Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
SYSTEM AND METHOD FOR VIEWING MEDICAL IMAGES
Document Type and Number:
WIPO Patent Application WO/2014/006465
Kind Code:
A1
Abstract:
A method facilitates viewing of DICOM medical images by providing a 16-bit DICOM image on a computer readable storage medium, text-converted metadata of the DICOM image and an html-compatible conversion of the DICOM pixel data on a computer readable storage medium. Pixel data of the DICOM image is converted by dividing the 16~bit image into two 8-bit color channels stored in an image referenced by a web page using a uniform resource locator. The two 8-bit color channels are later reassembled within a portable web browser according to instructions set forth in computer readable program code associated with, the web page.

Inventors:
COLACO VERNON (US)
VITTORIO ACCOMAZZI (CA)
Application Number:
PCT/IB2013/000695
Publication Date:
January 09, 2014
Filing Date:
January 04, 2013
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
INTERNAT MEDICAL SOLUTIONS INC (CA)
International Classes:
A61B5/00; G06F5/00; G06T1/00; G16H10/60; G16H30/20; G16H30/40
Other References:
LU ET AL.: "Research and Implementation of Converting DICOM Multi-Frame Medical Image to Multimedia Format.", 2010 INTERNATIONAL CONFERENCE ON MULTIMEDIA TECHNOLOY., October 2010 (2010-10-01), pages 1 - 5
DESAI ET AL.: "Medical image transcoder for telemedicine based on wireless communication devices.", 3RD INTERNATIONAL CONFERENCE ON ELECTRONICS COMPUTER TECHNOLOGY., April 2011 (2011-04-01), pages 389 - 393
LIU ET AL.: "Medical Image Conversion with DICOM.", CANADIAN CONFERENCE ON ELECTRICAL AND COMPUTER ENGINEERING., April 2007 (2007-04-01), pages 36 - 39
TENG: "Managing DICOM image metadata with desktop operating systems native user interface.", 22ND IEEE INTERNATIONAL SYMPOSIUM ON COMPUTER- BASED MEDICAL SYSTEMS., August 2009 (2009-08-01), pages 1 - 5
Attorney, Agent or Firm:
LEDWELL, Kent (160 Elgin Street Suite 260, Ottawa Ontario K1P 1C3, CA)
Download PDF:
Claims:
CLAIMS

What is claimed is:

1. A method for facilitated viewing of medical images, comprising:

providing a 16 bit DICOM image on a computer readable storage medium:

converting metadata of the DICOM image to text format

storing the text formatted metadata to a computer readable storage medium; and converting pixel data of the DICOM image to html compatible format.

2. The method for facilitated viewing of medical images as set forth in claim 1, wherein:

converting pixel data of the DICOM image to html compatible format comprises: splitting the 16 bit DICOM image into two 8 bit channels,

3. The method for facilitated viewing of medical images as set forth in claim 2, wherein:

converting pixel date of the DICOM image to html format comprises:

losslessly compressing each of the two 8 bit channels.

4. The method for facilitated viewing of medical images as set forth in claim 3, wherein:

lossless compression results in a png format.

5. The method for facilitated viewing of medical images as set forth in claim 4, further comprising:

loading the compressed 8 bit channels in an fimg' element.

6. The method for facilitated viewing of medical images as set forth in claim 5, further comprising:

rendering the !img' element in a html 5 canvas object.

7. The method for facilitated viewmg of medical images as set forth in claim 6, further comprising:

iterating through all pixel values of the canvas object to reconstruct the original 16 bit DICOM image.

8. The method for facilitated viewing of medical images as set forth in claim 7, further comprising:

storing the html compatible formatted DICOM image to a computer readable storage medium.

9. The method for facilitated viewmg of medical images as set forth in claim 7, farther comprising:

providing, to a web browser, DICOM image pixel data as offset from image

beginning.

10. A medical image viewer, comprising:

a portable html 5 capable browser stored on a computer readable medium;

one or more DICOM images converted into html format and stored on the computer readable medium; and

one or more DICOM images.

