Quantitative measurement of thyroid blood flow for differentiation of painless thyroiditis from Graves' disease

The prevalence of positive thyroid autoantibodies in patients with subacute thyroiditis: a systematic review and meta-analysis

PURPOSE

Subacute thyroiditis (SAT) is a transient inflammatory disorder of the thyroid gland with a possible viral etiology. We conducted this study to estimate the pooled prevalence of thyroid autoantibodies in SAT patients. This question arose due to the varying reports on the positivity rates of thyroid autoantibodies among SAT patients.

METHODS

We searched PubMed, Embase, Scopus, and Web of Science from their inception until March 25th, 2023. Observational studies reporting the positivity rate of thyroid autoantibodies for more than ten patients were included. We used the Joanna Briggs Institute's (JBI) critical appraisal checklist to assess the quality of the included studies. Pooled prevalence estimates with 95% confidence intervals were calculated using the random effects model. Subgroup analyses were performed to find sources of heterogeneity.

RESULTS

Out of 1373 identified records, 32 studies involving 2348 SAT patients were included in our study. Thyroglobulin antibody (TgAb) and thyroid peroxidase antibody (TPOAb) were positive in 22.8% and 12.2% of patients, respectively. The Study design, mean erythrocyte sedimentation rate and mean thyroid-stimulating hormone of patients were identified as sources of heterogeneity. As our secondary objectives, we found a recurrence rate of 14.7% and permanent hypothyroidism in 11.6% of patients.

CONCLUSION

The results of our study revealed a low TPOAb positivity rate in SAT patients, consistent with its non-autoimmune etiology. The TgAb positivity rate in SAT patients was higher than that of the general population, possibly explained by the transient release of thyroglobulin into the bloodstream during the thyrotoxic phase, leading to subsequent TgAb production. Furthermore, our findings demonstrate a notable recurrence rate and permanent hypothyroidism among SAT patients, highlighting the importance of ongoing follow-up care.

Thyroid storm in pregnancy: a review

BACKGROUND

Thyroid storm is a state of circulating thyroid hormone excess leading to multiorgan dysfunction and systemic decompensation. It typically occurs in the setting of poorly controlled hyperthyroidism and a precipitating illness or event. Management of thyroid storm in pregnancy poses unique diagnostic and therapeutic challenges.

MAIN BODY

Thyroid storm is a clinical diagnosis characterized by hyperpyrexia, tachyarrhythmias, congestive heart failure, gastrointestinal and neuropsychiatric disturbances. However, diagnostic scoring systems have not been validated in pregnancy. Treatment involves specialist consultation, supportive care, and pharmacological options such as anti-thyroid medications, beta blockers, iodine solutions, glucocorticoids, and cholestyramine. These must be adapted and modified in pregnancy to prevent fetal and maternal complications.

CONCLUSION

There is a critical need to recognize thyroid storm during pregnancy and initiate proper medical interventions promptly.

Thyroid ultrasound pattern in primary hypothyroidism is similar to Graves' disease: a report of three cases

Ultrasound can identify important characteristics in primary hypothyroidism and diffuse hyperthyroidism (Graves' disease). Therefore, sonologists are actively investigating ultrasound criteria to differentiate between these two conditions. Nevertheless, practice shows the absence of such ultrasonic landmarks. For the first time in the literature, three cases of primary hypothyroidism have demonstrated an ultrasound pattern identical to that of Graves' disease. This pattern includes the presence of goiter, marked total hypoechogenicity of the parenchyma, significantly or moderately increased blood flow intensity ('thyroid inferno'), and elevated peak systolic velocity of the superior thyroid arteries. These signs are less common in hypothyroidism compared to hyperthyroidism. Diagnostic data suggest that the pathogeneses of primary hypothyroidism and Graves' disease share the same mechanisms, leading to similar thyroid ultrasound patterns. One of these shared mechanisms is presumably thyroid overstimulation by the autonomic nervous system, which is adequate to the body's hormonal requirements in hypothyroidism but excessive in hyperthyroidism.

Quantitative Diagnosis Progress of Ultrasound Imaging Technology in Thyroid Diffuse Diseases

High-frequency ultrasound (HFUS), the imaging modality of choice for thyroid screening, is most commonly used in the study of diffuse thyroid disease (DTD) with Hashimoto's thyroiditis (HT) and Graves' disease (GD). DTD can involve thyroid function and severely affect life quality, so early diagnosis is important for the development of timely clinical intervention strategies. Previously, the diagnosis of DTD relied on qualitative ultrasound imaging and related laboratory tests. In recent years, with the development of multimodal imaging and intelligent medicine, ultrasound and other diagnostic imaging techniques have gradually become more widely used for quantitative assessment of the structure and function of DTD. In this paper, we review the current status and progress of quantitative diagnostic ultrasound imaging techniques for DTD.

Duplex Hemodynamic Parameters of Both Superior and Inferior Thyroid Arteries in Evaluation of Thyroid Hyperfunction Disorders

Background

Thyrotoxicosis may be caused by Graves’ disease or destructive thyroiditis. Differentiation between causes of thyrotoxicosis is crucial as management will differ. ^99mTechnetium (Tc)-pertechnetate thyroid scintigraphy is currently the gold standard for this purpose, however, is expensive and uses ionizing radiation.

Objective

To evaluate the role of color flow Doppler Ultrasound (CDU) of the superior thyroid (STA) and inferior thyroid arteries (ITA) as an inexpensive, non-invasive tool that can aid in differentiating between Graves’ disease and thyroiditis and compare it with thyroid scintigraphy.

Methods

Sixty-nine patients with newly-diagnosed thyrotoxicosis and 30 controls were enrolled. Thyroid functions, thyroid scintigraphy, and CDU of STA and ITA with measurements of peak systolic velocity (PSV) and end diastolic velocity (EDV), were performed. According to thyroid scintigraphy results, patients were divided into two groups: 42 patients with Graves’ disease and 27 patients with thyroiditis.

Results

PSV and EDV of both STA and ITA were significantly higher in patients with Graves’ disease than thyroiditis (p-values <0.001). The STA-PSV had an equal sensitivity and specificity of 66.7%; cut-off value 76.57 cm/s, while those of STA-EDV were 73.8%, and 77.8% respectively; cut-off value 28.22 cm/s. ITA-PSV had a sensitivity and specificity of 76.2% and 77.8%, respectively; cut-off value 62.12 cm/s), while those of ITA-EDV were 78.6% and 77.8%, respectively; cut-off value 5.22 cm/s.

Conclusion

CDU parameters of the STA and ITA could be used as an alternative to thyroid scintigraphy for discriminating between Graves’ disease and thyroiditis.

Usefulness of Real-Time Quantitative Microvascular Ultrasonography for Differentiation of Graves' Disease from Destructive Thyroiditis in Thyrotoxic Patients

BACKGROUND

Microvascular ultrasonography (MVUS) is a third-generation Doppler technique that was developed to increase sensitivity compared to conventional Doppler. The purpose of this study was to compare MVUS with conventional color Doppler (CD) and power Doppler (PD) imaging to distinguish Graves' disease (GD) from destructive thyroiditis (DT).

