SOPClassUID = dataset.GetString(DicomTag.SOPClassUID),
            InstanceNumber = dataset.GetString(DicomTag.InstanceNumber),
            ImageType = dataset.GetString(DicomTag.ImageType),
            
            // Technical Parameters
            Rows = dataset.GetString(DicomTag.Rows),
            Columns = dataset.GetString(DicomTag.Columns),
            BitsAllocated = dataset.GetString(DicomTag.BitsAllocated),
            BitsStored = dataset.GetString(DicomTag.BitsStored),
            PixelSpacing = dataset.GetString(DicomTag.PixelSpacing),
            SliceThickness = dataset.GetString(DicomTag.SliceThickness),
            
            // Equipment Information
            Manufacturer = dataset.GetString(DicomTag.Manufacturer),
            ManufacturerModelName = dataset.GetString(DicomTag.ManufacturerModelName),
            StationName = dataset.GetString(DicomTag.StationName),
            InstitutionName = dataset.GetString(DicomTag.InstitutionName),
            SoftwareVersions = dataset.GetString(DicomTag.SoftwareVersions)
        };
    }
}

public class DicomMetadata
{
    // Patient
    public string PatientName { get; set; }
    public string PatientID { get; set; }
    public string PatientBirthDate { get; set; }
    public string PatientSex { get; set; }
    public string PatientAge { get; set; }
    
    // Study
    public string StudyInstanceUID { get; set; }
    public string StudyDate { get; set; }
    public string StudyTime { get; set; }
    public string StudyDescription { get; set; }
    public string AccessionNumber { get; set; }
    public string ReferringPhysician { get; set; }
    
    // Series
    public string SeriesInstanceUID { get; set; }
    public string Modality { get; set; }
    public string SeriesDescription { get; set; }
    public string SeriesNumber { get; set; }
    public string BodyPartExamined { get; set; }
    
    // Image
    public string SOPInstanceUID { get; set; }
    public string SOPClassUID { get; set; }
    public string InstanceNumber { get; set; }
    public string ImageType { get; set; }
    
    // Technical
    public string Rows { get; set; }
    public string Columns { get; set; }
    public string BitsAllocated { get; set; }
    public string BitsStored { get; set; }
    public string PixelSpacing { get; set; }
    public string SliceThickness { get; set; }
    
    // Equipment
    public string Manufacturer { get; set; }
    public string ManufacturerModelName { get; set; }
    public string StationName { get; set; }
    public string InstitutionName { get; set; }
    public string SoftwareVersions { get; set; }
}

Browsing Todos os tags

Lista todas as tags em um arquivo DICOM para uma inspeção completa:

public class DicomTagBrowser
{
    public List<DicomTagInfo> GetAllTags(string filePath)
    {
        DicomFile dicomFile = DicomFile.Open(filePath);
        var tags = new List<DicomTagInfo>();
        
        foreach (var element in dicomFile.Dataset)
        {
            var tagInfo = new DicomTagInfo
            {
                Tag = element.Tag.ToString(),
                TagHex = $"({element.Tag.Group:X4},{element.Tag.Element:X4})",
                Keyword = element.Tag.DictionaryEntry?.Keyword ?? "Unknown",
                Name = element.Tag.DictionaryEntry?.Name ?? "Private Tag",
                VR = element.ValueRepresentation.Code,
                Length = element.Length,
                Value = GetDisplayValue(element)
            };
            
            tags.Add(tagInfo);
        }
        
        return tags;
    }

    private string GetDisplayValue(DicomElement element)
    {
        try
        {
            // Handle different value representations
            if (element.Length == 0)
                return "(empty)";
            
            if (element.Length > 256)
                return $"(binary data, {element.Length} bytes)";
            
            // Try to get string value
            var values = element.Get<string[]>();
            if (values != null && values.Length > 0)
            {
                return string.Join(" \\ ", values);
            }
            
            return "(unable to display)";
        }
        catch
        {
            return $"(binary data, {element.Length} bytes)";
        }
    }
}

public class DicomTagInfo
{
    public string Tag { get; set; }
    public string TagHex { get; set; }
    public string Keyword { get; set; }
    public string Name { get; set; }
    public string VR { get; set; }
    public long Length { get; set; }
    public string Value { get; set; }
}

