PTH and adenoma: Applying the cutoff value of 20% concentration difference between the jugular PTH values, considering the standard error of 10% because we do not have enough patients for the sample calculation, in cases of bilateral cervical scanning where preoperative imaging exams were negative or conflicting (16 patients in our sample), using this method as a possible examination for localization of adenoma laterality, we could identify and avoid bilateral cervical exploration in 10 cases (62.5%).