Chronic autoimmune thyroiditis is currently considered as the main cause for hypothyroidism and its diagnosis is based on clinical manifestations and laboratory tests results. The most significant laboratory marker for this disease is the presence of anti-thyroperoxidase and anti-thyroglobulin antibodies, the latter being the most sensitive one. Aspiration biopsy shows high sensitivity and specificity but, considering the invasiveness of this method it is reserved for cases of suspected nodules or fast growing goiter. Scintigraphy is unnecessary for the diagnosis, considering its low specificity and sensitivity. Both B-mode and duplex color Doppler ultrasonography have rapidly evolved, becoming a simple, noninvasive and reproducible method with high sensitivity for the diagnosis of chronic autoimmune thyroiditis. Echogenicity is a relevant parameter at B-mode ultrasonography because of the close correlation with cytopathological findings besides the high sensitivity in the diagnosis of the disease. Although this is not a specific parameter for chronic autoimmune thyroiditis, considering that it may also be found in Graves' disease, postpartum thyroiditis and subacute thyroiditis, such disorders can be easily differentiated both by clinical-laboratory and duplex color Doppler findings. Thus, the present study is aimed at evaluating the significance of thyroid echogenicity in the diagnosis of chronic autoimmune thyroiditis.

Keywords: Ultrasonography, Echogenicity, Thyroiditis, Chronic, Autoimmune

The thymus is a small gland which is responsible for the production of T-lymphocytes. This organ is larger during the gestation period and can extend into the neck and present different anatomic variants. Ultrasound can identify the thymus via suprasternal, parasternal and sternal approaches, and through the neck when its position is atypical. During adolescence, ultrasound evaluation of the thymus is more difficult due to its involution and reduction in size, and interposition of the lung. The appearance of normal thymus is typical on the ultrasound and produces a unique echo pattern that is less echogenic than the normal thyroid gland with multiple echogenic lines and foci, representing a cross section of either a connective-tissue septum or a blood vessel within a septum. Recognition of normal thymic tissue can be very important in order to avoid unnecessary investigations or surgery of a normal thymus mimicking an abnormal mass.

Keywords: Thymus, Ultrasound, Neck ultrasound

Unlike supraclinoid aneurysms, true aneurysms of the extracranial internal carotid artery are extremely rare (less than 4% of the peripheral aneurysms). The commonest presentation is a pulsatile neck swelling below the angle of the jaw associated with hoarseness, dysphagia and pain (neural compression). Concomitance with other peripherical aneurysms is frequent and caused by atherosclerosis. The morphological and hemodynamic features are very well evaluated by Doppler ultrasound, when the acoustic window is satisfactory. Identification and evaluation of these aneurysms are very important to prevent thrombosis, rupture, dissections, massive strokes and embolic brain infarcts, besides helping in the decision of the best treatment.

Keywords: Aneurysm, Extracranial internal carotid artery, Ultrasound, Doppler ultrasound, Color duplex Doppler ultrasound

Ultrasound assessment of neck lymphadenopathy can be difficult as sometimes the same pattern is seen both in inflammatory (specific or not) and neoplastic diseases (lymphoproliferative or metastatic). An adequate follow-up of these lymphadenopathies requires evaluation of some important ultrasound features, and relies on the ability of localizing these nodes. We reviewed the literature with the aim of establishing the most significant ultrasonographic features on gray-scale ultrasound and Doppler ultrasound that can help in the study of the lymph nodes of the neck. We also describe the localization of lymph nodes based on computed tomography anatomic landmarks. The aspects analyzed on B-mode were: number (isolated nodule or conglomeration), shape, echotexture/echogenicity, calcification, cystic necrosis and/or hemorrhagic necrosis, size, contours and extra nodal extension. Doppler aspects reviewed were color mapping and spectral analysis (pulsatility index and resistive index). Some patterns usually described for malignant nodes are round morphology, marked hypoechoic, peripheral vascularization and high pulsatility index and resistive index. We concluded that an accurate diagnosis requires the evaluation of multiple aspects seen on B-mode and Doppler ultrasound.

Keywords: Lymph nodes, Neck, Ultrasound, Color duplex-Doppler ultrasound