Retrieve DICOM instance

Get a DICOM instance within a given study.

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For detailed documentation that includes this code sample, see the following:

Code sample

Go

Before trying this sample, follow the Go setup instructions in the Cloud Healthcare API quickstart using client libraries. For more information, see the Cloud Healthcare API Go API reference documentation.

To authenticate to Cloud Healthcare API, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import (
	"context"
	"fmt"
	"io"
	"os"

	healthcare "google.golang.org/api/healthcare/v1"
)

// dicomWebRetrieveInstance retrieves a specific instance.
func dicomWebRetrieveInstance(w io.Writer, projectID, location, datasetID, dicomStoreID, dicomWebPath string, outputFile string) error {
	// projectID := "my-project"
	// location := "us-central1"
	// datasetID := "my-dataset"
	// dicomStoreID := "my-dicom-store"
	// dicomWebPath := "studies/1.3.6.1.4.1.11129.5.5.1113639985/series/1.3.6.1.4.1.11129.5.5.1953511724/instances/1.3.6.1.4.1.11129.5.5.9562821369"
	// outputFile := "instance.dcm"
	ctx := context.Background()

	healthcareService, err := healthcare.NewService(ctx)
	if err != nil {
		return fmt.Errorf("healthcare.NewService: %w", err)
	}

	storesService := healthcareService.Projects.Locations.Datasets.DicomStores.Studies.Series.Instances

	parent := fmt.Sprintf("projects/%s/locations/%s/datasets/%s/dicomStores/%s", projectID, location, datasetID, dicomStoreID)

	call := storesService.RetrieveInstance(parent, dicomWebPath)
	call.Header().Set("Accept", "application/dicom; transfer-syntax=*")
	resp, err := call.Do()
	if err != nil {
		return fmt.Errorf("RetrieveInstance: %w", err)
	}

	defer resp.Body.Close()

	if resp.StatusCode > 299 {
		return fmt.Errorf("RetrieveInstance: status %d %s: %s", resp.StatusCode, resp.Status, resp.Body)
	}

	file, err := os.Create(outputFile)
	if err != nil {
		return fmt.Errorf("os.Create: %w", err)
	}
	defer file.Close()
	if _, err := io.Copy(file, resp.Body); err != nil {
		return fmt.Errorf("io.Copy: %w", err)
	}

	fmt.Fprintf(w, "DICOM instance retrieved and downloaded to file: %v\n", outputFile)

	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the Cloud Healthcare API quickstart using client libraries. For more information, see the Cloud Healthcare API Java API reference documentation.

To authenticate to Cloud Healthcare API, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import com.google.api.client.http.HttpHeaders;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.HttpResponse;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.healthcare.v1.CloudHealthcare;
import com.google.api.services.healthcare.v1.CloudHealthcare.Projects.Locations.Datasets.DicomStores.Studies.Series.Instances;
import com.google.api.services.healthcare.v1.CloudHealthcareScopes;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.auth.oauth2.GoogleCredentials;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Collections;

public class DicomWebRetrieveInstance {
  private static final String DICOM_NAME = "projects/%s/locations/%s/datasets/%s/dicomStores/%s";
  private static final String DICOMWEB_PATH = "studies/%s/series/%s/instances/%s";
  private static final JsonFactory JSON_FACTORY = new GsonFactory();
  private static final NetHttpTransport HTTP_TRANSPORT = new NetHttpTransport();

  public static void dicomWebRetrieveInstance(String dicomStoreName, String dicomWebPath)
      throws IOException {
    // String dicomStoreName =
    //    String.format(
    //        DICOM_NAME, "your-project-id", "your-region-id", "your-dataset-id", "your-dicom-id");
    // String dicomWebPath = String.format(DICOMWEB_PATH, "your-study-id", "your-series-id",
    // "your-instance-id");

    // Initialize the client, which will be used to interact with the service.
    CloudHealthcare client = createClient();

    // Create request and configure any parameters.
    Instances.RetrieveInstance request =
        client
            .projects()
            .locations()
            .datasets()
            .dicomStores()
            .studies()
            .series()
            .instances()
            .retrieveInstance(dicomStoreName, dicomWebPath);

    // Execute the request and process the results.
    HttpResponse response = request.executeUnparsed();

    String outputPath = "instance.dcm";
    OutputStream outputStream = new FileOutputStream(new File(outputPath));
    try {
      response.download(outputStream);
      System.out.println("DICOM instance written to file " + outputPath);
    } finally {
      outputStream.close();
    }

    if (!response.isSuccessStatusCode()) {
      System.err.print(
          String.format("Exception retrieving DICOM instance: %s\n", response.getStatusMessage()));
      throw new RuntimeException();
    }
  }

  private static CloudHealthcare createClient() throws IOException {
    // Use Application Default Credentials (ADC) to authenticate the requests
    // For more information see https://cloud.google.com/docs/authentication/production
    GoogleCredentials credential =
        GoogleCredentials.getApplicationDefault()
            .createScoped(Collections.singleton(CloudHealthcareScopes.CLOUD_PLATFORM));

    HttpHeaders headers = new HttpHeaders();
    headers.set("X-GFE-SSL", "yes");
    // Avoid parsing multipart boundaries by setting 'application/dicom' HTTP header.
    // Add 'transfer-syntax=*' to avoid transcoding by returning the file in the format it
    // was originally stored in.
    headers.setAccept("application/dicom; transfer-syntax=*");
    // Create a HttpRequestInitializer, which will provide a baseline configuration to all requests.
    HttpRequestInitializer requestInitializer =
        request -> {
          new HttpCredentialsAdapter(credential).initialize(request);
          request.setConnectTimeout(60000); // 1 minute connect timeout
          request.setReadTimeout(60000); // 1 minute read timeout
        };

    // Build the client for interacting with the service.
    return new CloudHealthcare.Builder(HTTP_TRANSPORT, JSON_FACTORY, requestInitializer)
        .setApplicationName("your-application-name")
        .build();
  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in the Cloud Healthcare API quickstart using client libraries. For more information, see the Cloud Healthcare API Node.js API reference documentation.

