Attenuation coefficient measurement in the thyroid

OBJECTIVE

To assess the feasibility of a novel method of measuring the attenuation coefficient in the thyroid, which offers less variability of results than the conventional method.

METHODS

In our new method, the attenuation coefficient was evaluated on the basis of the following equation with sound field correction: alpha = -1/4[Fc(z)-epsilon(z)] x d/dz[log(M0(z))-tau(z)]. In our system, the attenuation coefficient was also evaluated by the spectral shift central frequency method at the same time. In this study, we used 32 cases of normal thyroid, 26 cases of Graves disease, and 11 cases of Hashimoto thyroiditis in the system.

RESULTS

With this novel method, attenuation coefficient values of the thyroid (mean +/- SD) were 1.50 +/- 0.26 dB x cm(-1) x MHz(-1) in the normal group, 0.91 +/- 0.23 dB x cm(-1) x MHz(-1) in the Graves disease group, and 1.10 +/- 0.27 dB x cm(-1) x MHz(-1) in the Hashimoto thyroiditis group. The novel method recorded a statistically significant difference between normal and diseased thyroids (P < .0001) and between Graves disease and Hashimoto thyroiditis groups (P = .0035). Statistical variation of the attenuation coefficient values obtained using the novel method was much smaller than that of those obtained by the spectral shift central frequency method in every group.

CONCLUSIONS

This new method is considered usable for evaluating the attenuation coefficient of the thyroid in vivo.

Relation between quantitative description of ultrasonographic image and clinical and laboratory findings in lymphocytic thyroiditis

OBJECTIVE

Relations between measurable properties of B-mode ultrasound images of thyroid gland and clinical and laboratory findings in patients with chronic inflammation of thyroid gland were studied.

METHODS

Data from 65 patients with lymphocytic thyroiditis (LT) and 38 control subjects were analysed. Raw values of individual B-mode image pixels and standard co-occurrence second-order texture features were selected as quantitative image features. Thyroid antibodies, thyrotropin level, thyroxine replacement therapy, and body mass index were used as clinical variables.

RESULTS

In the LT group, significant differences (t-tests, p<0.05) in image features were found for body mass indices (BMI) under and over 25 kg.m(-2), for thyroxine replacement therapy, and for the presence and absence of thyroid antibodies. Forward stepwise multiple regression was performed for the clinical or laboratory values as dependent variables and image features as independent variables. The following correlations were found: 1. between BMI and four image features in the normal group; 2. between the dose of thyroxine replacement therapy and two of image features in the LT group; and 3. for the level of thyroid antibodies in the LT group: five image features have correlated with the level of anti-thyroglobulin and three image features with level of anti-thyroperoxidase.

CONCLUSION

These findings suggest the possibility of using quantitative indicators of ultrasound image of thyroid gland as predictors of the presence or absence of thyroid antibodies in patient's blood or as an auxiliary tool for dose recommendation of thyroxine replacement therapy.

Hypothyroidism presenting as a hot pertechnetate nodule

The authors report an uncommon finding of hot nodule on Tc-99m sodium pertechnetate thyroid scan in three patients with hypothyroidism. Data indicate that hypothyroidism is secondary to Hashimoto's disease (HD). There was a concordant aspect on I-131 scan in two; a nodular discrepancy (cold nodule with I-131) was associated with the highest microsomal antibodies titer. The findings of thyroid scan and ultrasonographic findings indicate that hot nodules may be observed either on initial or advanced stages of HD. Color flow Doppler sonography, showed an absence of internal increase of vascularization. These data suggest that the observed hot nodules correspond to localized hyperplasia of the less diseased portions secondary to chronic stimulation by TSH.

Increased 18F-FDG uptake mimicking thyroid cancer in a patient with Hashimoto's thyroiditis

We report the case of a 68-year-old patient with a known paravertebral malignant schwannoma, sent to us for postoperative staging. A combined whole-body PET/CT scan showed only poor (18)F-fluorodeoxyglucose uptake in the region of the primary tumor but distinct increased fluorodeoxyglucose uptake in the left and right thyroid gland. Thyroid sonography showed two hypoechogenic nodules. Ultrasound-guided fine-needle aspiration biopsy of one nodule showed oxyphil transformed cells, compatible with malignancy. Based on these findings, the patient underwent a subtotal thyroidectomy. Histopathology of the specimen revealed a chronic follicular Hashimoto's thyroiditis. This case demonstrates that Hashimoto's thyroiditis can mimic thyroid cancer in PET but also in sonography and fine-needle aspiration biopsy.

