This study aims to determine the retention time of iodinated contrast agents (ICA) in the coronary artery. The mechanical aspect of ICA displacement was studied in order to better understand the effect of these produc...This study aims to determine the retention time of iodinated contrast agents (ICA) in the coronary artery. The mechanical aspect of ICA displacement was studied in order to better understand the effect of these products on the inner wall of the artery of patients with coronary artery stenosis, undergoing repeated imaging examinations with iodinated contrast agents. ICA flow, ICA and blood flow in the artery were modelled. The fluid was regarded to be viscous, incompressible and Newtonian. Blood flow was presumed to be unidirectional, laminar and unstationary. Iodine flow velocity and retention time were calculated using the Runge-Kutta 4th order method programmed in C++ and MatLab R2013a language. The results showed that for coronary artery CT-scans, ICA retention time is 1 minute 40 seconds and for coronary arteriography it is between 2.41 and 3.61 seconds. The values calculated were compared to theoretical values and to clinical observations. The results enabled us to validate our model.展开更多
Background:More than 75 million procedures with intravascular iodine-based contrast media(ICM)are performed worldwide every year,and some patients undergoing these procedures do not have normal thyroid function.The lo...Background:More than 75 million procedures with intravascular iodine-based contrast media(ICM)are performed worldwide every year,and some patients undergoing these procedures do not have normal thyroid function.The long-term effects of ICM in patients with mild thyroid dysfunction(TD)are unclear.Methods:This prospective cohort study was conducted in China.Patients with stable angina pectoris with total triiodothyronine(TT3)reduction,normal thyroid-stimulating hormone,and reverse triiodothyronine(rT3)were enrolled and divided into high-dose(≥100 mL ICM)and low-dose groups(<100 mL ICM).We dynamically investigated the trends in thyroid function,rT3,and thyroid antibodies one year after ICM exposure.Results:A total of 154 patients completed 6 months of follow-up and 149 completed 1 year of follow-up.Thyroglobulin antibody(TGAB)levels were elevated in 41(26.6%)patients before ICM exposure,11(7.1%)of whom also had elevated thyroid peroxidase antibody levels.Transient subclinical TD occurred 6 months after ICM exposure;75.5%(34/45)of post-operative TD occurred in the high-dose group.One patient developed severe hypothyroidism with myxedema,requiring drug intervention 1 year after ICM exposure.The level of rT3 showed no statistically significant changes during post-operative follow-up(P=0.848).The TGAB level decreased at 6th month(P<0.001),but increased at 1 year after ICM exposure(P=0.002).Conclusions:Patients with T3 reduction are at a risk of transient subclinical TD and hypothyroidism after a single large dose of ICM.Follow-up of this population at 9-12 months after ICM exposure is warranted.展开更多
文摘This study aims to determine the retention time of iodinated contrast agents (ICA) in the coronary artery. The mechanical aspect of ICA displacement was studied in order to better understand the effect of these products on the inner wall of the artery of patients with coronary artery stenosis, undergoing repeated imaging examinations with iodinated contrast agents. ICA flow, ICA and blood flow in the artery were modelled. The fluid was regarded to be viscous, incompressible and Newtonian. Blood flow was presumed to be unidirectional, laminar and unstationary. Iodine flow velocity and retention time were calculated using the Runge-Kutta 4th order method programmed in C++ and MatLab R2013a language. The results showed that for coronary artery CT-scans, ICA retention time is 1 minute 40 seconds and for coronary arteriography it is between 2.41 and 3.61 seconds. The values calculated were compared to theoretical values and to clinical observations. The results enabled us to validate our model.
基金supported by grants from the Hospital Level Project of Tianjin Chest Hospital in 2018(No.2018XKC08)funded by the Tianjin Key Medical Discipline(Specialty)Construction Project.
文摘Background:More than 75 million procedures with intravascular iodine-based contrast media(ICM)are performed worldwide every year,and some patients undergoing these procedures do not have normal thyroid function.The long-term effects of ICM in patients with mild thyroid dysfunction(TD)are unclear.Methods:This prospective cohort study was conducted in China.Patients with stable angina pectoris with total triiodothyronine(TT3)reduction,normal thyroid-stimulating hormone,and reverse triiodothyronine(rT3)were enrolled and divided into high-dose(≥100 mL ICM)and low-dose groups(<100 mL ICM).We dynamically investigated the trends in thyroid function,rT3,and thyroid antibodies one year after ICM exposure.Results:A total of 154 patients completed 6 months of follow-up and 149 completed 1 year of follow-up.Thyroglobulin antibody(TGAB)levels were elevated in 41(26.6%)patients before ICM exposure,11(7.1%)of whom also had elevated thyroid peroxidase antibody levels.Transient subclinical TD occurred 6 months after ICM exposure;75.5%(34/45)of post-operative TD occurred in the high-dose group.One patient developed severe hypothyroidism with myxedema,requiring drug intervention 1 year after ICM exposure.The level of rT3 showed no statistically significant changes during post-operative follow-up(P=0.848).The TGAB level decreased at 6th month(P<0.001),but increased at 1 year after ICM exposure(P=0.002).Conclusions:Patients with T3 reduction are at a risk of transient subclinical TD and hypothyroidism after a single large dose of ICM.Follow-up of this population at 9-12 months after ICM exposure is warranted.
