Computer Assisted Surgical Planner for Craniofacial Reconstruction – Imaging Techniques Mohammad Azam Rana 1 , Halim Setan 1 , Zulkepli Majid 1 and Albert K. Chong 2 1 Department of Geomatic Engineering, Faculty of Geoinformation Science & Engineering, Universiti Teknologi Malaysia 2 School of Surveying, University of Otago, Dunedin, New Zealand mazamrana@hotmail.com 1 , halim@fksg.utm.my 2 , zulkepli@fksg.utm.my 3 & chonga@albers.otago.ac.nz 4 Abstract Computer Tomography (CT) and Magnetic Resonance Imagery (MRI) have had an enormous impact in medicine. Using medical imagery, Computer Assisted Surgery (CAS) systems decrease the invasiveness of surgical procedures, increase accuracy and facilitate surgical planning and analysis. Craniofacial anomalies and fine anatomic details of facial traumic injuries can be well studied with such imaging techniques. This research is focused on reconstruction of human hard/soft tissues and anthropometric landmarks for craniofacial surgery. The data capture devices used include CT scanner, 3D Laser Scanner and Close Range Photogrammetry. The visualization of soft tissue superimposed on hard tissue, display of tissue with varying opacity, and cutting of tissues for detailed analysis and planning has been demonstrated in this paper. Keywords: CAS, surgical planner, soft tissue, hard tissue, cutting 1. Introduction Radiological science in the last two decades has witnessed a revolutionary progress in medical imaging and computerized medical image processing. The development and advances in multidimensional medical imaging modalities such as X-ray Mammography, X-ray Computed tomography (CT), Single Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET), Ultrasound, Magnetic Resonance Imaging (MRI) and functional Magnetic Resonance Imaging (fMRI) have provided important radiological tools in diagnosis and treatment evaluation and intervention of critical diseases for significant improvement in health care [1][2]. The clinical significance of radiological imaging modalities in diagnostic and treatment of diseases is overwhelming. While planar X-ray imaging was the only radiological imaging method in the early part of the last century, several modern imaging modalities are in practice today to acquire anatomical, physical, metabolic and functional information from the human body. The commonly used medical imaging modalities capable of producing multidimensional images for radiological applications are CT, MRI, SPECT, PET and Ultrasound. Simple planar radiographic imaging methods such as X-rays and mammograms usually provide images on a film through an external radiation source (X-ray). These planar radiographic imaging methods provide high quality analog images that are shadow or two-dimensional projected images of three-dimensional organs. On the other hand, recent complex medical imaging techniques such as X-ray CT, MRI, SPECT, PET and ultrasound provide multi-dimensional digital images. These multi- dimensional digital images of physiological structures can be manipulated to visualize hidden characteristic diagnostic features that are difficult or impossible to see with planar imaging methods. In many critical radiological applications, the multi- dimensional visualization and quantitative analysis of physiological structures provide extremely valuable information for diagnosis and treatment. The computerized processing and analysis of medical imaging modalities provide a powerful tool that helps physicians to make important clinical decisions. The organization of this paper is as follows. First, in section 2, we give an overview of medical imaging modalities. In section 3 we elaborate the imaging methods being used in this research. Section 3.1 discusses Laser Scanning, section 3.2 discusses Close Range Proceedings of the Geometric Modeling and Imaging― New Trends (GMAI'06) 0-7695-2604-7/06 $20.00 © 2006 IEEE