Model-Based%20Registration%20of%20X-ray%20Mammograms%20and%20MR%20Images%20of%20the%20Female%20Breast

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Model-Based Registration of X-ray Mammograms and
MR Images of the Female Breast

• N.V. Ruiter, T.O. Müller, R. Stotzka, H.
  Gemmeke,Forschungszentrum Karlsruhe, Germany

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Motivation
Support multimodal breast cancer diagnosis
MR image

• ?

• Locate lesion in complementary modality

• O

• O

X-ray mammogram
? Registration Find geometric
correspondence
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Registration Problem
Images not directly comparable !

• X-ray mammography
• 2D projection
• Large deformation
• Only one projection per deformation

? Add information using a biomechanical
model
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Process of Registration
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Problems of Deformation Model

• Large deformation of soft tissue
• Details of deformation process unknown
• Exact patient position
• 3D shape of breast
• Thickness of deformed breast
• Compression force
• Tissues of the breast
• Only large scale structures resolved in MR image
• Material models in literature
• Inconclusive
• Not plausible for large deformation

Plate compression
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Specification of Deformation Model

• Adapt global parameters
• Projection angle by non-linear scaling
• Volume is preserved ? estimate thickness
• Finite Element Model
• Large deformations (gtgt5), (nearly)
  incompressible materials
• Material model
• Evaluation of models for breast tissue
• ? Neo Hookean model, homogeneous tissues
• Two step modeling of deformation
• 1st step Mammographic deformation
• 2nd step Fine tuning using mammogram

Mammographicdeformation
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Results with Clinical Datasets

• Six clinical data sets Lesion position in X-ray
  mammograms and MR image known
• Smallest visible lesions in MR images 5 mm

• Prediction of lesion position
• MRI ? X-ray
• Mean center distance 4.3 mm (2.3 6 mm)
• Mean area overlap 81

• X-ray ? MRI
• Mean center distance 3.9 mm (1.6 6.4 mm)
• Mean volume overlap 91

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Results with Clinical Datasets

• MRI ?X-ray craniocaudal example

X-ray mammogram
Direct MR projection
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Conclusions

• Registration overcomes 3D deformation
• Successful first evaluation
• Localization with approx. 5 mm deviation
  (smallest visible lesion)
• Clinical evaluation
• Possible applications
• Support multimodal breast cancer diagnosis
  (also alternative 3D modalities)
• Simulation of breast deformation

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Thank you !
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Results with Clinical Datasets

• X-ray ? MRI

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3D Localization in MR Image

• Two simulations necessary

Oblique X-ray mammogram
Cranio-caudal X-ray mammogram
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Registrierungskomponenten I

• ? Integration Deformationsmodell in
  Registrierung
• MRT ? patientenspezifische Geometrie FE Modell
  
• I. Simulation Mammographische Deformation
• Projektionswinkel und Länge? 2D Registrierung
• Dickenänderung? aus Volumenerhaltung

?
MRT
FE Modell
FE Modell mit Platten
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Registrierungskomponenten II

• II.Simulation Feinabstimmung Mammogramm

1. Ergebnis der I.Simulation Näherung 3D
   deformierte Brust
2. Vergleich Konturen Schätzung 3D Brust
3. II.Simulation mit korrigierten Randbedingungen

? Individuell deformierte 3D Brust
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Objective and Problems
Register X-ray mammograms and MR volumes? Locate
lesion in complementary modality

• MR Image
• 3D volume, undeformed breast

• X-ray mammography
• 2 projections, 2D,hugely deformed breast
• Only 1 projection per deformation? Images not
  directly comparable !

• Additional information by model of deformation

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Motivation
Support multimodal breast cancer diagnosis
MR volume

• Fuse X-ray mammograms and MR volume
• Predict lesion position in complementary modality

• ?

• O

• O

X-ray mammogram

• Registration Find geometric correspondence