Grey-scale analysis allows a quantitative evaluation of thyroid echogenicity in the patients with Hashimoto's thyroiditis

OBJECTIVE

In the present study we have performed a grey-scale quantitative analysis of thyroid echogenicity in the patients affected by Hashimoto's thyroiditis (HT), obtaining a numerical estimate of the degree of hypoechogenicity associated with the appearance of thyroid dysfunction.

MATERIALS AND METHODS

The study group included 89 patients with serum positivity for thyroglobulin (TgAb) and/or peroxidase (TPOAb) antibodies. Ultrasound (US) evaluation of thyroid gland and biochemical assay of serum thyrotropin (TSH), free-thyroxine (FT4) and free-triiodiothyronyne (FT3) were performed in all patients, and in 40 healthy subjects enrolled as control group. Thyroid echogenicity was compared with that of the surrounding neck muscles, using the grey-scale histogram analysis. The echogenicity was expressed in grey-scales (GWE).

RESULTS

In HT patients, the mean of thyroid echogenicity was lower when compared to the normal thyroid (61.9 +/- 8.3 GWE vs. 71.9 +/- 3.1 GWE; P = 0.01). In all HT patients the lowest limit of thyroid echo distribution was in the echogenicity range of the surrounding muscle, the overlapping ranging between 3.4% and 95.0% (mean +/- SD 48.4 +/- 20.9%). The extension of like-muscle hypoechogenicity into the thyroid gland was significantly correlated with serum TSH values (r = 0.37; P < 0.001), serum FT4 values (r = -0.60; P < 0.001), and serum TPOAb values (r = 0.31; P = 0.004). Nobody was hypothyroid when the hypoechogenicity was less than 38.0%, whereas hypothyroidism occurred in all cases with hypoechogenicity of more than 68.9%. The receiving operating characteristic curve demonstrated that 48.3% was the best cut-off for identifying hypothyroid patients with sensitivity, specificity and diagnostic accuracy of 88.9%, 86.3% and 87.6%, respectively.

CONCLUSIONS

In conclusion, the grey-scale quantitative analysis has provided a measure of thyroid hypoechogenicity associated with the appearance of hypothyroidism during the course of HT. The results of the present study would encourage the application of the computerized grey-scale analysis as complementary tool to US evaluation in the patients affected by HT.

Gallium-67 imaging in a patient with malignant thyroid lymphoma that spontaneously regressed after subtotal gastrectomy

A patient presented with malignant thyroid lymphoma in association with Hashimoto disease. Abnormal, intense Ga-67 accumulation in the thyroid was seen. The patient underwent subtotal gastrectomy for cancer and the malignant thyroid lymphoma regressed spontaneously. Ga-67 accumulation in the thyroid also decreased. The resected stomach was positive for Helicobacter pylori. The patient achieved complete clinical response after H. pylori eradication. Regression of the malignant thyroid lymphoma might be related to H. pylori eradication and the subtotal gastrectomy.

F-18-FDG-PET in a patient with Hashimoto's thyroiditis and MALT lymphoma recurrence of the thyroid

We report on the case of a 86-year-old male patient with a rapidly growing nodule within the right lobe of the thyroid gland, which after hemithyroidectomy, turned out to be a mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid gland. In addition, Hashimoto's thyroiditis was reported in the thyroid tissue adjacent to the MALT lymphoma. During follow-up a second nodule emerged within the left lobe and, because of evidence of MALT lymphoma recurrence, F-18-FDG-PET was performed. F-18-FDG-PET imaged a clearly increased accumulation within the whole left lobe and isthmus. Thus, no differences in the degree of hypermetabolism could be imaged between the nodule and the adjacent thyroid tissue. To our knowledge, this is the first report about F-18-FDG-PET in a patient with MALT lymphoma of the thyroid. Literature search revealed only a few cases of MALT lymphomas in locations other than the thyroid gland that were studied with F-18-FDG-PET. In no case was F-18 FDG accumulation seen in the MALT lesions. However, clear F-18 FDG accumulation was reported in some patients with Hashimoto's thyroiditis. It is concluded that the intensive F-18-FDG accumulation within the whole left lobe and isthmus of the presented case was due to the coexisting Hashimoto's thyroiditis. Consequently, F-18-FDG-PET imaging does not seem to be indicated in a patient with MALT lymphoma and known Hashimoto's thyroiditis in order to evaluate the status of the MALT lymphoma.

