agenda : update master tracers update validation vs pathology
DESCRIPTION
X PMT meeting – June 6, 2012. Agenda : Update master tracers Update validation vs pathology Hippocampal 3D Object for AR Visualization Papers Next c ongress presentations & meetings. Benchmark Images. ADNI scans: 2 x 5 Scheltens’s atrophy score x 2 sides x 2 magnet strengths (1.5-3T) - PowerPoint PPT PresentationTRANSCRIPT
Agenda:
- Update master tracers- Update validation vs pathology- Hippocampal 3D Object for AR Visualization- Papers- Next congress presentations & meetings
X PMT meeting – June 6, 2012
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 subjectsreceived feedback in cases of little compliance to the Harmonized Protocolcorrected segmentations accordingly
Benchmark Images
Left Hippocampus Right Hippocampus Intra-rater 1.5T vs 3T (n=10) MB 0.971 (0.729-0.994) 0.969 (0.114-0.995) RG 0.955 (0.829-0.989) 0.956 (0.845-0.989) GP 0.889 (-0.015-0.980) 0.926 (0.056-0.987) LA 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
1 tracer? (which one? A master? A naive qualified on harmo prot??O 3? (meglio 1…)
Segmentation based on Harmonized Protocol:
Tot ante mortemTot 43 postmortem MRIs
TOT images……
Analysis based on the information available for each dataset
Mayo ClinicAD + CTRL dataset
with pathologically confirmed diagnosis (Braak’s stages),
but not postmortem hippocampal measurement
Mony DeLeon15 AD + 5 CTRL at 1.5T
postmortem MRI and quantitative histology
(possible additional AD cases)
Liana Apostolova(23 hippos at 7T)
CA1 neuronal counts,tau and Abeta
immunoreactivity measures?
?
?
?how many
Validation versus pathology
Originally designated sample: (Bobinski et al., 2000)11 AD + 4 CTRLpostmortem MRI and quantitative histology
de Leon: 15 AD + 5 CTRLpostmortem 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
CTR SUBJ
Affected SUBJ
Manual Tracing (Simon)
Tool N° 1(FSL-FIRST)
Tool N° 2(FreeSurfer) …
Segmentation Procedures
…
…
*MODELs inAR
MODELs to be
ComparedthroughSPHARM
Common in all
Manual
Tool2
Tool1
vs.
* * *
*
CTR
Aff Subj
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 PROTOCOLSASSESSMENT OF SOURCES OF
VARIANCE TRAINING SET DEVELOPMENT
VALIDATION VS PATHOLOGY
GOLD STANDARD
Harmonized ProtocolADNI scans: 2 x 5 Scheltens’s
atrophy score x 2 sides x 2 magnet strengths (1.5-3T)
Total per rater: 40 hippos
Harmonized ProtocolADNI 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 rater and center
Local ProtocolADNI scans: 2 x 5 Scheltens’s atrophy scores
x 2 sides x 2 magnet strengths (1.5-3T)
Harmonized ProtocolADNI scans: 2 x 5 Scheltens’s atrophy score x
2 sides x 2 magnet strength (1.5-3T)Total per rater: 40 hippos Harmonized Protocol:
Pathological datasets: Mayo Clinic and NYU
Total: about 40 hippos
TrainingADNI scans: 10 at 1.5T x 2 sides x 7
SUs x 2 tracing roundsTotal per rater: 40 hippos
20 naïve tracers 5 master tracers 1 tracer
REFERENCE PROBABILISTIC MASKS
with 95% C.I.
QUALIFICATION QUALIFICATION
Best 5 naïve tracers
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, VancouverAbstract n. 26292, poster presentationDefinition of Harmonized Protocol for Hippocampal SegmentationSession Date and Time: Saturday, July 14, 2012
- AAIC 2012, Vancouver Abstract n. 26291, oral presentationDefinition of Harmonized Protocol for Hippocampal SegmentationSession Title: Neuroimaging 4: MCI: imaging markers of AD pathologyPresentation Number: O2-11-02Session Start Day Time: Jul 16 2012 3:30PM
AAIC – July 2012Location: 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
VI Hippocampal Protocol Harmonization Meeting
GANTT