Color-Doppler in the imaging work-up of primary hyperparathyroidism

Primary hyperparathyroidism (PHP) is a rare disease that must be suspected in all the cases of recurrent calcium nephrolithiasis, and that may be totally corrected by surgery. The imaging techniques permit to locate the hyperplastic gland or adenoma before intervention, but their usefulness in patients without a history of previous neck surgery is still debated. Several imaging techniques have been proposed with the aim of locating parathyroid hyperfunctioning glands, including high resolution sonography (US) with color-Doppler (CD), scintigraphy, computed tomography (CT) and magnetic resonance imaging (MRI). We report here a case of recurrent calcium oxalate nephrolithiasis sustained by PHP, which demonstrates how US coupled with CD and echocontrast enhancement is useful in the preoperative location of parathyroid glands. US is the first choice technique in the evaluation of PHP because it is less expensive and useful in detailing lesions of the neck when carried out by a skilled operator. CD should be regarded as a useful complement of US enhancing its sensitivity (80 vs 90%) especially in the cases of associated thyroid gland diseases. Tc-99m SESTAMIBI scintigraphy coupled with MRI is mandatory in high risk surgical patients, namely in those undergoing repeated neck surgery. In conclusion, considering that surgeon must explore all the four parathyroid glands (because of the possibility of multiple adenomas or hyperplasia) a well definite location of the adenomatous lesion may reduce the risks and the time of intervention, and allow the use of alternative procedures, such as videoscopic surgery. On this view and in terms of economy, only US and CD coupled with Tc-99 SESTAMIBI scintigraphy should be considered before surgery.