Extracção de Metadados Específicos

Diferentes modalidades de imagem têm atributos únicos:

public class ModalityMetadataExtractor
{
    public object ExtractModalitySpecificData(string filePath)
    {
        DicomFile dicomFile = DicomFile.Open(filePath);
        var dataset = dicomFile.Dataset;
        
        string modality = dataset.GetString(DicomTag.Modality);
        
        return modality switch
        {
            "CT" => ExtractCtMetadata(dataset),
            "MR" => ExtractMrMetadata(dataset),
            "CR" or "DX" => ExtractRadiographyMetadata(dataset),
            "US" => ExtractUltrasoundMetadata(dataset),
            "MG" => ExtractMammographyMetadata(dataset),
            _ => ExtractGenericMetadata(dataset)
        };
    }

    private CtMetadata ExtractCtMetadata(DicomDataset dataset)
    {
        return new CtMetadata
        {
            KVP = dataset.GetString(DicomTag.KVP),
            XRayTubeCurrent = dataset.GetString(DicomTag.XRayTubeCurrent),
            ExposureTime = dataset.GetString(DicomTag.ExposureTime),
            SliceThickness = dataset.GetString(DicomTag.SliceThickness),
            SpacingBetweenSlices = dataset.GetString(DicomTag.SpacingBetweenSlices),
            ConvolutionKernel = dataset.GetString(DicomTag.ConvolutionKernel),
            GantryTilt = dataset.GetString(DicomTag.GantryDetectorTilt),
            TableHeight = dataset.GetString(DicomTag.TableHeight),
            RotationDirection = dataset.GetString(DicomTag.RotationDirection),
            CTDIvol = dataset.GetString(DicomTag.CTDIvol),
            WindowCenter = dataset.GetString(DicomTag.WindowCenter),
            WindowWidth = dataset.GetString(DicomTag.WindowWidth)
        };
    }

    private MrMetadata ExtractMrMetadata(DicomDataset dataset)
    {
        return new MrMetadata
        {
            MagneticFieldStrength = dataset.GetString(DicomTag.MagneticFieldStrength),
            SequenceName = dataset.GetString(DicomTag.SequenceName),
            ScanningSequence = dataset.GetString(DicomTag.ScanningSequence),
            SequenceVariant = dataset.GetString(DicomTag.SequenceVariant),
            RepetitionTime = dataset.GetString(DicomTag.RepetitionTime),
            EchoTime = dataset.GetString(DicomTag.EchoTime),
            InversionTime = dataset.GetString(DicomTag.InversionTime),
            FlipAngle = dataset.GetString(DicomTag.FlipAngle),
            SliceThickness = dataset.GetString(DicomTag.SliceThickness),
            EchoTrainLength = dataset.GetString(DicomTag.EchoTrainLength),
            PixelBandwidth = dataset.GetString(DicomTag.PixelBandwidth),
            ImagingFrequency = dataset.GetString(DicomTag.ImagingFrequency)
        };
    }

    private RadiographyMetadata ExtractRadiographyMetadata(DicomDataset dataset)
    {
        return new RadiographyMetadata
        {
            KVP = dataset.GetString(DicomTag.KVP),
            ExposureTime = dataset.GetString(DicomTag.ExposureTime),
            XRayTubeCurrent = dataset.GetString(DicomTag.XRayTubeCurrent),
            Exposure = dataset.GetString(DicomTag.Exposure),
            ExposureIndex = dataset.GetString(DicomTag.ExposureIndex),
            TargetExposureIndex = dataset.GetString(DicomTag.TargetExposureIndex),
            DeviationIndex = dataset.GetString(DicomTag.DeviationIndex),
            DistanceSourceToDetector = dataset.GetString(DicomTag.DistanceSourceToDetector),
            DistanceSourceToPatient = dataset.GetString(DicomTag.DistanceSourceToPatient),
            Grid = dataset.GetString(DicomTag.Grid),
            ViewPosition = dataset.GetString(DicomTag.ViewPosition)
        };
    }

    private UltrasoundMetadata ExtractUltrasoundMetadata(DicomDataset dataset)
    {
        return new UltrasoundMetadata
        {
            TransducerType = dataset.GetString(DicomTag.TransducerType),
            TransducerFrequency = dataset.GetString(DicomTag.TransducerFrequency),
            DepthOfScanField = dataset.GetString(DicomTag.DepthOfScanField),
            MechanicalIndex = dataset.GetString(DicomTag.MechanicalIndex),
            ThermalIndex = dataset.GetString(DicomTag.SoftTissueThermalIndex),
            FrameTime = dataset.GetString(DicomTag.FrameTime),
            NumberOfFrames = dataset.GetString(DicomTag.NumberOfFrames)
        };
    }

