RESUMEN
ObjectiveTo evaluate the impact of patient's heart rate(HR)on coronary CT angiography(CTA)image quality(IQ)and reconstruction timing in dual-source CT(DSCT).Methods Ninety-five patients with suspicion of coronary artery disease were examined with a DSCT scanner(Somatom Definition.Siemens)using 32×0.6 mm collimation.All patients were divided three groups according to the heart rate(HR):group 1,HR≤70 beats per minute(bpm),n=26;group 2,HR＞70 bpm to≤90 bpm, n=37;group 3,HR＞90 bpm,n=32. No beta-blockers were taken before CT scan.50-60 ml of nonionic contrast agent were injected with a rate of 5 ml/s. Images were reconstructed from 10%to 100% of the R-R interval using single-segment reconstruction. Two readers independently assessed IQ of all coronary segments using a 3-point scale from excellent(1)to non-assessable(3)for coronary segments and the relationshiD between IQ and the HR. ResuitsOverall mean IQ score was 1.31 ±0.55 for all patients with 1.08±0.27 for group 1,1.32±0.58 for group 2 and 1.47±0.61 for group 3. The IQ was better in the LAD than the RCA and LCX(P＜0.01).Only 1.4%(19/1386)of coronary artery segments were considered non-assessable due to the motion artifacts.Optimal image quality of all coronary segments in 74 patients(77.9%)can be achieved with one reconstruction data set.The best IQ was predominately in diastote(88.5%)in group 1,while the best IQ was in systole(84.4%)in group 3. ConclusionsDSCT can achieve the optimal IQ with a wide range of HR using single-segment reconstruction. With the increasing of HR,the timing of data reconstruction for the best IQ shifts from mid-diastole to systole.
RESUMEN
Objective To explore the scan technique and image quality of coronary artery imaging with dual-source CT without oral Betaloc preparation.Methods Plain and enhanced dual-source CT coronary artery imaging without oral Betaloc preparation was performed in 215 patients with clinically suspected coronary heart disease or early-stage coronary lesions.Calcium scoring with plain scan images and multi-planar reconstruction(MPR),maximum intensity projection(MIP)and volume rendering technique (VRT)reconstruction with enhanced scan images were made in all cases.The scan technique and post reconstruction experience was summarized.The image quality was classified as three grades,and coronary segments classified according to AHA standards were evaluated.Results The median of calcium score of the 215 cases was 82.2(2.3—1827.9).The average heart rate of the enhanced scan was(80.6?15.3) (57—139)bpm.The post reconstruction methods with which coronary segments could be shown as best as possible consisted of(1)multiphases screening methods,(2)bi-phase or multiple-phase complement method,and(3)premature beat removing or arrhythmia shifting method.Altogether 3026 coronary segments were evaluated,among them 97.5% were evaluated as grade 1 image quality,2.0% were evaluated as grade 2 and 0.5% were evaluated as grade 3.The coronary segments in 91 cases were completely normal, while 112 segments with
RESUMEN
Objective To explore the scanning technique and image quality of coronary artery imaging with dual-source CT without oral Betaloc preparation in the patients with high heart rate.Methods 412 cases were undergone coronary imaging with dual-source CT (including plain and enhanced scans) ,among them,there were 30 cases with heart rate more than 100 bpm.Multi-planar reconstruction(MPR),maximum intensity projection(MIP) and volume rendering (VR) were performed using contrast-enhanced images.The image quality was classified into 3 grades, and coronary segments named according to AHA standard were evaluated.Results The average heart rate during enhanced scan in the 30 cases was (115.6?11.8)(101～139)bpm,the average breath hold time was (5.7?1.2) s.The best reconstruction phase was in the systolic phase. Altogether 424 coronary segments were evaluated, among them 93.9%(398/424)belonged to the first grade,5.0%(21/424)belonged to the second grade,and 1.2%(5/424) belonged to the third grade. Conclusion Without oral administration of Betaloc preparation, good coronary artery images can be obtained in the patients with high heart rate by dual-source CT.
RESUMEN
Objective To evaluate the appearance of CT in patients with severe acute respiratory syndrome (SARS) in the recovery phase, and to study the correlation of CT findings with pulmonary function.Methods From June to August in 2003, 100 patient with confirmed SARS accepted examination in our hospital. Among them, 91 patients (39 men, 52 women, mean age 36.4 years, age range 19- 66 years) received CT examination and pulmonary function test on the same day. The interval between SARS onset and the examination ranged from 52 to 125 days (mean 87.4 days). CT appearances of pulmonary parenchymal abnormalities including distribution and extent of involvement were quantitatively analyzed, and four levels on CT scan including the aortic arch, the tracheal carina, the pulmonary venous confluence, and the dome of right diaphragm were selected to score the lesions. The correlation of CT scores with the results of pulmonary function tests was studied.Results Of the 91 cases, 47 patients had normal CT appearance in the recovery phase, whereas the other 44 patients still had parenchymal abnormalities, including residual ground-glass opacification and reticular shadow. CT visual score had correlation with DLco% ( r =-0.618, P