Preoperative imaging in primary hyperparathyroidism. (a) Sestamibi with SPECT displaying focal retention in the left lower position (arrow) after 30 and 75 minutes washout, respectively. (b) Corresponding cervical ultrasound from the same patient showing a large hypoechoic cystic parathyroid adenoma (arrow). The left thyroid lobe (T), trachea (Tr), and left internal jugular vein (IJ) are indicated. (c) Four-dimensional parathyroid CT scan depicting an ectopically positioned left superior paraesophageal parathyroid adenoma (arrow). IJ: internal jugular vein; T: trachea; E: esophagus; CCA: common carotid artery.
