Clinical Application Of Energy Spectrum CT And Quantitative Analysis Of Urate Deposition In Gouty Arthritis

Objective: To explore the clinical application value of energy spectrum CT in the diagnosis of gouty arthritis,to quantitatively analyze the deposition of urate in periarticular tissues,and to evaluate the application value of quantitative parameters of energy spectrum CT in identifying gouty arthritis patients,asymptomatic hyperuricemia patients,and other arthritis patients,providing objective imaging evidence for clinical diagnosis and treatment of gouty arthritis.Methods:(1)Energy spectrum CT was used to scan the joints of 64 clinically suspected gouty arthritis patients and 18 asymptomatic hyperuricemia patients.GSI Viewer software was used for post processing on the GE AW 4.6 workstation.The concentration of urate in the urate deposition area,paraarticular soft tissue,and bone was measured using the material separation and quantitative function of the base material map,and three-dimensional reconstruction and pseudocolor coding of urate were performed;(2)Based on the results of three-dimensional reconstruction and uric acid salt pseudo color coding,the diagnostic efficacy of energy spectrum CT based material images and pseudo color coding in gouty arthritis was evaluated;(3)Compare the differences in urate deposition in different tissue structures of the affected joints of the same type of patients,and the differences in urate deposition in the same tissue structure around the affected joints of different types of patients.Draw ROC curves for each group of parameters,and evaluate the quantitative parameters of urate deposition for identifying gouty arthritis patients diagnostic efficacy of asymptomatic hyperuricemia and other arthritis patients;(4)To analyze the differences in the regularity and clinical characteristics of urate deposition in patients with gout arthritis during acute episodes,and to analyze the linear correlation between the blood uric acid and creatinine values of gout patients and the urate deposition in the tissues around the affected joints.Results:(1)Energy spectrum CT based material images and pseudo color coding can clearly display the deposition of urate around the joint.Its diagnostic sensitivity is 88.10%,specificity is 86.36%,and ROC curve shows AUC of 0.872;(2)The correlation coefficient(ICC)of uric acid concentration measured by the two measurers for gouty arthritis,asymptomatic hyperuricemia,and other arthritis patients was>0.75,with good consistency;(3)In patients with gouty arthritis,there was a statistically significant difference in the concentration of uric acid(hydroxyapatite)in the urate deposition area,paraarticular soft tissue,and bone tissue(p<0.001).In asymptomatic hyperuricemia patients and other arthritis patients,the concentration of uric acid(hydroxyapatite)in paraarticular soft tissue was greater than the concentration of uric acid(hydroxyapatite)in bone tissue,The differences were statistically significant(p<0.001);There were statistically significant differences in the concentration of uric acid(hydroxyapatite)in the soft tissue around the joints among the three groups of patients(p<0.001).Among them,gouty arthritis group is the highest,followed by asymptomatic hyperuricemia group,and other arthritis groups are the lowest;(4)The sensitivity,specificity,and AUC of uric acid(hydroxyapatite)concentration in paraarticular soft tissue and bone to distinguish gout and other arthritis groups were 83.33%,54.76%,95.45%,77.27%,0.927,and 0.614,respectively;The sensitivity,specificity,and AUC of identifying gout and asymptomatic hyperuricemia groups by the concentration of uric acid(hydroxyapatite)in paraarticular soft tissue and bone were 83.33%,52.38%,88.89%,83.33%,0.812,and 0.624,respectively;The sensitivity,specificity,and AUC of identifying asymptomatic hyperuricemia and other arthritis groups by the concentration of uric acid(hydroxyapatite)in paraarticular soft tissue and bone were 94.44%,100%,72.73%,18.18%,0.828,and 0.510,respectively;(5)In patients with gouty arthritis,the blood uric acid level was linearly positively correlated with the concentration of uric acid(hydroxyapatite)in the paraarticular soft tissue(p<0.05),while the blood uric acid level was linearly negatively correlated with the concentration of uric acid(hydroxyapatite)in the periarticular urate deposition area(p<0.05).Conclusion:(1)Energy spectrum CT has good diagnostic efficacy for gouty joints,providing a noninvasive imaging method for its diagnosis;(2)The concentration of uric acid(hydroxyapatite)in different tissues of the same type of patients is different,and the concentration of uric acid(hydroxyapatite)in different types of patients’ paraarticular tissues is also different.Quantitative parameters of urate deposition by energy spectrum CT has good diagnostic value in differentiating gout patients,asymptomatic hyperuricemia patients,and other arthritis patients;(3)There is a correlation between blood uric acid and the concentration of uric acid(hydroxyapatite)in periarticular urate deposition areas and peripheral soft tissue,suggesting that hypouricemic therapy has a positive effect on reducing the deposition of urate crystals in periarticular tissues and promoting the disintegration of urate crystals.