| Objective: Evaluate the changes of volume and distribution of monosodium urate(MSU)crystals based on dual-energy CT(DECT)in foot and ankle of gout patients after treatment,and explore the relationship between the volume changes of MSU crystals and clinical laboratory examination,to provide the basis for the application of DECT in efficacy evaluation of gout patients.Materials and methods: We collected 63 patients with gout in the gout clinic of the Affiliated Hospital of Qingdao University from January 2020 to September 2022.All patients received baseline DECT examination of foot and ankle and the results showed foot and ankle existed MSU crystals.After an average of 6 months of urate-lowering therapy(ULT)in accordance with the Guidelines for the Diagnosis and management of Hyperuricemia and Gout in China(2019),they underwent follow-up foot and ankle DECT examination.At the same time,we collected clinical laboratory examination.The beforeand after-treatment volume of MSU crystals in 63 patients was quantified by DECT gout post-processing software,and the distribution of MSU crystals in the foot and ankle was evaluated by the semi-quantitative scoring system.The t test and Mann-Whitney U test were used to analyze the changes of MSU crystals and other clinical and laboratory indicators before and after treatment.Patients were divided into attainment group(the treatment goal was reached,SUA≤360μmol/L,31 patients)and non-attainment group(the treatment goal was not reached,SUA>360μmol/L,32 patients)according to whether the treatment goal was achieved to preliminarily investigate the relationship between SUA and MSU crystals.Spearman rank correlation coefficient was used to analyze the correlation between MSU crystals changes and clinical and laboratory indicators.Results:(1)Distribution of MSU crystals in foot and ankle before ULT: MSU crystals was most common in the ankle joint(82.5%),the average score of ankle joint and first metatarsophalangeal joint were the highest(3 points).(2)Changes of MSU crystals in foot and ankle after ULT: MSU crystals volume in foot and ankle decreased from 1.16cm~3 to 0.63 cm~3,semi-quantitative score was decreased from6 points to 5 points,the MSU crystal scores of all anatomical sites were reduced,and the difference were statistically significant(P<0.05).The total dissolution rate of MSU crystals in the soft tissue was the highest(18.2%).(3)Changes of laboratory indicators before and after ULT: SUA decreased from520μmol/L to 368μmol/L,and the difference was statistically significant(P <0.05).There was no statistical significance in changes of other indicators(P >0.05).(4)Comparison between the attainment and non-attainment groups: there was a statistically significant difference in age and SUA between the attainment and non-attainment groups(P <0.05),and no statistically significant difference in the remaining indicators between the two groups(P >0.05).(5)Correlation between MSU crystals volume changes and clinical or laboratory indicators:MSU crystals volume decrease was positively correlated with baseline MSU crystals volume(r =0.908,P <0.05).There was no significant correlation between MSU crystals volume changes and SUA or other indicators.Conclusion: The volume of MSU crystals in the foot and ankle detected by DECT decreased after ULT in gout patients.The rate of MSU crystal dissolution varied in different anatomical sites,with the highest rate of dissolution of MSU crystals in soft tissues.There was no significant correlation between changes in SUA and MSU crystals.DECT can objectively and quantitatively assess changes in MSU crystals after ULT,providing a theoretical basis for the application of DECT in assessing the efficacy of treatment in gout patients. |
PDF Full Text Request