肾脏CTP与CTA对比研究:图像质量与辐射剂量

Comparative Study of Renal CTP Functional Imaging and CTA Imaging:Image Quality and Radiation Dose

目的分析比较肾脏CT灌注成像(CTP)与CT血管造影(CTA)的图像质量和辐射剂量,以探讨低剂量肾脏CTP显示肾脏血管的价值。方法前瞻性搜集行CT肾动脉检查患者252例。随机分为A、B、C三组,每组84例。A组(低剂量CT灌注组)行CTP扫描模式,管电压100 kV,管电流60 mA,三维自适应迭代剂量降低(AIDR 3D);B组(常规CT灌注组)行CTP扫描模式,管电压100 kV,管电流100 mA,AIDR 3D技术;C组(CTA组)行常规CTA扫描模式,管电压120 kV,管电流自动毫安调制。对比分析三组图像左肾动脉CT值、左肾静脉CT值、对比噪声比(CNR)、信噪比(SNR)、图像质量主观评分及有效辐射剂量(ED)。结果 A组图像左肾动脉CT值、左肾静脉CT值最高,C组图像左肾动脉CT值、左肾静脉CT值最低,三组之间差异有统计学意义(P<0.01,P<0.01)。B组SNR值、CNR值优于A组、C组,A、B组与C组之间差异有统计学意义(P<0.01,P<0.01)。A、B组图像质量主观评分优于C组,差异存在统计学意义(P=0.000)。A、B、C三组的辐射剂量分别为(13.78±0.06)mSv、(16.64±1.16)mSv、(20.36±1.11) mSv,差异有统计学意义(F=1056.699,P=0.000)。A组较C组下降了32.3%。结论与常规肾脏CTA扫描模式相比,低剂量肾脏CTP扫描可以获得较高的图像质量,较低的辐射剂量,同时获得肾血流、肾功能等更多影像资料,具有较高的临床应用价值。

Objective To compare the image quality and radiation dose of renal CTP and CTA imaging,and to investigate the value of low dose renal CTP imaging in displaying renal vessels with high quality. Methods CT renal artery examination was prospectively performed in 252 patients which were randomly divided into three groups:A,B and C,with 84 cases in each group.Group A(low dose CT perfusion group) underwent CT perfusion scan mode,tube voltage 100 kV,tube current 60 mA,adaptive iterative dose reduction 3 D(AIDR 3 D). Group B(routine CT perfusion group) underwent CT perfusion scan mode, tube voltage 100 kV,tube current 100 mA,AIDR 3 D. Group C(CTA group) underwent conventionalCTA scan model,tube voltage 120 kV,tube current modulation automatic m A. The difference of CT value between left renal artery and left renal vein,CNR and SNR of the left renal artery were record and compared. The subjective scoring of CTA and CTP images and effective radiation dose were compared and analyzed. Results There were significant differences on CT value of left renal artery and left renal vein between the three groups( P < 0. 01,P < 0. 01),and the group A had the highest,the group C had the lowest. The SNR and CNR of group B were superior to group A and C,and there was significant difference between group A,B and group C( P < 0. 01,P < 0. 01). The subjective score of image quality in group A and B was better than that in group C,and the difference was statistically significant( P = 0. 000). The radiation doses of group A,B and C were 13. 78 ± 0. 06,16. 64 ± 1. 16,20. 36 ± 1. 11 m Sv,respectively,and there was significant difference between the three groups( F = 1056. 699,P = 0. 000). Compared with the C group,the radiation dose decreased by 32. 3% in group A. Conclusion Compared with routine renal CTA scanning,low dose renal CTP imaging can acquire higher image quality,lower radiation dose,and obtain more images of renal blood flow and renal function,and this has high clinical value.