目的: 探讨金标准明确诊断的痛风患者中双能CT(dual energy computed tomography, DECT)检出尿酸盐结晶的影响因素。方法: 选择2011年6月至2018年12月,在北京大学第一医院门诊或住院患者关节滑液偏振光分析尿酸晶体阳性诊断为急性或慢性痛风的病例资料进行回顾性分析,所有患者均接受关节液或痛风石分析和DECT扫描。采用卡方检验、二元Logistics回归及t检验,分析DECT结果与临床资料、实验室检查及药物治疗的关系。结果: 共29例患者入组本研究,22例DECT检出尿酸盐结晶,7例未检出,根据是否检出尿酸盐晶体分为两组,与DECT阴性组相比较,DECT阳性组年龄更高[(47±12)岁vs.(39±11)岁,P=0.15], 体重指数(body bass index,BMI)更高[(27.9±3.7) kg/m²vs.(22.8±2.1) kg/m²,P=0.002],痛风病程更长[(135±102)个月vs.(45±53)个月, P=0.035];阳性组既往血尿酸最高值亦高于DECT阴性组[(643±121) μmol/L vs.(543±103) μmol/L,P=0.043];阳性组患者DECT时血清尿酸值虽然高于DECT阴性组[(558±150) μmol/L vs.(513±88.9) μmol/L,P=0.497], 但差异无统计学意义;DECT检查阳性组与阴性组相比较,检查时处于急性期的患者分别为18例(81.8%) vs.4例(57%), P=0.311;服用降尿酸药物的患者分别为22例(100%) vs.5例(71%), P=0.052;反复典型发作的患者分别为22例(100%) vs.6例(85%), P=0.241。各关节症状与DECT发现尿酸盐结晶一致性比较,右膝关节最高(Kappa=0.627), 其后依次为左第一跖趾(metatarsophalangeal 1, MTP1, Kappa=0.58)、右MTP1(Kappa=0.551)、左膝(Kappa=0.494),均具统计学意义,踝关节症一致性较低(右踝:Kappa=0.19,左踝:Kappa=0.256),均无统计学意义。与DECT尿酸盐晶体检出率有关的变量分别为BMI[2.307(1.139~4.670) kg/m², P=0.02]、痛风病程 [ 0.306(0.906~4.881)年,P=0.186]、既往尿酸最高值 [0.023(0.981~2.764) mg/dL, P=0.137]。结论: BMI较大、既往最高尿酸值较高、痛风病程较长的痛风患者DECT检出的敏感性越高。

Objective: To explore the risk factors of detection of uric acid crystals by dual energy CT (DECT) in patients with gout diagnosed by gold standard. Methods: From June 2011 to December 2018, clinical data of 29 patients were collected who were diagnosed with acute or chronic gout by positive polarized light analysis of joint synovial fluid in First Hospital of Peking University. Chi-square test, Logistic regression and t-test were used. The relationship between DECT and the clinical data, laboratory examination and drug treatment were analyzed. Results: In this study, 29 patients were included, of whom, 22 patients were detected with uric acid crystals by DECT, and 7 patients were not. According to whether the uric acid crystals were detected or not by DECT, the patients were divided into two groups. Compared with the negative group,the patients were older in positive group [(47±12) vs. (39±11) years, P=0.15], had higher body bass index (BMI) [(27.9±3.7) vs. (22.8±2.1) kg/m², P=0.002], longer gout disease duration [(135±102) vs.(45±53) months, P=0.035], higher in the highest serum uric acid in history [(643±121) vs. (543±103) μmol/L, P=0.043]. Although uric acid near DECT in positive group was higher than in negative group, there was no statistical difference [(558±150) vs. (513±89) μmol/L, P=0.497]. Comparing positive group with negative group, the percentage of the patients in acute phase was higher than in chronic phase [18(81.8%) vs. 4(57%), P=0.311];the percentage of the patients taking uric-acid-lowering drugs was higher than the other group [22(100%) vs. 5 (71%), P=0.052];the percentage of the patients with recurrent typical attacks was higher than that of those without typical attacks [22 (100%) vs.6 (85%), P=0.241]. The consistency of symptoms and the finding of uric acid crystals by DECT had been compared between the joints. The right knee joint had the highest consistency (Kappa=0.627), followed by the left MTP1 (Kappa=0.58), the right metatarsophalangeal 1(MTP1, Kappa=0.551) and the left knee (Kappa=0.494), all of which had statistical significance. The consistency of the ankle joint was lower (the right ankle joint: Kappa=0.19, the left ankle joint: Kappa=0.256), showing no statistical significance. BMI (kg/m²) [2.307 (1.139-4.670), P=0.02], gout duration (years) [0.306 (0.906-4.881), P=0.186], and the highest uric acid level in history (mg/dL) [0.023 (0.981-2.764), P=0.137] had relationship to the positive result of urate crystals in DECT. Conclusion: Gout patients with larger BMI, higher previous highest uric acid value and longer gout duration had higher sensitivity of the positive result in DECT.