1 1. A method for facili tated viewing of medical images, comprising:

providing a 16 bit DICOM image on a computer readable storage medium;

converting metadata of the DICOM image to html format;

storing DICOM image pixel data as offset from image begirming; and

storing the html formatted metadata and pixel data offset on a computer readable storage medium.

12. The method for facilitated viewing of medical images as set forth in claim 11 , further comprising:

accessing the 16 bit DICOM image as byte stream using the offset.

AMENDED CLAIMS

received by the International Bureau on 01 November 2013 (01 .1 1 .2013)

What is claimed is:

1. A method for facilitated viewing of medical images, comprising:

providing a 16 bit DICOM image on a computer readable storage medium;

converting metadata of the DICOM image to text format;

storing the text formatted metadata to the computer readable storage medium; and converting pixel data of the DICOM image to an html compatible fotmat which preserves 16 bit data resolution of the DICOM image.

2. The method for facilitated viewing of medical images as set forth in claim 1, wherein:

converting pixel data of the DICOM image to the html compatible format comprises splitting the 16 bit DICOM image into two 8 bit channels.

3. The method for facilitated viewing of medical images as set forth in claim 2f wherein:

converting pixel data of the DICOM image to the html format comprises losslessly compressing each of the two 8 bit channels.

4. The method fof facilitated viewing of medical images as set forth in claim 3, wherein:

the two 8 bit channels are compressed using png format.

5. The method for facilitated viewing of medical images as set forth in claim 4, further comprising:

loading the compressed 8 bit channels in an 'img' element.

6. The method for facilitated viewing of medical images as set forth in claim 5, further comprising:

rendering the 'img1 element into a htmlS canvas object,

7. The method for facilitated viewing of medical images as set forth in claim 6, further comprising:

iterating through all pixel values of the html5 canvas object to reconstruct the original 16 bit DTCOM image.

8. The method for facilitated viewing of medical images as set forth in any one of claims 1 to 7, further comprising:

storing the html compatible formatted DICOM image to the computer readable storage medium.

9. The method for facilitated viewing of medical images as set forth in claim 7, further comprising:

providing, to a web browser, DICOM image pixel data as offset from image beginning.

10. A medical image viewer, comprising:

a portable htmlS capable browser stored on a computer readable medium;

one or more DICOM images converted into html format and stored on the computer readable medium, wherein the converted html format preserves 16 bit data resolution of the DICOM images; and

one or more DICOM images.

11. A method for facilitated viewing of medical images, comprising:

providing a 16 bit DICOM image on a computer readable storage medium;

converting metadata of the DICOM image to html format;

storing DICOM image pixel data as offset from image beginning; and storing the html formatted metadata and pixel data offset on the computer readable storage medium.

12. The method for facilitated viewing of medical images as set forth in claim 11, further comprising:

accessing the 16 bit DICOM image as a byte stream using the offset.

13. The method for facilitated viewing of medical images as set forth in claim 1, wherein the text formatted metadata is stored using a same file name as the DICOM image,

14. The method for facilitated viewing of medical images as set forth in claim 11, wherein storing DICOM image pixel data as offset from image beginning includes storing in the metadata position of the DICOM image pixel data as offset from beginning of the DICOM image,

15. The method for facilitated viewing of medical images as set forth in claim 1, wherein converting metadata of the DICOM image to text format includes converting the metadata into a JSOM data structure.

16. The method for facilitated viewing of medical images as set forth in claim 2, wherein splitting the 16 bit DICOM image into two 8 bit channels includes splitting the 16 bit DICOM image into two color channels.

17. The method for facilitated viewing of medical images as set forth in claim 4, wherein losslessly compressing the two 8 bit channels comprises using pixel format BGR24.

18. The method for facilitated viewing of medical images as set forth in claim 2, wherein splitting the 16 bit DICOM image into two 8 bit channels includes splitting the 16 bit DICOM image into a first 8 bit channel comprising higher order bits of the 16 bit DICOM image and a second 8 bit channel comprising lower order bits of the 16 bit DICOM image.

