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Abstract:
Shear wave elastography (SWE) is a modern method for the assessment of tissue stiffness. There has been a growing interest in the use of this technique for characterizing thyroid focal lesions, including preoperative diagnostics. Aim: The aim of the study was to assess the clinical usefulness of SWE in medullary thyroid carcinoma (MTC) diagnostics. Materials and methods: A total of 169 focal lesions were identified in the study group (139 patients), including 6 MTCs in 4 patients (mean age: 45 years). B-mode ultrasound and SWE were performed using Aixplorer (SuperSonic, Aix-en-Provence), with a 4–15 MHz linear probe. The ultrasound was performed to assess the echogenicity and echostructure of the lesions, their margin, the halo sign, the height/width ratio (H/W ratio), the presence of calcifications and the vascularization pattern. This was followed by an analysis of maximum and mean Young’s (E) modulus values for MTC (EmaxLR, EmeanLR) and the surrounding thyroid tissues (EmaxSR, EmeanSR), as well as mean E-values (EmeanLRz) for 2 mm region of interest in the stiffest zone of the lesion. The lesions were subject to pathological and/or cytological evaluation. Results: The B-mode assessment showed that all MTCs were hypoechogenic, with no halo sign, and they contained micro- and/ or macrocalcifications. Ill-defined lesion margin were found in 4 out of 6 cancers; 4 out of 6 cancers had a H/W ratio > 1. Heterogeneous echostructure and type III vascularity were found in 5 out of 6 lesions. In the SWE, the mean value of EmaxLR for all of the MTCs was 89.5 kPa and (the mean value of EmaxSR for all surrounding tissues was) 39.7 kPa Mean values of EmeanLR and EmeanSR were 34.7 kPa and 24.4 kPa, respectively. The mean value of EmeanLRz was 49.2 kPa. Conclusions: SWE showed MTCs as stiffer lesions compared to the surrounding tissues. The lesions were qualified for fine needle aspiration biopsy based on B-mode assessment. However, the diagnostic algorithm for MTC is based on the measurement of serum calcitonin levels, B-mode ultrasound and FNAB.

Keywords:
medullary thyroid carcinoma, thyroid, ultrasound, shear wave elastography

Abstract:
Aim: The aim of the research was to assess the echogenicity of benign adrenal focal lesions using new ultrasound techniques. Material and method: 34 benign adrenal masses in 29 patients were analyzed retrospectively. The examinations were conducted using Aplio XG (Toshiba, Japan) ultrasound scanner with a convex probe 1–6 MHz in the B-mode presentation with the combined use of new ultrasound techniques: harmonic imaging and spatial compound sonography. The size of the adrenal tumors, their echogenicity and homogeneity were analyzed. Statistical analysis was conducted using the STATISTICA 10 software. Results: The following adrenal masses were assessed: 12 adenomas, 10 nodular hyperplasias of adrenal cortex, 7 myelolipomas, 3 pheochromocytomas, a hemangioma with hemorrhage and a cyst. The mean diameter of nodular hyperplasia of adrenal cortex was not statistically different from that of adenomas (p = 0.075). The possibility of differentiating between nodular hyperplasia and adenoma using the parameter of hypoechogenicity or homogeneity of the lesion was demonstrated with the sensitivity and specificity of 100% and 41.7%, respectively. The larger the benign adrenal tumor was, the more frequently did it turn out to have a mixed and inhomogenous echogenicity (p < 0.05; ROC areas under the curve: 0.832 and 0.805, respectively). Conclusions: A variety of echogenicity patterns of benign adrenal focal lesions was demonstrated. The image of an adrenal tumor correlates with its size. The ultrasound examination, apart from its indisputable usefulness in detecting and monitoring adrenal tumors, may also allow for the differentiation between benign lesions. However, for lesions found incidentally an algorithm for the assessment of adrenal incidentalomas is applicable, which includes computed tomography and magnetic resonance imaging.

Keywords:
adrenal glands, adrenal masses, ultrasound, echogenicity