METHODS

This prospective study included 101 subjects (46 GDs, 47 DTs, and eight normal controls) from October 2020 to November 2021. All ultrasonography examinations were performed using microvascular flow technology (MV-Flow). The CD, PD, and MVUS images were semi-quantitatively graded according to blood flow patterns. On the MVUS images, vascularity indices (VIs), which were the ratio (%) of color pixels in the total grayscale pixels in a defined region of interest, were obtained automatically. Receiver operating characteristic curve analysis was performed to verify the diagnostic performance of MVUS. The interclass correlation coefficient and Cohen's kappa analysis were used to analyze the reliability of MVUS (ClinicalTrials.gov:NCT04879173).

RESULTS

The area under the curve (AUC) for CD, PD, MVUS, and MVUS-VI was 0.822, 0.844, 0.808, and 0.852 respectively. The optimal cutoff value of the MVUS-VI was 24.95% for distinguishing GD and DT with 87% sensitivity and 80.9% specificity. We found a significant positive correlation of MVUS-VI with thyrotropin receptor antibody (r=0.554) and with thyroid stimulating immunoglobulin bioassay (r=0.841). MVUS showed high intra- and inter-observer reliability from various statistical method.

CONCLUSION

In a real time and quantitative manner, MVUS-VI could be helpful to differentiate GD from thyroiditis in thyrotoxic patients, with less inter-observer variability.

Painful Subacute Thyroiditis is Commonly Misdiagnosed as Suspicious Thyroid Nodular Disease

Objective

To investigate and characterize the clinical and radiologic features of 10 patients with painful subacute thyroiditis with ultrasound findings considered suspicious for malignancy or for whom biopsy of a suspicious area was recommended by an attending radiologist.

Patients and Methods

Ten patients with painful subacute thyroiditis were seen from June 1, 2016, through January 1, 2019. All 10 patients presented to an endocrine or thyroid clinic with a neck ultrasound report stating findings suspicious for malignancy or nodular disease. Clinical, laboratory, radiographic, and pathologic data were (retrospectively collected and) reviewed.

Results

The mean ± SD patient age was 49.0±15.0 years at diagnosis; 8 patients were female. All the patients presented with a low or undetectable serum thyrotropin level. Six of 7 patients with available inflammatory markers had elevated levels. Thyrotropin receptor antibodies were absent in all 6 patients tested. On follow-up imaging, 8 patients had complete resolution or improvement of described findings, 1 was lost to follow-up, and 1 had an incidental nodule that was biopsied after the episode of thyroiditis and found to be papillary thyroid carcinoma.

Conclusion

Painful subacute thyroiditis demonstrates specific sonographic patterns that may be misdiagnosed as suspicious thyroid nodular disease. Recognition of the innocent and transient nature of these findings is important for the proper management and monitoring of these patients.

Imaging "Thyroiditis": A Primer for Radiologists

A variety of inflammatory disorders, generically classified as "thyroiditis," can affect the thyroid gland diffusely, generating distinctive radiographic patterns. While a precise diagnosis can seldom be made based on sonographic appearance alone, interpreting these patterns in the correct clinical and biochemical context will help support the most appropriate diagnosis. We believe that the generic term "thyroiditis" is often not helpful and often may be incorrect. Therefore, it is important for radiologists to understand the sonographic and functional correlations to provide the most appropriate differential diagnosis in their reports. This brief review is designed to provide information and guidance for radiologists when dealing with various thyroid disorders which cause diffuse changes in the thyroid and underline the pitfalls most often encountered in clinical practice.

Clinical applications of Doppler ultrasonography for thyroid disease: consensus statement by the Korean Society of Thyroid Radiology

Doppler ultrasonography (US) is widely used for the differential diagnosis of thyroid nodules, metastatic cervical lymph nodes in patients with thyroid cancer, and diffuse parenchymal disease, as well as for guidance in various US-guided procedures, including biopsy and ablation. However, controversies remain regarding the appropriate use and interpretation of Doppler US. Therefore, the Korean Society of Thyroid Radiology organized a taskforce to develop a consensus statement on the clinical use of Doppler US for thyroid disease. The review and recommendations in this article are based on a comprehensive analysis of the current literature and the consensus of experts.

Thyroid dysfunction following pregnancy and implications for breastfeeding

Subclinical autoimmune thyroiditis exacerbates after delivery through immune rebound mechanisms and results in 5 types of thyroid dysfunction. The prevalence of postpartum thyroid dysfunction is around 5% in mothers in the general population. Typically, an exacerbation induces destructive thyrotoxicosis followed by transient hypothyroidism, known as postpartum thyroiditis. Late development of permanent hypothyroidism is found frequently and patients should be followed up once every one to two years. Destructive thyrotoxicosis in postpartum thyroiditis should carefully be differentiated from post-partum Graves' disease. Postpartum thyroiditis typically occurs 1-4 months after parturition whereas Graves' disease develops at 4-12 months postpartum. Anti-TSH receptor antibodies (TRAb) are typically positive and thyroid blood flow is high in Graves' disease, whereas these features are absent in postpartum thyroiditis. Postpartum Graves' disease should be treated with antithyroid drugs.

Quantitative Color Doppler Ultrasonography Measurement of Thyroid Blood Flow in Patients with Graves' Disease

BACKGROUND

Graves' Disease is an autoimmune disorder characterized by increased levels of thyroid hormones correlated with increased thyroid blood flow. Thyroid scintigraphy is an important and conventional method. However, it has limited accessibility, has ionizing radiation, and is expensive.

OBJECTIVES

To investigate the thyroid blood flow in patients with Graves' Disease by color Doppler Ultrasonography and a newly developed software Color Quantification.

METHODS

Forty-one consecutive subjects with GD and 41 healthy controls were enrolled. Color Doppler ultrasonography parameters of the thyroid arteries and Color Quantification values of the gland were measured by a radiologist. The correlations between thyroid blood flow parameters, levels of 99mTechnetium pertechnetate uptake, thyrotropin, and free thyroxine were evaluated. The diagnostic performances of these parameters were investigated.

RESULTS

The peak systolic-end diastolic velocities of thyroid arteries and Color Quantification values were increased in the study group (p < 0.05 for all). We observed negative correlations between thyrotropin levels and peak-systolic and end-diastolic velocities of superior thyroid arteries and Color Quantification values. There were positive correlations between 99mTechnetium uptake levels and thyroid blood flow parameters (p < 0.05 for all). In the diagnostic performance of thyroid blood flow parameters, we observed utilities significantly in peak-systolic and end-diastolic velocities of thyroid arteries and Color Quantification values (p < 0.05 for all).

CONCLUSION

The increased peak-systolic and end-diastolic velocities of thyroid arteries, and increased Color Quantification values might be helpful in the diagnosis of Graves' Disease.

Diagnostic testing for Graves' or non-Graves' hyperthyroidism: A comparison of two thyrotropin receptor antibody immunoassays with thyroid scintigraphy and ultrasonography

OBJECTIVE

Graves' disease (GD) is the most common cause of hyperthyroidism. In many cases, when the aetiological diagnosis of GD is not evident based on the clinical evaluation and thyroid function testing, it may become challenging to distinguish Graves' hyperthyroidism from other forms of thyrotoxicosis. The current study was primarly carried out to compare the diagnostic effectiveness of two TSH receptor antibody immunoassays (IMAs), ultrasonography and thyroid scintigraphy in hyperthyroidism scenario.

METHODS

We retrospectively analysed consecutive patients with newly diagnosed and untreated thyrotoxicosis who underwent thyroid functional tests, both TRAb and TSI measurements, thyroid scintigraphy and ultrasonography. TRAb assessment was carried out by Kryptor^® compact PLUS, while TSI by Immulite^® . Echo pattern 3 corresponded to 'thyroid inferno', and the final diagnosis of GD vs non-Graves' hyperthyroidism was made according to the thyroid scan (qualitative scintigraphy). Receiver operating characteristic (ROC) curves were drawn using the final diagnosis as reference. Clinical sensitivity and specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated for all the tests.

