1.5 T MRI, CT, ultrasonography and scintigraphy in hyperparathyroidism.

The enlarged parathyroid glands of twenty-four patients with primary, and 5 with tertiary, hyperparathyroidism were prospectively studied with MRI, CT, ultrasonography and subtraction scintigraphy prior to surgery. Sensitivities in a prospective study were 63, 60, 53 and 44% for the primary, and 71, 67, 44 and 11% for the tertiary, disease form. On MRI, diseased parathyroids showed the "typical" behaviour of tumours with high signal intensity on T2-weighted and low signal intensity in T1-weighted images. On CT, the lesions were hypodense and on US hypoechoic relative to the thyroid. Retrospective analysis of MRI and CT images yielded sensitivities of 87 and 85%, respectively.