韩磊
中国医学科学院阜外医院 放射科
BACKGROUND:Little is known about the influence of coronary atherosclerosis progression on the risk of major adverse cardiac events (MACE). Similarly, differences between men and women regarding atherosclerosis progression are poorly understood. The purpose of this study was to investigate the progression of coronary atherosclerosis by coronary CT angiography (coronary CTA) in men and women, and to evaluate its prognostic value regarding MACE.METHODS:This study included 1046 patients with suspected coronary artery disease (CAD) who underwent serial coronary CTA because of new or worsening symptoms or because follow-up coronary CTA had been recommended by attending physicians. Coronary atherosclerosis was semi-quantitatively assessed as follows: three-vessel plaque score (TVPS), severe proximal plaque score (SPPS), segment stenosis score (SSS), segment involvement score (SIS), and coronary artery calcium score (CACS). Patients were followed-up regarding the occurrence of MACE, defined as cardiac death, coronary revascularization, nonfatal myocardial infarction and hospitalization due to unstable angina. Follow-up information was gathered by clinical visits or telephone contacts.RESULTS:Follow-up was achieved in 953 (91.1%) patients (63.8% male; mean age, 53.9 ± 9.7 years) with a mean interval of 4.9 ± 1.1 years. MACE occurred in 132 (13.9%) patients. The average interscan time was 2.1 years. Compared with women, men had significantly higher progression of SPPS, SSS and SIS (6.6% vs. 3.5%, 28.0% vs. 18.3%, 26.6% vs. 16.8%, respectively, all P < 0.005). There was a strong association between the progression of SPPS as well as SSS and MACE, both for men (SPPS, HR:2.17, P < 0.001; SSS, HR:1.28, P = 0.023) and women (SPPS, HR:2.75, P < 0.001; SSS, HR:1.19, P = 0.027).CONCLUSIONS:Progression of coronary atherosclerosis as determined by coronary CTA is higher in men than women, it is associated with the risk of future MACE.
Journal of cardiovascular computed tomography 2017
OBJECTIVE:To investigate the feasibility of using lower iodine concentration (270 mgI/ml) contrast medium, lower X-ray tube voltage (100 kVp) and iterative reconstruction (IR) to reduce both iodine load and radiation dose but keep the image quality of coronary CT angiography (CCTA).METHODS:A total of 80 consecutive patients with suspected coronary artery disease were prospectively assigned to one of two groups via computer central system from January to May 2013. The control group (n = 40) was scanned using dual-source CCTA protocols of 120 kV, 370 mgI/ml Iopromide and filtered back projection reconstruction with a vascular algorithm (B26f). The study group (n = 40) was scanned using 100 kV, 270 mgI/ml Iodixanol and sinogram affirmed iterative reconstruction with a vascular algorithm (I26f). Other scan parameters and contrast injection protocol were similar between the two groups. Attenuation in the ascending aorta and coronary arteries along with image noise were measured. Images were reconstructed, measured and graded, and iodine load and effective radiation dose were calculated.RESULTS:The body mass index ((25.3 ± 3.0) kg/m² vs. (25.4 ± 3.0)kg/m², P = 0.852), image quality scores (4.70 ± 0.52 vs. 4.63 ± 0.59, P = 0.545), mean signal-to-noise ratios (22.2 ± 5.5 vs. 23.6 ± 5.8, P = 0.277), and contrast-to-noise ratios (35.6 ± 17.6 vs. 41.1 ± 17.6, P = 0.163) were similar between the control group and study group. Mean iodine loads were significantly reduced in the study group ((18.49 ± 0.75)g) compared to control group ((25.27 ± 0.94)g), P< 0.001). Mean effective radiation doses were also significantly reduced in the study group ((2.31 ± 0.73) mSv) compared to that in control group ((3.52 ± 1.16) mSv), P< 0.001).CONCLUSION:Use of low X-ray tube voltage and iterative reconstruction allows lower iodine load and effective radiation dose application at CCTA without image quality reduction.