19. The method for facilitated viewing of medical images as set forth in claim 18, wherein:

higher order bits of the 16 bit DICOM image are converted into the first 8 bit channel by downshifting bits of the 16 bit DICOM image and removing the remainder; and lower order bits of the 16 bit DICOM image are converted into the second 8 bit channel by masking ofT the higher order bits of the 1 bit DICOM image.

20. The method for facilitated viewing of medical images as set forth in claim 19, wherein the 16 bit DICOM image is re-assembled by upshifting bits of the first 8 bit channel and adding the upshifted bits to the bits of the second 8 bit channel.

21. The method for facilitated viewing of medical images as set forth in any one of claims 1 to 20, wherein the 16 bit DICOM image comprises a 16 bit grayscale image,

Description:
SYSTEM AND METHOB FOR VIEWING MEDICAL IMAGES BACKGROUND OF THE INVENTION

[001] The present invention relates generally to the field of image viewers. More particularly, the invention is related to image viewers for viewing medical images such as DICOM format images.

[Θ02] In the clinical practice it is very common to save patient's medical images to a media such as CD or DVD. This is usually done because the patient is required to be provided with a copy and images frequently need to be sent to a different institution.

[003] Medical images are saved in DICOM format, which is not supported by the common operating systems such as Microsoft Windows™ or Apple Macintosh™. Therefore when the images are stored on the media it is very common to include an application to view them because, although DICOM is an international standard, not all DICOM viewers are equivalent. DICOM is a very large standard and not all viewers are capable of properly displaying every modality. For certain modalities some specific processing might be necessary for proper viewing. Therefore the presence of the viewer on the media, does not only guarantee the images can be properly viewed, but also guarantees that the images can be viewed correctly according to the modality of the provided image.

[004] The technical challenge in creating a media viewer for viewing DICOM images is that the viewer needs to run on every system, including very old systems, regardless of the memory, central processing unit or operating system. Furthermore, the viewer application should not rely on any user permission because the computer systems ss hospitals typicaiiy have very tight security through which the user is not able to install any software nor make configuration changes. Thus the application should be capable of rtmroing directly from the media upon which the DICOM images are provided. For instance, currently, it is very common to require that a media yie er run on Windows XP™ operating systems released in 2001.

[005] The current solution for medical imaging media viewer is to use antiquated applications, created contemporaneously with Windows XP™ released. These applications satisfy the minimal requirement and will ran off the media. However, from a software engineering perspective, this approach has major drawbacks.

[006] Old applications are difficult to maintain, extend and support. The tools necessary to develop them are frequently no longer available or supported. Extension in particular is a critical aspect, medical imaging modalities have changed since these viewers were released and they will continue to change.

[007] In order to take advantage of new technologies, such as web viewing, companies are forced to create a second set of application independent from the media viewer. This requires duplicating the development effort in order to support both versions of a viewer.

SUMMARY OF THE INVENTION

[008] According to one aspect of the present invention, a method for facilitated viewing of DICOM medical images is provided. The method comprises the steps of providing a 16-bit DICOM image on a computer readable storage medium; converting metadata of the DICOM image to text format; storing the text formatted metadata to a computer readable storage medium; and converting pixel data of the DICOM image to toil compatible format.

[009] Further objects of the invention include converting pixel data of the DICOM image to html compatible format by splitting the 16-bit DICOM image into two 8-bit channels; converting pixel data of the DICOM image to html format by losslessly compressing the two 8-bit channels using png image format; loading the png image in an 'img' element; rendering the 'img' element in a html 5 canvas object; iterating through all pixel values of the canvas object to reconstruct the original 16-bit DICOM image; storing the html compatible formatted DICOM image to a computer readable storage medium and providing, to a web browser, DICOM image pixel data as offset from image beginning.

