CODEWITHSUNDEEP
node.jsimagedicom
Frédéric Falliere
Frédéric Falliere

Reputation: 1894

Getting image from dicom .DCM file in node.js

I would like to generate a thumbnail image from a .dcm file (Dicom) in node.js.

So far I've found a node modules called dicom-parser that extracts the metadata from a dcm file.

My test case :

var dicom = require('dicom-parser');
var fs = require('fs');

var dicomFileAsBuffer = fs.readFileSync('./FullPano.dcm');

var dataSet = dicom.parseDicom(dicomFileAsBuffer);

var pixelData = new Uint8Array(dataSet.byteArray.buffer, 
                                dataSet.elements.x00880200.items[0].dataSet.elements.x7fe00010.dataOffset, 
                                dataSet.elements.x00880200.items[0].dataSet.elements.x7fe00010.length);

fs.writeFileSync('test5.jpg', pixelData); // <----- not working :'(

To help you help me debug, here is the dataSet.elements.x00880200 object :

dataSet.elements.x00880200

But the pixelData stored in the tag x00880200 -> x7fe00010 is not in a standard format, either jpeg, jpg, png... The idea here is to get the thumbnail of a dcm image directly from a file, on the fly, server-side in nodejs.

From the dicom doc (see below), the tag 0088,0200 holds the data for the icon, aka thumbnail.

Icon Image Sequence

(0088,0200)

3

This icon image is representative of the Image.

Only a single Item is permitted in this Sequence.

I've come around the cornerstone libs : cornerstone-js and wado-image-loader. But neither are working in a node.js environment (made an issue about that). These libs can generate the "main" image of a dcm, but only once the dcm file is loaded on the cliend-side, in js. My requirement is to do that in nodejs, for the icon/thumbnail.

Upvotes: 2

Views: 6767

Answers (2)

Pantelis Georgiadis
Pantelis Georgiadis

Reputation: 51

A bit late but, if you are still looking for an answer, you can use dcmjs-imaging (full disclosure, I am the author). The library implements a DICOM image and overlay rendering pipeline, for Node.js and browser.
The library supports uncompressed data but also, optionally, decodes all major transfer syntaxes using a native WebAssembly module.
Given that you have already fetched the the DICOM bytes in an ArrayBuffer, you can use the following Node.js example to render the image in an RGBA pixel ArrayBuffer.

// Import objects
const dcmjsImaging = require('dcmjs-imaging');
const { DicomImage, NativePixelDecoder } = dcmjsImaging;

// Optionally register native decoders WebAssembly.
// If native decoders are not registered, only 
// uncompressed syntaxes would be able to be rendered.
await NativePixelDecoder.initializeAsync();

// Create an ArrayBuffer with the contents of the DICOM P10 byte stream.
const image = new DicomImage(arrayBuffer);

// Render image.
const renderingResult = image.render();

// Rendered pixels in an RGBA ArrayBuffer.
const renderedPixels = renderingResult.pixels;
// Rendered width.
const width = renderingResult.width;
// Rendered height.
const height = renderingResult.height;

Upvotes: 3

cneller
cneller

Reputation: 1582

If you are trying to save the image icon as a JPG, that may be your issue:

Only monochrome and palette color images shall be used. Samples per Pixel (0028,0002) shall have a Value of 1, Photometric Interpretation (0028,0004) shall have a Value of either MONOCHROME 1, MONOCHROME 2 or PALETTE COLOR, Planar Configuration (0028,0006) shall not be present.source

I'm not familiar with node.js, but the data in the Icon Image Sequence may not be appropriate for that call.

Note also that you are getting an optional, small, thumbnail of the image, not the actual image data, which can be found in the Pixel Data attribute (7FE0,0010).

Upvotes: 3

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