Table 3.

Diagnostic performance of ultrasound and scintigraphy

Single parathyroid gland	Group B	Group C	Group A	Significance group B vs. group C
Sensitivity: ultrasound	84 %	71 %	78 %	n.s.
Specificity: ultrasound	94 %	93 %	94 %	n.s.
Accuracy: ultrasound	91 %	87 %	89 %	n.s.
Prevalence: ultrasound	28 %	28 %	28 %	n.s.
Positive predictive value (PPV) ultrasound	85 %	79 %	82 %	n.s.

	Nuclear medicine (%)	Nuclear medicine (%)	Nuclear medicine (%)	Significance group B vs. group C
Sensitivity: scintigraphy	71	73	72	n.s.
Specificity: scintigraphy	90	90	90	n.s.
Accuracy: scintigraphy	85	85	85	n.s.
Prevalence: scintigraphy	28	28	28	n.s.
Positive predictive value (PPV) scintigraphy	74	73	74	n.s.
Overall sensitivity (use of both methods “in parallel”)	88	87	88
Positive predictive value (PPV) ultrasound vs. scintigraphy	n.s.	n.s.	<0.05

Side (right/left)	Group B (%)	Group C (%)	Group A (%)	Significance group B vs. group C
Sensitivity: ultrasound	91	78	85	n.s.
Specificity: ultrasound	95	93	94	n.s.
Accuracy: ultrasound	93	85	89	n.s.
Prevalence: ultrasound	53	52	53	n.s.
Positive predictive value (PPV) ultrasound	95	93	94	n.s.

	Nuclear medicine (%)	Nuclear medicine (%)	Nuclear medicine (%)	Significance group B vs. group C
Sensitivity: scintigraphy	77	80	78	n.s.
Specificity: scintigraphy	88	84	86	n.s.
Accuracy: scintigraphy	82	82	82	n.s.
Prevalence: scintigraphy	53	52	53	n.s.
Positive predictive value (PPV) scintigraphy	88	85	86	n.s
Overall sensitivity (use of both methods “in parallel”)	95	92	94
Positive predictive value (PPV) ultrasound vs. scintigraphy	n.s.	n.s.	n.s.