To authenticate to Cloud Healthcare API, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

const google = require('@googleapis/healthcare');
const healthcare = google.healthcare({
  version: 'v1',
  auth: new google.auth.GoogleAuth({
    scopes: ['https://www.googleapis.com/auth/cloud-platform'],
  }),
});
const fs = require('fs');
const util = require('util');
const writeFile = util.promisify(fs.writeFile);
const fileName = 'instance_file.dcm';

const dicomWebRetrieveInstance = async () => {
  // TODO(developer): uncomment these lines before running the sample
  // const cloudRegion = 'us-central1';
  // const projectId = 'adjective-noun-123';
  // const datasetId = 'my-dataset';
  // const dicomStoreId = 'my-dicom-store';
  // const studyUid = '1.3.6.1.4.1.5062.55.1.2270943358.716200484.1363785608958.61.0';
  // const seriesUid = '2.24.52329571877967561426579904912379710633';
  // const instanceUid = '1.3.6.2.4.2.14619.5.2.1.6280.6001.129311971280445372188125744148';
  const parent = `projects/${projectId}/locations/${cloudRegion}/datasets/${datasetId}/dicomStores/${dicomStoreId}`;
  const dicomWebPath = `studies/${studyUid}/series/${seriesUid}/instances/${instanceUid}`;
  const request = {parent, dicomWebPath};

  const instance =
    await healthcare.projects.locations.datasets.dicomStores.studies.series.instances.retrieveInstance(
      request,
      {
        headers: {Accept: 'application/dicom; transfer-syntax=*'},
        responseType: 'arraybuffer',
      }
    );
  const fileBytes = Buffer.from(instance.data);

  await writeFile(fileName, fileBytes);
  console.log(
    `Retrieved DICOM instance and saved to ${fileName} in current directory`
  );
};

dicomWebRetrieveInstance();

Python

Before trying this sample, follow the Python setup instructions in the Cloud Healthcare API quickstart using client libraries. For more information, see the Cloud Healthcare API Python API reference documentation.

To authenticate to Cloud Healthcare API, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

def dicomweb_retrieve_instance(
    project_id,
    location,
    dataset_id,
    dicom_store_id,
    study_uid,
    series_uid,
    instance_uid,
):
    """Handles the GET requests specified in the DICOMweb standard.

    See https://github.com/GoogleCloudPlatform/python-docs-samples/tree/main/healthcare/api-client/v1/dicom
    before running the sample."""
    # Imports Python's built-in "os" module
    import os

    # Imports the google.auth.transport.requests transport
    from google.auth.transport import requests

    # Imports a module to allow authentication using a service account
    from google.oauth2 import service_account

    # Gets credentials from the environment.
    credentials = service_account.Credentials.from_service_account_file(
        os.environ["GOOGLE_APPLICATION_CREDENTIALS"]
    )
    scoped_credentials = credentials.with_scopes(
        ["https://www.googleapis.com/auth/cloud-platform"]
    )
    # Creates a requests Session object with the credentials.
    session = requests.AuthorizedSession(scoped_credentials)

    # URL to the Cloud Healthcare API endpoint and version
    base_url = "https://healthcare.googleapis.com/v1"

    # TODO(developer): Uncomment these lines and replace with your values.
    # project_id = 'my-project'  # replace with your GCP project ID
    # location = 'us-central1'  # replace with the parent dataset's location
    # dataset_id = 'my-dataset'  # replace with the parent dataset's ID
    # dicom_store_id = 'my-dicom-store' # replace with the DICOM store ID
    # study_uid = '1.3.6.1.4.1.5062.55.1.2270943358.716200484.1363785608958.61.0'  # replace with the study UID
    # series_uid = '2.24.52329571877967561426579904912379710633'  # replace with the series UID
    # instance_uid = '1.3.6.2.4.2.14619.5.2.1.6280.6001.129311971280445372188125744148'  # replace with the instance UID
    url = f"{base_url}/projects/{project_id}/locations/{location}"

    dicom_store_path = "{}/datasets/{}/dicomStores/{}".format(
        url, dataset_id, dicom_store_id
    )

    dicomweb_path = "{}/dicomWeb/studies/{}/series/{}/instances/{}".format(
        dicom_store_path, study_uid, series_uid, instance_uid
    )

    file_name = "instance.dcm"

    # Set the required Accept header on the request
    headers = {"Accept": "application/dicom; transfer-syntax=*"}
    response = session.get(dicomweb_path, headers=headers)
    response.raise_for_status()

    with open(file_name, "wb") as f:
        f.write(response.content)
        print(
            "Retrieved DICOM instance and saved to {} in current directory".format(
                file_name
            )
        )

    return response

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