Stellar光子探测器双源CT大螺距泌尿系排泄期成像的临床应用

Clinical Application of High-pitch Excretory Phase Images during Dual-source CT Urography with Stellar Photon Detector

目的评价Stellar光子探测器双源CT大螺距泌尿系排泄期成像临床应用的可行性。方法 100例患者行Stellar光子探测器双源CT大螺距泌尿系排泄期成像扫描(管电压80 kV、参考管电流92 mAs、开启CARE Dose 4D及CARE kV,螺距3.0,滤波反投影图像重建)(A组),另100例患者行普通双源CT大螺距泌尿系排泄期成像扫描(管电压100 kV、参考管电流140 mAs、开启CARE Dose 4D,螺距3.0,滤波反投影图像重建)(B组)。采用Mann-Whitney U检验比较两组患者间泌尿系各节段充盈程度,独立样本t检验比较两组患者间泌尿系各节段对比剂CT值、图像噪声和有效放射剂量。结果 A组患者的肾盂、肾盏和输尿管充盈程度与B组相比差异无统计学意义(P均>0.05),但各泌尿系节段内对比剂CT值均明显较高(P均<0.01)。两组患者的图像噪声差异无统计学意义(P>0.05)。A组患者平均有效放射剂量为1.10 mSv,明显低于B组患者的3.79 mSv(P<0.01)。结论 Stellar光子探测器双源CT大螺距泌尿系排泄期成像在保持图像噪声的同时可以降低放射剂量,具有临床应用价值。

Objective To retrospectively evaluate the clinical feasibility of high-pitch excretory phase images during dual-source CT urography with Stellar photon detector. Methods Totally 100 patients received dual-source CT high-pitch urinary excretory phase scanning with Stellar photon detector [ 80 kV, ref. 92 mAs, CARE Dose 4D and CARE kV, pitch of 3.0, filter back projection reconstruction algorithm （FBP） ] （ group A） . Another 100 patients received dual-source CT high-pitch urinary excretory phase scanning with common de- tector （100 kV, ref. 140 mAs, CARE Dose 4D, pitch of 3.0, FBP） （group B） . Quantitative measurement of CT value of urinary segments （ Hounsfield units）, image noise （ Hounsfield units）, and effective radiation dose （millisievert） were compared using independent-samples t test between two groups. Urinary system subjec- tive opacification scores were compared using Mann-Whitney U test between two groups. Results There was no significant difference in subjective opacification score of intrarenal collecting system and ureters between two groups （ all P 〉 0. 05） . The group A images yielded significantly higher CT values of all urinary segments （ all P 〈 0.01 ） . There was no significant difference in image noise （ P 〉 0. 05 ） . The effective radiation dose of group A （ 1.1 mSv） was significantly lower than that of group B （ 3.79 mSv） （ P 〈 0.01 ） . Conclusion High-pitch low-tube-voltage during excretory phase dual-source CT urography with Stellar photon detector is feasi- ble, with acceptable image noise and lower radiation dose.