Jing Zou1, Juha Koivisto2, Jaakko Lähelmä3, Antti Aarnisalo4, Jan Wolff5, Ilmari Pyykkö6. 1. Hearing and Balance Research Unit, Field of Otolaryngology, School of Medicine, University of Tampere, Tampere, Finland Department of Otolaryngology-Head and Neck Surgery, Center for Otolaryngology-Head & Neck Surgery of Chinese PLA, Changhai Hospital, Second Military Medical University, Shanghai, China Jing.Zou@uta.fi. 2. Department of Physics, University of Helsinki, Helsinki, Finland. 3. PlanmecaOy, Helsinki, Finland. 4. Department of Otorhinolaryngology-Head and Neck Surgery, Helsinki University Central Hospital, Helsinki, Finland. 5. Hearing and Balance Research Unit, Field of Otolaryngology, School of Medicine, University of Tampere, Tampere, Finland Department of Oral and Maxillofacial Surgery/Oral Pathology, VU University Medical Center, Amsterdam, the Netherlands. 6. Hearing and Balance Research Unit, Field of Otolaryngology, School of Medicine, University of Tampere, Tampere, Finland.
Abstract
OBJECTIVE: To evaluate the impact of tube voltage, tube current, pulse number, and magnification factor on the image quality of a novel experimental set-up and the corresponding radiation. MATERIALS AND METHODS: Six human temporal bones with cochlear implant were imaged using various tube voltages, tube currents, pulse numbers, and magnification. The effect of radiation was evaluated using a metaloxide semiconductor field-effect transistor (MOSFET) dosimeter device on an anthropomorphic RANDO RAN102 male head phantom. A copper and aluminum combination filter was used for hardware filtration. RESULTS: Overall, 900 frames, 11 mA, and 88 kV provided the best image quality. In temporal bones imaged with the optimized parameters, the cochlea, osseous spiral lamina, modiolus, stapes, round window niche, and oval window landmarks were demonstrated with anatomic structures still fully assessable in all parts and acceptable image quality. The most dominant contributor to the effective dose was bone marrow (36%-37 %) followed by brain (34%-36%), remainder tissues (12%), extra-thoracic airways (7%), and oral mucosa (5%). CONCLUSIONS: By increasing the number of frames, the image quality of the inner ear details obtained using the novel cone-beam computed tomography improved.
OBJECTIVE: To evaluate the impact of tube voltage, tube current, pulse number, and magnification factor on the image quality of a novel experimental set-up and the corresponding radiation. MATERIALS AND METHODS: Six human temporal bones with cochlear implant were imaged using various tube voltages, tube currents, pulse numbers, and magnification. The effect of radiation was evaluated using a metaloxide semiconductor field-effect transistor (MOSFET) dosimeter device on an anthropomorphic RANDO RAN102 male head phantom. A copper and aluminum combination filter was used for hardware filtration. RESULTS: Overall, 900 frames, 11 mA, and 88 kV provided the best image quality. In temporal bones imaged with the optimized parameters, the cochlea, osseous spiral lamina, modiolus, stapes, round window niche, and oval window landmarks were demonstrated with anatomic structures still fully assessable in all parts and acceptable image quality. The most dominant contributor to the effective dose was bone marrow (36%-37 %) followed by brain (34%-36%), remainder tissues (12%), extra-thoracic airways (7%), and oral mucosa (5%). CONCLUSIONS: By increasing the number of frames, the image quality of the inner ear details obtained using the novel cone-beam computed tomography improved.