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Abstract Background The personalized, free-breathing, heart rate-dependent computed tomography angiography (CTA) protocol can significantly reduce the utilization of contrast medium (CM). This proves especially beneficial for patients with chronic obstructive pulmonary disease (COPD) undergoing coronary artery CTA examinations. Objective The aim of this study was to evaluate the feasibility of a personalized CT scanning protocol that was tailored to patients’ heart rate and free-breathing for coronary CTA of patients with COPD. Methods A total of 400 patients with COPD who need to undergo the coronary CTA were prospectively randomized into two groups (patients with vascular occlusion were excluded). Group A (n = 200) underwent CTA following a traditional protocol (70mL). The timing of the scans in Group B (n = 200) was determined according to the patient’s HR and free-breathing (30mL). Results No difference was found between the two groups in the CT values of RCA, LA, or LCX; (p = 0.131, 0.195 and 0.116). Subjective ratings of image quality (Table 2) were not statistically different between the two groups (p = 0.825). Conclusion By adopting a heart-rate dependent and free-breathing protocol, the contrast medium volume were reduced in coronary CTA for patients with COPD, while the image quality was remained comparable to those acquired with routine CTA protocol.

ObjectiveThis study aims to investigate the protective effects of Cordyceps sinensis against renal injury induced by low-dose contrast medium (CM) in coronary computed tomography angiography (CCTA) imaging, and to evaluate its efficacy using functional magnetic resonance imaging (fMRI).MethodsTwenty Beagle dogs with induced renal insufficiency were enrolled in the study and randomly assigned to one of four groups (n = 5 per group). Group A received Cordyceps sinensis for 1 week prior to undergoing heart rate-dependent personalized CM CCTA scanning; Group B received Cordyceps sinensis for 1 week followed by conventional dose CM CCTA scanning; Group C did not receive Cordyceps sinensis but underwent HR-dependent CM CCTA scanning; and Group D did not receive Cordyceps sinensis but underwent conventional dose CM CCTA scanning. Renal function was assessed using MRI before and after the intervention, with IVIM (Intravoxel Incoherent Motion) and BOLD (Blood Oxygen Level Dependent) imaging of the kidneys. Key parameters, including the pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), and R2*values, were quantified. Laboratory renal function markers were measured multiple times before and after the intervention, and their correlation with fMRI parameters was analyzed.ResultsCCTA imaging revealed that the CT values of the major coronary artery branches in all groups met the international diagnostic criteria for coronary arteries. No statistically significant differences in image quality were observed among the four groups (P > 0.05). In Groups A and D, significant changes were observed in renal function parameters, as well as in D, D*, f, and R2* values, both pre- and post-CCTA (P < 0.05). However, Groups B and C exhibited no significant changes pre- and post-CCTA (P > 0.05). A significant correlation was found between MRI parameters and laboratory renal function markers, with excellent inter- and intra-observer reproducibility, and high repeatability in the measurements.ConclusionHR-dependent personalized CM CCTA imaging did not compromise image quality. Administration of Cordyceps sinensis demonstrated a potential protective effect on renal function. The combination of IVIM and BOLD functional MRI offers a reliable, non-invasive approach to assess the protective effects of Cordyceps sinensis on renal injury induced by low-dose CCTA in Beagle dogs.