Diagnosis of thyroid lymphoma and follow-up evaluation using Ga-67 scintigraphy

A strong association between malignant lymphoma and Hashimoto's thyroiditis has frequently been reported. However, it is difficult to detect the lymphomatous transformation of Hashimoto's thyroiditis in the early stage. The purpose of the present study was to examine the usefulness of 67Ga scintigraphy in the diagnosis and evaluation of the therapeutic effects during follow-up, in patients with a suspected diagnosis of primary thyroid lymphoma. Twenty-five patients who were suspected of having primary thyroid lymphoma and had undergone 67Ga scintigraphy were studied. 67Ga planar scintigraphy was performed 72 hours after injection of 67Ga-citrate. The degree and pattern of 67Ga accumulation were graded visually. Histopathology on biopsy examination revealed thyroid lymphoma in 17 and Hashimoto's thyroiditis in 8 patients. Abnormal accumulation of 67Ga in the thyroid was seen in all of the 17 thyroid lymphoma cases with additional mediastinal and abdominal involvement in one. Fifteen of 17 thyroid lymphoma patients also underwent 67Ga scintigraphy 2-4 weeks after chemotherapy and/or radiotherapy. All 15 patients showed diminishing 67Ga accumulation and a good clinical course. In one patient with local recurrence, abnormal accumulation could be depicted by follow-up scintigraphy. However, diffuse or enlarged accumulation in the thyroid was seen in all of the 8 Hashimoto's thyroiditis cases. The degree of abnormal accumulation in the thyroid in clinically active phase thyroiditis was more intense than that in the chronic phase thyroiditis. 67Ga scintigraphy was helpful to confirm the diagnosis of thyroid lymphoma and to evaluate the therapeutic effects during follow-up. However, 67Ga scintigraphy may not always distinguish thyroid lymphoma from Hashimoto's thyroiditis, especially the active phase of the disease.

Postpartum thyroiditis presenting as a cold nodule and evolving to Graves' disease

We describe the case of a 30-year-old woman who, five months after giving birth, was referred with a solitary nodule in her anterior neck. Laboratory analysis, ultrasonography, pertechnetate (Tc99m) thyroid scan and cytological examination of fine needle aspiration biopsy performed on the nodule led us to diagnose postpartum thyroiditis (PPT). Twenty-eight months after parturition, overt hyperthyroidism developed, with raised thyroperoxidase and thyroid stimulating hormone receptor antibody titres, diffuse high uptake of Tc99m at thyroid scan, and high vascular flow throughout the gland at Color-Power imaging. The diagnosis of Graves' disease (GD) was established. The differential diagnosis of thyrotoxicosis in the postpartum period, and the possible aetiological relationships between PPT and GD are discussed. To our knowledge, this is the first published report of a PPT presenting as a cold nodule, and evolving to GD.

Relationship of clinical features and laboratory parameters to thyroid echogenicity measured by standardized grey scale ultrasonography in patients with Hashimoto's thyroiditis

BACKGROUND

Hashimoto's thyroiditis is associated with a diffuse reduction in thyroid echo levels. The purpose of this study was to determine the degree of hypoechogenicity in correlation to clinical features and laboratory parameters.

MATERIAL/METHODS

52 patients with Hashimoto's thyroiditis under substitutive therapy with levothyroxine (50-200 g daily) and 100 normal euthyroid volunteers (with no features of autoimmune disease who were not taking any thyroid medication) as controls were investigated. Determination of plasma free thyroxine (FT4) and TSH as well as peroxidase- (TPO), thyroglobulin- and TSH receptor (TSH-R) antibodies were performed. Thyroid volume was measured by conventional ultrasonography. Tissue echogenicity was characterized by standardized grey scale ultrasonography under defined operating conditions. Mean densities were given in a histogram range of grey scales between 0-63 GWE (= Grauwerteinheiten).

RESULTS

Patients with Hashimoto's thyroiditis revealed significantly lower echo levels (19.6+/-2.6 GWE) than controls (25.6+/-2.0 GWE, p<0.001). High graded hypoechogenicity was associated with large goiters, persistently increased TSH levels (subclinical hypothyroidism) and highly elevated TPO-antibodies.

CONCLUSIONS

Standardized grey scale ultrasonography allows for reproducable correlations between functional status and morphological characteristics of the thyroid gland in Hashimoto's thyroiditis. The results hint at a stronger inflammatory process in higher grades of hypoechogenicity.

