PACS (Systèmes d’archivage des images et de communication) et les services de téléradiologie transforment l’image médicale en permettant un accès à distance aux images diagnostiques. Cependant, la transmission des données des patients dans les environnements en nuage nécessite une attention attentive à la vie privée et la sécurité. Ce guide démontre comment mettre en œuvre la anonymisation DICOM pour les flux de travail dans le cloud et teleradiology en utilisant Aspose.Medical pour .NET.

Pourquoi Anonymiser pour Cloud et Teleradiologie?

Lorsque les images DICOM quittent le réseau hospitalier pour le stockage en nuage ou la lecture à distance, des considérations de confidentialité supplémentaires s’appliquent :

  • Résidence des données: Les données des patients peuvent traverser les limites géographiques lorsque différentes réglementations s’appliquent
  • Access de tiers: Les fournisseurs de services en nuage et en radiologie sont des partenaires d’affaires sous HIPAA
  • Réseau de transmission: les données qui traversent Internet nécessitent une protection supplémentaire
  • Environnements multi-tenants: les systèmes en nuage peuvent stocker des données de plusieurs organisations de santé
  • ** Radiologues à distance** : les lecteurs externes peuvent ne pas avoir besoin d’accès aux identifiants des patients

L’anonymisation crée une couche de sécurité qui protège la vie privée du patient même si d’autres mesures de sûreté échouent.

Cloud Upload Service d’anonymisation

Créer un service qui anonymise les fichiers DICOM avant le téléchargement dans le cloud :

using Aspose.Medical.Dicom;
using Aspose.Medical.Dicom.Anonymization;

public class CloudUploadAnonymizer
{
    private readonly ConfidentialityProfile _profile;
    private readonly Dictionary<string, string> _studyIdMapping;
    private readonly string _organizationPrefix;

    public CloudUploadAnonymizer(string organizationPrefix)
    {
        _organizationPrefix = organizationPrefix;
        _studyIdMapping = new Dictionary<string, string>();
        
        // Create profile optimized for cloud storage
        var options = ConfidentialityProfileOptions.BasicProfile |
                      ConfidentialityProfileOptions.RetainDeviceIdentity |
                      ConfidentialityProfileOptions.CleanDescriptions;
        
        _profile = ConfidentialityProfile.CreateDefault(options);
    }

    public CloudUploadResult AnonymizeForCloud(string inputPath, string outputPath)
    {
        var result = new CloudUploadResult
        {
            OriginalPath = inputPath,
            ProcessedAt = DateTime.UtcNow
        };

        try
        {
            DicomFile dicomFile = DicomFile.Open(inputPath);
            var dataset = dicomFile.Dataset;
            
            // Capture original identifiers for mapping
            string originalStudyUid = dataset.GetString(DicomTag.StudyInstanceUID);
            string originalPatientId = dataset.GetString(DicomTag.PatientID);
            string originalAccession = dataset.GetString(DicomTag.AccessionNumber);
            
            // Generate cloud-safe identifiers
            string cloudStudyId = GetOrCreateCloudStudyId(originalStudyUid);
            
            result.OriginalStudyUID = originalStudyUid;
            result.CloudStudyId = cloudStudyId;
            result.OriginalPatientId = originalPatientId;
            
            // Apply anonymization
            var anonymizer = new Anonymizer(_profile);
            anonymizer.Anonymize(dataset);
            
            // Apply cloud-specific identifiers
            dataset.AddOrUpdate(DicomTag.PatientID, $"{_organizationPrefix}-{cloudStudyId}");
            dataset.AddOrUpdate(DicomTag.PatientName, $"CloudStudy^{cloudStudyId}");
            dataset.AddOrUpdate(DicomTag.AccessionNumber, cloudStudyId);
            