RESULTS

A total of 124 untreated hyperthyroid patients were included in our study (GD, n = 86 vs non-Graves' hyperthyroidism, n = 38). ROC curves showed that the optimal cut-off values associated with the highest diagnostic sensitivity and specificity was 0.7 IU/L for TRAb Kryptor^® (93 [85.4-97.4] and 86.8 [71.9-95.5]) and 0.1 IU/L for TSI Immulite^® (94.2 [86.9-98.1] and 84.2 [68.7-93.9]), respectively. For the echo pattern 3, we found a good sensitivity (92.1%) and a high PPV (95.2%) but a quite low specificity value (69.8%) and a relative low NPV (57.5%). For thyroid scintigraphy, the TcTU cut-off value of 1.3% corresponded to the best limit for sensitivity and specificity in our patients (95.3 [88.5-98.7] and 96.4 [81.6-99.4]). The Passing-Bablok regression equation and the Bland-Altman test showed a great degree of correlation and agreement existed between TRAb Kryptor^® and Immulite^® TSI results.

CONCLUSIONS

Thyroid scintigraphy remains the most accurate method to differentiate causes of thyrotoxicosis. However, TRAb assays can be alternatively adopted in this setting, limiting the use of thyroid scintigraphy (TcTU evaluation) to TRAb-negative patients. Thyoid US is less accurate than both TRAb/TSI and thyroid scintigraphy, but the 'thyroid inferno' pattern provides a high PPV for GD.

Hyperthyroidism

Hyperthyroidism is a condition where the thyroid gland produces and secretes inappropriately high amounts of thyroid hormone which can lead to thyrotoxicosis. The prevalence of hyperthyroidism in the United States is approximately 1.2%. There are many different causes of hyperthyroidism, and the most common causes include Graves' disease (GD), toxic multinodular goiter and toxic adenoma. The diagnosis can be made based on clinical findings and confirmed with biochemical tests and imaging techniques including ultrasound and radioactive iodine uptake scans. This condition impacts many different systems of the body including the integument, musculoskeletal, immune, ophthalmic, reproductive, gastrointestinal and cardiovascular systems. It is important to recognize common cardiovascular manifestations such as hypertension and tachycardia and to treat these patients with beta blockers. Early treatment of cardiovascular manifestations along with treatment of the hyperthyroidism can prevent significant cardiovascular events. Management options for hyperthyroidism include anti-thyroid medications, radioactive iodine, and surgery. Anti-thyroid medications are often used temporarily to treat thyrotoxicosis in preparation for more definitive treatment with radioactive iodine or surgery, but in select cases, patients can remain on antithyroid medications long-term. Radioactive iodine is a successful treatment for hyperthyroidism but should not be used in GD with ophthalmic manifestations. Recent studies have shown an increased concern for the development of secondary cancers as a result of radioactive iodine treatment. In the small percentage of patients who are not successfully treated with radioactive iodine, they can undergo re-treatment or surgery. Surgery includes a total thyroidectomy for GD and toxic multinodular goiters and a thyroid lobectomy for toxic adenomas. Surgery should be considered for those who have a concurrent cancer, in pregnancy, for compressive symptoms and in GD with ophthalmic manifestations. Surgery is cost effective with a high-volume surgeon. Preoperatively, patients should be on anti-thyroid medications to establish a euthyroid state and on beta blockers for any cardiovascular manifestations. Thyroid storm is a rare but life-threatening condition that can occur with thyrotoxicosis that must be treated with a multidisciplinary approach and ultimately, definitive treatment of the hyperthyroidism.

Painless destructive thyroiditis in a patient with resistance to thyroid hormone: a case report

Background

Resistance to thyroid hormone (RTH) usually features a syndrome of inappropriate secretion of thyroid-stimulating hormone (SITSH) without suppression of the typical high thyroid hormone levels. However, some patients with RTH show thyroid-stimulating hormone (TSH) suppression due to thyrotoxicosis. We report a case of painless thyroiditis in a patient with RTH that was misdiagnosed as Graves’ disease because of TSH-suppressed thyrotoxicosis.

Case presentation

A sixteen-year-old boy consulted a local general physician for fatigue. He had a goiter, and biochemical analysis showed TSH < 0.1 μIU/mL, free triiodothyronine (FT3) of 2.70 pg/mL, and free thyroxine (FT4) of 3.6 ng/dL. He was diagnosed with Graves’ disease and was treated with 20 mg thiamazole. One year later, he was referred to the department of endocrinology because of SITSH. He was finally diagnosed with RTH due to the finding of a heterozygous missense mutation (methionine 334 threonine) in the thyroid hormone receptor β gene. Three years after cessation of thiamazole, his hyperthyroxinemia showed marked exacerbation with TSH suppression. We diagnosed him with painless destructive thyroiditis because of low technetium-99 m (Tc-99 m) uptake in the thyroid. Extreme hyperthyroxinemia was ameliorated, with a return to the usual SITSH levels, within 1 month without any treatment.

Conclusion

The present case demonstrates that diagnosing RTH is difficult when patients show hyperthyroxinemia with complete suppression of TSH to undetectable levels, and the data lead to misdiagnosis of RTH as Graves’ disease. The initial diagnosis is important, and Tc-99 m scintigraphy is useful for the differential diagnosis of thyrotoxicosis accompanying RTH.

Comparison between peak systolic velocity of the inferior thyroid artery and technetium-99m pertechnetate thyroid uptake in differentiating Graves' disease from thyroiditis

OBJECTIVES

The differentiation between the various etiologies of thyrotoxicosis, including those with hyperthyroidism (especially Graves' disease [GD], the most common cause of hyperthyroidism) and without hyperthyroidism (like thyroiditis), is an important step in planning specific therapy. Technetium-99m (99mTc) pertechnetate thyroid scanning is the gold standard in differentiating GD from thyroiditis. However, this technique has limited availability, is contraindicated in pregnancy and lactation, and is not helpful in cases with history of recent exposure to excess iodine. The aim of this study was to identify the diagnostic value of the peak systolic velocity of the inferior thyroid artery (PSV-ITA) assessed by color-flow Doppler ultrasound (CFDU) and compare the sensitivity and specificity of this method versus 99mTc pertechnetate thyroid uptake.

SUBJECTS AND METHODS

We prospectively analyzed 65 patients (46 with GD and 19 with thyroiditis). All patients were evaluated with clinical history and physical examination and underwent 99mTc pertechnetate scanning and measurement of TRAb levels and PSV-ITA values by CFDU. The diagnosis was based on findings from signs and symptoms, physical examination, and 99mTc pertechnetate uptake.

RESULTS

Patients with GD had significantly higher mean PSV-ITA values than those with thyroiditis. At a mean PSV-ITA cutoff value of 30 cm/sec, PSV-ITA discriminated GD from thyroiditis with a sensitivity of 91% and specificity of 89%.

CONCLUSION

Measurement of PSV-ITA by CFDU is a good diagnostic approach to discriminate between GD and thyroiditis, with sensitivity and specificity values comparable to those of 99mTc pertechnetate thyroid uptake.