123I-Interleukin-2: biochemical characterization and in vivo use for imaging autoimmune diseases

We describe in detail the labelling of interleukin-2 with I ( I-IL2), its biochemical characterization, the binding assay and its use for the detection of tissues infiltrated with mononuclear cells. Human recombinant IL2 was labelled using an enzymatic method and its biochemical characterization was performed using high performance liquid chromatography (HPLC) analysis of cyanogen bromide-cleaved protein. biological and binding assays were performed on CTLL-2 cell line and on activated peripheral blood lymphocytes. studies were performed 1 h after administration of 2-3 mCi of I-IL2 in 10 newly diagnosed type 1 diabetes patients, five pre-diabetic patients, 10 Hashimoto's thyroiditis patients, 10 coeliac disease patients and 10 normal volunteers. I-IL2 scintigraphy allowed the detection and quantification of activated mononuclear cells in several affected tissues. In detail, I-IL2 accumulation was detected in the thyroid of all patients affected by Hashimoto's thyroiditis, in the bowel of all coeliac disease patients and in the pancreas of all pre-type 1 diabetic patients. By contrast, in newly diagnosed type 1 diabetics, I-IL2 scan was positive in five of the 10 studied patients. I-IL2 scintigraphy may be useful for studying autoimmune phenomena and in diagnostic protocols to evaluate the presence of other tissue involvement in patients with an organ-specific autoimmune disease.

The prevalence of anti-thyroid peroxidase antibodies and autoimmune thyroiditis in children and adolescents in an iodine replete area

BACKGROUND

The iodine supply of the population in Berlin has normalized during the last 5 Years. Therefore autoimmune thyroiditis has become the most important differential diagnosis in children and adolescents with goiter.

OBJECTIVE

The aim of the present study was to define the prevalence of anti-thyroid peroxidase (TPO) antibodies and autoimmune thyroiditis in children and adolescents with a normalized iodine intake.

DESIGN

To enable the measurement of antibodies to thyroid peroxidase (anti-TPO-Ab) in a large cohort, a method to determine anti-TPO-Ab in dried filter paper blood spots was established. In co-operation with pediatricians the antibody prevalence was assessed and data regarding thyroid size, echostructure and the medical history concerning iodine intake and familial thyroid diseases were collected.

METHODS

660 children and adolescents participated in the study; urinary iodine, TSH and TPO-Ab were measured and an ultrasound of the thyroid gland was performed.

RESULTS

The sensitivity of the newly established filter paper assay was 91.8% and specificity was 100%. The results confirmed the improved iodine supply, with a median urinary iodine concentration of 139 microg iodine/g creatinine. The prevalence of anti-TPO-Ab was 3.4% with a female to male ratio of 2.7:1.

CONCLUSION

The prevalence of anti-TPO-Ab is lower or equal to data reported from other iodine sufficient areas. Data from a moderate iodine deficiency in schoolchildren range from 0.0 to 7.3%. Using the new filter paper method field studies can be implemented to monitor the effect of changes in iodine nutrition on thyroid autoimmunity. Furthermore, this study on the prevalence of anti-TPO-Ab in a cohort of healthy children and adolescents in an iodine replete area can serve as reference data for future investigations and for the comparison with other groups of patients with increased risks for thyroid autoimmunity.

Autoimmune diseases in vitiligo: do anti-nuclear antibodies decrease thyroid volume?

An increased prevalence of autoimmune thyroiditis (AT) in vitiligo patients is well known. The aim of this study was firstly, to evaluate the clinical course of patients with both vitiligo and AT and secondly, to identify additional autoimmune disorders affecting the thyroid gland in a large cohort of vitiligo patients. We analysed a study group of 106 vitiligo patients and 38 controls. A detailed thyroid examination including sonography was performed in all study participants. In addition, the study participants were HLA typed and screened for various autoimmune disorders. AT was significantly more frequent in vitiligo patients than in controls (21%versus 3%; P < 0.01). In 12 of the 22 patients with AT, vitiligo was the initial disease preceding AT by 4-35 years. In the other 10 patients with AT, both vitiligo and AT were diagnosed within one year. There were two individuals with diabetes mellitus type 1 and a single patient with Addison's disease. Anti-nuclear antibody (ANA), anti-smooth muscle cell antibody, and parietal cell antibody levels occurred with a similar frequency in patients and controls. In all vitiligo patients with both elevated ANA levels and AT (n = 6), the atrophic but not the goitrous variant was diagnosed. These vitiligo patients with both AT and elevated ANA levels had a significantly smaller thyroid volume compared to the vitiligo patients with AT whose ANA levels were normal (6.7 +/- 4.5 ml versus 13.4 +/- 9.1 ml, respectively; P < 0.05). The same was found in the entire study group: Thyroid volume of all vitiligo patients (with or without concomitant AT) was significantly smaller in the presence of ANA (6.9 +/- 5.3 versus 10.5 +/- 5.9 ml, respectively; P < 0.05). However, this phenomenon was not observed in the control group. There was a trend for a decreased frequency of HLA-DR3 (6.7%versus 23%) in our study group, but after correction for the number of comparisons, no HLA-allele was statistically significant associated neither with vitiligo nor with multiple autoimmune diseases in our patient sample. Our findings suggest that AT is the most frequent autoimmune disease associated with vitiligo. In our patients, AT presented simultaneously or after the onset of vitiligo but not before. Elevated ANA levels were associated with the atrophic variant of AT and may affect the volume of the thyroid gland, and there was no statistically significant association with the HLA system.

