Dual-energy CT Evaluation Of Muscle Ischemia In Peripheral Arterial Obstructive Disease

Background and Purpose:Peripheral arterial obstructive disease is a common disease of vascular surgery.It consists of two parts: artery stenosis and muscle ischemia.Assessing the condition and extent of muscle ischemia can provide important clinical value beyond the qualitative findings based on vascular anatomy.Therefore,this study aims to explore the diagnostic value of dual-energy CT in assessing muscle ischemia in lower extremity arterial occlusive disease and the degree of muscle ischemia in the arterial occlusive side.Materials and Methods:This study will evaluate 75 patients with Peripheral arterial obstructive disease（PAOD）who met the eligibility criteria（age range 68.65±9.60 years,19 females,56 males）.Dual-energy CT scans were performed on all patients,and only patients with unilateral significant hemodynamic abnormalities were included.All lesions were located unilaterally in the external iliac or/and superficial femoral artery.The opposite side of the occlusive side of the patient was used as the self control,and the patients were divided into ischemia group and control group.The measured occlusive length data were divided into short,medium and long groups according to TASC score.The software of Siemens post-processing workstation was used to calculate iodine base diagram and energy spectrum curve attenuation diagram（CT values at different Ke V levels）of the region of interest,and calculate the slope of energy spectrum curve.Statistical analysis was performed on all data according to SPSS software.The characteristics and differences of parameters between ischemic group（obstructive group）and control group（normal group）,as well as the correlation between different obstructive length and iodine concentration were analyzed and compared.Results:The mean ±SD of iodine concentration and energy spectrum slope in ischemic group and control group were（iodine concentration 0.48±0.18 VS 0.72±0.15;Energy spectrum slope（0.48±0.14 VS 0.60±0.15）.Compared with the control group,the average iodine concentration and energy spectrum slope of the ischemic group were significantly lower than that of the normal group（P<0.001）.The mean ±SD of iodine concentration and energy spectrum slope with or without side-branch cycle were（iodine concentration 0.47±0.13 VS 0.44±0.17;Energy spectrum slope 0.48±0.13 VS 0.47±0.14）.There was no statistical difference in iodine concentration and energy spectrum slope between those with and without side-branch circulation.The mean ±SD of iodine concentration was 0.59±0.14 VS 0.54±0.07 VS 0.33±0.07 in clinical groups（short,medium and long lesions）.Energy spectrum slope0.48±0.14 VS 0.51±0.18 VS 0.46±0.11）.There were significant differences between different lesion lengths and iodine concentration values（P=0.001）,and there was no difference in energy spectrum slope（P>0.05）.Correlation analysis of energy spectrum parameters showed that there was significant correlation between different lesion lengths and iodine concentration（R =-6.04 P <0.01）.Conclusion:Dual-energy CT can be used as an auxiliary diagnostic means for the evaluation of muscle blood supply for arterial obstructive diseases of lower extremities,and can indicate the situation and degree of muscle ischemia of vascular obstructive side of lower extremities with different lesion lengths.