摘要
目的比较容积CT剂量指数（CTDIvol）及体型特异性剂量评估（SSDE）在估算腹部CT扫描时患者所受辐射剂量的差异。方法采用Philips256螺旋cT扫描仪对180例患者进行上腹部CT增强扫描，在左肾静脉主干层面测量每例患者的左右径（LAT）、前后径（AP），计算有效直径（ED），同时记录每例被检者的CTDIvol值及体模的扫描直径，计算SSDE。将患者按照体质量指数（BMI）分为3组：A组，BMI〈20．0kg／m2;B组，BMI介于20．0—24．9kg／m2之间；C组，BMI〉24．9kg/m2。分别比较180例被检者及不同体质量指数组CTDIvol与SSDE之间的差异。结果180例被检者CTDIvcl和SSDE分别为（9．91±2．91）和（14．01±2．82）mGy，差异有统计学意义（t=-13．354，P〈0．01）。A组CTDIvol和SSDE分别为（7．96±1．83）和（12．83±2．52）rnGy（t=-8．417，P〈0．01）：B组分别为（9．28±1．76）和（13．62±2．18）mGy（t=-15．051，P〈0．01）；C组分别为（12．19±3．65）和（15．39±3．47）mGy（t=-4．535，P〈0．01）。此外，3组SSDE分别较CTDIvol平均增加了62．83％、47．80％和28．40％，即CTDIvol过低估算被检者的辐射剂量，且随着体质量指数的增加，CTDIvol与SSDE之间的差值越小。结论SSDE能够反映特定体型的被检者进行腹部CT扫描时所接受的辐射剂量。
Objective To compare the difference between volume computed tomography dose index （ CTDIvol ） and size-specific dose estimates （SSDE） in evaluating the radiation dose of abdominal CT scan. Methods Abdominal CT scan were performed on 180 patients with a Philips 256-slices spiral CT. The anterior-posterior dimension （AP） and lateral dimension （LAT） of each patients were measured at the level of left renal vein, and the effective diameter （ED） and SSDE were calculated with recorded CTDIvol Patients were categorized into 3 groups depending on body mass index （BMI）： group A, BMI 〈 20.0 kg/m2 ; group B, 20. 0 - 24. 9 kg/m2 ; group C, BMI 〉 24. 9 kg/m2. The differences between CTDIvol and SSDE of 180 patients and three different BMI groups were compared respectively. Results There was a significant difference between CTDIvol and SSDE of the 180 patients （t = - 13. 354, P 〈 0.01）, CTDIvol and SSDE were （9.91 ±2.91） and （14.01 ±2. 82） mGy, respectively. For group A, CTDIvol and SSDE were （7.96 ± 1.83 ） and （ 12. 83 ± 2. 52） mGy, respectively （ t = - 8. 417, P 〈 0.01 ）.Group B, CTDIvol and SSDE were （9.28 ± 1.76） and （ 13.62 ± 2. 18） mGy, respectively （t = - 15.051, P 〈0.01 ）. Group C, CTDIvol and SSDE were （ 12. 19 ±3.65） and （ 15.39 ± 3.47） mGy, respectively （t = -4. 535, P 〈 0. O1 ）. In addition, the mean percentage values of difference between CTDIvol and SSDE for the three groups were 62.83%, 47. 80%, 28.40%, respectively, which meant CTDIvol underestimated the radiation dose compared to SSDE. With the BMI increasing, the values of difference between CTDIvol and SSDE decreased. Conclusions SSDE can be used to estimate the radiation dose of abdominal CT scan for a given size person.
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2016年第1期74-77,共4页
Chinese Journal of Radiological Medicine and Protection
基金
宁夏留学人员创新创业项目（2013）
