Objective:To assess the predictive value for the risk of cardiogenic stroke (CS) in patients with paroxysmal atrial fibrillation (PAF) using quantification of left atrial appendage early blood stasis (LAA-BS) signs derived from left atrium-pulmonary vein CT examination.Methods:A retrospective analysis of 187 patients with PAF, who were confirmed to have LAA-BS by left atrium-pulmonary vein CT examinations, was conducted at Second Affiliated Hospital of Nantong University from January 2019 to December 2021. The ratio of LAA-BS CT values to ascending aorta (AA) CT values (HU BS/HU AA) and the ratio of LAA-BS volume to LAA volume (V BS/V LAA) were measured at the peak time of AA enhancement, which were used as characteristic quantitative indicators of LAA-BS. Using the median values of HU BS/HU AA and V BS/V LAA as cut-off points for grouping, the differences between the high-ratio and low-ratio groups were compared in terms of general information, clinical characteristics, and imaging characteristics. All enrolled patients were followed up with the primary outcome event of CS occurrence. The differences in the proportion of CS occurrence between the high-ratio and low-ratio groups were compared. The risk stratification analysis of the occurrence of CS in PAF patients was performed using Kaplan-Meier curves. Additionally, the predictive value of HU BS/HU AA, V BS/V LAA and other imaging indices for the risk of CS occurrence was assessed using Cox proportional risk regression models. Results:The incidence of hypertension and the proportion of patients with atrial fibrillation-stroke risk score (CHA 2DS 2-VASc)≥3 in the high V BS/V LAA group were higher than that in the low V BS/V LAA group, and the difference was statistically significant ( P=0.041, P=0.011). The left atrial volume (LAV) in patients in the low HU BS/HU AA group was greater than in the high HU BS/HU AA group, and the difference was statistically significant ( P=0.040). Kaplan-Meier analysis showed a higher incidence of CS in the low HU BS/HU AA group than in the high HU BS/HU AA group ( P=0.012). Similarly, the high V BS/V LAA group had a higher incidence of CS compared with the low V BS/V LAA group ( P=0.019). Subgroup analysis revealed a significantly higher incidence of CS in the subgroup with low HU BS/HU AA and high V BS/V LAA compared to other subgroups (all P<0.05). The Cox proportional hazards regression model, adjusting for confounding factors, identified low HU BS/HU AA and high V BS/V LAA as independent risk factors for CS occurrence in PAF patients ( P=0.005 and P=0.029). Conclusion:The HU BS/HU AA and V BS/V LAA quantified using left atrium-pulmonary vein CT imaging are predictive factors for CS occurrence in patients with PAF. These ratios synergistically contribute to the risk assessment of CS.

Objective:To assess the predictive value for the risk of cardiogenic stroke (CS) in patients with paroxysmal atrial fibrillation (PAF) using quantification of left atrial appendage early blood stasis (LAA-BS) signs derived from left atrium-pulmonary vein CT examination.Methods:A retrospective analysis of 187 patients with PAF, who were confirmed to have LAA-BS by left atrium-pulmonary vein CT examinations, was conducted at Second Affiliated Hospital of Nantong University from January 2019 to December 2021. The ratio of LAA-BS CT values to ascending aorta (AA) CT values (HU BS/HU AA) and the ratio of LAA-BS volume to LAA volume (V BS/V LAA) were measured at the peak time of AA enhancement, which were used as characteristic quantitative indicators of LAA-BS. Using the median values of HU BS/HU AA and V BS/V LAA as cut-off points for grouping, the differences between the high-ratio and low-ratio groups were compared in terms of general information, clinical characteristics, and imaging characteristics. All enrolled patients were followed up with the primary outcome event of CS occurrence. The differences in the proportion of CS occurrence between the high-ratio and low-ratio groups were compared. The risk stratification analysis of the occurrence of CS in PAF patients was performed using Kaplan-Meier