    private MammographyMetadata ExtractMammographyMetadata(DicomDataset dataset)
    {
        return new MammographyMetadata
        {
            ViewPosition = dataset.GetString(DicomTag.ViewPosition),
            ImageLaterality = dataset.GetString(DicomTag.ImageLaterality),
            BreastImplantPresent = dataset.GetString(DicomTag.BreastImplantPresent),
            CompressionForce = dataset.GetString(DicomTag.CompressionForce),
            BodyPartThickness = dataset.GetString(DicomTag.BodyPartThickness),
            AnodeTargetMaterial = dataset.GetString(DicomTag.AnodeTargetMaterial),
            FilterMaterial = dataset.GetString(DicomTag.FilterMaterial),
            KVP = dataset.GetString(DicomTag.KVP),
            ExposureTime = dataset.GetString(DicomTag.ExposureTime),
            OrganDose = dataset.GetString(DicomTag.OrganDose)
        };
    }

    private GenericMetadata ExtractGenericMetadata(DicomDataset dataset)
    {
        return new GenericMetadata
        {
            Modality = dataset.GetString(DicomTag.Modality),
            StudyDescription = dataset.GetString(DicomTag.StudyDescription),
            SeriesDescription = dataset.GetString(DicomTag.SeriesDescription)
        };
    }
}

// Modality-specific metadata classes
public class CtMetadata
{
    public string KVP { get; set; }
    public string XRayTubeCurrent { get; set; }
    public string ExposureTime { get; set; }
    public string SliceThickness { get; set; }
    public string SpacingBetweenSlices { get; set; }
    public string ConvolutionKernel { get; set; }
    public string GantryTilt { get; set; }
    public string TableHeight { get; set; }
    public string RotationDirection { get; set; }
    public string CTDIvol { get; set; }
    public string WindowCenter { get; set; }
    public string WindowWidth { get; set; }
}

public class MrMetadata
{
    public string MagneticFieldStrength { get; set; }
    public string SequenceName { get; set; }
    public string ScanningSequence { get; set; }
    public string SequenceVariant { get; set; }
    public string RepetitionTime { get; set; }
    public string EchoTime { get; set; }
    public string InversionTime { get; set; }
    public string FlipAngle { get; set; }
    public string SliceThickness { get; set; }
    public string EchoTrainLength { get; set; }
    public string PixelBandwidth { get; set; }
    public string ImagingFrequency { get; set; }
}

public class RadiographyMetadata
{
    public string KVP { get; set; }
    public string ExposureTime { get; set; }
    public string XRayTubeCurrent { get; set; }
    public string Exposure { get; set; }
    public string ExposureIndex { get; set; }
    public string TargetExposureIndex { get; set; }
    public string DeviationIndex { get; set; }
    public string DistanceSourceToDetector { get; set; }
    public string DistanceSourceToPatient { get; set; }
    public string Grid { get; set; }
    public string ViewPosition { get; set; }
}

public class UltrasoundMetadata
{
    public string TransducerType { get; set; }
    public string TransducerFrequency { get; set; }
    public string DepthOfScanField { get; set; }
    public string MechanicalIndex { get; set; }
    public string ThermalIndex { get; set; }
    public string FrameTime { get; set; }
    public string NumberOfFrames { get; set; }
}

public class MammographyMetadata
{
    public string ViewPosition { get; set; }
    public string ImageLaterality { get; set; }
    public string BreastImplantPresent { get; set; }
    public string CompressionForce { get; set; }
    public string BodyPartThickness { get; set; }
    public string AnodeTargetMaterial { get; set; }
    public string FilterMaterial { get; set; }
    public string KVP { get; set; }
    public string ExposureTime { get; set; }
    public string OrganDose { get; set; }
}

public class GenericMetadata
{
    public string Modality { get; set; }
    public string StudyDescription { get; set; }
    public string SeriesDescription { get; set; }
}

Aplicação baseada em Console Viewer

Crie uma ferramenta de linha de comando para inspecção rápida DICOM:

public class DicomViewerConsole
{
    public void DisplayMetadata(string filePath)
    {
        var viewer = new DicomMetadataViewer();
        var metadata = viewer.ExtractMetadata(filePath);
        
        Console.WriteLine("═══════════════════════════════════════════════════════════");
        Console.WriteLine("                    DICOM METADATA VIEWER                    ");
        Console.WriteLine("═══════════════════════════════════════════════════════════");
        Console.WriteLine($"File: {Path.GetFileName(filePath)}");
        Console.WriteLine();
        
