Accuracy of dual-energy computed tomography (CT), ultrasound, cone-beam CT, and spectral photon-counting CT for detecting calcium crystal deposition in the osteoarthritic hand: a cross-sectional diagnostic test study

To evaluate the diagnostic performance of dual-energy computed tomography (DECT), ultrasound (US), cone-beam computed tomography (CBCT), and multi-energy spectral photon-counting computed tomography (SPCCT) for detecting calcium pyrophosphate (CPP) and hydroxyapatite crystal deposition. We prospectively enrolled patients scheduled for finger-joint surgery due to osteoarthritis. Preoperative cross-sectional assessment included visual analogue scale pain, and in vivo index tests with DECT, US, and CBCT; the postoperative ex vivo index test was SPCCT of excised joint material. Reference tests comprised compensated polarized light microscopy of synovial fluid and histology with Alizarin Red S staining of excised joint material. Tests for crystals were scored on a binary basis. We calculated sensitivity, specificity, and likelihood ratios (LRs); a test with positive LR > 10 or negative LR We included 12 participants, nine of whom had at least one positive reference test for calcium crystals. None of the index tests met our predefined cut-offs for a very good test. The best sensitivity and specificity were 0.29 [95% confidence interval (CI) 0.04–0.71] and 0.67 (0.09–0.99) for DECT, 0.89 (0.52–1.00) and 1.00 (0.16–1.00) for US, 0.33 (0.07–0.70) and 0.67 (0.09–0.99) for CBCT, and 1.00 (0.66–1.00) and 0.00 (0.00–0.98) for SPCCT. Wide CIs reflected the small sample size. Participants with CPP in the synovial fluid had more pain than those without. SPCCT and US had high sensitivity for calcium crystal detection, although no test achieved the strict definition of a very good test. ClinicalTrials.gov (NCT04585113)

本研究旨在评估双能计算机断层扫描（dual-energy computed tomography, DECT）、超声（ultrasound, US）、锥形束计算机断层扫描（cone-beam computed tomography, CBCT）及多能量光谱光子计数计算机断层扫描（multi-energy spectral photon-counting computed tomography, SPCCT）检测焦磷酸钙（calcium pyrophosphate, CPP）与羟基磷灰石晶体沉积的诊断效能。我们前瞻性招募了因骨关节炎拟行手指关节手术的患者。术前横断面评估包含视觉模拟评分法（visual analogue scale, VAS）疼痛评估，以及采用DECT、US、CBCT开展的体内指标检测；术后对切除的关节组织行SPCCT检测，作为离体指标检测方案。参考标准包括滑液补偿偏振光显微镜检查，以及对切除关节组织行茜素红S染色的组织学检查。晶体检测采用二元评分法。我们计算了灵敏度、特异度及似然比（LRs）；阳性似然比>10或阴性似然比<0.1的检验被定义为优异检验。本研究共纳入12名受试者，其中9名至少有1项钙晶体参考检测结果为阳性。所有指标检测均未达到我们预设的优异检验临界值。DECT的最佳灵敏度与特异度分别为0.29[95%置信区间（confidence interval, CI）0.04~0.71]与0.67（0.09~0.99）；US分别为0.89（0.52~1.00）与1.00（0.16~1.00）；CBCT分别为0.33（0.07~0.70）与0.67（0.09~0.99）；SPCCT分别为1.00（0.66~1.00）与0.00（0.00~0.98）。较宽的置信区间反映了本研究样本量较小的局限。滑液中检出CPP的受试者疼痛评分高于未检出CPP的受试者。尽管所有检测均未达到优异检验的严格定义，但SPCCT与US对钙晶体检测具有较高的灵敏度。本研究已在临床试验.gov（NCT04585113）注册。