Transcript Document
QIBA
Proposed Phase 1A Project
V5.0
QIBA Phantom Subgroup
N Petrick
RSNA QIBA Phantom Group
November 13, 2008
1
Outline of proposal
Modified 1A reader study
Outstanding issues
2
N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Study objective
Measure intra- and inter reader bias
and variability on phantom lesions
for:
Uni-dimensional size measurement
Semi-automated 3D volumetric
measure
Compare with fullyNotautomated
going to size for specific effect or
significance but just report as pilot
algorithm?
3
N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Nodule/scan dataset
Nodules (10 attached nodules)
-10 & +100HU
10, 20 mm spheres
10 mm ovoid, lobulated, spiculated
Okay
Scanner
Philips 16 slice
Exposure (120 kVp):
100 mAs okay
100 mAs
Slice thickness (50% overlap)
0.75 & 5.0 mm slices
0.75 mm slices okay
Recon kernel
Standard/medium (Still on table: Detail/Lung kernel)
Pitch
1.2
2 repeat scans
40 segmentations in set
Okay
4
N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Study Protocol
Reader:
6 RadPharm radiologists
Software:
Need to determine this?
Wendy will visit RadPharm and
provide more info next week.
In-house review software (Siemens?)
Semi-automated 3D volume software
Uni-dimensional measure (RESIST)
Which fully automated software?
5
N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Study Protocol
Reading session:
Readers read all cases in 2 different reading session
Random ordering
One-dimensional measure
Semi-automated segmentation
Session separated by 3 week?
Include duplicate cases within each read session (1/3-1/2
of cases for intra-reader estimates)
Any time restrictions?
Probably not
Any specific instructions?
Probably not
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N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Analysis
Okay
Estimate intra- and inter-reader
variability in the different volume
estimate
Estimate bias from known truth
Estimate variability
Compare the bias and variability with
the different methods
7
N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Outstanding issues
Objective-Okay
This is pilot, no sizing will be done
May want to at least look at this to see if we have a
reasonable study design
Data collection: Okay
+100 HU (all 1A scanner settings)
Acquired: 10 mm & 20 mm sphere, ovoid, spic, lob
-10 HU (all 1A scanner settings)
Acquired: 10 mm & 20 mm sphere
Missing: 10 mm ovoid, spic, lob (Est: 12/01/08)
10 mm aspherics okay
100 mAs okay
8
N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Outstanding issues
Readers-Okay
6 okay (base on expected effect size?)
Software-Open source option is available to use
Need to finalize which software
Contact Bob Ford to discuss
Study Issues
GUI
AVT designed interface?
Standard PACs interface?
How will nodule locations be provided to readers?
Full scans with nodule centers
Extracted ROIs
Can cases be directly uploading into PACs?
How to randomize cases during reading sessions
Data format for segmentations/measurements
Truth/scoring format
ROIs or full scans with lesion marked
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N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Pilot Study
Study protocol
9 nodules for segmentation
3 nodules with each segm. method
2 readers
Needs to be determined
2 slice thickness
10 mm -10 HU, sphere, spiculated
10 mm, +100 HU, lob., ovoid
20 mm, +100 HU, sphere
Timeframe
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N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Outstanding issues
Statistical
Can we measure intra-reader variance
with only 2-4 repeat reads?
What effect size can we distinguish?
Again, may want to explore but this study
will only measure as in a pilot
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N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Outstanding issues
Other issues
Need to define QIBA publication policy
Determine research team makeup
Lisa Kinnard & Marios Gavrielides from
FDA lab
Other Issues
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N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Draft 1A: Submissions
Conferences
ASCO
5/29-6/2/09 Orlando
Abstract Deadline: 1/6/09
RSNA
End Nov, 2009, Chicago
Abstract Deadline: 4/15/09
Journal
NEJM!
Radiology
Oncology journals?
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N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Action Items
Rick Avila to follow-up with caBIG
AVT group
Rick Avila to lead effort of Lesion
Ground Truth subgroup
Reporting Mechanism to be
discussed at later date
14
N Petrick
RSNA QIBA Phantom Group
November 13, 2008
Work Items and workgroup
??
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N Petrick
RSNA QIBA Phantom Group
November 13, 2008