高清晰度CT不同扫描模式显示冠状动脉支架

Different scan modes of high-definition CT for coronary stent imaging

目的探讨HDCT高清（HD）与非高清（NHD）扫描模式显示不同内径支架的区别。方法选择冠状动脉支架植入术后接受CT冠状动脉造影（CTCA）检查的55例连续性患者，其中29例采用HD模式扫瞄（HD组），平均年龄（57．6±9．5）岁，体质指数（BMI）平均为（27．69±2．72）kg／m2，植入支架49枚；26例采用NHD模式扫描（NHD组），平均年龄（61．5±10．7）岁，BMI平均为（25．94±2．89）kg／m2，植入支架47枚。采用前瞻性心电门控方式扫描，管电压120kV，根据患者BMI设定管电流（350～690mAs）。观察测量所有支架内径，并对图像质量予以评分（1～3分）。分别计算两组支架的平均内径测量值及支架内腔显示率，并进行统计学分析。结果两组共88枚支架符合可评价条件。两组图像质量评分差异有统计学意义（Z=-2．194，P〈0．05）。HD组支架平均管腔显示率（56．45±9．20）％，NHD组为[（49．52±9．45）％，t=3．482，P〈0．051。两组显示内径2．50mm支架与内径≥4．00mm支架的差异无统计学意义，显示内径2．75mm、3．00mm、3．50mm支架差异有统计学意义。结论HDCTHD扫描模式对内径≥2．75mm且〈4．00mm的冠状动脉支架的显示效果优于NHD扫描模式；对于显示内径〈2．75mm或≥4．00mm支架，两种扫描方式无显著差异。

Objective To explore imaging differences of coronary stent with various diameters between high-definition （HD） and non-high-definition （NHD） scan mode with HDCT. Methods Fifty-five consecutive patients who underwent coronary stenting and CT coronary angiograply （CTCA） were selected. Twenty-nine patients underwent HD scan （HD group）, with the mean age of （57.6±9.5）, mean body mass index （BMI） of （27.69±2.72）kg/m2 , and 49 stents were implanted. Meanwhile, 26 patients underwent NHD scan （NHD group）, with the mean age of （61.5± 10.7） years, mean BMI of （25.94±2.89）kg/m2 , and 47 stents were implanted. All patients were scanned with prospective ECG-gating, with tube voltage of 120 kV and tube current set according to BMI （350-690 mAs）. Stent diameter was measured and image quality was assessed using a 1--3 point scale. The mean inner diameter and visibility of different type stents were calculated and compared between two groups. Results Totally 88 stents were accepted. There was statistical difference of imaging quality between two group （Z=-2. 194, P〈0. 05）. The average visibility of HD group was （56.45±9.20）%, of NHD group was （[49.52±9.45]）%, t=3. 482, P〈0. 05）. For visibility of stents with diameter of 2.50 mm or ≥4. 00mm, there was no statistical difference between two groups, whereas for stents with diameter of 2. 75 mm, 3.00 mm, 3.50 mm, there were statistical differences. Conclusion HD scan mode of HDCT is better than NHD to visualize stents from 2.75 mm to 4. 00 mm. For stents with diameter 〈2.75 mm or ≥4.00 mm, there is no significant difference between two modes.