Multi-modality parathyroid imaging: A shifting paradigm

Table 2 Differentiating features of various parathyroid lesions

	Parathyroid hyperplasia	Parathyroid adenoma	Parathyroid carcinoma
USG	Small; Ovoid; Well-circumscribed; Homogenously hypoechoic; Calcifications uncommon; No local invasion; CEUS - Homogeneous enhancement	Small; Ovoid; Well-circumscribed; Homogenously hypoechoic; Calcifications uncommon; No local invasion; CEUS - Peripheral enhancement with central washout on delayed image	Large; Irregular shape; Non circumscribed margins; Heterogenous echotexture; Intra-nodular calcifications; Local invasion
CT	Small hypodense lesion (as compared to thyroid gland); Intense arterial enhancement; Washout on the venous phase; May not be identifiable on CT	Small hypodense lesion (as compared to thyroid gland); Intense arterial enhancement; Washout on the venous phase	Lesions may show infiltration into the surrounding structures
MRI	Small sized; Well defined; Homogenous;Low on T1; High on T2; Avid enhancement	Small sized; Well defined; Homogenous;Low on T1; High on T2; Avid enhancement	Large; Ill-defined; Heterogenous

USG: Ultrasound; CT: Computed tomography; MRI: Magnetic resonance imaging; CEUS: Contrast enhanced ultrasound.