PTH and parathyroid gland adenoma: The optimal cutoff values for diagnosing parathyroid adenoma based on lesion volume, blood flow distribution, PTH concentration, E-min, E-mean, and E-max were 0.475 cm3, level 1.5, 281.85 ng/L, 11.620 kPa, 16.125 kPa, and 17.995 kPa, respectively.