Decreased salivary gland function in patients with autoimmune thyroiditis

BACKGROUND/AIMS

It has been speculated that impaired salivary flow contributes to autoimmune thyroiditis (chronic thyroiditis, Hashimoto's thyroiditis). To test this hypothesis, salivary function was measured by quantitative salivary scintigraphy in autoimmune thyroiditis patients, as well as in age- and gender-matched controls for comparison.

METHODOLOGY

One hundred and twenty patients with an autoimmune thyroiditis history of more than 10 years each and 36 healthy controls were enrolled in the study. All the 120 autoimmune thyroiditis patients had good blood sugar control. None had autonomic neuropathy. These 120 autoimmune thyroiditis patients were separated into two subgroups: group 1, 60 patients with xerostomia; and group 2, 60 patients without xerostomia. After intravenous injection of 5 mCi Tc-99m pertechnetate, sequential images at 1 min/frame were acquired for 30 min. The first- and 15th-minute uptake ratios (UR) were calculated from the tracer uptakes in the four major salivary glands over the background regions of interest (ROIs). Saliva excretion was stimulated by 1 tablet of 200 mg ascorbic acid given orally 15 min after injection of the tracer. Then, the maximal excretion ratios (ER) of the four major salivary glands after sialagogue stimulation were calculated.

RESULTS

Impaired salivary function, represented by significantly decreased UR and ER values, in autoimmune thyroiditis patients with xerostomia was demonstrated in this study. In addition, there was a significantly higher prevalence of salivary gland dysfunction in group 1 patients than in group 2 patients.

CONCLUSIONS

Significantly poorer salivary function was found in autoimmune thyroiditis patients with xerostomia compared with autoimmune thyroiditis patients without xerostomia and healthy controls by means of objective and quantitative salivary scintigraphy.

Thyroiditis and oncocytic carcinoma: incidental association? A case report

BACKGROUND

Several studies have reported an association between Hashimoto's disease and thyroid carcinoma although the cause/effect relationship is still controversial.

CASE REPORT

In this paper we report the case of a 38-year-old female who first presented with a clinical history of Hashimoto's thyroiditis. Ultrasound examination showed a diffuse thyroid irregularity more pronounced in the right lobe. FNAC (Fine Needle Aspiration Cytology) was performed in this area, and the cytological diagnosis was "Hashimoto's thyroiditis". The patient underwent clinical follow-up. Two years later, an ultrasound examination showed a nodular lump in the area previously aspirated. A new FNAC evidenced a Hurthle cell neoplasia. Therefore, the patient underwent surgery. The histological diagnosis was "Hurthle cell carcinoma".

CONCLUSION

In the present case, the clinical and ultrasound history suggest the development of a malignant lesion strictly related to thyroiditis, as previously reported by other studies on papillary carcinoma. A cause-effect relationship between chronic lymphocytic thyroiditis and oncocytic neoplasia is still a matter of controversy. Therefore, patients suffering from chronic thyroiditis require a careful follow-up and, in case of nodules development, FNAC is recommended.

Objective evidence of decreased salivary function in patients with autoimmune thyroiditis (chronic thyroiditis, Hashimoto's thyroiditis)

