In patients with hypercalcemia the usefulness and indications of imaging studies depend
on the pathological condition causing the disease. The main causes of hypercalcemia are primary
hyperparathyroidism (HPT) and malignancy, but an increased serum calcium level can also be the
consequence of several diseases affecting different organs, being the object of specific imaging
studies. Unfortunately, they are not able to confirm or exclude all those disorders, having the purpose
to examine the morphology of each organ involved in the pathogenesis of hypercalcemia, such as
parathyroid glands, kidneys and urinary tract, bones and other organs. In patients with HPT the aim of
imaging studies is to localize the enlarged PT glands, both in patients with single PT adenoma, and in
those with multiple glands disease. The first studies should be neck ultrasonography and sestamibi
scintigraphy. If they are negative or discordant, ectopic PT glands are suspected, and computed
tomography (CT) scan, magnetic resonance imaging (MR) and more recently positron emission
tomography (PET) should be suggested. Ultrasonography has a good accuracy in the detection of
renal stones, but unenhanced CT has the best sensitivity. In patients with bone metastases the first
imaging technique to be used is whole body bone scintigraphy, followed by plan x-ray of single sites,
while CT and MRI may complete the differential diagnosis. CT is usually suggested for mineralized
and rib lesions, MRI is preferable for bone marrow lesions, while 18F-fluoro-2-deoxyglucose (FDG)-
PET is useful in the detection of soft tissue or bone metastases.
