Feasibility and Diagnostic Accuracy for Assessment of Coronary Artery Stenosis of Prospectively Electrocardiogram-gated High-pitch Spiral Acquisition Mode Dual-source CT Coronary Angiography in Patients with Relatively Higher Heart Rates: in Comparison wit

Objective To prospectively investigate the diagnostic accuracy for coronary artery stenosis of prospectively electrocardiogram-triggered spiral acquisition mode (high pitch mode) dual-source computed tomography coronary angiography (CTCA) in patients with relatively higher heart rates (HR) compared with catheter coronary angiography (CCA). Methods Forty-seven consecutive patients with relatively higher HR (>65 and <100 bpm) (20 male, 27 female; age 55±10 years) who both underwent dual-source CTCA and CCA were prospectively included in this study. All patients were performed CTCA using high pitch mode setting at 20%-30% of the R-R interval for the image acquisition. All coronary segments were evaluated by two blinded and independent observers with regard to image quality on a three-point scale (1: excellent to 3: non-diagnostic) and for the presence of significant coronary stenoses (defined as diameter narrowing exceeding 50%). Considered CCA as the standard of reference, the sensitivity, specificity, positive predictive value and negative predictive value were calculated. Radiation dose values were calculated using the dose-length product. Results Image quality was rated as being score 1 in 92.4% of segments, score 2 in 6.1% of segmentsand score 3 in 1.5% of segments. The average image quality score per segment was 1.064±0.306. The HR variability of patients with image score 1, 2 and 3 were 2.29±1.06 bpm, 5.17±1.37 bpm, 8.88±1.53 bpm, respectively. The average HR variability of patients with different image scores were significantly different (F=170.402, P=0.001). The sensitivity, specificity, positive and negative predictive values were 92.6%, 97.0%, 87.6%, 98.3%, respectively, per segment and 90.0%, 95.2%, 85.3%, 96.9%, respectively, per vessel and 100%, 63.6%, 90.0%, 100%, respectively, per patient. The effective radiation dose was on average 0.86±0.16 mSv. Conclusion In patients with HR more than 65 bpm and below 100 bpm without cardiac arrhythmia, the prospectively electrocardiogram-gated high-pitch spiral acquisition mode with image acquired timing set at 20%-30% of the R-R interval provides a high diagnostic accuracy for the assessment of coronary stenoses combined with a 1.5% of non-diagnostic coronary segments and a radiation dose below 1 mSv.

Intravenous Contrast Material Administration at High-pitch Dual-source CT Coronary Angiography: Bolus-tracking Technique with Shortened Time of Respiratory Instruction Versus Test Bolus Technique

Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv,P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.

心脏电机械偶联与Flash双源CT冠状动脉成像在高心率患者中的应用(英文)

Objective To assess the image quality and effective radiation dose of prospectively electrocardiogram-triggered high-pitch spiral acquisition (flash spiral mode)dual-source CT coronary angiography in patients with high heart rate(HR).Methods From 1321 consecutive patients,seventy patients with HR≥70 bpm (group A) and seventy patients with HR<70 bpm (group B) underwent CT angiography and were prospectively included in this study.The start phase for image acquisition of the most cranial slice was selected at 20%-30% of the R-R interval for group A and at 60% of the RR interval for group B.Assessed the image quality and effective radiation dose of two group.Results (1)There were no significant differences in age,sex,BMI and scan time between the two groups.(2)Image qualities:The segments with non-diagnostic image quality occurred (i.e.score 3) had no significant difference between group A and group B (2.1% vs.1.5%,P=0.48).Non-diagnostic image quality was most often found in the RCA and LCX in both groups.(3)The estimated radiation dose was on average (1.00±0.15) mSv(0.7-1.82 mSv) in group A and (1.01±0.16)mSv (0.65-1.82 mSv) in group B.Conclusions Patients with high heart rates can be performed CTCA with high-pitch spiral acquisition mode.20%-30% of the R-R interval window for data acquisition for high-pitch dual-source CTCA may probably obtain good image quality with low doses.The highest HRs are 100 bpm with good image quality.HR variability is a great effect factor of image quality.The estimated radiation dose is about 1 mSv.

心房颤动患者的低剂量、大螺距双源CT冠状动脉成像的可行性研究(英文)

Objective The objective was to attempt to rule out whether high-pitch spiral acquisition dual-source computed tomography coronary angiography(CTCA)can be performed in patients with atrial fibrillation at low dose.Methods Ten patients with atrial fibrillation who were admitted for a first diagnostic coronary angiogram were screened for participation.All patients underwent dual-source CT.Patients were performed CTCA using the prospectively ECG-gated high-pitch mode and retrospective ECG gating spiral acquisition respectively with their permissions.The start phase for image acquisition of the most cranial slice was selected at 20%-30% of the R-R interval in all patients.Results Image qualities of prospectively ECG-gated high-pitch mode were rated as being excellent in 7 cases of all the patients and only 3 cases′ image qualities were graded score 2.By using retrospective ECG gating spiral acquisition mode,non-diagnostic image quality (score 3) occurred in 4 patients which were observed in RCA and 1 patient in LCX.The estimated radiation dose ranges from 0.68 to 1.887 mSv in flash mode and the radiation dose of spiral mode were very high ranging from 14.92 to 29.308 mSv.Conclusions Our case series suggest that patients with atrial fibrillation rhythm can be performed CTCA with high-pitch spiral acquisition mode.20%-30% of the RR interval window for data acquisition for high-pitch dual-source CTCA may probably obtain good image quality with low doses.

大螺距双源CT诊断巨大冠状动脉瘤合并冠状动脉右心室漏、单冠状动脉畸形(英文)

Introduction The second generation of dual-source CT systems is a new system allows computed tomoghaphy coronary angiography ( CTCA) examinations to be performed at high-pitch values of up to 3. 4[1-4]. In the HP acquisition mode that is unique to dual-source CT,the second detector system can be used to fill these gaps. By