Usefulness of diagnostic imaging in primary hyperparathyroidism

Background : In patients with primary hyperparathyroidism, prevention of urinary stone recurrence can be achieved by surgical removal of the enlarged parathyroid gland. To ensure the efficacy of surgery for primary hyperparathyroidism, preoperative localization of the enlarged gland is important. In the present study, usefulness of diagnostic imaging for localization of the enlarged gland was investigated in primary hyperparathyroidism. Methods : We retrospectively examined the findings of imaging studies and clinical records in 79 patients (97 glands) who underwent surgical treatment for primary hyperparathyroidism at Chiba University Hospital between 1976 and 2000. The detection rates of accurate localization were investigated for imaging techniques, such as ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), thallium‐201 and technetium‐99m pertechnetate (Tl‐Tc) subtraction scintigraphy and 99mTc‐methoxyisobutylisonitrile (MIBI) scintigraphy, and analysed in relation to the size and weight of the gland and pathological diagnosis. Results : The detection rates by US, CT, MRI, Tl‐Tc subtraction scintigraphy and MIBI scintigraphy were 70%, 67%, 73%, 38% and 78%, respectively. The overall detection rate changed from 50% to 88% before and after 1987. The detection rate of MIBI scintigraphy was superior to Tl‐Tc subtraction scintigraphy. Conclusion : In primary hyperparathyroidism, improvement of accurate localization of an enlarged parathyroid gland was demonstrated along with recent advances in imaging techniques including MIBI scintigraphy.