Mean peak systolic velocity of superior thyroid artery for the differential diagnosis of thyrotoxicosis: a diagnostic meta-analysis

BACKGROUND

Thyrotoxicosis is often caused by destructive thyroiditis (DT) or Graves' disease (GD), and a prompt and accurate differential diagnosis for thyrotoxicosis is needed as management strategy differs. A meta-analysis of published literature was performed to evaluate the diagnostic accuracy for differentiating GD from DT patients by the measurement of mean peak systolic velocity of superior thyroid artery (STA-PSV) using ultrasonography.

METHODS

The databases of Embase, Pubmed, Cochrane, Web of Science, Wanfang, and CNKI were retrieved without time limit to identify eligible studies. The statistical information and scientific quality were assessed and classified. The data were analyzed using Stata12.0 software.

RESULTS

A total of 11 studies with 1052 cases only from Asia were included. Meta-analysis results showed the pooled sensitivity and pooled specificity of STA-PSV by ultrasonography were 0.86 (95% CI, 0.80-0.90) and 0.93 (95% CI, 0.86-0.97) in distinguishing GD from DT, respectively, with the AUC of 0.94 (95% CI, 0.92-0.96) .

CONCLUSION

STA-PSV by ultrasonography is a useful diagnostic method in differentiating GD from DT. More studies from other countries are needed to further evaluate the accuracy of STA-PSV for the differential diagnosis of thyrotoxicosis.

Comparative frequency of four different types of pregnancy-associated thyrotoxicosis in a single thyroid centre

Background

Pregnancy and delivery markedly influence thyroid function. However, the comparative prevalence of gestational thyrotoxicosis (GT), new onset of Graves’ disease during pregnancy (GD during pregnancy), postpartum destructive thyrotoxicosis (PPT), and postpartum Graves’ thyrotoxicosis (PPGD) has not yet been determined.

Methods

We prospectively registered and performed a review of 4127 consecutive non treated female patients with thyrotoxicosis, seen between August 2008 and December 2013 in our outpatient clinic of Kuma Hospital. 187 out of the 4127 women had new diagnosis of thyrotoxicosis during pregnancy or in the postpartum period. We investigated the prevalence of new diagnosis of GT, GD during pregnancy, PPT and PPGD and compared the characteristics of these types of thyrotoxicosis. The postpartum period is defined as twelve months after delivery.

Results

Out of 187 pregnant or postpartum women, we identified 30 (16.0%) with GT, 13 (7.0%) with GD during pregnancy, 42 (22.5%) with PPT, and 102 (54.5%) with PPGD. The onset time of thyrotoxicosis during pregnancy, i.e., both GT and GD during pregnancy, was delayed by a couple of weeks when hCG peaked at 10 gestational weeks. Seventy-six percent of patients with PPT developed thyrotoxicosis between delivery and 4 months postpartum; on the other hand, 83.3% of patients with PPGD developed thyrotoxicosis at 6 months postpartum or later.

Conclusions

We named gestational thyrotoxicosis, new onset of Graves’ disease during pregnancy, postpartum destructive thyrotoxicosis, and postpartum Graves’ thyrotoxicosis as pregnancy-associated thyrotoxicosis. A clinically significant number of women developed Graves’ disease in the postpartum period in a single thyroid centre.

2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This document describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspecialty physicians and others providing care for patients with this condition.

METHODS

The American Thyroid Association (ATA) previously cosponsored guidelines for the management of thyrotoxicosis that were published in 2011. Considerable new literature has been published since then, and the ATA felt updated evidence-based guidelines were needed. The association assembled a task force of expert clinicians who authored this report. They examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to update the 2011 text and recommendations. The strength of the recommendations and the quality of evidence supporting them were rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' orbitopathy; and management of other miscellaneous causes of thyrotoxicosis. New paradigms since publication of the 2011 guidelines are presented for the evaluation of the etiology of thyrotoxicosis, the management of Graves' hyperthyroidism with antithyroid drugs, the management of pregnant hyperthyroid patients, and the preparation of patients for thyroid surgery. The sections on less common causes of thyrotoxicosis have been expanded.

CONCLUSIONS

One hundred twenty-four evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Hyperthyroidism

Hyperthyroidism is characterised by increased thyroid hormone synthesis and secretion from the thyroid gland, whereas thyrotoxicosis refers to the clinical syndrome of excess circulating thyroid hormones, irrespective of the source. The most common cause of hyperthyroidism is Graves' disease, followed by toxic nodular goitre. Other important causes of thyrotoxicosis include thyroiditis, iodine-induced and drug-induced thyroid dysfunction, and factitious ingestion of excess thyroid hormones. Treatment options for Graves' disease include antithyroid drugs, radioactive iodine therapy, and surgery, whereas antithyroid drugs are not generally used long term in toxic nodular goitre, because of the high relapse rate of thyrotoxicosis after discontinuation. β blockers are used in symptomatic thyrotoxicosis, and might be the only treatment needed for thyrotoxicosis not caused by excessive production and release of the thyroid hormones. Thyroid storm and hyperthyroidism in pregnancy and during the post-partum period are special circumstances that need careful assessment and treatment.

An Advantageous Role of Spectral Doppler Sonography in the Evaluation of Thyroid Dysfunction During the Postpartum Period

OBJECTIVES

To evaluate the diagnostic value of spectral Doppler sonography in women with thyroid dysfunction during the first postpartum year.

METHODS

This prospective observational clinical study included 83 consecutive untreated women: 32 with hyperthyroid postpartum thyroiditis, 32 with hypothyroid postpartum thyroiditis, and 19 with Graves disease, which first appeared within 12 months after delivery. Thyrotropin, free thyroid hormones, thyroid peroxidase antibodies, thyroglobulin antibodies, and thyrotropin receptor antibodies were measured. With a 7.5-MHz linear transducer, we measured the thyroid volume and peak systolic velocity (PSV) at the level of intrathyroid arteries.

RESULTS

Hyperthyroid postpartum thyroiditis appeared significantly earlier (mean ± SD, 4.4 ± 1.9 months after delivery) than hypothyroid postpartum thyroiditis (6.5 ± 2.1 months) and Graves disease (7.2 ± 2.7 months; P< .001). The thyroid volume in hyperthyroid postpartum thyroiditis (9.7 ± 6.3 mL) was significantly lower than in hypothyroid postpartum thyroiditis (14.7 ± 10.2 mL; P = .030) and Graves disease (19.4 ± 10.2 mL; P< .001). The PSV in hyperthyroid postpartum thyroiditis (9.4 ± 3.4 cm/s) was significantly lower than in hypothyroid postpartum thyroiditis (14.4 ± 3.9 cm/s; P < .001) and Graves disease (19.8 ± 7.0 cm/s; P < .001). With a cutoff level of 15 cm/s, the sensitivity and specificity of the PSV as a predictor of the correct diagnosis in hyperthyroid postpartum women were 94.7% and 96.8%, respectively. A multinomial logistic regression revealed PSV and the time after delivery at which the disorders presented as independent predictors of the differentiation between hyperthyroid postpartum thyroiditis and Graves disease (P = .003; P = .022).

CONCLUSIONS

Spectral Doppler sonography was shown to be a useful and accurate method for thyroid dysfunction evaluation during the postpartum period.

Sonographic appearance of thyroid glands in patients treated with intensity-modulated radiotherapy or conventional radiotherapy for nasopharyngeal carcinoma

BACKGROUND

This study aimed to investigate the sonographic appearances of the thyroid glands in nasopharyngeal carcinoma (NPC) patients whose cervical lymph nodes were treated with conventional radiotherapy (RT) or intensity-modulated radiotherapy (IMRT). The post-RT sonographic appearances of the thyroid glands in NPC patients were also correlated with the thyroid function.

