Реферат
Objective:To investigate the image quality, radiation dose, and diagnostic efficiency of the regimen of GE 256-slice Revolution CT low-dose scanning, combined with an individualized contrast agent, in the assessment of coronary in-stent restenosis.Methods:A total of 120 patients (with 142 stents) treated with coronary stent implantation at the Beijing Renhe Hospital from August 2020 to August 2022 were enrolled in this study. They were randomly divided into an observation group (60 cases with 70 stents) and a conventional group (60 cases with 72 stents) using the random number table method. Both groups received GE 256-slice Revolution CT examinations. Patients in the conventional group were injected with 70 ml of iopromide as a contrast agent each, while those in the observation group were given individualized doses based on their body mass indices (BMIs). A tube voltage of 120 kV and a tube current of 534 mA were applied to the conventional group, whereas the tube voltage and current for the observation group were adjusted within the ranges of 80-120 kV and 150-534 mAs based on patients’ BMIs. Both groups received coronary angiography 7-14 d after coronary computed tomography angiography (CCTA). Finally, the CT image quality, radiation dose, iodine intake, and diagnostic efficiency were compared between the two groups.Results:Both groups exhibited no significant differences in CT values, contrast-to-noise ratios, blooming artifacts, and stent diameters of the left main coronary artery ( P > 0.05). The conventional group manifested higher CT dose index, CT dose length product, effective dose, and iodine intake compared to the observation group ( t = 10.30, 8.75, 10.27, 4.60, P < 0.05). With coronary angiography result as the gold standard, the observation and conventional groups yielded Kappa values of 0.904 and 0.879, respectively, suggesting high consistency in diagnostic performance. Additionally, the two groups demonstrated nonsignificant differences in sensitivity and specificity ( P > 0.05). Conclusions:The regimen of GE 256-slice Revolution CT low-dose scanning, combined with an individualized contrast agent, yielding image quality and diagnostic efficiency equivalent to those of the conventional regimen, can effectively reduce radiation dose and iodine intake. Therefore, this regimen merits wide applicability.