Zhonghua xin xue guan bing za zhi 2015
OBJECTIVES:This study sought to determine whether a 50%-reduced radiation dose protocol using iterative reconstruction (IR) preserves image quality and diagnostic accuracy at coronary computed tomography angiography (CTA) as compared with a routine dose protocol using traditional filtered back projection (FBP).BACKGROUND:IR techniques show promise to decrease radiation requirements at coronary CTA. No study has performed a direct head-to-head, intraindividual comparison of IR algorithms with FBP vis-à-vis diagnostic accuracy and radiation dose at coronary CTA.METHODS:Sixty consecutive subjects (45 men, 53.3 ± 9.4 years of age) prospectively underwent coronary catheter angiography (CCA) and 2 coronary CTA scans. One coronary CTA acquisition used routine radiation dose settings and was reconstructed with FBP. For another scan, the tube current-time product was reduced by 50%, and data were reconstructed with IR. Studies were blindly and randomly interpreted. Image quality, radiation dose, and diagnostic accuracy were compared using CCA as the reference standard.RESULTS:Sensitivity and specificity for diagnosing ≥50% coronary artery stenosis on a per-segment level were 88.5% and 92.1% with FBP and 84.2% and 93.4% with IR, respectively. On a per-patient level, sensitivity and specificity were 100% and 93.1% with FBP and 96.8% and 89.7% with IR, respectively (all p > 0.05). With FBP versus IR, the area under the receiver-operating characteristic curve was 0.903 (95% confidence interval [CI]: 0.881 to 0.922) and 0.888 (95% CI: 0.864 to 0.909) on a per-segment level, and 0.966 (95% CI: 0.883 to 0.996) and 0.932 (95% CI: 0.836 to 0.981) on a per-patient level, respectively (p = 0.290 and 0.330). Compared with FBP, the iterative series showed no significant (p > 0.05) differences in image quality analyses. Median dose-length product was 52% lower for the IR protocol compared with the FBP protocol (109.00 [interquartile range: 82.00 to 172.50] mGy·cm vs. 52.00 [interquartile range: 39.00 to 84.00] mGy·cm, p < 0.001).CONCLUSIONS:Compared with a routine radiation dose FBP protocol, 50% reduced dose acquisition using IR preserves image quality and diagnostic accuracy at coronary CTA.
JACC. Cardiovascular imaging 2013
OBJECTIVES:To evaluate the diagnostic accuracy of sub-milliSievert (mSv) coronary CT angiography (cCTA) using prospectively ECG-triggered high-pitch spiral CT acquisition combined with iterative image reconstruction.METHODS:Forty consecutive patients (52.9 ± 8.7 years; 30 men) underwent dual-source cCTA using prospectively ECG-triggered high-pitch spiral acquisition. The tube current-time product was set to 50 % of standard-of-care CT examinations. Images were reconstructed with sinogram-affirmed iterative reconstruction. Image quality was scored and diagnostic performance for detection of ≥50 % stenosis was determined with catheter coronary angiography (CCA) as the reference standard.RESULTS:CT was successfully performed in all 40 patients. Of the 601 assessable coronary segments, 543 (90.3 %) had diagnostic image quality. Per-patient sensitivity for detection of ≥50 % stenosis was 95.7 % [95 % confidence interval (CI), 76.0-99.8 %] and specificity was 94.1 % (95 % CI, 69.2-99.7 %). Per-vessel sensitivity was 89.5 % (95 % CI, 77.8-95.6 %) with 93.2 % specificity (95 % CI, 86.0-97.0 %). The area under the receiver-operating characteristic curve on per-patient and per-vessel levels was 0.949 and 0.913. Mean effective dose was 0.58 ± 0.17 mSv. Mean size-specific dose estimate was 3.14 ± 1.15 mGy.CONCLUSIONS:High-pitch prospectively ECG-triggered cCTA combined with iterative image reconstruction provides high diagnostic accuracy with a radiation dose below 1 mSv for detection of coronary artery stenosis.KEY POINTS:• Cardiac CT with sub-milliSievert radiation dose is feasible in many patients • High-pitch spiral CT acquisition with iterative reconstruction detects coronary stenosis accurately. • Iterative reconstruction increases who can benefit from low-radiation cardiac CT.
European radiology 2013
OBJECTIVES:To investigate the radiation dose and image quality of prospective ECG-triggering dual-source CT angiography in infants with complex congenital heart disease (CHD) in comparison with retrospective ECG-gated scanning.METHODS:Ninety-six infants less than 1 year old (60/36 male/female, age: 4.8 ± 2.7 months, weight: 5.8 ± 1.8 kg) with complex CHD were enrolled. Three image acquisition protocols were set: group 1: 80 kV, 100 mA, retrospective ECG-gated protocol; group 2: 80 kV, 100 mA, prospective ECG-triggering protocol with acquisition window of 380 ms; group 3: 80 kV, 100 mA, prospective ECG-triggering protocol with acquisition window of 200 ms. Patients were selected to any one of the protocols randomly. The signal-to-noise ratios (SNR) were calculated in the ascending aorta and the pulmonary artery trunk. Image quality was assessed by a five-point score. A score of <3 represents non-diagnostic. Effective radiation dose (ED) was calculated.RESULTS:Image quality score of groups 1, 2 and 3 were 4.1 ± 0.4, 4.0 ± 0.6 and 4.2 ± 0.6 (p = 0.224). SNR of ascending aorta and pulmonary artery trunk among them had no statistical difference (all p>0.05). The average ED (median) of groups 1, 2 and 3 were 1.17 ± 0.07 mSv (1.25 mSv), 0.72 ± 0.24 mSv (0.78 mSv) and 0.48 ± 0.41 mSv (0.39 mSv). Any two of the three groups had significant differences (all p<0.001).CONCLUSION:Prospective ECG-triggering DSCT angiography associated with a significantly lower ED than retrospective protocol, while maintaining image quality for diagnosis. Prospective ECG-triggering DSCT angiography could be used as a very important second-line diagnostic tool in infants with complex CHD.
European journal of radiology 2012