METHODS

One hundred and three NPC patients who had completed RT of cervical lymph nodes using the anterior cervical field, 30 NPC patients who had completed RT of cervical lymph nodes using IMRT, and 61 healthy subjects were included in the study. Thyroid glands were sonographically assessed for their size, echogenicity, vascularity, and internal architecture. Thyroid function tests were also performed on each subject.

RESULTS

In comparison with the patients with abnormal thyroid function, the thyroid glands of the patients with normal thyroid function tended to be homogeneous and to have greater volume and echogenicity index (p < 0.05). Compared with those of the healthy subjects, the thyroid glands of patients previously treated with IMRT and those treated with the anterior cervical field showed significantly lower thyroid volume, lower incidence and number of nodules, and higher vascularity index (p < 0.05).

CONCLUSIONS

The patient's history of previous RT should be taken into consideration in the sonographic examination of the thyroid gland post-RT. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 43:210-223, 2015.

Differentiation between Graves' disease and painless thyroiditis by diffusion-weighted imaging, thyroid iodine uptake, thyroid scintigraphy and serum parameters

The aim of the present study was to assess the apparent diffusion coefficient (ADC) in diffusion-weighted imaging (DWI), thyroid radioactive iodine uptake (RAIU), thyroid scintigraphy and thyrotropin receptor antibody (TRAb) levels in the differential diagnosis between Graves' disease (GD) and painless thyroiditis (PT). A total of 102 patients with GD and 37 patients with PT were enrolled in the study. DWI was obtained with a 3.0-T magnetic resonance scanner, and ADC values were calculated. RAIU and thyroid scintigraphy were performed. Tissue samples were obtained from patients with GD (6 cases) following thyroidectomy, and from patients with PT (2 cases) following biopsy. Receiver operating characteristic (ROC) curves were drawn, optimal cut-off values were selected, and the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were assessed. It was found that the ADC, TRAb and RAIU were significantly higher in GD than in PT (P<0.05). ROC curves showed areas under the curves for RAIU, ADC and TRAb that were >0.900. RAIU was the reference method. Sensitivity, specificity, accuracy, PPV and NPV were 96.078, 91.892, 95.000, 97.059 and 89.474% for ADC, and 88.235, 75.676, 84.892, 90.909 and 70.000% for TRAb, after the optimal thresholds of 1.837×10^-3 mm²/sec and 1.350 IU/ml were determined respectively. Histopathology showed that tissue cellularity in PT was much higher than in GD due to massive lymphocytic infiltration. The results of the present study indicate that RAIU, ADC and TRAb are of diagnostic value for differentiating between GD and PT. DWI has great potential for thyroid pathophysiological imaging because it reflects differences in tissue cellularity between GD and PT.

Thyrotoxicosis of Pregnancy

Thyrotoxicosis presenting during pregnancy is a common clinical problem and can be challenging to differentiate between physiologic patterns of thyroid dysfunction during gestation and intrinsic hyperthyroidism. This review provides a summary of the differential diagnosis, clinical presentation, diagnostic options, potential adverse effects of maternal thyrotoxicosis to the fetus, and treatment recommendations for thyrotoxicosis arising in pregnancy.

Characteristics of patients with graves disease and intrathyroid hypovascularity compared to painless thyroiditis

OBJECTIVES

The purpose of this study was to assess the frequency and sonographic and laboratory characteristics of Graves disease with intrathyroid hypovascularity in Japanese patients and to compare these characteristics in patients with painless thyroiditis.

METHODS

A total of 194 consecutive patients with Graves disease and 21 patients with painless thyroiditis were enrolled. The patients underwent thyroid volume measurement, mean superior thyroid artery peak systolic velocity (PSV) measurement, power Doppler sonography, and proper blood testing to discriminate between Graves disease and painless thyroiditis. Based on the power Doppler sonographic findings, they were divided into 4 groups: from pattern 0 (most hypovascular thyroid) to pattern III (most hypervascular thyroid). Comparisons of multiple thyroid parameters were made among the groups.

RESULTS

The prevalence of Graves disease with pattern 0 (n = 27) was 13.9% among the patients with Graves disease. The sonographic and laboratory data for patients with Graves disease and pattern 0 were compared to those of the 21 patients with painless thyroiditis, which typically shows intrathyroid hypovascularity. Free triiodothyronine and thyroxine levels and the superior thyroid artery PSV were significantly lower in patients with Graves disease and pattern 0 than those with patterns I, II, and III (P < .05). The thyroid volume and thyrotropin receptor antibody level were significantly lower in patients with Graves disease and pattern 0 than those with pattern III. In the comparison between patients with Graves disease and pattern 0 and those with painless thyroiditis and pattern 0, apart from thyrotropin receptor antibody, only the superior thyroid artery PSV was different.

CONCLUSIONS

Although the clinical features of patients with Graves disease and intrathyroid hypovascularity were similar to those patients with painless thyroiditis, the superior thyroid artery PSV showed a moderate ability to discriminate these patients.

The Brazilian consensus for the diagnosis and treatment of hyperthyroidism: recommendations by the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism

INTRODUCTION

Hyperthyroidism is characterized by increased synthesis and release of thyroid hormones by the thyroid gland. Thyrotoxicosis refers to the clinical syndrome resulting from excessive circulating thyroid hormones, secondary to hyperthyroidism or due to other causes. This article describes evidence-based guidelines for the clinical management of thyrotoxicosis.

OBJECTIVE

This consensus, developed by Brazilian experts and sponsored by the Department of Thyroid Brazilian Society of Endocrinology and Metabolism, aims to address the management, diagnosis and treatment of patients with thyrotoxicosis, according to the most recent evidence from the literature and appropriate for the clinical reality of Brazil.

MATERIALS AND METHODS

After structuring clinical questions, search for evidence was made available in the literature, initially in the database MedLine, PubMed and Embase databases and subsequently in SciELO - Lilacs. The strength of evidence was evaluated by Oxford classification system was established from the study design used, considering the best available evidence for each question.

RESULTS

We have defined 13 questions about the initial clinical approach for the diagnosis and treatment that resulted in 53 recommendations, including the etiology, treatment with antithyroid drugs, radioactive iodine and surgery. We also addressed hyperthyroidism in children, teenagers or pregnant patients, and management of hyperthyroidism in patients with Graves' ophthalmopathy and various other causes of thyrotoxicosis.

CONCLUSIONS

The clinical diagnosis of hyperthyroidism usually offers no difficulty and should be made with measurements of serum TSH and thyroid hormones. The treatment can be performed with antithyroid drugs, surgery or administration of radioactive iodine according to the etiology of thyrotoxicosis, local availability of methods and preferences of the attending physician and patient.

Differentiation of postpartum Graves' thyrotoxicosis from postpartum destructive thyrotoxicosis using antithyrotropin receptor antibodies and thyroid blood flow

BACKGROUND

Postpartum thyroid dysfunction occurs in approximately 5-10% of women in the general population within one year of delivery. Differentiation of postpartum Graves' thyrotoxicosis (PPGr) from postpartum destructive thyrotoxicosis (PPDT) is essential because of the difference in treatment measures between the two. However, it is sometimes difficult because radioactive iodine uptake is contraindicated when patients are lactating. We examined the usefulness of determining the time of onset postpartum and measurement of antithyrotropin (anti-TSH) receptor antibodies and thyroid blood flow.