curves. Additionally, the predictive value of HU BS/HU AA, V BS/V LAA and other imaging indices for the risk of CS occurrence was assessed using Cox proportional risk regression models. Results:The incidence of hypertension and the proportion of patients with atrial fibrillation-stroke risk score (CHA 2DS 2-VASc)≥3 in the high V BS/V LAA group were higher than that in the low V BS/V LAA group, and the difference was statistically significant ( P=0.041, P=0.011). The left atrial volume (LAV) in patients in the low HU BS/HU AA group was greater than in the high HU BS/HU AA group, and the difference was statistically significant ( P=0.040). Kaplan-Meier analysis showed a higher incidence of CS in the low HU BS/HU AA group than in the high HU BS/HU AA group ( P=0.012). Similarly, the high V BS/V LAA group had a higher incidence of CS compared with the low V BS/V LAA group ( P=0.019). Subgroup analysis revealed a significantly higher incidence of CS in the subgroup with low HU BS/HU AA and high V BS/V LAA compared to other subgroups (all P<0.05). The Cox proportional hazards regression model, adjusting for confounding factors, identified low HU BS/HU AA and high V BS/V LAA as independent risk factors for CS occurrence in PAF patients ( P=0.005 and P=0.029). Conclusion:The HU BS/HU AA and V BS/V LAA quantified using left atrium-pulmonary vein CT imaging are predictive factors for CS occurrence in patients with PAF. These ratios synergistically contribute to the risk assessment of CS.

Objective:To investigate the predictive value for major adverse cardiovascular events (MACE) occurring within 1 year in patients with old myocardial infarction(OMI) using characteristics of myocardial scar derive from dual-energy CT (DECT) post-processing technique.Methods:OMI patients who received coronary CT angiography following dual-energy CT with late iodine enhancement (LIE-DECT) in the Second Affiliated Hospital of Nantong University from November 2019 to October 2022 were continuously included, and the images of all enrolled patients were reconstructed using 40 keV monoenergetic plus (Mono+) map, LIE (representing myocardial scar) was quantified on left ventricular short-axis images, including the LIE segments, the LIE score, and the LIE degree. All enrolled patients were followed up for MACE, defined as hospitalization for heart failure, malignant arrhythmia, and cardiac death. Regression analysis was used to investigate the relationship between the quantified value of myocardial scar and the occurrence of MACE, and receiver operating characteristic curve (ROC) was used to evaluate the efficacy of quantified value of myocardial scar in predicting MACE. The area under the curve (AUC) was compared using the DeLong test.Results:Finally, 231 patients with OMI were included, and MACE occurred in 37 cases (16.0%) within 1 year after LIE-DECT examination. The LIE segments 5 (4, 7), the LIE score 27 (13, 49) and the LIE degree 9.4%(7.5%, 15.5%) in the MACE group were higher than those in the non-MACE group 3 (2, 5), 9 (6, 15) and 6.7%(6.3%, 7.9%) (all P<0.001). Multivariable logistic regression analysis showed that after adjusting for confounders, the LIE segments ( OR=2.118, P<0.001), the LIE score ( OR=3.168, P<0.001), and the LIE degree ( OR=3.092, P<0.001) remained risk factors for the development of MACE. On ROC analysis, AUC of LIE segments, LIE score and LIE degree were 0.715, 0.822 and 0.806 (all P<0.001), with sensitivities of 81.1%, 86.5%, and 91.9%, and specificities of 53.6%, 69.6%, and 60.8%, respectively. DeLong′s test showed that the predictive efficacy of LIE score and LIE degree was higher than that of LIE segments ( Z=2.63, P=0.008; Z=1.96, P=0.049), and there were no significant differences in the predictive efficacy of LIE score and LIE degree ( Z=0.60, P=0.551). Conclusion:The LIE segments, the LIE score and the LIE degree detected by LIE-DECT 40 keV Mono+maps are risk factors for the occurrence of MACE in patients with OMI and have good efficacy in predicting the occurrence of MACE, which can be used as important indicators for assessing the clinical prognosis of OMI.

