[Usefulness of imaging techniques in secondary hyperparathyroidism]

For patients with chronic renal failure who develop secondary hyperparathyroidism (SHPT), imaging techniques can be useful, especially to evaluate the location, size and functional status of parathyroid glands. This review analyzes all available imaging procedures in the context of SHPT. We evaluate: 1) Cervical ultrasound (B-mode, Doppler, colour-Doppler and power-Doppler), 2) Scintigraphic studies (Tallium, 99mTc-MIBI and 99mTc-tetrofosmin), including non-standard image acquisition techniques (Pinhole, SPECT), 3) Positron emission tomography (PET), 4) Computed tomography (CT) and magnetic resonance imaging (MRI) and 5) hybrid scanners (SPECT/CT and PET/CT). Our recommendation is that SHPT patients who are initially non responders to medical therapy should be investigated using parathyroid scintigraphy and cervical ultrasound. 99mTc-MIBI uptake can be graded in a semiquantitative scale. Intense uptake indicates a low probability of success using medical treatment and parathyroidectomy should be considered. A moderate to faint uptake indicates that a more intensive medical therapy would probably be beneficial. In the case of no uptake of 99mTc-MIBI, PET should be performed. Where this is not available, MRI could be a possible alternative.