Comparison Of Dual-energy CT And Ultrasound In The Detection Of Urate Crystal Deposition In Lower Limb Gouty Arthritis

Purpose:Compare the ability of dual-energy computed tomography(DECT)and ultrasound(US)to detect urate crystal(MSU)crystals in patients with acute gouty arthritis of the legs.Material and methods:This study is a retrospective study and collect patients with gouty arthritis from September 2019 to March 2021 in the China-Japan Union Hospital of Jilin University.The inclusion criteria is the patients had a history of gout and recent lower limbs joint pain.A total of 75 patients were finally enrolled.Receive dual-energy CT and ultrasound examinations.The time span of the two examinations does not exceed in a week.The dual-energy CT examination results are post-processed by one radiologist to observe whether there is urate crystal deposits.The ultrasound examination is carried out by a sonographer to observe whether there is double-track sign.Then the radiologist and sonographer record the location of the urate deposition,the lower limbs were divided into two groups: one group is knee and the other group is ankle and foot.The knee joints were divided into intra-articular and extra-articular groups according to the anatomical structure.The ankles are divided into three study groups: A、B and C.Respectively: group A is the ankle joint;group B is the tarsal and metatarsal joints and tarsal bones;group C is the metatarsophalangeal joints and the metatarsals and phalanges.Chi-square test and Kappa test were used to analyze the above results.Results:A total of 75 patients participated in the study(61 males and 14females),age range 21-75 years old(average age 51.9 years),uric acid level(254.1-720.05μmol/L),average 485.27±108.05μmol/L,CRP range(4.71-11.3mg/L).65 out of 75 patients(86%)had a positive DECT test result,and 52 out of 75 patients(69%)had a positive ultrasound test result.The positive rate of DECT for urate crystal deposition was higher than that of US,P<0.05.The lower limbs were divided into knee and the ankle and foot,and the positive rate of two groups were different.In the knee joints,the positive rates of dual-energy CT and ultrasound in the extra-articular groups were different(p<0.05).In the ankles,the results of dual-energy CT and ultrasound examinations in group B and group C differed(p<0.05).Conclusion:Dual-energy CT is more sensitive to the detection of urate crystal deposition in the acute attack of lower extremity gouty arthritis,and it is a more accurate method for detecting urate crystals in knee and ankle gouty arthritis.