        PrintSection("PATIENT INFORMATION");
        PrintField("Patient Name", metadata.PatientName);
        PrintField("Patient ID", metadata.PatientID);
        PrintField("Birth Date", FormatDate(metadata.PatientBirthDate));
        PrintField("Sex", metadata.PatientSex);
        PrintField("Age", metadata.PatientAge);
        
        PrintSection("STUDY INFORMATION");
        PrintField("Study Date", FormatDate(metadata.StudyDate));
        PrintField("Study Time", FormatTime(metadata.StudyTime));
        PrintField("Description", metadata.StudyDescription);
        PrintField("Accession #", metadata.AccessionNumber);
        PrintField("Referring MD", metadata.ReferringPhysician);
        PrintField("Study UID", metadata.StudyInstanceUID);
        
        PrintSection("SERIES INFORMATION");
        PrintField("Modality", metadata.Modality);
        PrintField("Description", metadata.SeriesDescription);
        PrintField("Series #", metadata.SeriesNumber);
        PrintField("Body Part", metadata.BodyPartExamined);
        PrintField("Series UID", metadata.SeriesInstanceUID);
        
        PrintSection("IMAGE INFORMATION");
        PrintField("Instance #", metadata.InstanceNumber);
        PrintField("Image Type", metadata.ImageType);
        PrintField("Dimensions", $"{metadata.Columns} x {metadata.Rows}");
        PrintField("Bits Stored", metadata.BitsStored);
        PrintField("Pixel Spacing", metadata.PixelSpacing);
        PrintField("SOP Instance", metadata.SOPInstanceUID);
        
        PrintSection("EQUIPMENT");
        PrintField("Manufacturer", metadata.Manufacturer);
        PrintField("Model", metadata.ManufacturerModelName);
        PrintField("Station", metadata.StationName);
        PrintField("Institution", metadata.InstitutionName);
        PrintField("Software", metadata.SoftwareVersions);
        
        Console.WriteLine("═══════════════════════════════════════════════════════════");
    }

    private void PrintSection(string title)
    {
        Console.WriteLine();
        Console.WriteLine($"─── {title} ───");
    }

    private void PrintField(string label, string value)
    {
        string displayValue = string.IsNullOrEmpty(value) ? "(not specified)" : value;
        Console.WriteLine($"  {label,-15}: {displayValue}");
    }

    private string FormatDate(string dicomDate)
    {
        if (string.IsNullOrEmpty(dicomDate) || dicomDate.Length != 8)
            return dicomDate;
        
        return $"{dicomDate.Substring(0, 4)}-{dicomDate.Substring(4, 2)}-{dicomDate.Substring(6, 2)}";
    }

    private string FormatTime(string dicomTime)
    {
        if (string.IsNullOrEmpty(dicomTime) || dicomTime.Length < 6)
            return dicomTime;
        
        return $"{dicomTime.Substring(0, 2)}:{dicomTime.Substring(2, 2)}:{dicomTime.Substring(4, 2)}";
    }
}

Web API para Metadata Retrieval

Construir pontos finais REST para o acesso a metadados:

[ApiController]
[Route("api/[controller]")]
public class DicomMetadataController : ControllerBase
{
    private readonly string _uploadPath = Path.Combine(Path.GetTempPath(), "dicom_uploads");

    public DicomMetadataController()
    {
        Directory.CreateDirectory(_uploadPath);
    }

    [HttpPost("upload")]
    public async Task<IActionResult> UploadAndExtract(IFormFile file)
    {
        if (file == null || file.Length == 0)
            return BadRequest("No file provided");

        var filePath = Path.Combine(_uploadPath, $"{Guid.NewGuid()}.dcm");
        
        try
        {
            using (var stream = new FileStream(filePath, FileMode.Create))
            {
                await file.CopyToAsync(stream);
            }

            var viewer = new DicomMetadataViewer();
            var metadata = viewer.ExtractMetadata(filePath);
            
            return Ok(metadata);
        }
        finally
        {
            if (System.IO.File.Exists(filePath))
                System.IO.File.Delete(filePath);
        }
    }

    [HttpPost("tags")]
    public async Task<IActionResult> GetAllTags(IFormFile file)
    {
        if (file == null || file.Length == 0)
            return BadRequest("No file provided");

        var filePath = Path.Combine(_uploadPath, $"{Guid.NewGuid()}.dcm");
        
        try
        {
            using (var stream = new FileStream(filePath, FileMode.Create))
            {
                await file.CopyToAsync(stream);
            }

            var browser = new DicomTagBrowser();
            var tags = browser.GetAllTags(filePath);
            
            return Ok(tags);
        }
        finally
        {
            if (System.IO.File.Exists(filePath))
                System.IO.File.Delete(filePath);
        }
    }

