ABSTRACT
Objective:To investigate the feasibility of coronary CT angiography(CCTA)-feature tracking(FT) for assessing global and regional myocardial strain in patients with heart failure(HF).Methods:From July 2019 to December 2020, twenty-five patients diagnosed with HF from Peking Union Medical College Hospital were prospectively enrolled into the study. All patients underwent retrospective electrocardiogram-gated CCTA and cardiac MR (CMR) imaging within 7 days. CCTA-FT and CMR-FT were undertaken using cvi 42 dedicated commercial software to measure global and regional strain parameters, including global peak radial strain (GPRS), global peak circumferential strain (GPCS) and global peak longitudinal strain (GPLS), as well as peak radial strain (PRS), peak circumferential strain (PCS) and peak longitudinal strain (PLS) of left ventricular basal segment, middle segment and apical segment. Conventional left ventricular functional parameters were also calculated, including left ventricular ejection fraction (LVEF), left ventricular stroke volume (LVSV) and left ventricular mass index (LVMI). Paired t test or Wilcoxon signed-rank test was used to compare the differences of measurements between CCTA group and CMR group. Pearson or Spearman correlation analysis was used to analyze the correlation between the two groups. Inter-and intra-observer consistence in CCTA group was evaluated by intraclass correlation coefficient (ICC) analysis. Results:The effective radiation dose of CCTA examination was 6.00 (4.86,7.63) mSv. Inter-and intra-observer consistence in CCTA group was excellent, and the ICC value was 0.85-0.98. In the overall strain parameters, GPCS in CCTA group[-8.10%(-10.32%, -5.20%)] was significantly lower than that of CMR group[-8.49%(-13.79%, -5.95%)] ( Z=-2.15, P=0.031). There was no significant difference in GPRS and GPRS between the two measurement methods ( P>0.05). Strong correlations were observed between GPRS, GPCS and GPLS ( r=0.65, 0.63, 0.71,all P<0.001). For local strain parameters, PCS in the middle segment and apical segment of CCTA group were lower than those of CMR group ( Z=-2.17, -2.62, all P<0.05). There were no significant differences in PCS of basal segment, PRS and PLS of all segments between groups (all P>0.05). The PCS and PLS of basal segment, PRS of middle segment and PRS of apical segment were moderately correlated ( r=0.46, 0.52, 0.58, 0.53, P<0.05); The other local strain parameters were strongly correlated, the range of r value was from 0.64 to 0.70 (all P<0.001). For left ventricular functional parameters, LVEF, LVSV and LVMI showed no significant differences between groups ( P>0.05), and the correlation was extremely strong ( r=0.90, 0.89, 0.96, all P<0.001). Conclusions:The repeatability of CCTA-FT technique in measuring myocardial strain was good, and the correlation of parameters measured by CCTA-FT technique and CMR-FT technique was excellent. Therefore, CCTA-FT technique can be used as a new noninvasive and simple method to evaluate myocardial motor function.
ABSTRACT
Objective:To explore the feasibility in evaluating segmental extracellular volume (ECV) using dual-layer spectral detector CT in patients with heart failure with various percentages of delayed hyper-enhanced volume, using MRI as a reference.Methods:Twenty-seven patients with heart failure in Peking Union Medical College Hospital were prospectively enrolled in this study from July 2019 to January 2021. All the patients underwent both CT late iodine enhancement and MR late gadolinium enhancement imaging within a week. According to percentages of hyper-enhanced volume on cardiac MR image, myocardial segments were classified into 3 groups: 0-4% (group A), 5%-49% (group B) and 50%-100% (group C). ECV images were independently observed by 2 experienced radiologists. The correlation and agreement between CT-ECV and MRI-ECV for the whole myocardial assessment and for the segmental assessment were evaluated using Spearman correlation and Bland-Altman analysis. Inter-observer agreement was assessed using the ICC.Results:Of the 27 patients, 432 segments were analyzed, with 199 segments in group A, 151 segments in group B and 82 segments in group C. In the whole myocardial analysis, the CT-ECV and MRI-ECV were 32.25% (28.04%, 34.28%) and 32.27% (28.35%, 34.77%), respectively. A good correlation was found between CT-ECV and MRI-ECV ( r=0.969, P<0.001). Bland-Altman analysis between CT-ECV and MRI-ECV showed a small bias (0.4%), with 95% limits of agreement of -6.9% to 7.8%. as for the segmental myocardial assessment, the CT-ECV was 28.23% (26.18%, 29.92%) for group A, 33.29% (30.16%, 35.96%) for group B and 40.22% (34.06%, 46.70%) for group C. There was statistically significant difference in ECV among three groups (all P<0.001). Good correlations between CT-ECV and MRI-ECV were found in group A ( r=0.614, P<0.001), group B ( r=0.852, P<0.001) and group C ( r=0.953, P<0.001). Bland-Altman analysis between CT-ECV and MRI-ECV showed a small bias 2.0% (95% limits of agreement:-17.6%-21.6%) in group A, a small bias -0.4% (95% limits of agreement: -13.8%-12.9%) in group B and a small bias -1.8% (95% limits of agreement: -17.4%-13.9%) in group C. The ICC values between 2 observers were 0.877 and 0.945 on CT-ECV and MRI-ECV, respectively. Conclusions:The larger percentage of hyper-enhanced volume on cardiac MR image, the stronger correlation are between the CT-ECV and MRI-ECV. CT-ECV may be taken as an alternative tool for quantitative evaluation of myocardial tissue in patients with heart failure.
