Table 2.

Results of the contingency table analysis. SE = sensitivity, SP = specificity, PPV = positive predictive value, NPV = negative predictive value, 95% CI = 95% confidence interval of the difference.

Patient Level	SE (95% CI)	SP (95% CI)	PPV (95% CI)	NPV (95% CI)
80 kVp	0.93 (0.77–0.99)	0.4 (0.07–0.77)	0.90 (0.74–0.96)	0.5 (0.09–0.91)
135 kVp	0.79 (0.60–0.90)	1.0 (0.57–1.00)	1.0 (0.85–1.0)	0.45 (0.21–0.72)
50 keV	0.86 (0.69–0.94)	0.6 (0.23–0.93)	0.92 (0.76–0.99)	0.43 (0.16–0.75)
70 keV	0.96 (0.83–0.99)	0.4 (0.07–0.77)	0.9 (0.74–0.97)	0.67 (0.12–0.98)
Joint/Tendon Level
80 kVp	0.58 (0.50–0.66)	0.90 (0.87–0.92)	0.63 (0.54–0.70)	0.88 (0.85–0.90)
135 kVp	0.50 (0.43–0.58)	0.95 (0.93–0.97)	0.74 (0.65–0.82)	0.87 (0.84–0.89)
50 keV	0.51 (0.43–0.59)	0.93 (0.91–0.95)	0.69 (0.60–0.77)	0.87 (0.84–0.89)
70 keV	0.61 (0.53–0.68)	0.90 (0.87–0.92)	0.63 (0.55–0.70)	0.89 (0.86–0.91)
Joint Level
80 kVp	0.56 (0.47–0.64)	0.89 (0.85–0.92)	0.71 (0.61–0.79)	0.81 (0.76–0.85)
135 kVp	0.47 (0.38–0.56)	0.95 (0.91–0.97)	0.81 (0.70–0.88)	0.79 (0.74–0.83)
50 keV	0.50 (0.42–0.59)	0.90 (0.85–0.93)	0.70 (0.60–0.79)	0.79 (0.74–0.84)
70 keV	0.62 (0.52–0.70)	0.86 (0.81–0.90)	0.67 (0.58–0.75)	0.82 (0.77–0.87)
Tendon Level
80 kVp	0.66 (0.50–0.79)	0.91 (0.87–0.94)	0.48 (0.35–0.61)	0.95 (0.92–0.97)
135 kVp	0.61 (0.45–0.74)	0.95 (0.92–0.97)	0.62 (0.46–0.76)	0.95 (0.92–0.97)
50 keV	0.53 (0.37–0.68)	0.97 (0.94–0.98)	0.67 (0.49–0.81)	0.94 (0.91–0.96)
70 keV	0.58 (0.42–0.72)	0.93 (0.89–0.95)	0.51 (0.37–0.65)	0.94 (0.91–0.97)