目的:分析低电压、低碘对比剂剂量头颈CT A可行性.方法:随机抽取2018年3月—2019年4月期间在本院进行头颈部CT检查的受检者92例,随机分为对照组46例,CTA对比剂剂量为60ml、管电压120kVp;研究组46例,CTA对比剂剂量为0.3ml/kg,管电压100kVp,记录两组受检者使用对比剂的剂量、剂量长度乘积(DLP)、体型特异性剂量估计值(SSDE),对两组受检者检查结果进行评价.结果:研究组受检者在对比剂剂量、DLP、SSDE等均明显低于对照组受检者(P<0.05);两组受检者在CT扫描影像学成像评价中,不存在统计学意义(P>0.05).结论:低电压、低碘对比剂剂量头颈CTA能够有效的降低对比剂的使用剂量,同时还能降低头颈部CAT扫描辐射剂量,且所得到的影像学图像质量可以满足临床诊断的需求.

Objective To explore the feasibility and the effect of Test-Bolus with low tube voltage,low tube current,low dosage contrast medium(CM) ("Three-Lows") and thinner collimator in intracranial and cervical CT angiography (CTA).Methods 120 patients with suspected craniocervical vascular disease randomly divided into three groups(40 cases per group) underwent 64-MSCT with diffirent protocol of Test-Bolus for getting scan delay time (DT).Group A using conventional methods:kV =120,mA =60,CM =20 ml,thickness =5 mm;Group B and C:kV =80,mA =20,thickness =1.25 mm,CM B =20 ml,CMc (ml) =weight (kg) * 1 ml/kg * 10％.Time to peak (T),dosage of iodine per capita (I),dose length product (DLP),effective dose (ED) were recorded.The peak CT value (PCTValue) of monitored arteries,background noise (N),signal to noise ratio (SNR) and contrast to noise ratio (CNR) of images of Test-Bolus and mean CT values of aortic arch,M1 segment of middle cerebral artery of final raw images (AA CTValue,M1CTValue) were measured and assessed.Arterial displaying and interference from subclavian veins were further scored by two senior doctors.Results T,AA CTValue,M1CTValue,and image-quality-scores in three groups were not statistically different (P ＞ 0.05),T in group C is about 0.5 s sooner compared with group A and B;DLP and ED in group B [(2.87 ± 0.54)mGy · cm,(0.014 ±0.002)mSv] and group C [(2.93 ± 0.63)mGy · cm,(0.014 ±0.003)mSv] were both lower than group A [(61.05 ± 14.08)mGy · cm,(0.305 ±0.07)mSv],ED in group B and group C were only about 4.59％ of that in group A (P ＜0.05);I in group C was about 31.50％ of that in group B and C (P ＜ 0.05).Conclusion The Test-Bolus with "Three Lows" and thinner collimator applied to intracranial and cervical CTA is feasible for reducing the dosage of CM and radiation dose greatly.

[目的]探讨低剂量CT扫描结肠成像(CTC)检查前肠道准备及护理.[方法]回顾性分析2013年5月～2014年10月间接受低剂量CTC检查的102例患者资料.[结果]102例中,85例患者肠道准备良好,图像质量佳;12例肠道准备及图像质量稍差,能满足诊断要求;5例肠道准备及图像质量较差,病灶显示不清.[结论]做好CTC检查前肠道准备及护理工作,是此项检查成败的关键,有着重要意义.

Objective To study the consistence of low-dose CT colonography ( CTC) and sigmoidoscopy in the diagnosis, site and classification of colon carcinoma (CRC).Methods A total of 65 patients of CRC were con-firmed by pathology .All the patients were examined by endoscopy and low doses CTC .The location, types of tumour were observed by endoscopy and CTC , and Kappa consistence test was applied with the pathologic findings as golden standard, and calculated CT dose index(CTDIw) in prone was recorded.Results Sixty-one patients were diagnosed as having CRC by endoscopy and 4 were negative .In 61 positive patients , 8 tumors located in the rectum , 25 in the colon sigmoideum , 13 in the descending colon , 11 in the colon transversum , 8 in the ascending colon , and Borrmann showed,Ⅰin 38,Ⅱin 14,Ⅲin 7,Ⅳin 6.CTC diagnosed 60 cases of CRC and 5 cases with negative results .In 61 positive patients , 6 tumors located in the rectum , 23 in the colon sigmoideum , 15 in the descending colon , 10 in the colon transversum, 6 in the ascending colon, and Borrmann showed,Ⅰin 36,Ⅱin 16,Ⅲin 7,Ⅳin 6.There was high consistency between CTC and sigmoidoscopy in the diagnosis of CRC ( Kappa=0.881 , P<0.01 ) , with the coincidence of CTC was 98.5%.There was high consistency between CTC and sigmoidoscopy in the classification of CRC( Kappa values were 0.897 and 0.949 , P<0.01 ) .Conclusion Reduction of the effective dose to 1.68 mGy significantly affects images quality on CTC , there is high consistency between CTC and sigmoidoscopy in the diagno-sis, site and classification of CRC .

目的:探讨降低管电流宝石能谱CT低剂量扫描对结肠仿真内镜成像图像质量及辐射剂量的影响.方法:对45例临床怀疑为结肠息肉病变的患者平均分为3组,行宝石能谱CT降低管电流结肠仿真内镜成像,其中按固定管电流分别为50,30,15 mAs进行扫描,其他参数按常规进行,并对3组图像质量主观评分及有效辐射剂量进行评价.结果:固定管电流为50 mAs(A组)时,结肠仿真内镜成像(CTVC)及透明重组图像(Raysum)平均评分为(2.93±0.26)分,平均容积CT剂量指数(CTDIvol)与剂量长度乘积(DLP)分别为(1.68±0.00) mGy和(80.62±3.44) mGy cm;30 mAs(B组)时,上述平均评分为(2.53±0.52)分,剂量平均分别为(1.01±0.01) mGy和(45.09±5.54) mGy cm;15 mAs(C组)时,上述平均评分为(1.93±0.70)分,剂量平均分别为(0.05±0.00) mGy和(22.16±1.96) mGy cm.3组CTDIvol与DLP平均分别降低了80.05％、88.00％、94.06％和80.73％、88.95％、94.57％.结论:降低管电流在CTVC成像中,在管电流与辐射剂量分别降低88％以上的情况下,仍能兼顾图像质量,而降低至94.57％时,对图像质量影响较大.