Application of Care kV combined with Care Dose 4D in abdominal CT
10.3760/cma.j.issn.0254-5098.2017.01.013
- VernacularTitle:智能最佳管电压联合自动管电流在腹部CT 扫描中的应用
- Author:
Weiguo ZHANG
;
Tao JIANG
- Keywords:
Tomography,X-ray computed;
Intelligent optimum tube voltage technique ( Care kV);
Radiation dose
- From:
Chinese Journal of Radiological Medicine and Protection
2017;37(1):68-72
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the application of the intelligent optimum tube voltage ( Care kV) combined with automatic tube current ( Care Dose 4D) technique in dual source CT scanning for the abdomen .Methods 180 adult patients underwent whole abdominal CT examination from February 2016 to March 2016 of were selected as the retrospective research objects .On the basis of reference mAs of the image quality the patients were divided into three groups using completely randomized grouping method with 60 patients in each group, such as 250 mAs group, 200 mAs group, and 150 mAs group.The other scanning parameters and image reconstruction parameters were the same .The liver parenchyma CT values and image noise( SD) at the second hepatic portal level were measured .The signal-to-noise ratios ( SNR) in the three groups were compared as well as contrast to noise ratio ( CNR ) , noise ( SD ) , the average volume CT dose index (CTDIvol), dose length product (DLP) and effective dose(E).Results The kV and mAs values in the plain scan , arterial phase scan and portal phase scan in the three groups of patients had statistically significant differences(F=35.25, P<0.05).With the reducing of the refference mAs, the frequency of choosing lower kV in three groups of patients increased gradually .The CTDIvol, DLP and E of plain scan, arterial and portal phase in three groups of patientshad significant difference (F=31.51, P<0.05).With the decline of the reference mAs, the radiation dose decreased gradually , with 150 mAs group lowest.The SNR, CNR and noise of three phases in 250 mAs group and 200 mAs group had no statistically significant difference (F=1.61, P>0.05).In 250 mAs group and 150 mAs group, the SNR and the noise of plain scan and arterial phase images had no statistically significant difference ( F=1.98, P>0.05) , and SNR of portal phase images and CNR of three phases had statistically significant difference (F=27.64, P<0.05);In group 200 mAs and group 150 mAs, the SNR, CNR and noise of plain scan and arterial phase images had no statistically significant difference (F=1.95, P>0.05), and the SNR and CNR of portal phase images had significant difference (F=19.63, P<0.05).Conclusions For the combined use of Care kV and Care dose 4D,it is feasible to select appropriate reference mAs in reducing radiation dose without sacrificing imaging quality .
