Radiation dose evaluation of multi detector CT for head and neck (Excluding the Brain)

Abstract

The purpose of this study was to evaluate the radiation dose between two types of multiple detector rows CT. Radiation dose from various clinical protocol parameters for head and neck (not included the brain) were measured in radiology department, King Chulalongkorn Memorial Hospital with 4 and 16 multi-detector rows CT (MDCT). Central and surface radiation doses were measured in PMMA head phantom with an ionization chamber is inserted. The weighted CT dose index (CTDI[subscript w]) and average dose (Dave) were calculated for all protocol parameters. Image noise was measured from CT monitor after scanning in each protocol parameters. CTDI[subscript w] values and image noise for two MDCT scanners are compared. CTDI[subscript w] values of 16 MDCT, used routine protocol parameter for sequential mode, is 66.36 mGy and CTDI[subscript vol] is 24.77 mGy for spiral mode. CTDI[subscript w] value for Sensation 4 in sequential and spiral mode is 60.24 mGy and CTDI[subscript voi], 29.59 mGy. The study can be concluded that the radiation doses of Siemens Sensation 4 MDCT scanner were significantly greater than Sensation 16 at the same protocol parameter. The image quality related to the protocol parameter, the lower kv and mAs might be degraded image quality. The quality criteria guidelines may be helpful in determining optimal parameters.