Impaired salivary flow is found in Sjögren's syndrome, which is a common, chronic, autoimmune, inflammatory connective tissue disease, mainly affecting the exocrine glands. Histopathologically, lymphocytic infiltrations of the salivary glands are found in Sjögren's syndrome that are similar to those of the thyroid gland in autoimmune thyroiditis (chronic thyroiditis, Hashimoto's thyroiditis). To test this hypothesis by Daniels et al ., salivary function was measured by quantitative salivary scintigraphy in autoimmune thyroiditis patients, as well as in age- and sex-matched controls. Forty patients, each with a history of autoimmune thyroiditis of over 10 years, and 61 healthy controls were enrolled in the study. All of the 40 autoimmune thyroiditis patients had good blood sugar control. None presented autonomic neuropathy. They were separated into two subgroups: patient group 1, 20 patients with xerostomia; patient group 2, 20 patients without xerostomia. Two control groups of healthy subjects were included for comparison: control group 1, 36 subjects without xerostomia; control group 2, 25 subjects with xerostomia. After intravenous injection of 5 mCi (99m)Tc-pertechnetate, sequential images at 1 min per frame were acquired for 30 min. The first and 15th minute uptake ratios (URs) were calculated from the tracer uptakes in the four major salivary glands relative to the background regions of interest (ROIs). Saliva excretion was stimulated by one tablet of 200 mg ascorbic acid given orally 15 min after injection of the tracer. The maximal excretion ratios (ERs) of the four major salivary glands after sialagogue stimulation were calculated. Impaired salivary function, represented by significantly decreased UR and ER values, in autoimmune thyroiditis patients with xerostomia was demonstrated in this study. Significantly poorer salivary function was found in autoimmune thyroiditis patients with xerostomia, when compared with autoimmune thyroiditis patients without xerostomia and healthy controls with or without xerostomia, via objective and quantitative salivary scintigraphy. However, a larger series of autoimmune thyroiditis patients is necessary to confirm our findings.

Ultrasound measurement of the horizontal external eye muscles in patients with thyroid disease. Is orbital involvement associated with thyroid autoantibodies?

PURPOSE

To describe ophthalmic findings with emphasis on exophthalmometry and ultrasonic assessment of extraocular eye muscle diameter in a consecutive group of females with Graves' disease (GD), compared with healthy controls and patients with other thyroid diseases. We also investigated the relationship with biochemical markers of thyroid autoimmunity such as TSH receptor antibodies (TRAb) and anti-thyroid peroxidase antibodies (anti-TPO).

METHODS

Seventy adult women (age 26-74 years) with various types of thyroid disease consecutively entered the study at a tertiary referral center for thyroid-associated ophthalmopathy (TAO). Twenty-three had long-standing GD with TAO. Clinically, TAO was mainly absent in 22 with newly diagnosed GD and in seven with relapse of GD. Nine with Hashimoto's thyrolditis and nine with multinodular goiter were included for comparison and 18 healthy females served as controls. A full ophthalmic status included B-scan ultrasonic assessment of the four horizontal rectus muscle thicknesses, and a clinical NOSPECS score was attempted for each.

RESULTS AND CONCLUSIONS

Besides higher NOSPECS scores, the TAO subgroup had higher exophthalmometry and muscle thickness. The GD groups without significant TAO also scored higher in these ratings compared to controls. Hertel recordings, NOSPECS and muscle thicknesses were all correlated in GD but showed no correlation to thyroid antibodies (TRAb and anti-TPO). Thus, the muscle thickness did not correlate with thyroid autoimmune activity. Nevertheless, we found extraocular muscle assessment useful since a) thicker muscles were usually found in patients with GD, with or without evidence of TAO, and b) other space-occupying orbital lesions could be excluded, thereby reducing the need for the more elaborate imaging techniques (CT, MRI, etc.).

Thyroid ultrasound versus antithyroid peroxidase antibody determination: a cohort study of four hundred fifty-one subjects

Autoimmune thyroiditis is mirrored by a hypoechoic ultrasound pattern. We determined diagnostic precision of thyroid sonography compared to that of anti-thyroid peroxidase antibody (TPOAb) concentration. Ambulatory patients with unknown thyroid status (n = 451; 407 female, ages 44 +/- 16 years; 45 male, ages 50 +/- 14 years) excluding those with suspected hyperthyroidism or on drugs known to cause hypothyroidism were recruited consecutively. Subjects were recruited from a specialized thyroid outpatient unit with higher frequencies of thyroid disorders than in the general population. Before determination of thyroid function and TPOAb concentration thyroid volume (normal values: women < 12 mL, men < 14 mL) and echogenicity (grade 1 = normal: similar to submandibular gland, hyperechoic to neck muscles; grade 2: hypoechoic to submandibular gland, hyperechoic to neck muscles, grade 3: iso-/hypoechoic to neck muscles) were determined. Positive predictive value of grade 3 pattern for detection of autoimmune thyroiditis was 94% (with overt hypothyroidism) and 96% (with any degree of hypothyroidism), that of grade 2 or 3 85% and 87%, respectively. Negative predictive value of grade 1 pattern for detection of euthyroid TPOAb negative subjects was 91%. Goiter was present in 31% and 21% of TPOAb postive and negative subjects, respectively, while 11% and 15% had an atrophic thyroid gland (p = not significant [n.s.]). Given a high intraobserver and interobserver agreement abnormal thyroid ultrasound patterns were highly indicative of autoimmune thyroiditis and allowed the detection of thyroid dysfunction with 96% probability.

