HIGH-RESOLUTION PARATHYROID SONOGRAPHY

The purpose of this study was to assess the diagnostic utility of para thyroid ultrasonography to differentiate causes of hypercalcemia in do gs, We analyzed qualitative and quantitative ultrasound imaging findin gs and clinical pathology data from 33 dogs that underwent parathyroid ultrasound examination as part of the diagnostic evaluation for hyper calcemia. Diagnoses of the diseases causing hypercalcemia included par athyroid carcinoma (n = 5), parathyroid adenoma (n = 15), parathyroid adenomatous hyperplasia (n = 6), chronic renal insufficiency (n = 3), and hypercalcemia of malignancy (n = 4), All parathyroid lesions were round or oval and hypoechoic compared with surrounding thyroid parench yma, Adenomatous and adenocarcinomatous glands were 4 mm or larger in longest linear measurement on US examination and were statistically si gnificantly larger than hyperplastic glands, (p < 0.001) Linear measur ements of parathyroid glands acquired at the time of ultrasound examin ation correlated well with direct size determination after surgical ex cision. (r(2) = 0.9, p < 0.0001) Parathyroid lesions greater than or e qual to 4 mm are highly suspicious for parathyroid adenoma or carcinom a, while US lesions <4 mm most likely represent primary adenomatous hy perplasia or secondary parathyroid hyperplasia. Parathyroid size estim ation from ultrasound examination is an accurate predictor of true siz e.