BRIEF DESCRIPTION OF THE FIGURES

[0010] FIG, 1 illustrates a schematic view of a method of providing a portable media viewer according to a first exemplary embodiment of the present invention.

[001 Ij FIG. 2 illustrates a schematic view of a method of providing a portable media viewer according to a second exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION [00 ϊ 2] According to the preferred embodiment of the present invention, a media yiewer packages a portable version of a html 5 capable browser on a computer readable medium to deliver the viewer as an html page.

[0013] A DICOM image contains meta information regarding the patient, medical modality, type and date of examination, etc. This rneia information is stored in the DICOM image as key-value schema. Values may be of several types including string, integer and floating point or an array of these types. Keys and values are stored within DICOM images in binary form. Meta information needs to be provided to a user viewing the DICOM image.

[0014] In order to display the meta information, it is necessary to convert it. According to one embodiment of the present invention, the meta information is converted into a JSON data structure frequently used in JavaScript™ to store key-value pairs. Conversion includes parsing a binary stream of meta information using a DICOM library, Doriiig conversion, computer readable program code opens the DICOM image file and then loops through all tags for the key-value pairs of meta information to store the pairs in a JSON object as text values.

[0015] Exemplary code for converting DICOM metadata includes:

DicomFile df = newDieoniFik(dicom_ filejath)

for each (Element teg in df.DataSet)

{

string tagKey = tag.Tag oSoing();

mt tagMlt = tag.Vm; if(tagMlt > 0)

{

object tagVal = null;

if (tagMlt > 1)

{ object [] arrVal = new object[tagM It];

for (ini v = 0; v < tabMlt; v++)

a rr VaI[v] = tag.Get(v);

}

tagVal - arrVal;

else

{

tagVal = tag.Get(0);

}

JSON.add(tagKey, tagVal);

}

}

1 ] Having parsed meta information from the DICOM image and saved into an object easily presented to a web browser, in order to provide the user with a version of the DICOM image that is viewable within a portable web browser 22, pixel data from the DICOM image must be converted into a web digestible format, The 16-bit gray scale DICOM image is converted into two color 8-bit images by splitting the 16-bits in two 8~ bit channels such as red and green. Which color channel combination a developer uses is up to the individual developer. It is equally feasible to split the 16-bit grayscale image into the channels red and blue. Thus, for each pixel of the DICOM image, the 16-bit value is down-shifted to an 8-bit channel by effectively dividing by 256. This downshifted result is stored as a first value. In this division, the remainder would otherwise be truncated resulting in a loss of information. To overcome this loss, a mask operator is used to collect the remamder value from the division and store as a second value. Each of the two stored values are subsequently associated with a web image channel which may be tagged by a url. Exemplary code for splitting the 16-bit grayscale image into two 8-bit color channels includes:

for (int y = 0; y < nDicomlmageColumns; y++) for (int x = 0; x < nDicomlmageColumns; x++) ushort dicomGrayScale = DicomImage[x, y];

byte valueH = ( byte}(dicomGraySca3e » 8 );

byte valueL = (byte)(dicomOrayScale & OxFF);

WebIsiage[x,y].Red - valueL;

WebImage[x,y].Green = valueH;

}

}

[0017] The resulting two-channel web image is next compressed using lossless compression such as the png compression scheme. In some embodiments, implementation may be by Microsoft.NET using a standard Microsoft library. For this step, the pixel format BGR 24 is used.

[0018] The png image is then loaded in the html page by setting the source of the image element to the url containing the png image. Computer readable program code provided within the context of the url causes the png images to be loaded in an 'img' element having a tiled configuration of the two png channel images. This 'img' element is then rendered in an html 5 canvas object having the same size as the input image. Exemplary code for rendering the 'img' element includes:

var tCanvas = document-createEiementCcanvas 1 );

tCanvas.width - img.width:

tCanvas.faeight = img.height;

tContext - tCanva .getContext '2d , );

// draw img in canvas

Context drawlmage(img, 0, 0, img.width, img.height, 0, 0, img.width, img.height);

