Pancreatic neuroendocrine neoplasms: Magnetic resonance imaging features according to grade and stage

Table 6 Combination of magnetic resonance findings for differentiating G1 from G2-3 pancreatic neuroendocrine neoplasms

Number of features	Diagnostic performance
	Se	Sp	PPV	NPV
≥ 1	100 (82.8-100)	35.5 (19.8-54.6)	54.5 (38.9-69.3)	100 (67.8-100)
≥ 2	79.2 (57.3-92.1)	80.1 (61.9-91.9)	76 (54.5-89.8)	83.3 (64.5-93.7)
≥ 3	58.3 (36.9-77.2)	93.5 (77.1-98.9)	87.5 (60.4-97.8)	74.3 (57.6-86.4)
≥ 4	20.8 (7.9-42.7)	96.7 (81.5-99.8)	83.3 (36.5-99.1)	61.2 (46.2-74.4)
≥ 5	8.3 (1.4-28.5)	96.4 (86.4-99.4)	100 (19.8-100)	58.5 (44.2-71.6)

MR findings are ill-defined margins, vascular invasion, liver metastases, size > 17.5 mm, ADC < 1.21 < 10^-3 mm²/s. Diagnostic performances are expressed as percentages (95%CI). Se: Sensitivity; Sp: Specificity; PPV: Positive predictive value; NPV: Negative predictive value.