The Image Quality and Radiation Dose of 100-kVp versus 120-kVp ECG-Gated 16-Slice CT Coronary Angiography.
10.3348/kjr.2009.10.3.235
- Author:
Eun Ah PARK
1
;
Whal LEE
;
Jin Hwa KANG
;
Yong Hu YIN
;
Jin Wook CHUNG
;
Jae Hyung PARK
Author Information
1. Department of Radiology and the Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, 110-744, Korea. leew@radiol.snu.ac.kr
- Publication Type:Original Article ; Clinical Trial ; Comparative Study
- Keywords:
Cardiac CT;
Low kVp;
Radiation dose
- MeSH:
Adult;
Aged;
Aged, 80 and over;
Contrast Media/administration & dosage;
Coronary Angiography/*methods;
Electrocardiography/*methods;
Feasibility Studies;
Female;
Humans;
Iohexol/administration & dosage/analogs & derivatives;
Male;
Middle Aged;
Observer Variation;
*Radiation Dosage;
Radiographic Image Enhancement/methods;
Retrospective Studies;
Tomography, X-Ray Computed/*methods
- From:Korean Journal of Radiology
2009;10(3):235-243
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: This study was conducted to assess the feasibility of performing 100-kVp electrocardiogram (ECG)-gated coronary CT angiography, as compared to 120-kVp ECG-gated coronary CT angiography. MATERIALS AND METHODS: We retrospectively evaluated one hundred eighty five gender- and body mass index-matched 16-slice coronary CT sets of data, which were obtained using either 100 kVp and 620 effective mAs or 120 kVp and 500 effective mAs. The density measurements (image noise, vessel density, signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]) and the estimated radiation dose were calculated. As a preference test, two image readers were independently asked to choose one image from each pair of images. The results of both protocols were compared using the paired t-test or the Wilcoxon signed rank test. RESULTS: The 100-kVp images showed significantly more noise and a significantly higher vessel density than did the 120-kVp images. There were no significant differences in the SNR and CNR. The estimated reduction of the radiation dose for the 100-kVp protocol was 24%; 7.8 +/- 0.4 mSV for 100-kVp and 10.1 +/- 1.0 mSV for 120-kVp (p < 0.001). The readers preferred the 100-kVp images for reading (reader 1, p = 0.01; reader 2, p = 0.06), with their preferences being stronger when the subject's body mass index was less than 25. CONCLUSION: Reducing the tube kilovoltage from 120 to 100 kVp allows a significant reduction of the radiation dose without a significant change in the SNR and the CNR.