[0019] To extract the pixel data, and the computer readable program code causes an iteration through all the pixel values in the canvas element and reconstracis the original 16-bit value DICOM image. The green channel png is multiplied by 256 to produce a 16- bit value. The red channel pug is next added to the 16-bit value to yield the original

DICOM image. Exemplary code for extracting the pixel data includes:

var tBuffer = :: tContext.getImageData(0, 0, image, width, image.height); The pixel data element (Buffer is an array of 4 values for each pixel (red, green, blue and alpha).

var os = 0:

var bData = tBuffer.data;

var nPixels = img.width * irng.height;

for (var p— 0; p < nPixels; p-H-, pos += 4) {

var val = bDataj os] + bData[pos + 1} * 256;

pixelsjjp] = val;

[0020] The resulting extracted pixel data and the previously created JSON object may now be provided to a viewer using the portable browser provided on the media. As illustrated in FIG. 1, the original medical images 16, converted html-digestible files produced according to the method of the present invention and a portable browser 22 are supplied to a viewing party on a computer readable medium illustrated as a DVD or CD ROM 14 useable with a computer input device such as drive 12, Drive 12 interfaces with a central processing unit for providing data such as the converted html-digestible files from the computer readable medium to an output device such as a display or printer,

[0021] In the above-described approach, the original imag date was converted into a second copy for html consumption. In a hybrid approach, data duplication may be avoided. DICOM image metadata is converted into a JSON object as described above. However, for pixel data conversion, an extra key-pair value is included in the metadata which stores the position of the pixel date in the DICOM image as offset from the beginning of the image. When the html page accesses the DICOM image, as byte stream. 16-bit values will be retrieved from each of the locations described in the extra key- value pair in the JSON obj ect. [0022] A binary reader uses AJAX call to retrieve the DICOM image as byte stream.

Pixel is the array of the pixel retrieved. [0023] The image is accessed using AJAX which is a .standard technology allowing an html page to load information from a Web Server, or in the case of some browser, from local file system, in the background. Exemplary code to allow the web page to access the

DICOM image includes:

this. Start - function (ready) {

var req - new XMLHtlpRequestQ;

req.open('GET', rl, true);

req.onreadystatechange = function () {

if (req.readyState— 4) {

fileCorrterrts = req.responseTexi;

fileSize = fileContents.length;

if (ready != null) ready():

}

1

req.overrideMimeTypei'text'plain; charset ::: x-user-defined') ;

[0024] The XMLHttpRequest object implements the AJAX call to retrieve the byte stream. The command overrideMimeType prevents the html page will from trying to interpret the data retrieved such that the data will be handled as a byte stream.

[0025] To subsequently retrieve the pixel data, the application retrieves the offset from the meta extra key-value pair provided within the JSOM object of metal information and accesses the byte stream. Since the byte stream stores a list of 8-bit bytes, the 16-bit. values can be computed by simply multiplying the high byte by 256 aod adding the low bytes. Exemplary code to allow the web page to access the byte stream as 16-bit values includes:

var nPixels = width * height;

for (var p = 0; p < nPixels; p++) {

var val = bReader.ReadByteAt(2- * p + offset) + bReader.ReadByteAt(2 * p +

1 + offset) * 256;

pixebfp] ;; val;

}

[0026] According to the schematic illustrated in FIG. 2, DICOM medical image data pertaining to a DICOM medical image to be viewed, may be sent from a database server 40 over a network including intranet 42 internet 46 or a combination of the two to a remote computing device for presentation to a display at 48 using the method described above. The computer readable program code 44 may be stored on a memory of a computer operably coupled to the database server, may be stored on a memory of the remote computing device or may be stored on a combination of the two or an intermediate computing device. Program code 44 may be referenced by a url within a browser processed on the remote computing device to facilitate asynchronous delivery of DICOM medical image data within the browser of the remote computing device without interfering with the display and behavior of an existing page displayed within the browser.

[0027] While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.