Which Statement Is NOT True About Imaging of the Parathyroid

Which statement is NOT true about imaging of the parathyroid glands?

A) High resolution (7.5 to 15 MHz) linear transducers are routinely used to image abnormal parathyroid glands.
B) In a patient with a thick neck, a lower frequency (e.g., a 4 to 8 MHz convex transducer) may be required to enhance acoustic visualization.
C) In examinations for inferior parathyroid adenomas, the swallow maneuver briefly elevates the thyroid gland, permitting acoustic access to the most inferior aspect of the gland.
D) Sonography routinely is performed on patients with normal calcium levels.