64层螺旋CT儿童鼻窦低剂量扫描

Objective Our objective was to show that in low-dose MDCT of the sinuses in children the effective dose can be lowered to a level comparable to that used for standard radiographic images, with resultant CT scans that are still of diagnostic image quality. Methods With the same protocol (0.5s/rot and pitch 41), a pediatric cranium specimen were scanned with 120kV and 100kV respectively (Toshiba Aquilion 64-row spiral CT) at different mA (80，40，30，20，10). The CT dose index and images were compared among the different mA groups. The minimum kV and mA value was determined. Thirty-three children were examined to test the validity of the minimum kV and mA value. Results The CT radiation dose was significantly reduced when mA from 80mA to 10mA. With the same 30mA, the CT radiation dose of 100kV was obvious less than 120kV (3.1mGy<4.8mGy). The minimum kV and mA value was 100kV and 30 mA. Thirty-three children were examined with 100kV, 30mA. All images were measured up and in accord with clinic results. The average CTDIVOL and DLP were 3.03±0.09（mGy），30.63±2.58 (mGy.cm), and the effective radiation dose was 0.07±0.003(mSv),which was only 1/10 compared to the routine radiation dosage. Conclusion The CT radiation dose would be the lowest in diagnostic image quality for pediatric para-nasal sinus scanning at 100kV, 30mA (15mAs) with Toshiba Aquilion 64-row spiral CT.