[MRI study of parathyroid adenoma. Value of T2-weighted sequences]

The authors report a series of 22 patients operated for primary hyperparathyroidism. The parathyroid adenoma was located preoperatively by MRI and ultrasonography. Measurement of the relaxation time was performed in vitro at 37 degrees C in a 0.47 Tesla field during the 30 minutes following resection. The relaxation times obtained at a precession frequency of 20 mHz were 0.844 +/- 0.16 sec for T1 and 0.082 +/- 0.025 sec for T2. MRI had a sensitivity of 73% and a specificity of 88% for the localization of the parathyroid adenoma, while ultrasonography had a sensitivity of 73% and a specificity of 98%.