METHODS

Forty-two patients with newly developed thyrotoxicosis after delivery were examined: 18 had Graves' disease and 24 had destructive thyrotoxicosis. Serum free thyroxine (fT4), free triiodothyronine (fT3), and TSH were measured by chemiluminescent immunoassays. Anti-TSH receptor antibodies (TRAb), antithyroglobulin antibodies (TgAb), and antithyroid peroxidase antibodies (TPOAb) were measured by the Elecsys electrochemiluminescence immunoassay. Thyroid volume and blood flow (TBF) were measured quantitatively by color flow Doppler ultrasonography.

RESULTS

Onset of thyrotoxicosis was distributed from 2 to 12 months postpartum. Twelve (85.7%) of 14 patients who developed thyrotoxicosis at three months or earlier after delivery had PPDT. On the other hand, all 11 patients who developed thyrotoxicosis at 6.5 months or later had PPGr. All patients with PPGr had positive TRAb (14.9±14.9 IU/L, mean±standard deviation (SD)) and all patients with PPDT had negative TRAb (0.1±0.3 IU/L, p<0.0001). Fifteen (83.3%) of 18 PPGr patients had high TBF of more than 4.0% (8.9±4.4), and all PPDT patients had low TBF of <4.0% (1.6±1.0, p<0.0001). The fT3/fT4 ratio was higher in PPGr (64.0±23.9) than in PPDT (38.9±13.1, p<0.0002), but absolute values overlapped between the two.

CONCLUSION

Early onset of thyrotoxicosis postpartum was associated mainly with PPDT, and a late onset was suggestive of PPGr. Positive TRAb and high TBF >4.0% are indicators of postpartum onset of Graves' disease.

Diagnosis and management of Graves disease: a global overview

Graves disease is an autoimmune disorder characterized by goitre, hyperthyroidism and, in 25% of patients, Graves ophthalmopathy. The hyperthyroidism is caused by thyroid hypertrophy and stimulation of function, resulting from interaction of anti-TSH-receptor antibodies (TRAb) with the TSH receptor on thyroid follicular cells. Measurements of serum levels of TRAb and thyroid ultrasonography represent the most important diagnostic tests for Graves disease. Management of the condition currently relies on antithyroid drugs, which mainly inhibit thyroid hormone synthesis, or ablative treatments ((131)I-radiotherapy or thyroidectomy) that remove or decrease thyroid tissue. None of these treatments targets the disease process, and patients with treated Graves disease consequently experience either a high rate of recurrence, if receiving antithyroid drugs, or lifelong hypothyroidism, after ablative therapy. Geographical differences in the use of these therapies exist, partially owing to the availability of skilled thyroid surgeons and suitable nuclear medicine units. Novel agents that might act on the disease process are currently under evaluation in preclinical or clinical studies, but evidence of their efficacy and safety is lacking.

Association between plantar fascia vascularity and morphology and foot dysfunction in individuals with chronic plantar fasciitis

STUDY DESIGN

Single-cohort laboratory-based study.

OBJECTIVES

To identify whether plantar fascia vascularity and thickness are associated with foot pain and dysfunction in individuals with chronic plantar fasciitis. Background Altered plantar fascia vascularity and thickening of the fascia have been identified in individuals with chronic plantar fasciitis.

METHODS

Thirty-eight patients with chronic unilateral plantar fasciitis and 21 controls participated in this study. Proximal plantar fascia vascularization and thickness were assessed using ultrasound imaging, and pain and foot dysfunction were quantified with a visual analog scale and the Chinese version of the Foot Function Index, respectively. Paired t tests were used to assess the side-to-side differences in fascia thickness and vascularity index (VI) in the control and patient groups, and an unpaired t test was used to make comparisons with the patient group. Multiple regression analysis was performed to identify whether the VI and fascia thickness were associated with pain and foot dysfunction.

RESULTS

There were significantly higher VI (mean ± SD, 2.4% ± 1.4%) and fascia thickness (5.0 ± 1.3 mm) values in the affected feet when compared with the unaffected feet in the patient group (VI, 1.4% ± 0.5%; fascia thickness, 3.3 ± 0.7 mm) and with the dominant side of the controls (VI, 1.6% ± 0.4%; fascia thickness, 2.9 ± 0.6 mm). After accounting for age, gender, body mass index, and duration of symptoms, the VI explained 13% and 33% of the variance in pain scores measured with a visual analog scale and the pain subscale of the Foot Function Index, respectively; the VI and fascia thickness explained 42% of the variance in the Foot Function Index.

CONCLUSIONS

Individuals with unilateral chronic plantar fasciitis demonstrated significantly greater vascularity and thickened fascia on the affected side compared to the unaffected side and also to healthy controls. Fascia vascularity was associated independently with self-perceived pain, and both fascia vascularity and thickness were associated with foot dysfunction in patients with chronic plantar fasciitis. Public trials registry: Current Controlled Trials, ISRCTN49594569.

Thyroid Doppler indices in patients with sickle cell disease

OBJECTIVE

To evaluate the intrathyroidal hemodynamic changes and thyroidal volume in sickle cell disease (SCD) patients.

METHODS

Thirty-two patients with homozygous SCD and 32 control subjects were examined with color Doppler ultrasonography. None of the patients and control subjects had clinical or laboratory evidence of thyroid disease.

RESULTS

SCD patients had significantly higher resistance index (RI) and pulsatility index (PI) values and lower thyroid volume compared with control group.

CONCLUSION

Increased intrathyroidal RI and PI and decreased thyroid volume may be due to impaired thyroidal microcirculation. Further and follow-up studies are needed to explain the relationship between Doppler parameters and thyroid functions.

Use of color Doppler ultrasonography to measure thyroid blood flow and differentiate graves' disease from painless thyroiditis

BACKGROUNDS

Color Doppler ultrasonography (CDU) has not yet been established as a method to investigate the pathogenesis of thyrotoxicosis.

OBJECTIVES

Our first objective was to determine whether the measurement of peak systolic blood-flow velocity in the superior thyroid artery (STV) and thyroid tissue blood flow (TBF) using CDU could differentiate Graves' disease (GD) from painless thyroiditis (PT). The second objective was to examine the factors mediating increased blood flow to the thyroid gland in GD.

METHODS

Recruited patients had untreated GD or PT and visited the Department of Internal Medicine (I), Osaka Medical College, between April 1, 2006 and May 31, 2010. Age, gender, blood pressure, pulse rate, thyroid-stimulating hormone, free thyroxine, tri-iodothyronine, TSH receptor antibody and thyroid volume were evaluated in patients. In addition, bilateral measurements of STV, TBF and peak systolic velocity in the common carotid artery (CCV) were also performed. TBF was quantified by calculating the ratio of blood-flow pixels to total pixels in the region of interest using sagittal section images of the thyroid gland. Receiver-operating characteristic curve analysis was performed to determine the ability of STV and TBF measurements to differentiate GD from PT.

RESULTS

For the average of STV measured on both sides, the area under the receiver-operating characteristic curve (AUC) was 0.956. For the average of TBF measured on both sides, the AUC was 0.920. At an average STV cut-off value of 43 cm/s, the sensitivity to discriminate GD from PT was 0.87 and the specificity was 1.00. At an average TBF cut-off value of 3.8%, the sensitivity was 0.71 and the specificity was 1.00. In the GD group, neither blood pressure nor pulse rate correlated with the average STV or TBF. Moreover, there was no correlation between STV and CCV or between TBF and CCV on either side. However, STV was correlated with TBF (right side: R = 0.47; left side: R = 0.52).