            // Add cloud tracking metadata
            dataset.AddOrUpdate(DicomTag.InstitutionName, _organizationPrefix);
            
            dicomFile.Save(outputPath);
            
            result.CloudPath = outputPath;
            result.Success = true;
        }
        catch (Exception ex)
        {
            result.Success = false;
            result.ErrorMessage = ex.Message;
        }

        return result;
    }

    private string GetOrCreateCloudStudyId(string originalStudyUid)
    {
        if (!_studyIdMapping.ContainsKey(originalStudyUid))
        {
            string timestamp = DateTime.UtcNow.ToString("yyyyMMddHHmmss");
            string random = Guid.NewGuid().ToString("N").Substring(0, 8);
            _studyIdMapping[originalStudyUid] = $"{timestamp}-{random}";
        }
        return _studyIdMapping[originalStudyUid];
    }

    public Dictionary<string, string> GetStudyMapping()
    {
        return new Dictionary<string, string>(_studyIdMapping);
    }
}

public class CloudUploadResult
{
    public string OriginalPath { get; set; }
    public string CloudPath { get; set; }
    public string OriginalStudyUID { get; set; }
    public string CloudStudyId { get; set; }
    public string OriginalPatientId { get; set; }
    public DateTime ProcessedAt { get; set; }
    public bool Success { get; set; }
    public string ErrorMessage { get; set; }
}

L’intégration du flux de travail de la téléradiologie

Construire un pipeline d’anonymisation de la téléradiologie complète :

public class TeleradiologyAnonymizationPipeline
{
    private readonly CloudUploadAnonymizer _anonymizer;
    private readonly string _stagingDirectory;
    private readonly string _mappingDirectory;

    public TeleradiologyAnonymizationPipeline(
        string organizationId,
        string stagingDirectory,
        string mappingDirectory)
    {
        _anonymizer = new CloudUploadAnonymizer(organizationId);
        _stagingDirectory = stagingDirectory;
        _mappingDirectory = mappingDirectory;
        
        Directory.CreateDirectory(_stagingDirectory);
        Directory.CreateDirectory(_mappingDirectory);
    }

    public async Task<TeleradiologyBatch> ProcessStudyForRemoteReading(
        string studyDirectory,
        string priority = "ROUTINE")
    {
        var batch = new TeleradiologyBatch
        {
            BatchId = Guid.NewGuid().ToString(),
            Priority = priority,
            SubmittedAt = DateTime.UtcNow,
            Results = new List<CloudUploadResult>()
        };

        var dicomFiles = Directory.GetFiles(studyDirectory, "*.dcm", SearchOption.AllDirectories);
        
        // Create batch output directory
        string batchOutputDir = Path.Combine(_stagingDirectory, batch.BatchId);
        Directory.CreateDirectory(batchOutputDir);

        foreach (var inputFile in dicomFiles)
        {
            string relativePath = Path.GetRelativePath(studyDirectory, inputFile);
            string outputPath = Path.Combine(batchOutputDir, relativePath);
            
            Directory.CreateDirectory(Path.GetDirectoryName(outputPath));
            
            var result = _anonymizer.AnonymizeForCloud(inputFile, outputPath);
            batch.Results.Add(result);
        }

        // Save mapping file for this batch
        await SaveBatchMapping(batch);
        
        // Generate manifest for teleradiology service
        batch.ManifestPath = await GenerateTeleradiologyManifest(batch, batchOutputDir);
        
        batch.Success = batch.Results.All(r => r.Success);
        batch.TotalFiles = batch.Results.Count;
        batch.SuccessfulFiles = batch.Results.Count(r => r.Success);

        return batch;
    }

    private async Task SaveBatchMapping(TeleradiologyBatch batch)
    {
        var mapping = new
        {
            BatchId = batch.BatchId,
            SubmittedAt = batch.SubmittedAt,
            StudyMappings = _anonymizer.GetStudyMapping(),
            FileMappings = batch.Results.Select(r => new
            {
                r.OriginalPath,
                r.CloudPath,
                r.OriginalStudyUID,
                r.CloudStudyId,
                r.OriginalPatientId
            })
        };

        string mappingPath = Path.Combine(_mappingDirectory, $"{batch.BatchId}_mapping.json");
        string json = JsonSerializer.Serialize(mapping, new JsonSerializerOptions { WriteIndented = true });
        await File.WriteAllTextAsync(mappingPath, json);
    }

    private async Task<string> GenerateTeleradiologyManifest(
        TeleradiologyBatch batch, 
        string outputDirectory)
    {
        var manifest = new
        {
            Version = "1.0",
            BatchId = batch.BatchId,
            Priority = batch.Priority,
            SubmittedAt = batch.SubmittedAt.ToString("O"),
            TotalStudies = batch.Results
                .Where(r => r.Success)
                .Select(r => r.CloudStudyId)
                .Distinct()
                .Count(),
            TotalImages = batch.Results.Count(r => r.Success),
            Studies = batch.Results
                .Where(r => r.Success)
                .GroupBy(r => r.CloudStudyId)
                .Select(g => new
                {
                    CloudStudyId = g.Key,
                    ImageCount = g.Count(),
                    Files = g.Select(r => Path.GetFileName(r.CloudPath)).ToList()
                })
                .ToList()
        };

