PTH and Hypercalcemia: More recent studies found FCH-PET/CT sensitivity of 91 % (84/92 lesions) when defining lesions with both positive and inconclusive FCH uptakes as positive [19], 94 % in 101 patients with PTH-dependent hypercalcemia and negative or discordant conventional imaging (vs. 45 % and 44 % for MIBI scan and US, respectively) [20], 92 % in 103 patients (vs. 39–56 % for conventional scintigraphy) [21], and 62 % 47 patients after inconclusive first line imaging including US and subtraction scan [22].