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.

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.