Invited talk at Myocardial Velocity Imaging 2011 (Leuven)

Atlas-based patterns detection. Examples from asynchronous hearts.

Nicolas Duchateau, Mathieu De Craene, Gemma Piella, Bart Bijnens, Alejandro Frangi

Information and Communication Technologies Department, Universitat Pompeu Fabra, Barcelona, Spain .

Adelina Doltra, Etel Silva, Marta Sitges

Hospital Clínic de Barcelona, IDIBAPS, Spain.

Saturday, March 19, 2011

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What is an atlas?

Average anatomy+

Variation around this average

=


Fibers VelocitiesThickness Strain

GeometryPeyrat et al., T

MI 2007

Atlas-based integrated biomarkers


Probabilistic biomarkersEncode normalityP-value = abnormality

Integrated image-based biomarkers

d1 <?> d2 d1 d2

patient

atlas

d = ???

Atlas-based quantification of motion abnormalities

De Craene et al. FIMH 2009


Atlas-based quantification of motion abnormalities

Radial velocity

Long. velocity

p-value (log scale)

(mm/s)

(mm/s)

Atlas

Healthy subjects

Patient to study

Duchateau et al. MEDIA 2011


How to plot p-values?

p-value (log scale)


! Temporal evolution at a fixed anatomical point

p-value (log scale)

Red = large abnormality

! Local maps at fixed time t


Base

Apex

Time

IVC Systole Diastole

Blue = Inward (vr<0)Red = Outward (vr>0)

p-value (log scale)

How to plot p-values?

! Spatiotemporal maps of abnormality



Patient classification into specific etiologies of HF [Parsai]

" Correction of specific mechanisms of dyssynchrony conditions response

" Predicitive value of specific classes

• Septal flash [Parsai]• Septal rebound stretch [De boeck]• Apical transverse motion [Voigt]

Why quantifying abnormalities? CRT context

C1= Intra DYS

C2= Inter DYS

C3= Long AV

C4= Short AV

C5= Other

Response rate per

classvs. Global response

rate ?

Parsai et al., EHJ 2009

De Boeck et al., EJHF 2009

Voigt et al., EHJ 2009


Fig.3: Septal flash mechanismWhat is a “septal flash” ?

Healthy volunteer CRT candidate with SF

4

Parsai, Bijnens et al., EHJ 2009


2D echo, 4-chamber view

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Patient population

21 Healthy volunteers

! 60 frames/s0.24 x 0.24 mm2

88 candidates OFF / ON / FU (11±2 months)EF < 35%, QRS duration > 120ms, and (or) NYHA class III-IV

! 30 frames/s0.24 x 0.24 mm2

CRT response:Clinical 6min walking test increase " 10% or NYHA class reduction " 1 point

Echocardiographic LV end-systolic volume reduction " 15%

(in alive patients without heart transplantation)



OFF

PV-maps vs visual inspection: agreement?

Mid inferoseptal

!" #$%!"!" !! "

#$%!" ! #$

Atlas-based

M-m

ode

Cohen’s Kappa = 0.88Observed agreement = 0.94



OFF

[Bleeker] Response rate with the current guidelines:

0.7 (clinical response) 0.5 (echo response)

" Ejection fraction <35%

" QRS duration >120ms

" and/or NYHA classification III-IV)

Predictive value of SF at baseline?

RespondersResponders Response rate

Response rate

SensitivitySensitivity SpecificitySpecificity

Total Clin. Echo. Clin. Echo. Clin. Echo. Clin. Echo.

CRT 88 72 53 0.82 0.60

SF (Visual) 55 48 44 0.87 0.80 0.67 0.83 0.56 0.69

SF (Atlas) 60 52 44 0.87 0.73 0.72 0.83 0.50 0.54

Bleeker et al. AJC 2006


CRT #9Septal flash

CRT #8Septal flash

CRT #12Left-right

interaction

Blue = Inward (vp<0)Red = Outward (vp>0)


OFF Follow-upLocal p-value

(log scale)

Monitor CRT outcome


! Extend to 3D imaging modalities (tMRI)

Future work

3D tMRI image provided by KCL, London.Saturday, March 19, 2011

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! Work with the full strain tensor information

Non-responder to CRT

OFF Follow-up

Future work

3D Ultrasound images provided by Hospital Clinic, BCN.Saturday, March 19, 2011

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! Work with the full strain tensor information

Responder to CRT

OFF Follow-up

Future work

3D Ultrasound images provided by Hospital Clinic, BCN.Saturday, March 19, 2011

Conclusions! Atlas-based patterns detection

! Generic concept, extendable to other pathological patterns and image modalities

! Automatic and reproducible analysis ! Information available at any spatiotemporal location! Comparison OFF/Follow-up performed at the same

location! Intrinsic notion of abnormality

! Application to CRT and Septal Flash detection! Automatic/Visual detection in good statistical agreement! Quantify patient evolution at follow-up

! How closer the patient gets to “normality”! Applied to a large (88) population of patients


Acknowledgements

! Projects! euHeart. FP7 european project! cvREMOD. Spanish project for technology transfer

! Institutions ! Universitat Pompeu Fabra! Hospital Clínic de Barcelona


Invited talk at Myocardial Velocity Imaging 2011 (Leuven)

Technology

Transcript of Invited talk at Myocardial Velocity Imaging 2011 (Leuven)