Medical Physics Seminar – Monday, February 6, 2012
Tetrahedron Beam Computed Tomography for Image Guided Radiotherapy
Dr. Tiezhi Zhang (guest of Dr. T. Rockwell Mackie)
Clinical Associate Professor, William Beaumount Hospital, Royal Oak Michigan
Cone beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy (IGRT) but its image quality is significantly inferior to that of fan beam CT. With a single rotation, the volumes enclosed by a cone (pyramid) and tetrahedron are exactly the same. Hence a volumetric CT scan can also be achieved by rotating a tetrahedron, which is formed by a linear x-ray source array and a linear detector array aligned orthogonal to each other. Tetrahedron beam computed tomography (TBCT) system can achieve improved image quality due to its scatter rejection mechanism and the use of high performance detector. Besides IGRT, TBCT will be also very useful in many other applications due to its diagnostic image quality, low cost and mobility. Current and future development of TBCT system will be discussed.