Table 3.

Correlation between ¹⁸F-FDG uptake and clinical disease activity

18F-FDG uptake	Correlation coefficient
	Systemic score		ESR		CRP		Ferritin		Leukocyte		Neutrophil
	r	p value	r	p value	r	p value	r	p value	r	p value	r	p value
Visual grade of lymph node	0.664	0.013	0.462	0.112	0.265	0.382	0.338	0.259	0.091	0.767	–0.009	0.976
SUV intensity of lymph node	0.601	0.03	0.431	0.141	0.281	0.353	0.334	0.264	0.15	0.626	0.036	0.907
Visual grade of spleen	0.771	0.002	0.617	0.025	0.527	0.064	0.557	0.048	0.499	0.083	0.469	0.106
SUV intensity of spleen	0.676	0.011	0.456	0.118	0.512	0.073	0.477	0.1	0.499	0.082	0.413	0.16
Visual grade of bone marrow	0.734	0.004	0.761	0.003	0.395	0.182	0.363	0.222	0.775	0.002	0.711	0.006
SUV intensity of bone marrow	0.57	0.042	0.612	0.026	0.401	0.174	0.313	0.297	0.773	0.002	0.725	0.005

These data were assessed using a Spearman correlation. Systemic score by Pouchot et al. [3] assigns a score from 0 to 12 and adds 1 point for each of the following manifestations: fever, typical rash, pleuritis, pneumonia, pericarditis, hepatomegaly or abnormal liver function tests, splenomegaly, lymphadenopathy, leukocytosis ≥15,000/mm², sore throat, myalgia, and abdominal pain.

¹⁸F-FDG, ¹⁸F-fluorodeoxyglucose; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; SUV, standardized uptake value.