Transcript Diapositiva 1 - Hippocampal Protocol

X PMT meeting – June 6, 2012
Agenda:
- Update master tracers
- Update validation vs pathology
- Hippocampal 3D Object for AR Visualization
- Papers
- Next congress presentations & meetings
Benchmark Images
ADNI scans: 2 x 5 Scheltens’s atrophy score x 2 sides
x 2 magnet strengths (1.5-3T)
Total per rater: 40 hippos
The 5 Master Tracers
completed segmentation of R and L hippos of the 10
subjects
received feedback in cases of little compliance to the
Harmonized Protocol
corrected segmentations accordingly
Benchmark Images
MB
RG
GP
LA
Left Hippocampus
Right Hippocampus
Intra-rater 1.5T vs 3T (n=10)
0.971 (0.729-0.994)
0.969 (0.114-0.995)
0.955 (0.829-0.989)
0.956 (0.845-0.989)
0.889 (-0.015-0.980)
0.926 (0.056-0.987)
0.949 (0.757-0.988)
0.954 (0.791-0.989)
DW
0.959 (0.846-0.990)
0.974 (0.889-0.994)
Inter-rater (n=10)
1.5T
0.949 (0.864-0.986)
0.961 (0.897-0.989)
Inter-rater (n=10)
3T
0.949 (0.860-0.986)
0.965 (0.897-0.991)
Validation vs Pathology
Validation versus pathology
?
?
how
many
1 tracer? (which one? A master? A naive qualified on harmo prot??
O 3? (meglio 1…)
Mayo Clinic
AD + CTRL dataset
with pathologically confirmed
diagnosis (Braak’s stages),
but not postmortem hippocampal
measurement
?
Mony DeLeon
Liana Apostolova
15 AD + 5 CTRL at 1.5T
postmortem MRI and
quantitative histology
(possible additional AD cases)
(23 hippos at 7T)
CA1 neuronal counts,
tau and Abeta
immunoreactivity measures
Segmentation based on
Harmonized Protocol:
?
Tot ante mortem
Tot 43 postmortem MRIs
TOT images……
Analysis based on the information available for each dataset
Validation versus pathology
Originally designated sample: (Bobinski et al., 2000)
11 AD + 4 CTRL
postmortem MRI and quantitative histology
de Leon: 15 AD + 5 CTRL
postmortem MRI and quantitative histology
possible additional AD cases
Jack: AD + CTRL dataset with pathologically confirmed diagnosis
(controls and AD), but not post-mortem hippocampal measurement.
Liana? 23 (one side only) 7T 60-hour postmortem scans (in progress:
CA1 neuronal counts, tau and Abeta immunoreactivity measures)
Hippocampal 3D Object for AR Visualization
Segmentation
Procedures
Manual Tracing
(Simon)
Tool N° 1
(FSL-FIRST)
Tool N° 2
(FreeSurfer)
…
…
CTR SUBJ
vs.
…
Affected
SUBJ
CTR
*
*
MODELs to
be
Compared
through
SPHARM
*
…
*MODELs
in
AR
Aff Subj
*
Common
in all
Manual
Tool1
Tool2
Alg1
Alg2
Alg3
Alg n
Papers describing the project
Survey of protocols (preliminary phase; published, JAD 2011)
Operationalization (preliminary phase; I revision, Alzheimer’s &
Dementia, MS n. ADJ-D-12-00094)
Axes check short report (Brescia Team, in progress)
Delphi consensus (Brescia Team, in progress)
Master tracers’ practice and reliability (Brescia Team, in
progress)
Development of certification platform (Duchesne and coll)
Validation data and Protocol definition (Brescia Team)
Validation vs pathology (TBD)
VALIDATION VS CURRENT PROTOCOLS
ASSESSMENT OF SOURCES OF VARIANCE
TRAINING SET DEVELOPMENT
GOLD STANDARD
VALIDATION VS PATHOLOGY
20 naïve tracers
5 master tracers
1 tracer
Local Protocol
ADNI scans: 2 x 5 Scheltens’s atrophy scores
x 2 sides x 2 magnet strengths (1.5-3T)
QUALIFICATION
Harmonized Protocol
ADNI scans: 2 x 5 Scheltens’s atrophy score x
2 sides x 2 magnet strength (1.5-3T)
Total per rater: 40 hippos
Assessment of variance due to rater and center
Training
ADNI scans: 10 at 1.5T x 2 sides x 7 SUs
x 2 tracing rounds
Total per rater: 40 hippos
Harmonized Protocol
ADNI scans: 2 x 5 Scheltens’s atrophy
score x 2 sides
x 2 magnet strengths (1.5-3T)
Total per rater: 40 hippos
REFERENCE PROBABILISTIC MASKS
with 95% C.I.
QUALIFICATION
Harmonized Protocol:
Pathological datasets:
Mayo Clinic and NYU
Total: about 40 hippos
Best 5 naïve tracers
Harmonized Protocol
ADNI scans: 2 sides x 5 Scheltens’s atrophy scores x 3
time points (bl-1y-2y) x 3 scanners (+ retracing @ bl)
x 2 magnet strengths (1.5-3T)
Total per rater: 240 hippos
Assessment of variance due to side, trace-retrace,
atrophy, time, scanner, rater
TRAINING SET
Assessment of agreement with
volume on pathology or ex vivo MRI
and correlation with neuronal density
Next congress presentations
AIC 2012, Vancouver
Abstract n. 26292, poster presentation
Definition of Harmonized Protocol for Hippocampal Segmentation
Session Date and Time: Saturday, July 14, 2012
-
- AAIC 2012, Vancouver
Abstract n. 26291, oral presentation
Definition of Harmonized Protocol for Hippocampal Segmentation
Session Title: Neuroimaging 4: MCI: imaging markers of AD
pathology
Presentation Number: O2-11-02
Session Start Day Time: Jul 16 2012 3:30PM
VI Hippocampal Protocol Harmonization Meeting
AAIC – July 2012
Location:
Fairmont Waterfront Vancouver, Princess Louisa Room
Date & Time: Wednesday, July 18, 2012 at 1:00 PM - 2:30 PM
AGENDA:
Benchmark Images
Qualification Platform
Improvement of the Harmonized Protocol (based on the
benchmark tracing phase)
Validation Phase 2 Advancing
Paper Publication
Publication Policy
GANTT