Statistical analysis revealed that the AUCs for the number of enlarged external iliac lymph nodes and the blood pool-phase affected/unaffected hip joint radiotracer activity ratio were significantly higher than those of CRP, ESR, and synovial fluid PMN% (p value < 0.05), indicating the superior diagnostic performance of counting the number of enlarged iliac lymph nodes and the blood pool phase ratio for diagnosing PJI. Here, CRP is linked to juvenile polyposis syndrome.