title: Ultrasound tomography imaging of radiation dose distributions in polymer gel dosimeters: preliminary study.
abstract: A novel imaging system for investigation of absorbed dose distributions in radiotherapy polymer gel dosimeters using ultrasound is introduced. A prototype transmission ultrasound computed tomography (UCT) imaging system is developed and evaluated. The imaging capabilities of the system are assessed through investigation of an irradiated polyacrylamide gel test phantom. Images based on transmitted signal amplitude and time of flight (TOF) of the ultrasonic signal through the phantom are reconstructed using a filtered backprojection technique. In general, the reconstruction of the square field in the TOF image was superior to the transmission image, however, transmission images displayed superior contrast to TOF images. The image quality achieved with this prototype system is promising and could be significantly enhanced through improvements, in particular through the development of more sophisticated experimental equipment. It is concluded that UCT is a viable technique for imaging absorbed dose distributions in polymer gel dosimeters and investigations are continuing to further improve the system.
authors.affiliation: Centre for Medical, Health and Environmental Physics, Queensland University of Technology, Brisbane, Australia.
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Mather
authors.forename: Clive
authors.initials: C
authors.lastname: Baldock
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D005782:Gels; D007091:Image Processing, Computer-Assisted; D015233:Models, Statistical; D019047:Phantoms, Imaging; D011108:Polymers; D011874:Radiometry / Q000379:methods*; D014054:Tomography / Q000379:methods*; D014057:Tomography, X-Ray Computed; D014465:Ultrasonics; D014463:Ultrasonography / Q000379:methods*
chemical_list: D000180:Acrylic Resins; D005782:Gels; D011108:Polymers; C016680:polyacrylamide gels