CRP and juvenile polyposis syndrome: The sensitivity of MARS MRI for the diagnosis of PJI was 80.65%, which was not statistically different with culture, CRP, ESR, SF-WBCs, and SF-PMN%; the specificity was 75%, which was not statistically different with culture, CRP, ESR, and SF-WBC; Youden’s index was 0.56, which was lower than culture (0.64), CRP (0.74), SF-WBCs (0.70), SF-PMNs% (0.61), and higher than ESR (0.41).