        string manifestPath = Path.Combine(outputDirectory, "manifest.json");
        string json = JsonSerializer.Serialize(manifest, new JsonSerializerOptions { WriteIndented = true });
        await File.WriteAllTextAsync(manifestPath, json);
        
        return manifestPath;
    }
}

public class TeleradiologyBatch
{
    public string BatchId { get; set; }
    public string Priority { get; set; }
    public DateTime SubmittedAt { get; set; }
    public List<CloudUploadResult> Results { get; set; }
    public string ManifestPath { get; set; }
    public bool Success { get; set; }
    public int TotalFiles { get; set; }
    public int SuccessfulFiles { get; set; }
}

Intégration de stockage Azure Blob

Téléchargez des fichiers DICOM anonymisés vers Azure Blob Storage :

using Azure.Storage.Blobs;
using Azure.Storage.Blobs.Models;

public class AzureDicomUploader
{
    private readonly BlobContainerClient _containerClient;
    private readonly TeleradiologyAnonymizationPipeline _pipeline;

    public AzureDicomUploader(
        string connectionString,
        string containerName,
        string organizationId)
    {
        _containerClient = new BlobContainerClient(connectionString, containerName);
        _containerClient.CreateIfNotExists();
        
        _pipeline = new TeleradiologyAnonymizationPipeline(
            organizationId,
            Path.Combine(Path.GetTempPath(), "dicom_staging"),
            Path.Combine(Path.GetTempPath(), "dicom_mappings"));
    }

    public async Task<AzureUploadResult> UploadStudyAsync(
        string studyDirectory,
        string priority = "ROUTINE")
    {
        var result = new AzureUploadResult
        {
            StartedAt = DateTime.UtcNow
        };

        try
        {
            // Anonymize the study
            var batch = await _pipeline.ProcessStudyForRemoteReading(studyDirectory, priority);
            result.BatchId = batch.BatchId;

            if (!batch.Success)
            {
                result.Success = false;
                result.ErrorMessage = "Anonymization failed for some files";
                return result;
            }

            // Upload anonymized files to Azure
            string batchDirectory = Path.GetDirectoryName(batch.ManifestPath);
            var filesToUpload = Directory.GetFiles(batchDirectory, "*.*", SearchOption.AllDirectories);

            foreach (var filePath in filesToUpload)
            {
                string blobName = $"{batch.BatchId}/{Path.GetRelativePath(batchDirectory, filePath)}";
                
                BlobClient blobClient = _containerClient.GetBlobClient(blobName);
                
                using (var stream = File.OpenRead(filePath))
                {
                    await blobClient.UploadAsync(stream, new BlobUploadOptions
                    {
                        HttpHeaders = new BlobHttpHeaders
                        {
                            ContentType = GetContentType(filePath)
                        },
                        Metadata = new Dictionary<string, string>
                        {
                            { "batch_id", batch.BatchId },
                            { "priority", priority },
                            { "uploaded_at", DateTime.UtcNow.ToString("O") }
                        }
                    });
                }
                
                result.UploadedFiles.Add(blobName);
            }

            // Clean up staging directory
            Directory.Delete(batchDirectory, true);

            result.Success = true;
            result.CompletedAt = DateTime.UtcNow;
            result.BlobContainerUri = _containerClient.Uri.ToString();
        }
        catch (Exception ex)
        {
            result.Success = false;
            result.ErrorMessage = ex.Message;
        }

        return result;
    }

    private string GetContentType(string filePath)
    {
        return Path.GetExtension(filePath).ToLower() switch
        {
            ".dcm" => "application/dicom",
            ".json" => "application/json",
            _ => "application/octet-stream"
        };
    }
}

public class AzureUploadResult
{
    public string BatchId { get; set; }
    public DateTime StartedAt { get; set; }
    public DateTime CompletedAt { get; set; }
    public bool Success { get; set; }
    public string ErrorMessage { get; set; }
    public string BlobContainerUri { get; set; }
    public List<string> UploadedFiles { get; set; } = new List<string>();
}

