成人踝、腕关节低剂量螺旋CT扫描可行性研究

目的：比较256层螺旋CT在不同剂量条件下所获得的图像质量，以评价踝、腕关节低剂量扫描对关节正常结构显示及其图像质量的影响，从而探讨256层螺旋CT踝、腕关节低剂量扫描的可行性及其临床价值。方法收集在本院就诊的成年患者106例（130个腕、踝）。常规剂量条件组120 kV/240 mAs （对照组），低剂量条件组100 kV/100 mAs，100 kV/80 mAs，100 kV/60 mAs，80 kV/60 mAs（实验组）。对所得原始数据进行重建处理后，以同层面感兴趣区测得CT值计算标准差（SD）记为客观评分，由两位放射科专家以双盲的方式对各扫描剂量条件下所得图像进行主观评分，用统计软件对所得分数进行数据分析。结果当扫描条件为120 kV/240 mAs，100 kV/100 mAs，100 kV/80 mAs，100 kV/60 mAs，80 kV/60 mAs时，剂量长度乘积（dose length product, DLP）分别为235.74±17.34，43.94±6.33，40.88±4.17，26.48±3.41，18.19±1.72，主观评分为3.97±0.16，3.58±0.51，3.29±0.46，3.06±0.27，2.65±0.53，客观评分分别为7.76±1.68，10.18±3.97，23.03±4.17，34.88±6.27，43.83±7.17。结论当扫描条件降至100 kV/60 mAs，患者DLP降至（26.48±3.41） mGy·cm，主观评分为3.06±0.27，所得图像中优级图像比例降低，但低剂量下的横断及三维图像能够较好显示解剖关系，符合临床需要，并保护了患者。

Feasibility research about low-dose spiral CT scanning on ankle and wrist articulation in adults

Objective To compare the image quality under different doses conditions, and to evaluate the effect of low-dose scanning of ankle articulation and wrist articulation on the representation of normal structure and on the image quality under the condition of applying 256-slices spiral CT scanning, then to explore the feasibility and clinical significance of 256-slices low-dose spiral CT scanning of temporal bone. Methods The data of 106 （130 wrist and ankle） patients who were received CT examination in our hospital were collected. Conventional dose condition was 120 kV/240 mAs （control group）, low-dose condition groups were 100 kV/100 mAs, 100 kV/80 mAs, 100 kV/60 mAs and 80 kV/60 mAs （experimen-tal groups）. With the reconstruction of the acquired images, the standard deviation （SD） of CT in the regions of interest at the same level was used as the objective score; by double-blind review from two experts of radiology, evaluation of images under all kinds of the scanning doses was as subjective score. The score was analyzed with statistical method. Results When scanning dose conditions were 120 kV/240 mAs, 100 kV/100 mAs, 100 kV/80 mAs, 100 kV/60 mAs, 80 kV/60 mAs, DLP was 235.74±17.34,43.94±6.33,40.88±4.17,26.48±3.41,18.19±1.72 , respectively; subjective score was 3.97±0.16, 3.58±0.51, 3.29±0.46, 3.06±0.27, 2.65±0.53, respectively;objective score （noise） was 7.76±1.68, 10.18±3.97, 23.03±4.17, 34.88± 6.27, 43.83±7.17, respectively. Conclusion When scanning condition is decreased to 100 kV/60 mAs, the dose of patient decreased from （235.74±17.34） mGy·cm to （26.48±3.41） mGy·cm, subjective score was 3.06 ±0.27, the CT 3D image quality tended to be in sound level, the portion of superior quality image decreased, but with low dose volume, the axial images and 3D images could represent the anatomical relation better, which could meet the clinical demand and protect the patient.