OBJECTIVE: The aim of this study was to evaluate sonographic features of thyroid gland in patients with thyroiditis. MATERIALS AND METHODS: During a nine-month period, 38 patients previously diagnosed with thyroiditis by the Ultrasound Unit of "Instituto de Radiologia da Faculdade de Medicina da Universidade de São Paulo", São Paulo, SP, Brazil, were studied. Thirteen-six of these patients were women in the age range between 17 and 78 years. The following variables were observed and studied: thyroid volume, echogenicity, echotexture, and the presence of level VI chain lymph nodes (pre-tracheal, the preferential site of thyroid drainage), besides the gland dimensions. RESULTS: Thirteen patients had goiter; 37 of 38 thyroid glands presented heterogeneous echotexture and diffuse hypoechogenicity. Thyroiditis was diagnosed by laboratory tests in all patients. Level VI chain (pre-tracheal) lymph nodes were observed in 28 cases, all of them with reactional features. Of these cases, ten patients were submitted to fine needle aspiration biopsy, and the cytological result indicated inflammatory reaction. No case of nodule-simulating focal thyroiditis was found. CONCLUSION: The thyroid gland sonographic hypoechogenicity and heterogeneity, in association with the presence of cervical chain lymph nodes, constitute findings of great importance in the diagnosis of thyroiditis when correlated with clinical and laboratory tests findings.

Keywords: Ultrasound, Thyroid, Thyroiditis

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

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

OBJECTIVE: To assess the hemodynamic changes considered normal after transjugular intrahepatic porto-systemic shunt (TIPS) placement and the efficacy of TIPS parameters suggestive of stenosis using Doppler sonography. MATERIALS AND METHODS: Sixteen patients were prospectively evaluated from December, 2001 to March, 2003 after TIPS placement. Evaluations were performed 24 to 48 hours after the procedure and then at intervals of 30 days, three months, six months and one year using B mode, color Doppler, power Doppler and spectral Doppler in different TIPS related sites. Angiography was performed only to confirm Doppler findings and treatment. RESULTS: To date the only statistically significant parameters for diagnosis of TIPS stenosis were continuous flow pattern in the proximal third of TIPS and the velocity gradient between the two sites (p < 0.001). Different non-statistically significant parameters were also observed. CONCLUSION: Doppler sonography is an efficient tool for the diagnosis of shunt patency and TIPS related complications such as stenosis. However, it is necessary to study a larger number of patients in order to determine a group of parameters that would help in the follow-up of these patients, thus using portal angiography only for indicated treatment.

Keywords: Portal hypertension, Transjugular intrahepatic portosystemic shunt, Ultrasound, Doppler ultrasound studies, Stents and prostheses

Objective: To evaluate the sensitivity and specificity of high-resolution ultrasonography in the assessment of intra-capsular temporomandibular disorders. Materials and Methods: The authors have studied 38 patients (76 joints) with complaint of temporomandibular disorder. All the patients underwent ultrasonography and magnetic resonance imaging (gold standard for the evaluation) and the results were compared. Results: Among 24 joints demonstrating disc displacement at magnetic resonance imaging of patients at rest, 7 were confirmed at ultrasonography; in 13, the discs could not be visualized; and in 4, no sonographic abnormality was observed. In 48 joints, the articular discs could not be visualized at ultrasonography of patients at rest. Among them, 41 exhibited normal positioning at magnetic resonance imaging, and 7 exhibited anterior disc displacement. Morphological changes of the mandibular condyle were visualized in 13 joints at magnetic resonance imaging, and in 2 at ultrasonography. Conclusion: With the present study, the authors can conclude that ultrasonography offers high sensitivity and specificity in the diagnosis of the articular disc location with the patient at rest, either to analyze anatomical position or to analyze disc displacement. On the other hand, it does not offer significant results to analyze articular discs in patients with open mouth as well as to analyze disc/condyle morphological changes.

Keywords: Ultrasonography; Temporomandibular joint; Magnetic resonance imaging.

OBJECTIVE: To assess the accuracy of ultrasound in the visualization of the brachial plexus and to determine the value of the method in comparison with that of magnetic resonance imaging (MRI). MATERIALS AND METHODS: This was an anatomical study of the brachial plexuses of 20 asymptomatic adults (40 plexuses), comparing ultrasound and MRI in terms of their accuracy. In the ultrasound study, a high-frequency linear transducer was used, and a neurovascular coil was used in the MRI study. To estimate the frequency of visualization, the brachial plexus was divided into segments. RESULTS: The cervical nerve roots, the upper trunk, and the middle trunk were the segments that were best visualized on ultrasound. On MRI, the degree of visualization was excellent for most of the segments. In the comparison between ultrasound and MRI, the C6, C7, upper trunk, and middle trunk segments showed equivalent degrees of visualization, with a high level of agreement between the two methods. CONCLUSION: In the brachial plexus, ultrasound can be used in the assessment of the cervical nerve roots, as well as of the upper and middle trunks, although it provides limited visualization of the remaining segments. Ultrasound and MRI showed a high level of agreement for the visualization of the C6, C7, and middle trunk segments.

Keywords: Brachial plexus/anatomy & histology; Ultrasonography; Magnetic resonance imaging.