Péter Bujtár1, János Simonovics2, Gergely Zombori3, Zsolt Fejer4, Attila Szucs5, Attila Bojtos6, Wilson Otto Batista7, Károly Váradi2, George K B Sándor8. 1. Department of Oral and Maxillofacial Surgery, University Hospitals of Oulu; Department of Oral and Maxillofacial Surgery, Southern General Hospital, Glasgow, United Kingdom. Electronic address: bujpet@yahoo.co.uk. 2. Department of Machine and Product Design, Faculty of Mechanical Engineering, Budapest University of Technology and Economics (BME), Budapest, Hungary. 3. Centre for Medical Image Computing (CMIC), University College London, London, United Kingdom. 4. Department of Human Morphology and Developmental Biology and Department of Anatomy, Histology and Developmental Biology, Semmelweis University, Budapest, Hungary. 5. Department of Oral-Maxillofacial Surgery and Stomatology, Semmelweis University, Budapest, Hungary. 6. Department of Mechatronics, Optics and Engineering Informatics, Faculty of Mechanical Engineering, Budapest University of Technology and Economics (BME), Budapest, Hungary. 7. Federal Institute of Education, Science, and Technology (IFBA), Salvador, Bahia, Brazil. 8. Oral and Maxillofacial Surgery, University of Oulu; Biomeditech, Institute of Biomedical Technology, University of Tampere, Tampere, Finland.
Abstract
OBJECTIVE: This study aimed to explore whether cone beam computed tomography (CBCT) and multislice computed tomography (MSCT) can be used to quantify tissue density and to determine if the Hounsfield unit scale is applicable. STUDY DESIGN: A clinical MSCT scanner and effective energy adjusted photon beam attenuation references were used to compare the gray scale of CBCT images of the mandible region. A phantom was scanned using axial cadaver slices and 4 different homogeneous reference objects. The consistency of the references' gray values and 12 linear profile lines from both scanner data sets were compared. RESULTS: The gray values of the 2 scans showed strong correlation with quantified position-dependent differences as an outcome of the validation process. CONCLUSIONS: The introduced internal, in-scan validation is able to estimate and has a potential to compensate for the differences between MSCT and CBCT protocols. This validation serves as a guide in situations where the users can expect deviations.
OBJECTIVE: This study aimed to explore whether cone beam computed tomography (CBCT) and multislice computed tomography (MSCT) can be used to quantify tissue density and to determine if the Hounsfield unit scale is applicable. STUDY DESIGN: A clinical MSCT scanner and effective energy adjusted photon beam attenuation references were used to compare the gray scale of CBCT images of the mandible region. A phantom was scanned using axial cadaver slices and 4 different homogeneous reference objects. The consistency of the references' gray values and 12 linear profile lines from both scanner data sets were compared. RESULTS: The gray values of the 2 scans showed strong correlation with quantified position-dependent differences as an outcome of the validation process. CONCLUSIONS: The introduced internal, in-scan validation is able to estimate and has a potential to compensate for the differences between MSCT and CBCT protocols. This validation serves as a guide in situations where the users can expect deviations.