Objectives To investigate the performance of cranial PET/CT for the diagnosis of giant cell arteritis (GCA). Methods All patients with a suspected diagnosis of GCA were prospectively enrolled in this study and had a digital PET/CT with evaluation of cranial arteries if they had not started glucocorticoids more than 72 hours previously. The diagnosis of GCA was retained after at least 6 months of follow-up if no other diagnosis was considered by the clinician and the patient went into remission after at least 6 consecutive months of treatment. Cranial PET/CT was considered positive if at least one arterial segment showed hypermetabolism similar to or greater than liver uptake. Results For cranial PET/CT, sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) were 73.3%, 97.2%, 91.7% and 89.7%, respectively. For extracranial PET/CT, diagnostic performance was lower (Se = 66.7%, Sp = 80.6%, PPV = 58.8%, NPV = 85.3%). The combination of cranial and extracranial PET/CT improved overall sensitivity (Se = 80%) and NPV (NPV = 90.3%) while decreasing overall specificity (Sp = 77.8%) and PPV (PPV = 60%). Conclusion Cranial PET/CT can be easily combined with extracranial PET/CT with a limited increase in examination time. Combined cranial and extracranial PET/CT showed very high diagnostic accuracy for the diagnosis of GCA. Trial registration ClinicalTrials.gov, https://clinicaltrials.gov, NCT05246540.

中文翻译：

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颅动脉 PET/CT 对巨细胞动脉炎的敏感诊断

目的探讨头颅PET/CT诊断巨细胞动脉炎（GCA）的性能。方法 所有疑似 GCA 诊断的患者均前瞻性地纳入本研究，如果他们在 72 小时前未开始使用糖皮质激素，则进行数字 PET/CT 评估颅动脉。如果临床医生没有考虑其他诊断并且患者在至少连续 6 个月的治疗后进入缓解状态，则在至少 6 个月的随访后仍保留 GCA 的诊断。如果至少一个动脉段显示代谢亢进类似于或大于肝脏摄取，则颅脑 PET/CT 被认为是阳性的。结果 对于头颅 PET/CT，敏感性 (Se)、特异性 (Sp)、阳性预测值 (PPV) 和阴性预测值 (NPV) 分别为 73.3%、97.2%、91.7% 和 89.7%，分别。对于颅外 PET/CT，诊断性能较低（Se = 66.7%，Sp = 80.6%，PPV = 58.8%，NPV = 85.3%）。颅内和颅外 PET/CT 的组合提高了总体敏感性 (Se = 80%) 和 NPV (NPV = 90.3%)，同时降低了总体特异性 (Sp = 77.8%) 和 PPV (PPV = 60%)。结论 头颅PET/CT可与颅外PET/CT联合应用，检查时间增加有限。联合颅内和颅外 PET/CT 对 GCA 的诊断显示出非常高的诊断准确性。试验注册 ClinicalTrials.gov，https://clinicaltrials.gov，NCT05246540。3%)，同时降低整体特异性 (Sp = 77.8%) 和 PPV (PPV = 60%)。结论 头颅PET/CT可与颅外PET/CT联合应用，检查时间增加有限。联合颅内和颅外 PET/CT 对 GCA 的诊断显示出非常高的诊断准确性。试验注册 ClinicalTrials.gov，https://clinicaltrials.gov，NCT05246540。3%)，同时降低整体特异性 (Sp = 77.8%) 和 PPV (PPV = 60%)。结论 头颅PET/CT可与颅外PET/CT联合应用，检查时间增加有限。联合颅内和颅外 PET/CT 对 GCA 的诊断显示出非常高的诊断准确性。试验注册 ClinicalTrials.gov，https://clinicaltrials.gov，NCT05246540。