成人骨盆骨折16层螺旋CT低剂量与常规剂量扫描的对照研究

目的评价成人骨盆骨折低剂量CT扫描的临床价值。方法选取骨盆骨折行CT检查的成人患者110例,随机抽取20例为常规剂量240mA扫描,剩余90例按体重指数（bodymass index,BMI）随机分成3组低剂量组（第一组BMI〈19kg/m2,第二组20kg/m2≤BMI〈28kg/m2,第三组BMI≥28kg/m2）,管电流分别使用40、80、120mAs,其余扫描参数同常规剂量组。记录各扫描剂量产生的容积CT剂量指数（CTDIvo）l和剂量长度乘积（DLP）。按正常图像（优）、图像有少许伪影（良）、图像有严重伪影（差）评定图像质量,并对图像满足诊断率进行比较。结果除120mA组的满足诊断率为93.3%,其余各组图像的满足诊断率均为100%,各低剂量组40、80、120mA的CTDIvol分别是常规剂量组的17.4%、34.8%和52.2%;其DLP分别是常规剂量组的19%、38%和57%,低剂量组的CTDI与DLP值均显著低于常规剂量组。结论骨盆骨折的低剂量CT扫描在满足临床诊断的同时可以较CT扫描常规剂量减少,可明确地减低受检者的辐射剂量。

Application of 16-slice spiral CT in pelvic fracture patients:comparison of low-dose vs standard-dose

Objective To assess the clinical application of 16-slice low dose spiral CT in the pelvic fracture patients.Methods A hundred and ten adult patients with pelvic fracture underwent pelvis examinations with 16-slice spiral CT.Twenty patients of them underwent conventional dose scans,while another 90 patients were randomly divided into three groups according to body mass index（BMI）：40 mAs（BMI〈19 kg/m^2）,80 mAs（20 kg/m^2≤BMI〈28 kg/m^2）,120 mAs（BMI≥28 kg/m^2）.Weighted CT dose index（CTDI）,scanning lenth and dose length produce（DLP） were recorded when scanning.The imoge quality was evaluated according to 3 grades：normal image,image with mild artifact,image with serious artifact and the rate of diagnostic accuracy were evaluated.Results The diagnostic accuracy of 40,80,120 and 240 mA were 100%,100%,93.3%,100%,respectively.The CTDI of 40,80,120 mA were 17.4%,34.8%,52.2% of 240 mA,respectively.The DLP of 40,80,120 mA were 19%,38%,57% of 240 mA,respectively.CTDI and DLP values of low dose groups were statistically lower than that of conventional dose group.Conclusion 16-slice low dose spiral CT can significantly reduce the radiation dose than the conventional dose and can also provide good image quality.