Improving the stratification power of cardiac ventricular
shape
Revealing differences in anatomical remodelling of the systemic
right ventricle
E.Zacur1, J.Wong2, R.Razavi2, T.Geva3, G.Greil2, P.Lamata1
1 Dept. Biomedical Engineering, Kings College London, UK2 Div.
Imaging Sciences, Kings College London, London, UK3 Boston
Childrens Hospital, Harvard Medical School, USA
Take home messagesModels to reveal biomarkers
Shape biomarkerModel: smooth ellipsoidUnveil differences in
development
OverviewHLHS: the clinical problem and hypothesis
Coping with data
Revealing growth differences
How good is the picture?
HLHS
Hypoplastic Left Heart Syndrome (I)
4 in 10.000 births
Hypoplastic Left Heart Syndrome (II)Challenges:Complex surgery -
different schoolsSmall numbers many factorsOpportunity: huge impact
for life
Shunts: two schools
modified Blalock-Taussig (MBT)right ventricle-to-pulmonary
artery (RVPA)
Impact of shunt choice?Outcome (transplantation free) [1]:Early
outcome: RVPA betterMid outcome (32 months): equal
Hypothesis: scar in RVPA introduces an adverse remodelling
(growth) and impaired RV function as compared to MBT.[1] Frommelt
et al (2014). "Impact of initial shunt type on cardiac size and
function in children with single right ventricle anomalies before
the Fontan procedure: the Single Ventricle Reconstruction Extension
Trial", JACC 64(19):2026-2035.
Computational Anatomy is able to reveal differences in RV growth
caused by a choice of shunt technique.
clinicalDataModel fittingPrincipal Component Analysis
Model: ellipsoidMinimise acquisition / segmentation
artefacts
Mesh personalization[2] Lamata P et al (2011), An accurate, fast
and robust method to generate patient-specific cubic Hermite
meshes. Med Image Anal. 15(6):801-13[3] Lamata P et al (2014), An
automatic service for the personalization of ventricular cardiac
meshes. J R Soc Interface. 11(91):20131023.
Common shape changes?Shape variation due to:Errors,
artefactsPhysiological causesDecompose shape in orthogonal
componentsReduce dimensionalityGet the salient modes
M
1
2
3
4
5
113
128
Revealing growth differences
Mean
34
Mode 1
Modes 2, 3, 4
RVPA shunt
MBT shunt
Mode 1
Stage I (all) vs MBT
Stage I (all) vs RVPA
How good is the picture?
Better than traditionalDifferences never revealed beforeRisk:
black boxMitigation plan: map of regional changes
Function correlates with shape (remodelling) Impaired
contraction in RVPA [4]
[4] Wong et al (2015). "Using cardiac magnetic resonance and
computational modelling to assess the systemic right ventricle
following different Norwood procedures: a dual centre study", J
Card Mag Res, 17(Suppl 1):M12.
Still a blurry pictureData issues: short axis stack,
etcProcessing issues. Fitting error / LV length = 1.43/78 mmAdult
LV: 1.28/95 mm
Take home messagesModels to reveal biomarkers
Shape biomarkerModel: smooth ellipsoidUnveil differences in
development
Acknowledgements