CONCLUSIONS

The results demonstrate that STV and TBF are useful for differentiating GD from PT. Furthermore, the increased STV and TBF found in GD are not related to hyperthyroidism-induced increases in systolic blood pressure, pulse rate or CCV.

Clinical review: Clinical utility of TSH receptor antibodies

CONTEXT

TSH receptor antibodies (TRAb) cause Graves' disease (GD) hyperthyroidism. Widely available TRAb measurement methods have been significantly improved recently. However, the role of TRAb measurement in the differential diagnosis of hyperthyroidism, the prediction of remission of GD hyperthyroidism, the prediction of fetal/neonatal thyrotoxicosis, and the clinical assessment of Graves' ophthalmopathy (GO) are controversial.

EVIDENCE ACQUISITION

We reviewed and analyzed the literature reporting primary data on the clinical use of TRAb. We focused our analyses on clinical studies analyzing third-generation TRAb assays.

EVIDENCE SYNTHESIS

The performance of TRAb in the differential diagnosis of overt hyperthyroidism is excellent, with sensitivity and specificity in the upper 90%. TRAb can accurately predict short-term relapses of hyperthyroidism after a course of antithyroid drugs but are less effective in predicting long-term relapses or remissions. Pregnancies in women with GD with negative TRAb are highly unlikely to result in fetal hyperthyroidism, whereas high titers of TRAb in pregnancy require careful fetal monitoring. GD patients with GO frequently have high TRAb levels. However, there are insufficient data to use the test to predict the clinical course of GO and response to treatment.

CONCLUSIONS

Third-generation TRAb assays are suitable in the differential diagnosis of hyperthyroidism. In GD, TRAb should be tested before deciding whether methimazole can be stopped. TRAb should be used in pregnant women with GD to assess the risk of fetal thyrotoxicosis. The use of TRAb in GO requires further studies.

Subacute granulomatous (de Quervain) thyroiditis: grayscale and color Doppler sonographic characteristics

OBJECTIVES

To describe the sonographic characteristics of subacute granulomatous (De Quervain) thyroiditis.

METHODS

We retrospectively identified all patients at our institution during the last 11 years who had thyroid sonography with findings suggestive of subacute granulomatous thyroiditis. We then reviewed clinical data and laboratory results to establish the clinical diagnosis. A final diagnosis of subacute granulomatous thyroiditis was made on the basis of clinical symptoms, suppressed thyrotropin, an elevated erythrocyte sedimentation rate, and/or reduced or absent radionuclide uptake while hyperthyroid.

RESULTS

Our study population consisted of 35 patients. Twenty-seven patients (79.4%) met clinical criteria for subacute thyroiditis. Symptoms included neck pain in 26 of 27 patients with subacute thyroiditis. The erythrocyte sedimentation rate ranged from 22 to 101 mm/h. In 21 cases (77.8%), sonography revealed focal, poorly defined, nonovoid areas of decreased echogenicity. Findings were bilateral in 16 patients and unilateral in 5. In the remaining 6, the gland or an entire lobe was diffusely heterogeneous. Color Doppler interrogation was performed in 20 patients. Flow was decreased to the sonographically abnormal areas in 19 (95%) and slightly increased in 1 patient. In all 9 patients who underwent radionuclide scanning, focal defects or large areas of decreased or absent uptake were found during the time of suppressed thyrotropin. Enlarged lymph nodes were noted in 16 patients (59.3%).

CONCLUSIONS

The positive predictive value of sonography for diagnosing subacute granulomatous thyroiditis is 79.4%. The most common sonographic appearance is poorly defined regions of decreased echogenicity with decreased vascularity in the affected areas.

Peak systolic velocity of superior thyroid artery for the differential diagnosis of thyrotoxicosis

AIM

The differentiation of destruction-induced thyrotoxicosis and Graves' disease (GD) is of great importance for selection of proper therapy. Radioactive iodine uptake (RAIU) is the gold standard for differentiating these two conditions but its application has remained somewhat limited. Thyroid color Doppler flow sonography (CDFS) is a potential alternative of RAIU but more supporting evidence is warranted. In the present study, a standard operative procedure was developed to measure the mean peak systolic velocity of superior thyroid artery (STA-PSV) and evaluate its role in the differential diagnosis of thyrotoxicosis.

METHODS

A total of 135 patients with untreated thyrotoxicosis were enrolled into one retrospective study (GD, n = 103; thyroiditis, n = 32) and another prospective study recruited 169 patients (GD, n = 118; thyroiditis, n = 51). Thirty normal controls were also enrolled. Thyroid function, anti-TSH-receptor antibody (TRAb), RAIU, CFDS of thyroid and STA-PSV were performed for each patient. Receiver operator curve (ROC) was used to evaluate the diagnostic value of STA-PSV in a retrospective study so as to seek the optimal cutoff point. Then the cutoff point value was used to validate its diagnostic value in a prospective study and in another thyrotoxicosis population.

RESULTS

STA-PSV of GD was significantly higher than that of thyroiditis in both retrospective and prospective studies. The area under the ROC curve of mean STA-PSV was 0.8799 and 0.9447 in the retrospective and prospective studies respectively. If a mean STA-PSV cutoff point of 50.5 cm/s was set from the retrospective analysis for the prospective study, the sensitivity and specificity in distinguishing GD from thyroiditis were 81.04% and 96.08% respectively. Mean STA-PSV and TRAb had similar area under ROC. The coefficients of variation in STA-PSV measurement were lower than 10% for the euthyroid, thyroiditis and GD groups.

CONCLUSIONS

STA-PSV is a feasible supplement alternative of RAIU for differentiating the causes of thyrotoxicosis.

Significant role of serum CRP in differentiating inflammatory from non-inflammatory causes of thyrotoxicosis

BACKGROUND

C-reactive protein (CRP), which is a marker of inflammation, has not been widely studied in inflammatory thyroid disorders particularly in sub-acute thyroiditis (SAT).

AIM

This study was aimed to find the significance of CRP level rise in patients with SAT and compare that to the rise in erythrocyte sedimentation rate (ESR), a gold standard laboratory parameter in establishing the diagnosis of SAT.

MATERIALS AND METHODS

Serum CRP levels were measured at initial presentation in 28 subjects with SAT(12 male, 16 female, age (Mean +SD) 37.96 ±8.5 years),and 19 patients with Graves' disease (2 male, 17 female, age [Mean +SD] 36.8 ±16.5 years) as controls. Erythrocyte sedimentation rate (ESR) was measured in all 28 patients with SAT by Westergrens' method. Either Tc(99) nucleotide thyroid scan or high resolution ultrasonography (HR-USG) was performed to differentiate SAT from Graves' disease.Fine needle aspiration cytology (FNAC) of thyroid was performed selected patients.

RESULTS

Serum CRP level was high in 61% of SAT patients but in none of the Graves'patients. Mean (SEM) (90%CI) serum CRP level (mg/L) was also significantly higher (P <0.0004) in the SAT group [27.55 (5.76) (15.72-39.38)], than in the Graves' group [4.09 (0.12) (3.81-4.36)]. The sensitivity of serum CRP was 73.33%, specificity 53.85%, positive predictive value (PPV) 64.71%, and negative predictive value (NPV) 63.64% as compared to the sensitivity (53.57%), specificity (15.38%), PPV (57.69 %), and NPV (13.33%) of ESR.

