摘要
目的探讨双源CT低管电压冠状动脉成像技术的应用价值及不同心率对图像质量和辐射剂量的影响。方法对323例临床怀疑冠心病患者进行双源CT低管电压（100kVp）和常规管电压回顾性心电门控冠状动脉成像增强扫描，检查前不使用p受体阻滞剂控制心率。按患者扫描时的平均心率对低管电压组201例进行分组，≤59次／rain为A组（50例），60—69次／min为B组（64例），70～91次／min为C组（62例），≥91次／min为D组（25例）。对照组（管电压120kVp）为E组（122例）。评价各组的最佳重建时相图像，记录各组的增强扫描序列的螺距、CT容积剂量指数（CTDIval）、剂量长度乘积（DLP）及有效剂量（E）值，比较各组患者的扫描螺距、图像质量评分和辐射剂量值等，分析心率对图像质量和辐射剂量的影响。结果A—D4组螺距分别为（0．24±0．03）、（0．29±0．04）、（0．33±0．05）、（0．38±0．06），差异有统计学意义（F=62．57，P〈0．05）；A—E5组CTDI“值分另0为（21．59±7．97）、（20．24±6．03）、（18．23±7．55）、（18．14±5．75）、（38．62±16．21）mGy（F=85．16，P〈0．05）；E值分别为（5．31±2．18）、（4．85±1．70）、（4．49±1．86）、（4．37±1．50）、（8．75±4．07）mSv（F=44．83，P〈0．05）；图像评分分别为（4．65±O．46）、（4．55±0．53）、（4．55±0．53）、（4．47±0．72）、（4．66±0．44）分（F=1．89，P〉0．05）。结论双源CT低管电压（100kVp）技术冠状动脉成像在不控制心率情况下可获得较好的图像质量；在自动心电门控剂量窗时，中低心率对辐射剂量的影响较小，高心率可使有效辐射剂量降低，但获得优质图像质量的可能性减小。
Objective To evaluate the application value of dual-source CT coronary angiography in low tube voltage setting and the influence of heart rate on image quality and radiation doses. Methods 323 patients suspected of coronary artery disease received retrospective ECG-gating coronary angiography with dual-source CT scanner, who were divided into low tube voltage group （ 100 kVp, n = 201 ） and conventional voltage group （120 kVp, E group,n = 122）. No beta-blockers were taken before CT scan. All patients in low tube voltage group were divided into four groups according to the heart rate （HR） ： group A, HR≤59 beats per minute （bpm） , n =50; group B, 60≤HR 〈69 bpm, n =64; group C, 70≤HR 〈91 bpm, n = 62; group D, HR ≥ 91 bpm, n = 25. All images were transferred to a workstation for further processing. The best R-R interval reconstruction images of all groups were evaluated. The value of pitch, CT volume dosage index（ CTDI,o, ） , dose length product（DLP） and effective dose （E） were recorded. The pitch,the score of imaging quality of coronary artery segments and the radiation dose were compared with One-Way ANOVA. The influence of heart rate on image quality and radiation doses of coronary artery was analyzed. Results The value of pitch in groups A-D was 0. 24 ± 0. 03, 0. 29 ±0.04, 0. 33 ± 0.05, 0.38 ± 0. 06, respectively, with statistical difference （ F = 62. 57, P 〈 0. 05 ）. The value of CTDIvol in groups A-E was （21.59 ±7.97） , （20. 24 ± 6. 03） ,（18.23 ±7.55） ,（18.14 ±5.75） , （38.62 ± 16.21） mGy, respectively, with statistical difference （F = 85.16, P 〈 0.05）. The value of E in group A-E was （5.31±2.18）, （4.85±1.70）, （4.49 ±1.86）, （4.37 ±1.50）, （8.75 ±4.07）mSv, respectively,with statistical difference （ F = 44. 83, P 〈 0.05 ）. The image score was （4. 65±0. 46 ）, （4. 55 ±0. 53 ）, （4.55±0.53）,（4.47 ±0.72）,（4.66±0.44）（F=l.89,P〉0. 05）. Conclusions Nobeta-blockers was taken before CT scan, and a high quality image could be acquired by using dual-source CT coronary angiography in low tube voltage setting（ 100 kVp）. When the auto EGG-gating is selected, medium and low HR have little influences on radiation dose, while the radiation dose could be decreased significantly at higher HR, but the possibility to obtain the high quality image decreased.
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2012年第5期530-534,共5页
Chinese Journal of Radiological Medicine and Protection
关键词
心率
冠状动脉
体层摄影术
辐射剂量
Heart rate
Coronary artery
Tomography
Radiation dosage
