Kidoh Masafumi, Nakaura Takeshi, Nakamura Shinichi, Nakamura Shota, Sakaino Naritsugu, Harada Kazunori, Uemura Shouzaburou, Yamashita Yasuyuki
Diagnostic Radiology, Amakusa Medical Center, Kumamoto, Japan Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Japan
Diagnostic Radiology, Amakusa Medical Center, Kumamoto, Japan Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Japan.
Acta Radiol. 2014 Jun;55(5):545-53. doi: 10.1177/0284185113500669. Epub 2013 Aug 22.
The use of the smallest contrast dose is highly desirable in performing cardiac computed tomography (CT), especially for patients with cardiovascular diseases to prevent contrast-induced nephropathy.
To evaluate the feasibility of 20% reduced contrast dose protocol in cardiac CT using 100 kVp and high-tube-current-time product setting.
Fifty patients were scanned with our conventional 120 kVp protocol, and the other 50 patients underwent scans using a tube voltage of 100 kVp, a high-tube-current-time product, and a 20% reduced contrast dose. We evaluated estimated effective dose (ED), CT attenuation, image noise, and contrast-to-noise ratio (CNR) of the ascending aorta. We also evaluated CT attenuation of the coronary arteries. Two radiologists independently assessed image quality of coronary arteries.
There was no significant difference in the ED between the 100 kVp and 120 kVp protocols (21.7 mSv ± 1.6 vs. 21.8 mSv ± 1.1, P=0.65). There was no significant difference in the CNR of the ascending aorta between the 100 kVp and 120 kVp protocols (18.8 ± 3.5 vs. 18.7 ± 3.8, P=0.98). Mean CT attenuation of the coronary arteries of the 100 kVp protocols was significantly higher than that of 120 kVp protocols (P<0.05). There was no significant difference in the overall image quality of the coronary artery between the 100 kVp and 120 kVp protocols (3.7 ± 0.4 vs. 3.7 ± 0.5, P=0.65).
For cardiac CT a voltage setting of 100 kVp and a high-tube-current-time product enable 20% reduction in the contrast dose without affecting the quality of coronary artery images compared with a 120 kVp and standard-contrast-dose CT protocol.
在进行心脏计算机断层扫描（CT）时，非常希望使用最小的对比剂剂量，尤其是对于患有心血管疾病的患者，以预防对比剂诱导的肾病。
评估在心脏CT中使用100 kVp和高管电流时间乘积设置减少20%对比剂剂量方案的可行性。
50例患者采用我们传统的120 kVp方案进行扫描，另外50例患者采用100 kVp管电压、高管电流时间乘积和减少20%对比剂剂量进行扫描。我们评估了升主动脉的估计有效剂量（ED）、CT衰减、图像噪声和对比噪声比（CNR）。我们还评估了冠状动脉的CT衰减。两名放射科医生独立评估冠状动脉的图像质量。
100 kVp和120 kVp方案之间的ED无显著差异（21.7 mSv±1.6对21.8 mSv±1.1，P = 0.65）。100 kVp和120 kVp方案之间升主动脉的CNR无显著差异（18.8±3.5对18.7±3.8，P = 0.98）。100 kVp方案冠状动脉的平均CT衰减显著高于120 kVp方案（P<0.05）。100 kVp和120 kVp方案之间冠状动脉的整体图像质量无显著差异（3.7±0.4对3.7±0.5，P = 0.65）。
对于心脏CT，与120 kVp和标准对比剂剂量CT方案相比，100 kVp的电压设置和高管电流时间乘积可使对比剂剂量减少20%，而不影响冠状动脉图像质量。