L’intégration AWS S3

Téléchargez DICOM anonymisé sur Amazon S3:

using Amazon.S3;
using Amazon.S3.Transfer;

public class AwsDicomUploader
{
    private readonly IAmazonS3 _s3Client;
    private readonly string _bucketName;
    private readonly TeleradiologyAnonymizationPipeline _pipeline;

    public AwsDicomUploader(
        IAmazonS3 s3Client,
        string bucketName,
        string organizationId)
    {
        _s3Client = s3Client;
        _bucketName = bucketName;
        
        _pipeline = new TeleradiologyAnonymizationPipeline(
            organizationId,
            Path.Combine(Path.GetTempPath(), "dicom_staging"),
            Path.Combine(Path.GetTempPath(), "dicom_mappings"));
    }

    public async Task<S3UploadResult> UploadStudyAsync(
        string studyDirectory,
        string priority = "ROUTINE")
    {
        var result = new S3UploadResult
        {
            StartedAt = DateTime.UtcNow
        };

        try
        {
            // Anonymize
            var batch = await _pipeline.ProcessStudyForRemoteReading(studyDirectory, priority);
            result.BatchId = batch.BatchId;

            if (!batch.Success)
            {
                result.Success = false;
                result.ErrorMessage = "Anonymization failed";
                return result;
            }

            // Upload to S3
            var transferUtility = new TransferUtility(_s3Client);
            string batchDirectory = Path.GetDirectoryName(batch.ManifestPath);

            await transferUtility.UploadDirectoryAsync(new TransferUtilityUploadDirectoryRequest
            {
                BucketName = _bucketName,
                Directory = batchDirectory,
                KeyPrefix = batch.BatchId,
                SearchOption = SearchOption.AllDirectories
            });

            // Clean up
            Directory.Delete(batchDirectory, true);

            result.Success = true;
            result.S3Uri = $"s3://{_bucketName}/{batch.BatchId}/";
            result.CompletedAt = DateTime.UtcNow;
        }
        catch (Exception ex)
        {
            result.Success = false;
            result.ErrorMessage = ex.Message;
        }

        return result;
    }
}

public class S3UploadResult
{
    public string BatchId { get; set; }
    public DateTime StartedAt { get; set; }
    public DateTime CompletedAt { get; set; }
    public bool Success { get; set; }
    public string ErrorMessage { get; set; }
    public string S3Uri { get; set; }
}

L’anonymisation en temps réel

Créer un portail API qui anonymise DICOM en temps réel pour les lecteurs dans le cloud :

[ApiController]
[Route("api/[controller]")]
public class CloudDicomGatewayController : ControllerBase
{
    private readonly CloudUploadAnonymizer _anonymizer;
    private readonly ILogger<CloudDicomGatewayController> _logger;

    public CloudDicomGatewayController(ILogger<CloudDicomGatewayController> logger)
    {
        _anonymizer = new CloudUploadAnonymizer("GATEWAY");
        _logger = logger;
    }

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

        var tempInput = Path.GetTempFileName();
        var tempOutput = Path.GetTempFileName();

        try
        {
            // Save uploaded file
            using (var stream = new FileStream(tempInput, FileMode.Create))
            {
                await file.CopyToAsync(stream);
            }

            // Anonymize
            var result = _anonymizer.AnonymizeForCloud(tempInput, tempOutput);

            if (!result.Success)
            {
                return StatusCode(500, $"Anonymization failed: {result.ErrorMessage}");
            }

            // Return anonymized file
            var fileBytes = await System.IO.File.ReadAllBytesAsync(tempOutput);
            
            // Add tracking headers
            Response.Headers.Add("X-Cloud-Study-Id", result.CloudStudyId);
            Response.Headers.Add("X-Processed-At", result.ProcessedAt.ToString("O"));

            return File(fileBytes, "application/dicom", $"{result.CloudStudyId}.dcm");
        }
        finally
        {
            if (System.IO.File.Exists(tempInput))
                System.IO.File.Delete(tempInput);
            if (System.IO.File.Exists(tempOutput))
                System.IO.File.Delete(tempOutput);
        }
    }

