4D XCAT Phantom for Multimodality Imaging Research W. Paul Segars, PhD Carl E. Ravin Advanced Imaging Labs Duke University

X-ray CT Simulation Computational Models and Medical Imaging Simulation Computer model of X-ray CT scanner Simulated CT Images of the Phantom Computational models or phantoms –Provide a model of the subject’s anatomy and physiology Models of the physics of the imaging process –Simulate imaging procedures on the phantom patient

Computational Models Exact anatomy and physiology of the computer phantom are known providing a gold standard to evaluate and improve devices and techniques Computer phantoms have been used extensively to: –Optimize imaging systems design and protocols –Aid in the development and evaluation of new image reconstruction and correction algorithms

Computational Models Realistic models of anatomy and physiology are vital Without such, simulated results may not be indicative of what would occur in live experiments The development of realistic computational models is one of the most active areas of research in imaging and radiation dosimetry

XCAT Phantoms MaleFemale Based on Human Imaging Data Structures realistically defined using NURBS surfaces, widely used in computer graphics 5

Detailed Brain Model based on MRI 4D XCAT Phantom Anatomy

Detailed Breast Models of Different Densities Based on Breast CT 4D XCAT Phantom Anatomy

Imaging Simulations using the Computerized XCAT Phantoms 8

MRI CT Ultrasound Breast Imaging Simulations Using the 4D XCAT Phantom Mammography Tomosynthesis Positron Emission Mammography

10 Simulation of 4D Data End-diastole End-systole End-expirationEnd-inspiration Cardiac ModelRespiratory Model

Population of 4D XCAT Phantoms Create a population of hundreds of detailed phantoms to represent the public at large from infancy to adulthood Modeling patient variability is essential to mimic clinical trials Include cardiac and respiratory motions for 4D simulations First library of 4D phantoms

58 Adult Phantoms 12

42 Pediatric Phantoms 13

Anatomical Variations BMI: 21.9BMI: 22.7BMI: 28.5BMI: 36.1 Males

Anatomical Variations Females BMI: 18.2BMI: 22.3BMI: 28.6BMI: 35.5

The population of XCAT phantoms provide a valuable resource for investigating different imaging devices and the effects of anatomy and motion in imaging Combined with accurate models for the imaging process, the phantoms can provide a wealth of realistic, predictive imaging data to serve as a known truth from which to evaluate and improve imaging devices and techniques Conclusion

The phantoms have enormous potential to research new image acquisition strategies, image processing and reconstruction methods In future work, we plan to further expand this library, ultimately to a population of hundreds of phantoms ranging in age from newborn to adult Such a large compilation of phantoms will provide a great research tool for the imaging community Conclusion