[Ultrasonography of the thyroid and parathyroid gland].
ABSTRACT Ultrasonography is the most important imaging tool in the diagnosis of thyroid disease. The results of real-time B-imaging of the thyroid gland along with physical signs and basal TSH can aid in the diagnosis of thyroid dysfunction, of for instance, a small, hypoechogenic gland in Hashimoto's and radiation thyroiditis, or an enlarged, hypoechogenic and pulsating gland in Graves' disease. Although recent improvements in technology have increased sensitivity of colored duplexsonography, certain sonographic differentiation of benign and malignant lesions as well as of active (hormone secreting) and inactive nodules is not yet possible. Diagnostic interpretation of ultrasonographic findings is feasible only when the history of the patient, physical examination and the laboratory evaluation are taken into account. Ultrasound detects thyroid nodules, is useful for following nodule size, in guiding fine needle biopsies and in the aspiration of cysts. Highly experienced investigators in ultrasound can assist preoperatively in the localization of parathyroid adenomas in primary and tertiary hyperthyroidism (when followed by (99m)Tc szintigraphy plus SPECT).
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ABSTRACT: Experienced surgeons have the highest sensitivity in the localization of parathyroid adenomas in patients with primary hyperparathyroidism. Correct preoperative localization, however, allows unilateral neck exploration with subsequently reduced operative time and complication rate. In this prospective study, we investigated the accuracy of preoperative high-resolution ultrasound in combination with colour-Doppler sonography for the detection of parathyroid lesions. Ninety-eight patients (mean age 59.1 years, range 15-86) who referred to our department with symptomatic primary hyperparathyroidism were included in the study from January 1998 to June 2002. Sonography was performed by experienced examiners. The exact diagnosis was based on surgical findings and histology in all patients. The overall sensitivity for the sonographical localization of the adenomas on the correct side of the neck was 86 %. Twenty-three percent of the adenomas located on the cranial margin of the thyroid gland were diagnosed correctly, as were 92 % of the lesions located caudally (p = 0.0001). The detection of feeding vessels was possible by colour-Doppler sonography in 60 % of the cases. The diagnosis was correct for 93 % of these suspected adenomas. No vessels were detected in the remaining lesions, and only 39 % of these tumours were diagnosed correctly (p = 0.0001). High-resolution ultrasonography by experienced examiners is a highly sensitive procedure for the preoperative diagnosis of parathyroid adenomas in patients with primary hyperparathyroidism. With this method, a unilateral neck exploration is sufficient in about 90 % of the patients. Additionally, detection of feeding vessels by colour-Doppler sonography is an important indication of a parathyroid lesion. Nonetheless, the experienced surgeon remains the standard of reference.Ultraschall in der Medizin 05/2003; 24(2):85-9. · 4.12 Impact Factor
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ABSTRACT: Interferon-alpha (IFN alpha) is the main therapeutic agent in patients infected with the hepatitis C virus (HCV). It is rather safe, but is known to induce the production of autoantibodies and can lead to the occurrence of autoimmune disease. This minireview focuses on the induction of autoimmune thyroid disease (AITD) in HCV-infected patients treated with IFN alpha. Females carry a higher risk to develop AITD upon IFN alpha treatment, with a relative risk of 4.4 (95% confidence interval 3.2-5.9). The presence of thyroid peroxidase antibodies before therapy has a relative risk for AITD of 3.9 (95% confidence interval 1.9-8.1). IFN alpha-associated AITD can consist of autoimmune primary hypothyroidism, Graves' hyperthyroidism, and destructive thyroiditis, with hypothyroidism being the most common side effect. The clear association between AITD and IFN alpha use suggests that high endogenous IFN alpha levels may also be associated with naturally occurring AITD. High endogenous IFN alpha levels are seen in patients infected with certain viruses. It is concluded that IFN alpha is one of the environmental factors capable of triggering the onset of AITD in genetically susceptible individuals.Thyroid 07/2003; 13(6):547-51. · 3.54 Impact Factor
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ABSTRACT: The aim of the study was to correlate the sonographic [ultrasound (US)] and color-Doppler (CFD) findings with the results of US-guided fine needle aspiration biopsy (FNA) and of pathologic staging of resected carcinomas to establish: 1) the relative importance of US features as risk factors of malignancy; and 2) a cost-effective management of nonpalpable thyroid nodules. Four hundred ninety-four consecutive patients with nonpalpable thyroid nodules (8-15 mm) were evaluated by US, CFD, and US-FNA. Ninety-two patients with inadequate cytology were excluded from the study. All patients with suspicious or malignant cytology underwent surgery, whereas subjects with benign cytology had clinical and US control 6 months later. Thyroid malignancies were observed in 18 of 195 (9.2%) solitary thyroid nodules and in 13 of 207 (6.3%) multinodular goiters. Cancer prevalence was similar in nodules greater or smaller than 10 mm (9.1 vs. 7.0%). Extracapsular growth (pT(4)) was present in 35.5%, and nodal involvement in 19.4% of neoplastic lesions, with no significant differences between tumors greater or smaller than 10 mm. At US cancers presented a solid hypoechoic appearance in 87% of cases, irregular or blurred margins in 77.4%, an intranodular vascular pattern in 74.2%, and microcalcifications in 29.0%. Irregular margins (RR 16.83), intranodular vascular spots (RR 14.29), and microcalcifications (RR 4.97) were independent risk factors of malignancy. FNA performed on hypoechoic nodules with at least one risk factor was able to identify 87% of the cancers at the expence of cytological evaluation of 38.4% of nonpalpable lesions. The majority of nonpalpable thyroid tumors can be identified by cytological evaluation of lesions presenting hypoechoic appearance in conjunction with one independent risk factor. Due to the nonnegligible prevalence of extracapsular growth and nodal metastasis, US-FNA should be performed on all 8-15 mm hypoechoic nodules with irregular margins, intranodular vascular spots or microcalcifications. Nonpalpable lesions of the thyroid without risk factors should be followed by means of clinical and US evaluation.Journal of Clinical Endocrinology & Metabolism 06/2002; 87(5):1941-6. · 6.43 Impact Factor