Anderson M E, Moore T L, Lunt M, Herrick A L
University of Liverpool Adademic Rheumatology Unit, University Hospital Aintree, Liverpool, UK.
Rheumatology (Oxford). 2007 Mar;46(3):533-8. doi: 10.1093/rheumatology/kel330. Epub 2006 Oct 2.
To test the hypothesis that in a patient with Raynaud's phenomenon (RP), a difference of >1 degrees C between the fingertips and the dorsum of the hand ['distal-dorsal difference' (DDD), fingers cooler] is specific for underlying structural vascular disease as occurs in systemic sclerosis (SSc), and to evaluate other thermographic parameters in the separation of secondary from primary RP.
A retrospective analysis of the case notes and thermography results of patients attending thermography, primarily over a 2-yr period. Multinomial logistic regression was used to ascertain whether thermography variables differed between groups with primary RP (56 patients), undifferentiated connective tissue disease (21 patients) and SSc (45 patients), with adjustment for age, sex and smoking.
A DDD >1 degrees C in any finger at 30 degrees C had a positive predictive value of 70%, and a negative predictive value of 82%, in identifying the patient with RP secondary to SSc. From the results of the multinomial logistic regression, a score was derived incorporating age, number of fingers with DDD >1 degrees C at 30 degrees C and maximum rewarming gradient. This score (with a suitable cut-off) was 82% sensitive and 82% specific in identifying RP secondary to SSc, with a positive predictive value of 73% and a negative predictive value of 89%.
Parameters derived from thermography (incorporating both a heat and cold challenge) aid in the prediction of SSc in patients with RP.
验证如下假设，即雷诺现象（RP）患者中，指尖与手背之间温差>1℃ ["指端-手背温差"（DDD），手指温度更低] 是系统性硬化症（SSc）中潜在结构性血管疾病的特异性表现，并评估其他热成像参数在区分继发性与原发性RP中的作用。
对主要在2年期间接受热成像检查的患者的病历和热成像结果进行回顾性分析。采用多项逻辑回归来确定原发性RP患者（56例）、未分化结缔组织病患者（21例）和SSc患者（45例）之间热成像变量是否存在差异，并对年龄、性别和吸烟情况进行校正。
在30℃时，任何手指的DDD>1℃在识别继发于SSc的RP患者时，阳性预测值为70%，阴性预测值为82%。根据多项逻辑回归结果，得出一个包含年龄、30℃时DDD>1℃的手指数量和最大复温梯度的评分。该评分（采用合适的临界值）在识别继发于SSc的RP时，敏感性为82%，特异性为82%，阳性预测值为73%，阴性预测值为89%。
热成像得出的参数（包括热刺激和冷刺激）有助于预测RP患者的SSc。