Objective:To evaluate the reliability of cardiac late iodine enhancement dual-energy CT (LIE-DECT) multiparameter post-processing technique for evaluating the presence, location, and extent of cardiac scars in patients with heart failure (HF), using cardiac MR (CMR) late gadolinium enhancement (LGE) as a reference standard.Methods:Thirty-nine HF patients who underwent cardiac LIE-DECT and LGE-CMR examinations in the Second Affiliated Hospital of Nantong University from November 2019 to November 2021 were prospectively collected, all enrolled HF patients underwent LIE-DECT post-processing to reconstruct monoenergetic plus (Mono+) map (40 keV), iodine map and Rho/Z map, to evaluate the enhancement degree, location and extent of left ventricular myocardial LIE on the left ventricular short-axis map, respectively, and compared with LGE-CMR. Cohen′s Kappa test was used to assess the intra-and inter-observer consistency of LIE by DECT multiparameter technique and the consistency of LIE presence and location by DECT multiparameter technique and by CMR. The diagnostic efficacy of DECT multiparameter technique in diagnosing myocardial scar was calculated.Results:Of the 39 patients included, 32 patients were detected by CMR with LGE in 147 segments, including 37 subendocardial patterns, 19 transmural patterns, 74 mid-wall patterns, and 17 epicardial patterns. The intra-observer consistency Kappa values of 40 keV Mono+map, iodine map and Rho/Z map were 0.878, 0.930 and 0.835 ( P all<0.001), respectively. The inter-observer consistency Kappa values were 0.838, 0.892 and 0.808 ( P all<0.001), respectively. The LIE of 40 keV Mono+map, iodine map and Rho/Z map were in good agreement with CMR, Kappa values were 0.903, 0.883 and 0.810 ( P all<0.001), respectively. For the per-patient analysis, the accuracies of 40 keV Mono+map, iodine map and Rho/Z map were 92.3% (36/39), 92.3% (36/39) and 82.1% (32/39), respectively. For the segment-based analysis, the accuracies of 40 keV Mono+map, iodine map and Rho/Z map accuracy were 96.1% (492/512), 95.3% (488/512) and 92.6% (474/512), respectively. In Bland-Altman analysis, the consistency bias between scar extent measured by 40 keV Mono+map, iodine map, Rho/Z map and that measured by LGE-CMR were -2.03%, -2.21%, -2.65%, and the 95% limit of agreement were -12.20%-8.14%, -12.69%-8.28% and -14.85%-9.58%, respectively. Conclusion:LIE-DECT multiparameter technique can detect myocardial scar in HF patients well, which is consistent with LGE-CMR.

Objective To evaluate the relationship between myocardial perfusion imaging quality and reconstruction time of dual-souce CT (DSCT).Methods Myocardial perfusion imaging was performed in 28 subjects using second-generation DSCT.The coronary arteries of all selected subjects were normal.280 ms temporal resolution was used,and the image of 30 ％-80 ％ R-R phase was reconstructed by retrospective ECG gating interval 5 ％.The artifact area of myocardial perfusion iodine map image of each R-R interval were obtained.Average segment artifacts of the heart bottom,central,apical,apical level of heart level were calculated and statistical analyzed.Results The artifact area of myocardial perfusion iodine map of the heart bottom,central,apical,and the whole heart had statistically significant differences (all P＜0.01),and the minimum artifact area was in60％ R-R phase ([0.31±±0.28]cm2,[0.18±0.23]cm2,[0.13±0.13]cm2,[0.22± 0.18]cm2).There was no difference between different phases of the heart apical level (P=0.634).The minimum artifact area of myocardial perfusion iodine map of the heart bottom,central,apical,apical level in 60％ R-R phase at the heart apical,the difference had statistically significant (F 3.701,P=0.014),there was no difference between the heart apical and central (P＞0.05),but the difference between the heart apical and other parts had statistically significant (P＜0.05).Conclusion Using 280 ms temporal resolution,second-generation DSCT can achieve the optimal myocardial perfusion imaging quality using 60％ R-R phase reconstruction.