论文部分内容阅读
目的通过对选用不同前置滤线器模式所得到的图像质量和放射剂量的对照研究,探讨64层螺旋 CT(MSCT)冠状动脉成像时以较低放射剂量获得较高图像质量的可行性。方法按照统一的纳入标准,连续选取60例患者,进行 CT 冠状动脉检查。将患者分为 L、C 2组,每组30例。L 组选用体部滤线器(large bowtie)模式,C 组选用心脏滤线器(cardiac bowtie)模式。扫描中采用相同的参数,由2名有经验的影像诊断医师以双盲法分别对 L、C 组图像进行质量评分,测量各组图像噪声值,计算其均值及标准差,记录并比较 L 和 C 组平均 CT 剂量指数(CTDI)、剂量长度乘积(DLP)和有效剂量(ED)的差值。对2组图像质量评分、噪声值、CTDI、DLP 及 ED 值差异进行统计学分析。结果(1)L、C 2组图像质量评分分别为3.72、3.73分,2组间差异无统计学意义(t=0.17 P>0.05);(2)L、C 2组图像噪声值均值分别为30.05、27.80,C 组图像噪声明显低于 L 组(降低约7.5%),2组间差异有统计学意义(t=3.59,P<0.05);(3)L、C 2组平均 CTDI、DLP、ED 分别为83.97和77.66 mGy;1007.64和931.92 mGy/cm;17.13和15.84 mSy。C 组 CTDI、DLP、ED 明显低于L组(降低约7.5%),2组差异有统计学意义(P 均<0.01)。结论在64层 MSCT 冠状动脉成像时使用心脏滤线器模式可以有效地减少受检者接受的 X 线剂量,同时可以得到高质量的诊断图像。
Objective To investigate the feasibility of obtaining higher image quality at lower radiation dose in 64-slice spiral CT (MSCT) coronary angiography by comparing the image quality and radiation dose obtained by using different prefilter models. Methods According to the uniform inclusion criteria, 60 consecutive patients were selected for CT coronary artery examination. Patients were divided into L, C 2 group, 30 cases in each group. L group use large body bowel (large bowtie) mode, C group use the heart of the controller (cardiac bowtie) mode. The same parameters were used in the scanning. Two experienced diagnosticians evaluated the quality of L and C images respectively by double-blind method. The noise of each group was measured, the mean and standard deviation were calculated, and L And group C, the average CT dose index (CTDI), dose length product (DLP) and the effective dose (ED) of the difference. The differences of two groups of image quality score, noise value, CTDI, DLP and ED were statistically analyzed. Results (1) The image quality scores of L and C 2 groups were 3.72 and 3.73 respectively, there was no significant difference between the two groups (t = 0.17 P> 0.05). (2) (P <0.05). (3) The mean of noise in group C and group C was significantly lower than that in group L CTDI, DLP, ED were 83.97 and 77.66 mGy; 1007.64 and 931.92 mGy / cm; 17.13 and 15.84 mSy, respectively. The CTDI, DLP and ED in group C were significantly lower than those in group L (about 7.5% reduction). There was significant difference between the two groups (all P <0.01). Conclusions The use of a cardiac filter mode in 64-slice MSCT coronary angiography can effectively reduce the dose of X-rays received by the subject while providing high-quality diagnostic images.