Transcript Diapositiva 1 - Hippocampal Protocol

XII PMT meeting – September 26, 2012
Agenda:
- New benchmark ICC and Dice’s
- Training set for Naïve
- Beta testers proposals
- Congress presentations
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
5 Master Tracers’ segmentations:
Corrections after check for overlapping discrepancies
Improved Harmonized Protocol (HP) in many points
HP re-sent to panelists
Benchmark Images
Overlapping agreement
Volume ICCs
Left Hippocampus
1.5T images: 0.73
3T images:
0.75
Maximum level for
Right Hippocampus
Intra-rater 1.5T vs 3T (n=10)
MB
0.981 (0.928-0.995)
0.986 (0.776-0.997)
RG
0.968 (0.879-0.992)
0.974 (0.902-0.994)
GP
0.943 (0.335-0.989)
0.968 (0.541-0.994)
LA
0.966 (0.819-0.992)
0.971 (0.818-0.993)
DW
0.981 (0.930-0.995)
0.986 (0.944-0.997)
Inter-rater (n=10)
human tracers???
1.5T
0.957 (0.881-0.988)
0.971 (0.916-0.992)
Inter-rater (n=10)
3T
0.943 (0.791-0.986)
0.962 (0.863-0.990)
? TIMING for Certif. Platform ?
Will need to recap with available tracers in the 20 centres
Training set for Naïve Tracers
- Liana Apostolova (7T)
-Brescia - Normative Archive
(1.5 and 3T;
12 images (different severity) per magnet field strength?)
Publication Policy
STANDARD FORM for submission:
TITLE of PROPOSAL:
PI / CENTRE:
AIM of the PROJECT:
METHODS of the PROJECT:
WHAT IS ASKED to the SC of the HARMONIZED HIPPOCAMPAL PROTOCOL
WHAT IS OFFERED to the HARMONIZED HIPPOCAMPAL PROTOCOL
PROJECT/COMMUNITY:
Beta tester submissions
Masami Nishikawa (comparison of VSRAD performance;
segmentation of human phantoms x HP)
Lei Wang
(library of atlases;
validation vs other algorithm/s x HP?)
Ronald Pierson
(train ANN of Brain Image Analysis, LLC
validation vs other algorithm/s x HP?)
Beta tester submissions
Lei Wang: use of “local” labels
“construction of a library of atlases for the purposes of mapping
MR scans such as the ADNI data set”
Asks: use of label already segmented based on local protocol
Asks: to be informed as to when harmonized labels are available
Offers: solving the conversion of MultiTracer files into more
common format
Beta tester submissions
Masami Nishikawa
Project aim: to validate the new version of VSRAD (Voxel-based
Specific Regional analysis system for Alzheimer’s Disease),
comparing it versus the Harmonized Protocol as the gold standard
method to manually measure hippocampal volume.
Asks: Harmonized Protocol
Offers: Hippocampal segmentations on 3 healthy volunteers scanned
twice by the 7 different machines will contribute for the validation of
the Harmonized Protocol.
Beta tester submissions
Ronald Pierson
Project aim: Compare the results of the current hippocampal
segmentation with other hippocampal definitions using BRAINS (Brain
Research: Analysis of Images, Networks, and Systems)
Asks: Harmonized Protocol
Asks: ADNI IDs of benchmark subjects
Offers: not clear
Congress Presentations
- CTAD (October, 29-31 2012)
Definition of the Harmonized Protocol for Hippocampal Segmentation
- DGPPN Symposium 2012 Berlin (Andreas Fellgiebel)
Segmentation of the hippocampus: Towards a joint EADC-ADNI harmonized protocol
- AAN 2013
EADC-ADNI Benchmark Images of Harmonized Hippocampal Segmentation
Papers describing the project
DONE
Survey of protocols (preliminary phase; published, JAD 2011)
Operationalization (preliminary phase; I revision, Alzheimer’s &
Dementia, MS n. ADJ-D-12-00094)
IN PROGRESS
Axes check short report (Brescia Team, in progress)
Delphi consensus (Brescia Team, in progress)
Master tracers’ practice and reliability (Brescia Team, in progr)
PLANNED
Development of certification platform (Duchesne and coll)
Validation data (Brescia Team – companion paper 1)
Protocol definition (Brescia Team – companion paper 2)
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
GANTT
CSF exclusion (n. labels)
using a single CSF label to exclude a
large CSF pool
using the same CSF label containing
two (or more) separate CSF area on
the same slice, for each hippocampus