Abeer A Almashraqi1,2, Eman A Ahmed3,4, Nashwa S Mohamed3,5, Imad H Barngkgei6,7, Nader A Elsherbini8, Esam S Halboub2,9. 1. 1 Department of Oral Radiology, Faculty of Dentistry, Ibb University, Ibb, Yemen. 2. 2 Department of Maxillofacial Surgery and Diagnostic Sciences, College of Dentistry, Jazan University, Jazan, Saudi Arabia. 3. 3 Department of Oral and Maxillofacial Radiology, College of Oral and Dental Medicine, Cairo University, Cairo, Egypt. 4. 4 Department of Oral and Maxillofacial Radiology, Faculty of Oral and Dental Surgery, Misr University for Science and Technology, Giza, Egypt. 5. 5 Department of Oral and Maxillofacial Radiology, Faculty of Oral and Dental Medicine, Misr International University, Cairo, Egypt. 6. 6 Department of Oral Medicine, Faculty of Dentistry, Damascus University, Damascus, Syria. 7. 7 Department of Oral Medicine, Faculty of Dentistry, Syrian Private University, Damascus, Syria. 8. 8 Department of Medical Radiation Physics, Kasr Al-Aini Center of Oncology and Nuclear Medicine, Faculty of Medicine, Cairo University, Cairo, Egypt. 9. 9 Department of Oral Medicine and Diagnosis, Faculty of Dentistry, Sana'a University, Sana'a, Yemen.
Abstract
OBJECTIVES: This in vitro study aimed to assess radiation dose and image quality of different low-dose multidetector CT (MDCT) and CBCT imaging protocols in comparison with the standard MDCT protocol for maxillary sinus imaging. METHODS: Effective dose (E) and image quality of 10 MDCT (changing effective milliampere second starting from 141.3 EmAs to 20 EmAs) and 3 CBCT protocols (changing milliampere second and voxel size) were assessed throughout scanning an anthropomorphic head and neck Alderson Rando phantom. E values were calculated using thermoluminescent dosemeters (TLDs) fixed at 6 sensitive organs (14 sites) on the Rando phantom. Image quality was assessed objectively (by calculating the standard deviation values of the radiographic density of water) and subjectively (by assessing the diagnostic image quality using a four-graded scale: 1 = very good, 2 = good, 3 = acceptable and 4 = unacceptable). RESULTS: Two MDCT protocols (120 kV/32 EmA and 120 kV/25 EmA) had lower radiation doses with statistically significant differences (p < 0.001) compared with that of the standard MDCT protocol (120 kV/141.3 EmA), and they preserved a good diagnostic image quality. One CBCT protocol (120 kV/20 mA) had a reasonable radiation dose and good image quality. There were no statistically significant differences between the above-mentioned lower dose MDCT and CBCT protocols (p > 0.05) with respect to the radiation dose and image quality. CONCLUSIONS: The low-dose MDCT and CBCT protocols are viable methods for maxillary sinus examination as evaluated using the above-mentioned phantom that yield a good diagnostic image quality using E approximately 7 and 11 times lower than that of the standard MDCT, respectively. These findings were evaluated in the in vivo part of this project.
OBJECTIVES: This in vitro study aimed to assess radiation dose and image quality of different low-dose multidetector CT (MDCT) and CBCT imaging protocols in comparison with the standard MDCT protocol for maxillary sinus imaging. METHODS: Effective dose (E) and image quality of 10 MDCT (changing effective milliampere second starting from 141.3 EmAs to 20 EmAs) and 3 CBCT protocols (changing milliampere second and voxel size) were assessed throughout scanning an anthropomorphic head and neck Alderson Rando phantom. E values were calculated using thermoluminescent dosemeters (TLDs) fixed at 6 sensitive organs (14 sites) on the Rando phantom. Image quality was assessed objectively (by calculating the standard deviation values of the radiographic density of water) and subjectively (by assessing the diagnostic image quality using a four-graded scale: 1 = very good, 2 = good, 3 = acceptable and 4 = unacceptable). RESULTS: Two MDCT protocols (120 kV/32 EmA and 120 kV/25 EmA) had lower radiation doses with statistically significant differences (p < 0.001) compared with that of the standard MDCT protocol (120 kV/141.3 EmA), and they preserved a good diagnostic image quality. One CBCT protocol (120 kV/20 mA) had a reasonable radiation dose and good image quality. There were no statistically significant differences between the above-mentioned lower dose MDCT and CBCT protocols (p > 0.05) with respect to the radiation dose and image quality. CONCLUSIONS: The low-dose MDCT and CBCT protocols are viable methods for maxillary sinus examination as evaluated using the above-mentioned phantom that yield a good diagnostic image quality using E approximately 7 and 11 times lower than that of the standard MDCT, respectively. These findings were evaluated in the in vivo part of this project.
Authors: Denis Tack; Jacques Widelec; Viviane De Maertelaer; Jean-Marie Bailly; Christian Delcour; Pierre Alain Gevenois Journal: AJR Am J Roentgenol Date: 2003-10 Impact factor: 3.959