Multi-Modality Image registration

1. By
Habib Baluwala
MULTI-MODALITY
MEDICAL IMAGE
REGISTRATION/FUSION

2. Medical Image Fusion
• Combines complementary information from different image
modalities into a single image
• Revolutionized medical diagnosis
• Whole body Oncology
• Brain
• Cardiology
• Radiotherapy and surgical planning
• Helps to raise clinical value of certain modalities like PET
• Fusion Approaches
• Hybrid imaging – External markers
• Software approach

3. 3
PET (Metabolic info)+CT (Anatomical info) = Fused Image
• Improved anatomical
localization
• Improved staging of
cancer
• Radiotherapy planning
• High spatial
resolution (as high as
0.5 mm)
• Good tissue
contrast
• Differentiate between
benign and malignant
tumours
• Better sensitivity in
the detection of distant
metastases
CT-PET HYBRID SCANNER

4. PET/MRI HYBRID SCANNERS
• Advantages
• No Ionizing radiation
• Better characterization of soft tissues , bone marrow and spine
• Disadvantages
• Attenuation correction is challenging
• Segmentation-based
• Atlas-based

5. Hybrid scanners
• Advantages
• More precise co-registration and anatomic localization
• Low computational complexity
• Disadvantages
• Not economical
• Full utilization of the device is seldom achieved
• Software registration might still be needed to compensate for non-rigid
registration

6. Software approach - Registration
• Advantages
• Provides flexibility
• Economical
• Disadvantages
• Time-consuming
• Observer dependent
• Computationally expensive

7. Similarity function/ Cost function
• Segmentation based approaches
• Statistical voxel intensity-based approaches
• NMI (Normalised Mutual Information)
• MI (Mutual Information)
• NCC (Normalized cross correlation)
• Learning based similarity measures
• KL distance based(Kullback-Leibler distance)

8. Transformation model
• Optical flow
• Spline based methods
• Fluid registration
• Elastic registration
• Demon’s registration

9. Visualization of data
• Adjacent (side-by-side) displays
• Window displays
• Fade in/out displays
• Checkerboard displays
• Gaze-contingent multi-modality displays
• Hybrid fused displays
• Interleaved video displays

10. New applications
• Interventional radiology using ultrasound
• Ablation
• Biopsy
• Pain Management
• Ultrasound-CT registration
• External- markers based
• Software based

11. Final Words
• Email : habibbaluwala@gmail.com