The continuing importance of thyroid scintigraphy in the era of high-resolution ultrasound

At the molecular level, the uptake of radioiodine and pertechnetate is proportional to the expression of the thyroidal sodium/iodine symporter (NIS). Qualitative and quantitative scintigraphic evaluation of the thyroid is performed with a gamma camera fitted with an on-line computer system and enables determination of the iodine uptake or the technetium uptake (TCTU) as an iodine clearance equivalent. Despite new molecular genetic insights into congenital hypothyroidism, the iodine-123 or pertechnetate scan remains the most accurate test for the detection of ectopic thyroid tissue. Following the identification of specific mutations of the genes coding for the NIS, thyroid peroxidase and pendrin, the discharge test has lost its role in establishing the diagnosis of inherited dyshormonogenesis, but it is still of value in the assessment of defect severity. In PDS mutations the test can be used to establish the diagnosis of syndromic disease. Quantitative pertechnetate scintigraphy is the most sensitive and specific technique for the diagnosis and quantification of thyroid autonomy. The method has proved to be valuable in risk stratification of spontaneous or iodine-induced hyperthyroidism, in the estimation of the target volume prior to radioiodine therapy and in the evaluation of therapeutic success after definitive treatment. In iodine deficiency areas the thyroid scan remains indispensable for the functional characterisation of a thyroid nodule and is still a first-line diagnostic procedure in cases of suspected thyroid malignancy. This is especially of importance in patients with Graves' disease, among whom a relatively high prevalence of cancer has been found in cold thyroid nodules. While determination of the TCTU is without any value in the differentiation between autoimmune thyroiditis and Graves' disease in most cases, it is of substantial importance in the differentiation between hyperthyroid autoimmune thyroiditis and Graves' disease.

Discordant effect of IFN-beta1a therapy on anti-IFN antibodies and thyroid disease development in patients with multiple sclerosis

Interferon-beta1b (IFN-beta1b) therapy is associated with a relatively high risk of developing thyroid disease. IFN-beta1a is regarded as less immunogenic than IFN-beta1b because of its structural homology to natural IFN-beta. We assessed the effect of 1 year of IFN-beta1a treatment on thyroid function and autoimmunity in 14 multiple sclerosis (MS) patients. The results were compared with those obtained in a series of 31 MS patients treated with IFN-beta1b. The prevalence of positive binding antibody (BAb) titer and neutralizing (NAb) anti-IFN antibody titer in the two groups was also assessed. The BAb and NAb positivity rate in IFN-beta1a-treated patients was significantly lower than in the group submitted to IFN-beta1b therapy (7% vs. 84% and 0% vs. 30%, respectively). Although the incidence of thyroid dysfunction was slightly higher in IFN-beta1b-treated patients than in those undergoing IFN-beta1a treatment (33% vs. 23%, respectively), it did not reach statistical significance. Thyroid disease was unrelated to the presence of positive serum BAb or NAb titer in both the group undergoing IFN-beta1a therapy and in that treated with IFN-beta1b. In both groups, thyroid disease developed mostly in women (71%) against a background of preexisting thyroiditis and a diffuse hypoechoic ultrasound thyroid pattern (80%). IFN-beta1a treatment was associated with a significantly lower prevalence of both BAb and NAb-positive titers than was IFN-beta1b. Conversely, thyroid disease was similar and unrelated to the presence of positive anti-IFN-beta antibody titer. Therefore, routine thyroid assessment may be advised during IFN-beta1a treatment, especially in patients with preexisting thyroiditis.

Hashimoto's thyroiditis presenting as single hot nodule and hypothyroidism

Radionuclide thyroid scanning of patients with Hashimoto's thyroiditis (HT) may mimic other thyroid disorders including cold nodules, multinodular goiter and rarely hot nodules. The association of single hot nodules in such patients in the face of primary hypothyroidism has not been previously reported. We describe 6 female patients with HT who presented either with symptoms of overt thyroid failure or a sensation of lump in the neck (and later found to have mild thyroid failure) who had single firm thyroid nodules. These nodules were hot by both 99mTc pertechnetate and radioiodine thyroid scans. In three of 4 patients followed up for longer than 6 months on adequate thyroid replacement therapy the nodules regressed by up to 60%. Given "Best practice" recommendations patients with thyroid failure and single thyroid nodules would not be submitted to radionuclide scanning and this presentation of HT would have gone undetected.

