Patients who retained at least one well-perfused parathyroid gland (ICG 2 ≥ 1) had significantly higher PTH levels (Figure 2A), and were less likely to develop hypoparathyroidism on postoperative day one than those without any well ICG-enhanced parathyroid gland (ICG 2 = 0) (p = 0.038) (Table 4). Here, PTH is linked to hypoparathyroidism.