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Programs & Resources

LIDC - Reader Marking Process

Slide 1
LIDC Radiologists' Markings
A Multiple Reader/ Multiple Session Process

  1. Blinded Read
    Each Radiologist reads independently
    (Blinded to other readers' markings)
  2. Unblinded Read
    Each Radiologist re-reads, but is shown their own blinded read markings as well as blinded read markings of other radiologists reading the same case (unblinded to other reader's markings).
  • Note: No forced consensus at blinded OR unblinded read


Slide 2

  1. Nodules > 3mm:
    • Contour complete nodule volume,
    • Provide subjective ratings
  2. Nodules
    • Mark centroid only, no ratings
  3. Non-Nodules > 3mm:
    • Mark centroid only, no ratings
  4. Non-Nodules
    • Not marked at all


Slide 3
The Blinded Read

Slides 4-16
The slides illustrate the blinded reading process, with images of the computer screen seen during the marking.

Slide 17
End Blinded Reading Session

  • Writes xml file
    • Saves Contours of Nodules > 3mm
    • Saves locations of Nodules
    • Saves Locations of Non-Nodules > 3mm
    • Other info.


Slide 18 UnBlinded Reading Session

  • Begins when all assigned radiologists have completed blinded read
  • Read in xml files that represent blinded reads
  • NOTE: No forced consensus on either location of nodules nor on boundaries.


Slide 19

  • Read ALL markings
  • Decide which to keep
    • Can keep, delete or revise their own
    • Can reject/delete other's markings
    • Can copy other's markings (for non-Nods or Nod
    • Create their own contours based on others' markings (for Nod > 3mm)


Slides 20-43
The slides illustrate the unblinded reading process, with images of the computer screen seen during the marking.

Slide 44
We are also collecting Radiologists' subjective assessment of nodules > 3mm in terms of shape, density, etc.

Slide 45
Screen shot showing the collection of assessment of nodules.

Slide 46
End UnBlinded Reading Session

  • When ALL markings have either been confirmed or rejected, write the xml file from this reader that:
    • Saves final contours of Nodules > 3mm
    • Saves final subjective Ratings for Nodules > 3mm
    • Saves final locations of Nodules
    • Saves final locations of Non-Nodules > 3mm
    • Other bookkeeping info (institution of reader, etc.)