    [HttpPost("batch-prepare")]
    public async Task<IActionResult> PrepareBatchForCloud([FromBody] BatchPrepareRequest request)
    {
        var pipeline = new TeleradiologyAnonymizationPipeline(
            request.OrganizationId,
            Path.Combine(Path.GetTempPath(), "staging"),
            Path.Combine(Path.GetTempPath(), "mappings"));

        var batch = await pipeline.ProcessStudyForRemoteReading(
            request.StudyDirectory,
            request.Priority);

        return Ok(new
        {
            batch.BatchId,
            batch.Success,
            batch.TotalFiles,
            batch.SuccessfulFiles,
            batch.ManifestPath,
            StagingDirectory = Path.GetDirectoryName(batch.ManifestPath)
        });
    }
}

public class BatchPrepareRequest
{
    public string OrganizationId { get; set; }
    public string StudyDirectory { get; set; }
    public string Priority { get; set; } = "ROUTINE";
}

Service de réidentification

La mise en œuvre assure la réidentification pour les rapports de lecture :

public class ReidentificationService
{
    private readonly string _mappingDirectory;

    public ReidentificationService(string mappingDirectory)
    {
        _mappingDirectory = mappingDirectory;
    }

    public ReidentificationResult Reidentify(string batchId, string cloudStudyId)
    {
        var result = new ReidentificationResult();

        try
        {
            string mappingFile = Path.Combine(_mappingDirectory, $"{batchId}_mapping.json");
            
            if (!File.Exists(mappingFile))
            {
                result.Success = false;
                result.ErrorMessage = "Mapping file not found";
                return result;
            }

            string json = File.ReadAllText(mappingFile);
            var mapping = JsonSerializer.Deserialize<BatchMapping>(json);

            // Find original identifiers
            var fileMapping = mapping.FileMappings
                .FirstOrDefault(f => f.CloudStudyId == cloudStudyId);

            if (fileMapping == null)
            {
                result.Success = false;
                result.ErrorMessage = "Study not found in mapping";
                return result;
            }

            result.OriginalPatientId = fileMapping.OriginalPatientId;
            result.OriginalStudyUID = fileMapping.OriginalStudyUID;
            result.Success = true;
        }
        catch (Exception ex)
        {
            result.Success = false;
            result.ErrorMessage = ex.Message;
        }

        return result;
    }
}

public class BatchMapping
{
    public string BatchId { get; set; }
    public DateTime SubmittedAt { get; set; }
    public Dictionary<string, string> StudyMappings { get; set; }
    public List<FileMapping> FileMappings { get; set; }
}

public class FileMapping
{
    public string OriginalPath { get; set; }
    public string CloudPath { get; set; }
    public string OriginalStudyUID { get; set; }
    public string CloudStudyId { get; set; }
    public string OriginalPatientId { get; set; }
}

public class ReidentificationResult
{
    public bool Success { get; set; }
    public string OriginalPatientId { get; set; }
    public string OriginalStudyUID { get; set; }
    public string ErrorMessage { get; set; }
}

Les meilleures pratiques pour l’anonymisation Cloud PACS

  • Safe mapping storage: Gardez les fichiers d’identification en chiffrement et séparés des données anonymisées
  • Utiliser des identifiants cohérents: Assurez-vous que le même patient/étude reçoit le seul identificateur anonymisé à travers les téléchargements
  • Logging d’audit de mise en œuvre: Suivez toutes les opérations d’anonymisation et de réidentification
  • Teste soigneusement: Vérifiez qu’il n’y a pas de fuites de PHI à travers les tags privés ou les données intégrées
  • Sécurité réseau Consider: Utilisez TLS pour tous les téléchargements en nuage et le stockage crypté en repos

Conclusion

L’anonymisation des fichiers DICOM pour le Cloud PACS et la téléradiologie nécessite une gestion soigneuse des identifiants des patients tout en maintenant l’intégrité d’étude pour la lecture à distance. Aspose.Médical pour .NET fournit la base pour construire des pipelines de anonymisation sécurisées qui s’integrent avec Azure, AWS et autres plates-formes cloud. En implémentant les pistes de mappage d’identité appropriées et de contrôle, vous pouvez permettre des flux de travail modernes dans le teleradiology tandis que la protection de la vie privée du patient.

Pour plus d’informations sur l’anonymisation de DICOM, visitez le Aspose.Documentation médicale.

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