Abstract
Objectives: To ultrasonographically (US) evaluate the predictability of localizing abnormal parathyroid glands in patients with secondary hyperparathyroidism (SHPT).
Methods: Between August 1935 and June 1997, surgical exploration was performed after US examination on 42 patients with SHPT. US examinations were performed using a 7.5MHz transducer. The accuracy of the US findings was analyzed.
Results: All patients had hyperplastic parathyroid glands; Four exhibited 5 abnormal glands, 30 had 4 abnormal glands, 6 showed 3 abnormal glands, and 2 had 2 abnormal glands. Concerning the accuracy of diagnosis, the sensitivity of US was 77%, and the positive predictive value was 97%. The sensitivity of detecting lesions less than 10mm in length was 31%, 10mm to 14mm was 79%, 15mm to 19mm was 90%, and over 20mm was 92%. The sensitivity of detecting lesions less than 5mm in width was 45%, 5mm to 7mm was 82%, 8mm to 10mm was 86%, and over 11mm was 100%. The sensitivity of detecting lesions less than 100mm3 in volume was 25%, 100 to 199mm3 was 78%, 200 to 499mm3 was 81%, 500 to 999mm3 was 96%, and over 1000mm3 was 91%. There were 4 false-positive findings in 3 patients. The correct diagnoses were thyroid cancer, lymph node, thyroid calcification and a vessel. More than 78% of glands longer than 10mm in length, 5mm in width and 100mm3 in volume were detected by US. Of the 10 glands not detected by US, 7 glands were examined by scintigraphy (RI) and 2 of these glands showed abnormal accumulation.
Conclusions: To localize abnormal secondary hyperplastic parathyroid glands, US showed over 78% accuracy in detecting glands with diameters longer than 10mm in length, 5mm in width and 100mm3 in volume. RI may help to find abnormal glands that were overlooked by US.
