Image modifications

Defacing

This profile applies defacing to the image data of the DICOM instance.

This profile can only be applied to images in the Axial orientation of the following SOP:

  • 1.2.840.10008.5.1.4.1.1.2 - CT Image Storage
  • 1.2.840.10008.5.1.4.1.1.2 - Enhanced CT Image Storage

This profile element requires the following parameters:

  • name: description of the action applied
  • codename: clean.recognizable.visual.features
  • condition: optional, defines a condition to evaluate if this profile element should be applied to this DICOM instance

Pixel Data Cleaning

This profile applies a mask defined by the user on the DICOM instance pixel data to remove identifying information burned in the image.

The details on the masks definition can be found below.

This profile is applied only on the following SOP:

  • 1.2.840.10008.5.1.4.1.1.6.1 - Ultrasound Image Storage
  • 1.2.840.10008.5.1.4.1.1.7.1 - Multiframe Single Bit Secondary Capture Image Storage
  • 1.2.840.10008.5.1.4.1.1.7.2 - Multiframe Grayscale Byte Secondary Capture Image Storage
  • 1.2.840.10008.5.1.4.1.1.7.3 - Multiframe Grayscale Word Secondary Capture Image Storage
  • 1.2.840.10008.5.1.4.1.1.7.4 - Multiframe True Color Secondary Capture Image Storage
  • 1.2.840.10008.5.1.4.1.1.3.1 - Ultrasound Multiframe Image Storage
  • 1.2.840.10008.5.1.4.1.1.77.1.1 - VL Endoscopic Image Storage

Or if the tag value Burned In Annotation (0028,0301) is “YES”

This profile element requires the following parameters:

  • name: description of the action applied
  • codename: clean.pixel.data
  • condition: optional, defines a condition to evaluate if this profile element should be applied to this DICOM instance

The condition parameter can be used to exclude the images coming from a specific machine for example.

profileElements:
  - name: "Clean pixel data"
    codename: "clean.pixel.data"
    condition: "!tagValueContains(#Tag.StationName,'ICT256')"

Masks Definition

The mask definition requires the following parameters:

  • stationName: source station name that is matched against the attribute Station Name in the DICOM instance. It allows the mask to be specific depending on the station that generated the image. The value can also be set to * to match any station.
  • color: color of the mask in hexadecimal
  • rectangles: defines the list of rectangles to apply to mask identifying information

The mask definition can have these optional parameters:

  • imageWidth: mask specific to an image of a given width in pixels, this value will be matched against the value of the Columns attribute in the DICOM instance
  • imageHeight: mask specific to an image of a given height in pixels, this value will be matched against the value of the Rows attribute in the DICOM instance.

The selection of the mask based on the image size requires both attributes to be set, height and width. The definition of the width or height solely is not supported.

A rectangle is defined by the following required parameters:

  • x: x coordinate of the upper left corner of the rectangle
  • y: y coordinate of the upper left corner of the rectangle
  • width: width of the rectangle
  • height: height of the rectangle

The upper left corner of the image corresponds to the coordinates (0,0).

The schema below illustrate the definition of a rectangle having the following parameters (25, 75, 150, 50).

Rectangles example Rectangles example

The example below shows how to define a default mask (stationName: *), a mask specific to the R2D2 station and a more specific mask applied only depending on the image size.

Depending on the instance image size and station name, the following actions will be performed:

  • The instance Rows, Columns and Station Name attributes are retrieved.
  • These values are matched against the masks defined in the masks list. If an exact match is found using the imageWidth, imageHeight and stationName values, this mask is used for the cleaning pixel action. In this example, if the instance contains the value 1024 in the Rows and Columns attribute and “R2D2” in the station name attribute, the third mask will be selected.
  • If no match is found, the image size attributes are removed and a match is performed only on the station name attribute. In this example, if the instance contains “R2D2” in the Station Name attribute, the second mask will be selected without any regards for the image size of the instance.
  • If no match is found, the default mask will be selected, here the first one.
masks:
  - stationName: "*"
    color: "ffff00"
    rectangles:
      - "25 75 150 50"
  - stationName: "R2D2"
    color: "00ff00"
    rectangles:
      - "25 25 150 50"
      - "350 15 150 50"
  - stationName: "R2D2"
    imageWidth: 1024
    imageHeight: 1024
    color: "00ffff"
    rectangles:
      - "50 25 100 100"

Pixel Data Cleaning Exceptions

In some cases, often based on the manufacturer and equipment, pixel data can contain embedded identifying information. Below is an exhaustive example illustrating how to apply cleaning pixel profile element depending on the station that produced the image, applicable to any DICOM modality.

name: "Clean pixel data"
version: "1.0"
minimumKarnakVersion: "0.9.2"
defaultIssuerOfPatientID:
profileElements:
  - name: "Add tag BurnedInAnnotation if does not exist"
    codename: "action.add.tag"
    condition: "tagValueContains(#Tag.StationName, 'ICT256') && !tagIsPresent(#Tag.BurnedInAnnotation)"
    arguments:
      value: "YES"
      vr: "CS"
    tags:
      - "(0028,0301)"

  - name: "Set BurnedInAnnotation to YES"
    codename: "expression.on.tags"
    condition: "tagValueContains(#Tag.StationName, 'ICT256')"
    arguments:
      expr: "Replace('YES')"
    tags:
      - "(0028,0301)"

  - name: "Clean pixel data"
    codename: "clean.pixel.data"

  - name: "DICOM basic profile"
    codename: "basic.dicom.profile"

masks:
  - stationName: "*"
    color: "ffff00"
    rectangles:
      - "25 75 150 50"
  - stationName: "ICT256"
    color: "00ff00"
    rectangles:
      - "25 25 150 50"
      - "350 15 150 50"