    [HttpPost("modality-specific")]
    public async Task<IActionResult> GetModalityMetadata(IFormFile file)
    {
        if (file == null || file.Length == 0)
            return BadRequest("No file provided");

        var filePath = Path.Combine(_uploadPath, $"{Guid.NewGuid()}.dcm");
        
        try
        {
            using (var stream = new FileStream(filePath, FileMode.Create))
            {
                await file.CopyToAsync(stream);
            }

            var extractor = new ModalityMetadataExtractor();
            var data = extractor.ExtractModalitySpecificData(filePath);
            
            return Ok(data);
        }
        finally
        {
            if (System.IO.File.Exists(filePath))
                System.IO.File.Delete(filePath);
        }
    }
}

Exportação de Metadados

Gerar relatórios de metadados em vários formatos:

public class MetadataReportGenerator
{
    public void GenerateCsvReport(string dicomDirectory, string outputPath)
    {
        var viewer = new DicomMetadataViewer();
        var records = new List<string>();
        
        // Header
        records.Add("FileName,PatientID,PatientName,StudyDate,Modality,SeriesDescription,Rows,Columns");
        
        var files = Directory.GetFiles(dicomDirectory, "*.dcm", SearchOption.AllDirectories);
        
        foreach (var file in files)
        {
            try
            {
                var metadata = viewer.ExtractMetadata(file);
                
                var record = string.Join(",",
                    EscapeCsv(Path.GetFileName(file)),
                    EscapeCsv(metadata.PatientID),
                    EscapeCsv(metadata.PatientName),
                    EscapeCsv(metadata.StudyDate),
                    EscapeCsv(metadata.Modality),
                    EscapeCsv(metadata.SeriesDescription),
                    metadata.Rows ?? "",
                    metadata.Columns ?? "");
                
                records.Add(record);
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error processing {file}: {ex.Message}");
            }
        }
        
        File.WriteAllLines(outputPath, records);
    }

    public void GenerateJsonReport(string dicomDirectory, string outputPath)
    {
        var viewer = new DicomMetadataViewer();
        var metadataList = new List<object>();
        
        var files = Directory.GetFiles(dicomDirectory, "*.dcm", SearchOption.AllDirectories);
        
        foreach (var file in files)
        {
            try
            {
                var metadata = viewer.ExtractMetadata(file);
                metadataList.Add(new
                {
                    FileName = Path.GetFileName(file),
                    Metadata = metadata
                });
            }
            catch (Exception ex)
            {
                metadataList.Add(new
                {
                    FileName = Path.GetFileName(file),
                    Error = ex.Message
                });
            }
        }
        
        var json = JsonSerializer.Serialize(metadataList, new JsonSerializerOptions 
        { 
            WriteIndented = true 
        });
        
        File.WriteAllText(outputPath, json);
    }

    private string EscapeCsv(string value)
    {
        if (string.IsNullOrEmpty(value))
            return "";
        
        if (value.Contains(",") || value.Contains("\"") || value.Contains("\n"))
        {
            return $"\"{value.Replace("\"", "\"\"")}\"";
        }
        
        return value;
    }
}

Exemplo de uso

class Program
{
    static void Main(string[] args)
    {
        // Activate license
        Metered metered = new Metered();
        metered.SetMeteredKey("your-public-key", "your-private-key");

        string dicomFile = @"C:\DICOM\sample.dcm";
        
        // Console viewer
        var consoleViewer = new DicomViewerConsole();
        consoleViewer.DisplayMetadata(dicomFile);
        
        // Browse all tags
        var browser = new DicomTagBrowser();
        var tags = browser.GetAllTags(dicomFile);
        
        Console.WriteLine($"\nTotal tags: {tags.Count}");
        
        // Generate report for directory
        var reportGenerator = new MetadataReportGenerator();
        reportGenerator.GenerateCsvReport(@"C:\DICOM\Studies", @"C:\Reports\metadata.csv");
    }
}

Conclusão

Construir um visualizador de metadados DICOM dá-lhe capacidades essenciais para o desenvolvimento da imagem médica. Se você precisa de um inspetor de linha de comando rápida, uma API da web para integração, ou ferramentas de relatório de pacote, Aspose.Medical para .NET fornece a base para extrair e analisar atributos DIKOM. Essas técnicas são valiosas para resolução de problemas, garantia de qualidade e construção de aplicações de imagens médicas.

Para mais informações sobre o trabalho com os arquivos DICOM, visite o Aspose.Documentação médica.

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