Contrast-Enhanced Ultrasound Qualitative and Quantitative Characteristics of Parathyroid Gland Lesions

Abstract

Background and Objectives: preoperative differentiation of enlarged parathyroid glands may be challenging in conventional B-mode ultrasound. The aim of our study was to analyse qualitative and quantitative characteristics of parathyroid gland lesions, using multiparametric ultrasound protocol—B-mode, Colour Doppler (CD), and contrast-enhanced ultrasound (CEUS)—and to evaluate correlation with morphology in patients with hyperparathyroidism (HPT). Materials and Methods: consecutive 75 patients with 88 parathyroid lesions and biochemically confirmed HPT prior to parathyroidectomy were enrolled in the prospective study. B-mode ultrasound, CD, and CEUS were performed with the subsequent qualitative and quantitative evaluation of acquired data. We used 1 mL or 2 mL of intravenous ultrasound contrast agent during the CEUS examination. Correlation with post-surgical morphology was evaluated. Results: seventy parathyroid adenomas were hypoechoic and well contoured with increased central echogenicity (44.3%), peripheral-central vascularization (47%), and polar feeding vessel (100%). Twelve hyperplasias presented with similar ultrasound appearance and were smaller in volume (p = 0.036). Hyperplasias had a tendency for homogenous, marked intense enhancement vs. peripherally enhanced adenomas with central wash-out in CEUS after quantitative analysis. No significant difference was observed in contrasting dynamics, regardless of contrast media volume use (1 mL vs. 2 mL). We achieved 90.9% sensitivity and 72.7% specificity, 93% positive predictive value (PPV), 87.3% negative predictive value (NPV), and 87.3% accuracy in the differentiation of parathyroid lesions prior to post-processing. In a quantitative lesion analysis, our sensitivity increased up to 98%, specificity 80%, PPV 98%, and NPV 80% with an accuracy of 96.4%. Conclusions: CEUS of parathyroid lesions shows potential in the differentiation of adenoma from hyperplasia, regardless of the amount of contrast media injected. The quantitative analysis improved the sensitivity and specificity of differentiation between parathyroid lesions. Hyperplasia was characterized by homogeneous enhancement, fast uptake, and homogeneous wash-out appearance; adenoma—by peripheral uptake, central wash-out, and reduced hemodynamics. The use of CEUS quantification methods are advised to improve the ultrasound diagnostic role in suspected parathyroid lesions.

Application value of contrast‐enhanced ultrasound in preoperative localization of microwave ablation for primary hyperparathyroidism

“…Parathyroid adenoma and parathyroid hyperplasia presented with early and homogeneous hyperenhancement, with central washout in the later phases. 26,27 But benign lymph nodes were observed centrifugal and homogenous enhancement, and a complete bright ring in the subcapsule of the lymph nodes. 28,29 The three imaging methods had different abilities in the localization diagnosis of parathyroid adenomas of different sizes.…”

“…In addition, CEUS can effectively distinguish between parathyroid glands and lymph nodes according to the enhancement characteristics. Parathyroid adenoma and parathyroid hyperplasia presented with early and homogeneous hyperenhancement, with central washout in the later phases 26,27 . But benign lymph nodes were observed centrifugal and homogenous enhancement, and a complete bright ring in the subcapsule of the lymph nodes 28,29 …”

Recurrent renal secondary hyperparathyroidism caused by supernumerary mediastinal parathyroid gland and parathyromatosis: A case report

“…In this case, 99m Tc-MIBI/SPECT failed to find the suspected parathyroid tissues in the neck, but US detected two lesions with a small volume located at the primary site. Previous studies showed that the suspected parathyroid lesions could be identified accurately by using CEUS ( 35 ). Indeed, in this case, two lesions, detected by US, presented with a vascularization pattern of parathyroid tissues, which can help diagnose parathyromatosis and prepare a surgery plan.…”

The Dark Side of Ultrasound Imaging in Parathyroid Disease

“…The usefulness of the US increases in pathological conditions [ 43 ]. In fact, hyperfunctioning PGs become more easily identified, usually appearing on the B-mode grey-scale US as enlarged, circumscribed, hypoechoic, oval-shaped lesions, delineated by hyperechoic connective tissue [ 17 ] ( Figure 1 a,b,d and Figure 2 a).…”

“…CEUS is an approved, safe method consisting of the intravenous injection of a microbubble contrast agent during an US performance-detecting tissues characteristic microvascularization pattern [ 13 , 14 , 15 ]. The use of quantitative post-processing software tools, overcoming the limit of the subjective examiner’s interpretation, improves this technique’s diagnostic role, facilitating the differential diagnosis between parathyroid lesions and other mimicking structures with an accuracy of 96.4% [ 16 , 17 ].…”