Endocrine Abstracts

Introduction: Primary hyperparathyroidism (PHPT) is the third most frequent endocrinopathy, after type 2 diabetes mellitus and thyroid disease. It is most commonly caused by an overactive parathyroid gland resulting in high serum parathormone (PTH) concentrations and consequent high serum calcium concentrations. PHPT is nowadays commonly asymptomatic, with high prevalence among postmenopausal women (female – male ration 3–4:1).

Materials and methods: We evaluated 20 consecutive patients diagnosed with primary hyperparathyroidism, from October 2018 to June 2019. All cases presented solitary parathyroid adenoma werecertified by pathology report after surgery (-parathyroid adenoma excision). Pacients were evaluated clinically, biochemically and by ultrasound: 2 B ultrasound, Power Doppler, shear wave elastography with computer assisted quantitative measurement of tissue elasticity with high accuracy linear probe on Supersonic Aixplorer machine and strain elastography using Hitachi Preirus (Hitachi Medical Corporation, Tokyo, Japan) machine.

Results: We evaluated 20 consecutive patients (male to female ratio 1:19) with mean age of 57.3 ± 13.33, mostly postmenopausal women with confirmed primary hyperparathyroidism. The parathyroid adenoma tissue was compared with the normal thyroid tissue and the surrounding muscle tissue. Using SWE elastography, we found that the mean SWE value for parathyroid adenoma is 4.74 ± 2.745 kPa, compared to mean SWE of thyroid tissue 11.718 ± 4.206 kPa, respectively muscle tissue 16.362 ± 3.829 kPa. Parathyroid adenoma tissue was also evaluated with strain elastography with color maps (qualitative) and with strain ratio (semi-quantitave data). The initial qualitative analysis, found 15 out of 20 cases with score 1 on color map evaluation, according to Rago criteria. Semi-quantitative analysis using strain elastography, found a strain ratio of 1.46 ± 1.45 for parathyroid/thyroid pair and 1.79 ± 0.90 for parathyroid/muscle. Comparing the two elastographic methods, we have found that shear wave elastography method has a higher sensitivity and specificity, if parathyroid adenoma is compared with thyroid tissueor surrounding muscle – AUC curve 0.70, 95% CI [0.544; 0.876 ], compared with the specificity and sensitivity of strain elastography – AUC curve 0.646, 95% CI [ 0.442; 0.850].

Conclusion: To conclude, the aim of this prospective study was to quantify the value of strain elastography and 2D shear wave elastography in localizing parathyroid pathology. Although strain elastography can be a useful qualitative tool by using color mapping, 2D-SWE elastography can offer a better differentiation on tissue elasticity when diagnosing parathyroid adenomas. By using this elastographic technique, a value less than 7 kPa for mean elasticity index is suggestive for parathyroid adenoma.