Scintigraphic findings of MALT lymphoma of the thyroid

Mucosa-associated lymphoid tissue (MALT) lymphoma has been established as a distinct entity among non-Hodgkin's lymphomas, and the most common primary site is the stomach. We describe scintigraphic findings in a patient with MALT lymphoma of the thyroid. A 71-year-old woman with Hashimoto's thyroiditis suffered from rapid cervical swelling, and ultrasonography and CT revealed a thyroid nodule. The nodule showed accumulation of 99mTc pertechnetate comparable to the surrounding thyroid tissue, mimicking a benign nodule. Both 67Ga and 201Tl imaging visualized the lesion as an increased uptake area. After radiotherapy, abnormally increased uptake disappeared on 67Ga images, which predicted a favorable outcome. MALT lymphoma of the thyroid may be visualized as a warm nodule on 99mTc pertechnetate scintigraphy.

Selenium supplementation in patients with autoimmune thyroiditis decreases thyroid peroxidase antibodies concentrations

In areas with severe selenium deficiency there is a higher incidence of thyroiditis due to a decreased activity of selenium-dependent glutathione peroxidase activity within thyroid cells. Selenium-dependent enzymes also have several modifying effects on the immune system. Therefore, even mild selenium deficiency may contribute to the development and maintenance of autoimmune thyroid diseases. We performed a blinded, placebo-controlled, prospective study in female patients (n = 70; mean age, 47.5 +/- 0.7 yr) with autoimmune thyroiditis and thyroid peroxidase antibodies (TPOAb) and/or Tg antibodies (TgAb) above 350 IU/ml. The primary end point of the study was the change in TPOAb concentrations. Secondary end points were changes in TgAb, TSH, and free thyroid hormone levels as well as ultrasound pattern of the thyroid and quality of life estimation. Patients were randomized into 2 age- and antibody (TPOAb)-matched groups; 36 patients received 200 microg (2.53 micromol) sodium selenite/d, orally, for 3 months, and 34 patients received placebo. All patients were substituted with L-T(4) to maintain TSH within the normal range. TPOAb, TgAb, TSH, and free thyroid hormones were determined by commercial assays. The echogenicity of the thyroid was monitored with high resolution ultrasound. The mean TPOAb concentration decreased significantly to 63.6% (P = 0.013) in the selenium group vs. 88% (P = 0.95) in the placebo group. A subgroup analysis of those patients with TPOAb greater than 1200 IU/ml revealed a mean 40% reduction in the selenium-treated patients compared with a 10% increase in TPOAb in the placebo group. TgAb concentrations were lower in the placebo group at the beginning of the study and significantly further decreased (P = 0.018), but were unchanged in the selenium group. Nine patients in the selenium-treated group had completely normalized antibody concentrations, in contrast to two patients in the placebo group (by chi(2) test, P = 0.01). Ultrasound of the thyroid showed normalized echogenicity in these patients. The mean TSH, free T(4), and free T(3) levels were unchanged in both groups. We conclude that selenium substitution may improve the inflammatory activity in patients with autoimmune thyroiditis, especially in those with high activity. Whether this effect is specific for autoimmune thyroiditis or may also be effective in other endocrine autoimmune diseases has yet to be investigated.

Quantitative indicators of sonographic image of thyroid gland and their relation to antithyroid antibodies in Hashimoto's lymphocytic thyroiditis

Sonography is a widely used non-invasive diagnostic tool and its main advantage is low cost in comparison with other diagnostic methods such as immunological analyses. In this work it is presented the relation between a sonographic image of thyroid gland and an immunological status of the patients with Hashimoto's lymphocytic thyroiditis (chronic inflammation of the thyroid gland). The results, evaluated on a set of 740 B-mode sonographic images from 37 subjects, show that raw values of individual image pixels in sonogram of thyroid gland with presence and without presence of anti-thyroid antibodies are significantly different (means 31.87 and 44.56; standard deviations 8.6 and 11.82; t = 3.4; p = 0.0017) and that they can be used for the prediction of presence of anti-thyreoglobulin and anti-thyreoperoxidasis antibodies. This result suggests the possibility to use this method in clinical diagnostic process for reducing the costs. Also the correlation between the image features and the level of antibodies was examined. The highest correlation was found for inverse difference moment and the level of anti-thyreoperoxidasis (coefficient of determination 0.43).