ABSTRACT
Objective:To evaluate the feasibility of high concentrated contrast media combined with monochromatic images to improve image quality with double low scanning in dual-layer spectral coronary CT angiography.Methods:Fifty-six patients with suspected coronary artery disease were enrolled and randomly separated into two groups. All patients were scanned at 120 kVp in step-and-shoot mode using a dual-layer detector CT (IQon spectral CT). Patients were either injected with 18 ml high concentration contrast medium(400 mgl/ml) at 2 ml/s (group A) or 45 ml contrast medium (370 mgl/ml) at 4 ml/s (group B). Forty to 80 keV monoenergetic images with 10 keV increment and conventional image (group A2) were reconstructed for group A, conventional poly-energetic image was reconstructed for group B. Region of interest was placed on aorta root (AO), middle segment of left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) to measure the attenuation and noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Image quality was assessed by two reviewers independently with a 4-point scale on image quality (1-undiagnostic,4-excellent). The objective and subjective image evaluation were compared using the Kruskal-Wallis test. The Steel Dwass was used for multiple comparisons between monoenergetic images in Group A and conventional images in Group B, after the Kruskal-Wallis test.Results:There were significant differences among the attenuation, noise, SNR and CNR of group B, group A2, and monoenergetic images(all P<0.001).The CT value in the aortic root was significantly higher at 40-50 keV monoenergetic images than that in group B(all P<0.05), and similarly, the CT value in LAD,LCX and RCA at 40 keV were superior than that in group B(all P<0.001). There was no significant difference in the noise of the aortic root among 40 keV image, group A2 and group B(all P>0.05),while the noise in the 50-80 keV monoenergetic images were significantly lower than that in Group B(all P<0.001). The SNR and CNR in the aortic root were significantly higher at 40-60 keV monoenergetic images than that in group B(all P<0.001).The SNR in LAD and RCA at 40，50 keV and the CNR in LAD and RCA at 40-60 keV were higher than that in group B(all P<0.01).The SNR at 40-60 keV and CNR at 40-70 keV in LCX were superior than that in group B(all P<0.05). There were significant differences among the subjective image quality score of group B, group A2, and monoenergetic images(all P<0.001).The subjective image quality score of 40，50 keV images were not significantly different from that in group B (all P>0.05),while the score in 60-80 keV image and group A2 were lower than that of Group B(all P<0.001). Conclusion:40，50 keV low monochromatic images derived from dual-layer spectral detect CT combined with high concentrated contrast media can provide comparable or superior image quality with double low scanning in CCTA study.
ABSTRACT
BACKGROUND:Simple pedicle screw fixation for thoracolumbar fractures has better outcomes, but there are some deficiencies, such as poor applicability for severe compression or burst fractures, strong vertebral pain, easy to cause vertebral wound denervation and paraspinal muscle injury, and slow recovery. OBJECTIVE:To investigate the clinical effects of pedicle screw fixation combined with artificial bone graft for the treatment of thoracolumbar fractures. METHODS:A total of 126 patients with thoracolumbar vertebral compression fractures, who had undergone pedicle screw fixation without bone graft (control group,n=62) and with bone graft (test group,n=64) were enroled. The fracture healing, anterior vertebral height ratio, sagittal Cobb angle, and loss rate of vertebral height after 6 months were observed by X-ray in the two groups. RESULTS AND CONCLUSION:Al patients were folowed up, and had complete fracture healing after 12-16 months. The anterior vertebral height and Cobb angle were both improved in the two groups at 1 week after operation (P 0.05). New bone formation was observed in the test group at 6 months after operation, and patients were pain-free; but the speed of bone formation was slower in the control group, and patients stil suffered from painful thoracolumbar fractures. There was no difference in the loss of anterior vertebral height and Cobb angle between the two groups (P> 0.05). These findings indicate that pedicle screw fixation combined with artificial bone graft lead to a better recovery in thoracolumbar fractures.
ABSTRACT
HIV-1 integrase (IN) is an essential enzyme for retroviral replication. There is no analogue for this enzyme in human cells so that inhibition of IN will not bring strong effect on human body. Thus, HIV-1 IN has become a rational target for therapy of AIDS. This review provides a comprehensive report of alpha, gamma-diketo IN inhibitors discovered in recent years. Compilation of such data will prove to be beneficial in developing QSAR, pharmacophore hypothesis generation and validation, virtual screening and synthesis of compounds with higher activity.