CONCLUSION

There is significantly higher rise in serum CRP level in patients with SAT is compared to patients with Graves' disease. It correlates well with the rise in ESR. Such findings of this pilot study highlight the scope of using serum CRP as a diagnostic marker of SAT specially in situations when it may be confused with Graves' disease, another common cause of thyrotoxicosis. It is logical to carry out studies to find a particular cut-off for serum CRP which can serve as an objective parameter for grading the inflammation in patients with SAT.

Benign conditions of the thyroid gland

Infectious and autoimmune diseases account for the majority of benign conditions of the thyroid gland. They are usually diagnosed and followed by clinical examination and laboratory analyses, but when imaged, ultrasonography and computed tomography are the modalities of choice. In particular, fine needle aspiration under ultrasound guidance may be invaluable for diagnostic and therapeutic purposes.

Thyrotoxicosis

Hyperthyroidism describes the sustained increase in thyroid hormone biosynthesis and secretion by a thyroid gland with increased metabolism. Although the use of radioiodine scanning serves as a useful surrogate that may help characterize the cause of thyrotoxicosis, it only indirectly addresses the underlying physiologic mechanism driving the increase in serum thyroid hormones. In this article, thyrotoxic states are divided into increased or decreased thyroid metabolic function. In addition to the diagnosis, clinical presentation, and treatment of the various causes of hyperthyroidism, a section on functional imaging and appropriate laboratory testing is included.

Subacute, silent, and postpartum thyroiditis

Subacute, silent, and postpartum thyroiditis are temporary forms of thyroid dysfunction caused by thyroid gland inflammation. They classically present with a triphasic course: a brief period of thyrotoxicosis due to release of preformed thyroid hormone that lasts for 1 to 3 months, followed by a more prolonged hypothyroid phase lasting up to 6 months, and eventual return to a euthyroid state. However, the types and degree of thyroid dysfunction are variable in these disorders, and individual patients may present with mild or more severe cases of thyrotoxicosis alone, hypothyroidism alone, or both types of thyroid dysfunction.

A case of painless thyroiditis in a very early stage of pregnancy

We report a case of painless thyroiditis detected during the first trimester of pregnancy. A 29-year-old Japanese woman was hospitalized because of thyrotoxicosis and she was confirmed to be pregnant. The gestational age was 4 weeks. Blood examinations revealed negative TSH receptor antibodies, however, we started potassium iodide because we were unable to rule out Graves' disease. Thyroid hormone levels were normalized in 3 weeks and remained low even after discontinuation of medication. She received replacement therapy with levothyroxine sodium hydrate till 3 months after delivery. Painless thyroiditis can be one of the differential diagnoses of thyrotoxicosis in a very early stage of pregnancy.

A case report of subacute thyroiditis during pregnancy: difficulties in differential diagnosis and changes in cytokine levels

INTRODUCTION

Thyroid dysfunction during pregnancy may result in both maternal and neonatal complications. Subacute thyroiditis (SAT) is an extremely rare cause of both hyper- and hypothyroidism in pregnant women.

CASE DESCRIPTION

A case of first trimester SAT is presented. Diagnosis of SAT was based on fine-needle aspiration biopsy. The disease resolved spontaneously without need for prednisone administration but a hypothyroid phase treated with T4 throughout pregnancy occurred. The pregnancy resulted in a healthy full term infant. We measured various cytokine levels in an attempt to follow their course during SAT as well as throughout the remaining period of pregnancy. Serum thyreoglobulin (Tg) levels correlated best with thyroid function tests (TFTs) and the course of SAT.

CONCLUSIONS

The diagnosis of SAT at a pregnancy setting may be intriguing. The measurement of circulating cytokines is not helpful in the differential diagnosis or monitoring of the disease.

Thyroid ultrasonography

BACKGROUND

The recent prevalence of ultrasonography (US) has facilitated the early detection and qualitative evaluation of thyroid nodules. Furthermore, novel technical developments are extending the application range of US for other thyroid diseases.

METHODS

The use of US to differentiate between thyroid carcinoma and benign nodule, between a metastatic lymph node and a reactive node, between thyroid lymphoma and chronic thyroiditis, and between destruction-induced thyrotoxicosis and Graves' disease is introduced.

RESULTS

Classification systems for thyroid nodule have shown high diagnostic accuracy for thyroid carcinomas except follicular carcinoma. US diagnosis of lymph node metastasis showed high specificity but low sensitivity. Patients who were suspected of thyroid lymphoma based on US findings should undergo incisional biopsy or thyroidectomy for diagnosis of the histologic type if fine-needle aspiration biopsy findings suggest lymphoma. Patients should be carefully followed even if they were diagnosed as negative based on cytologic findings. Measurement of thyroid blood flow is helpful for diagnosing destruction-induced thyrotoxicosis, such as painless thyroiditis, by distinguishing the lesion from Graves' disease.

CONCLUSIONS

Ultrasonography is useful for diagnosing various thyroid diseases, including thyroid carcinoma. The remaining issue to be resolved is the diagnosis of follicular carcinoma. Trials using novel techniques to differentiate these lesions are expected.

Color-flow doppler sonography in patients with subclinical thyroid dysfunction

OBJECTIVE

To assess the value of color-flow Doppler sonography (CFDS) in evaluating intrathyroidal blood flow and velocity in patients with subclinical thyroid dysfunction.

METHODS

In this prospective study, patients with subclinical hypothyroidism, patients with subclinical hyperthyroidism, and euthyroid patients without known thyroid autoimmune disease who served as controls were included. Subclinical thyroid dysfunction was defined as normal se-rum free thyroxine (FT4) and free triiodothyronine (FT3) in the presence of high (subclinical hypothyroidism), or low-suppressed (subclinical hyperthyroidism) serum thyrotropin (TSH) levels. Serum FT4, FT3, TSH, and antibodies to thyroid peroxidase and thyroglobulin were measured in all participants. In addition, TSH receptor antibody levels were determined in patients with subclinical hyperthyroid-ism. All participants underwent conventional sonography and CFDS. Mean peak systolic velocity (PSV) and resistive index were obtained from multiple extranodular thyroid parenchyma samplings and inferior thyroid artery measurements.

RESULTS

The study population included 27 patients with subclinical hypothyroidism, 15 patients with subclinical hyperthyroidism, and 20 euthyroid patients. Patients with subclinical hypothyroidism had significantly higher mean intrathyroidal PSV values than control patients (19.9 +/- 5.6 cm/s vs 15.7 +/- 4.4 cm/s; P = .008), whereas patients with subclinical hyperthyroidism had significantly higher mean PSV values than control patients at the inferior thyroid artery level (29.7 +/- 10.7 cm/s vs 21.9 +/- 6.8 cm/s; P = .014). Compared with control patients, a greater proportion of patients with subclinical hypothyroidism and patients with subclinical hyperthyroidism had marked CFDS patterns (78% vs 15% [P<.001] and 53% vs 15%; [P<.001], respectively). A significant association was found between positivity for thyroid autoantibodies and intense CFDS patterns. No correlation was found between TSH or thyroid hormone levels and CFDS pattern or blood flow velocity.

CONCLUSION

We have demonstrated that significantly increased thyroid blood flow velocity and vascularity are already present in patients with mild thyroid dysfunction.