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Abstract Background: Patients with higher thrombus burden have higher procedural complications and more long-term adverse cardiac events. Detecting patients with high thrombus burden (HTB) before coronary intervention could help avoid procedural complications. Objective: The research aimed to analyze the R wave peak time (RWPT) on the electrocardiogram to predict thrombus burden before coronary angiography in patients with acute ST-segment elevation myocardial infarction (STEMI). Materials and Methods: A total of 159 patients with STEMI were included in the study conducted at a tertiary medical center. The thrombolysis in myocardial infarction (TIMI) thrombus scale was applied to assess the thrombus burden. TIMI thrombus grades 0, 1, 2, and 3 were accepted as low; 4 and 5 had HTB. RWPT was measured from the beginning of the QRS complex to the R-peak from the leads pointing to the infarct-related artery. Results: Patients were divided into two groups according to their angiographically defined thrombus burden as low and high. The low thrombus burden group (LTB) comprised fifty-four patients, whereas the HTB group comprised 105 patients. In the LTB group, RWPT was 47.96 ± 9.17 ms, and in the HTB group was 53.58 ± 8.92 ms; it was significantly longer (p < 0.01). Receiver operating characteristic analysis showed that a cut-off value of preprocedural RWPT of > 46.5 ms predicted the occurrence of HTB with a sensitivity and specificity of 87.62% and 51.85%, respectively (AUC 0.682, 95% CI 0.590-0.774, p < 0.001). Conclusion: The present study evaluated the relationship between the RWPT and thrombus burden in STEMI patients. Based on the results, RWPT is an independent predictor of HTB.
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Objective:To evaluate the influence factors of the peak time in computed tomography (CT) portal venography.Methods:Twenty-eight patients who underwent CT perfusion (CTP) examination in Minhang Hospital Affiliated to Fudan University from October 2020 to December 2021 were retrospectively collected. The CT enhancement time-density curves of the main portal vein trunk and abdominal aorta were obtained at the cross section of the left and right branches of portal vein. The peak time of portal vein and abdominal aorta, the enhanced CT attenuation of the liver and spleen parenchyma enhancement at the peak value of portal vein were measured. Pearson correlation and regression analysis were performed.Results:The peak time of abdominal aorta was (16.39±2.68)s, and portal vein was (27.12±4.65)s. The enhanced CT attenuation of liver and spleen parenchyma were (84.64±20.21)HU and (142.28±25.15)HU, respectively. The peak time of portal vein was positively correlated with the peak time of abdominal aorta ( r=0.825, P<0.001), and there was no statistical correlation with the enhanced CT values of liver and spleen. Multiple linear regression analysis showed that the peak time of abdominal aorta was an independent factor affecting the peak time of portal vein ( b=1.326, t=5.874, P<0.001). The regression equation was the peak time of portal vein=4.185+ 1.451× the peak time of abdominal aorta. The peak time of portal vein in cirrhosis group was (27.78±4.48)s, and that in noncirrhosis group was (26.8±4.81)s, with no significant difference between the two groups ( P=0.614). Conclusions:There was a linear correlation between the peak time of portal vein and the abdominal aorta, and the results could be helpful to optimize the setting of delay time before CT portal venography.
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Objective The purpose of this study was to evaluate the practicability and efficiency of iFlow assistant function in lower extremity vascular disease angioplasty.Methods Retrospective analysis to 22 patients with lower extremity vascular disease in our single center from Septmber 2013 to November 2013, 19 males and 3 females with mean age(66.31 ± 7.46)years, iFlow technology was utilized to analyze the Region Of Interest(ROI) Peak Time(PeakTime) in pre-and post-angioplasty of lower extremity artery and assessed the state of vessel stenosis and blood flow perfusion, as well Doppler ultrasound in postoperative was used to double identify iFlow results.The results of vessel lesion, such as state of stenosis and occlusion were diagnosed by two senior doctors individually, as well as ROI Peak Time was recorded by technician.Results The iFlow technique performed that the ROI PeakTime in the region of interest was significantly decreased in postoperative in comparison to pre-angioplasty [(0.48 ± 0.39) s vs.(1.32 ± 0.60) s, t =8.836, P ＜ 0.001].The Doppler ultrasound in postoperative showed that the ankle-brachial index was significantly increased compared within preoperative (0.97 ± 0.16 vs.0.49 ± 0.11, t =-10.205, P ＜ 0.001).The results of iFlow technique in intraoperative were consistent with those of Doppler ultrasound in postoperative.Conclusion iFlow technique is effective to evaluate hemodynamic change of blood flow in vessel lesion in pre-and postangioplasty, which is assistive technique to assess the efficiency and prognosis in angioplasty.
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Objective:To evaluate the optimal scan delay time of 64 rows spiral CT cerebral angiography by the comparative study of high and low dose test bolus.Methods:Select 69 adult voluntaty patients,take test bolus with 20ml and 60ml contrast medium respectively,then getting 2 peak time of test bolus with high and low dose,calculate the difference of 2 peak time.Results:The arterial peak time difference between high and low dose test bolus of 69 cases,57(83%) cases are 10 seconds,while the venous peak time difference of the same 69 cases,59(85.5%) cases are 8 seconds.Conclusion:The scan delay time of 64 rows spiral CT cerebral angiography could be set by using a peak time of low dose test bolus,plus 8(seconds Median 10 seconds reduce 2 seconds scan time which are taken from the start slice to interest slice),so as to guarantee the satisfactory image quality and ensuring success of the examination.