Superior thyroid artery mean peak systolic velocity for the diagnosis of thyrotoxicosis in Japanese patients

A meta-analysis: elucidating diagnostic thresholds of peak systolic flow velocities in thyroid arteries for the discrimination of Graves' disease and destructive thyrotoxicosis

Objective

This meta-analysis examines peak systolic velocities (PSVs) in thyroid arteries as potential biomarkers for thyroid disorders, which includes treated and untreated Graves' disease(GD) and destructive thyrotoxicosis(DT).

Methods

A search across databases including PubMed, Google Scholar, Embase, and Web of Science identified studies assessing peak systolic flow velocity in the inferior thyroid artery (ITA-PSV) and superior thyroid artery (STA-PSV) diagnostic efficacy in GD and DT.And the search was restricted to publications in the English language.The analysis compared STA-PSV and ITA-PSV across patient groups, evaluating intra-group variances and synthesizing sensitivity and specificity data.

Results

The analysis covered 18 studies with 1276 GD, 564 DT patients, and 544 controls. The difference of STA-PSV between GD group, DT group and normal group and the difference of ITA-PSV were analyzed in subgroups, and there was no statistical significance between subgroups when comparing any two groups. Normal subjects displayed intra-group ITA-PSV and STA-PSV differences with established cut-off values of 20.33 cm/s (95% CI, 17.48-23.18) for ITA-PSV and 25.61 cm/s (95% CI, 20.37-30.85) for STA-PSV. However, no significant intra-group differences were observed in the STA-PSV and ITA-PSV cut-off values among groups with GD or DT. The combined cut-off values for these patient groups and normal subjects were 68.63 cm/s (95% CI, 59.12-78.13), 32.08 cm/s (95% CI, 25.90-38.27), and 23.18 cm/s (95% CI, 20.09-26.28), respectively. The diagnostic odds ratio(DOR) for these values was 35.86 (95% CI, 18.21-70.60), and the area under the summary receiver operating characteristic (SROC) curve was 0.91, with a sensitivity estimate of 0.842 (95% CI, 0.772-0.866).

Conclusion

PSVs in thyroid arteries are useful diagnostic tools in distinguishing DT from GD. A PSV above 68.63 cm/s significantly improves GD diagnosis with up to 91% efficacy. No notable differences were found between superior and inferior thyroid arteries in these conditions.

A Review of Testing for Distinguishing Hashimoto's Thyroiditis in the Hyperthyroid Stage and Grave's Disease

Hashimoto's thyroiditis (HT) and Graves' disease (GD) are two very common autoimmune thyroid diseases (AITD). In this review, we use "HT in the hyperthyroidism stage" to refer to early HT with clinical manifestations of hyperthyroidism. In clinical practice, it is not easy to distinguish between HT in the hyperthyroidism stage and GD as they exhibit very similar clinical symptoms. The current literature lacks so far studies that systematically compare and summarize hyperthyroidism due to HT and GD from varied aspects. It is necessary to focus on all the clinical indices of HT in the hyperthyroidism stage and GD, for accurate diagnosis. Multiple databases such as PubMed, CNKI, WF Data, and CQVIP Data were used to search the literature concerning HT in the hyperthyroidism stage and GD. The information extracted from the relevant literature was summarized and further analyzed. To differentially diagnose hyperthyroidism as HT or GD, it is recommended to first focus on serological tests, followed by imaging tests, as well as the thyroid I131 uptake index. In pathology, fine needle aspiration cytology (FNAC) is the gold standard for the differential diagnosis of HT and GD. Test results from cellular immunology and genetics could also be used to accurately diagnose between the two diseases, which may be further developed and studied in the future. In this paper, we reviewed and summarized the difference between HT in the hyperthyroidism stage and GD from the following six aspects: blood tests, imaging, thyroid I131 uptake, pathology, cellular immunology, and genetics.

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.

Diagnostic Utility of Mean Peak Systolic Velocity of Superior Thyroid Artery in Differentiating Graves' Disease from Thyroiditis

Background Differentiating Graves’ disease from thyroiditis can be at times clinically challenging. The gold standard test (thyroid nuclear imaging scan) is expensive, not routinely available, and has radiation exposure. Color Doppler ultrasonography of thyroid represents a suitable alternate which can be used for differentiating these conditions by studying thyroid blood flow parameters.

Aim We aimed to investigate the use of thyroid blood flow parameters’ assessment of the superior thyroid artery (STA) and common carotid artery (CCA) with color Doppler ultrasonography for differentiating Graves’ disease from thyroiditis.

Materials and Methods This is a cross-sectional study on 111 patients with newly diagnosed thyrotoxicosis (82 with Graves’ disease and 29 with thyroiditis) and 45 years of age and sex-matched healthy controls. All patients underwent detailed clinical and necessary investigations. Color Doppler ultrasonography of the thyroid gland and spectral flow analysis of both superior thyroid arteries was done using standard protocol. Sensitivity and specificity for mean peak systolic velocity of STA (STA-PSV) cut-offs were calculated using receiver operating characteristic curves.

Results Patients with Graves’ disease have significantly higher free tri-iodothyronine (FT3) levels, free thyroxine (FT4) levels, antithyroid stimulating hormone receptor antibody (TRAb) levels, and thyroid volume as compared with those with thyroiditis. The mean STA-PSV of patients with Graves’ disease was significantly higher than thyroiditis and control group. Mean STA-PSV greater than 54.3 cm/s had 82.9% sensitivity and 86.2% specificity in diagnosing Graves’ disease. Mean PSV-STA/PSV-CCA ratio of 0.40 was 80.5% sensitive and 86.2% specific for Graves’ disease.

Conclusion Mean STA-PSV has high sensitivity and specificity in differentiating Graves’ disease from thyroiditis and can be used routinely in clinical practice as a cheap and invaluable diagnostic tool.

Color Duplex Doppler US can Follow up the Response of Radioiodine in Graves' Disease by Evaluating the Thyroid Volume and Peak Systolic Velocity

PURPOSE

 The objective of this study was to prove the efficacy of Doppler ultrasonography (US-Doppler) in the follow-up of patients with GD treated with radioactive iodine.

METHODS

 97 patients (77 female and 20 male) with a mean age of 42 years (SD ± 15) and with prior diagnosis of GD were treated with radioiodine. In total, 88.5 % achieved euthyroidism or hypothyroidism after treatment. The study was documented before treatment and one, three, and six months after treatment with radioactive iodine (131I) by a single investigator. The volume, echogenicity, echotexture and vascularization of the glands as well as the peak systolic velocity (PSV) of the inferior thyroid arteries were evaluated and compared with the laboratory data.

RESULTS

 Thyroid volume and PSV had a statistically significant correlation with hormone levels (p < 0.05). The mean pre-dose therapeutic thyroid volume was 43.01 ± 3.88 cm³ and was 11.58 ± 11.26 cm³ 6 months after treatment. The mean PSV before 131I was 90.06 ± 44.13 cm/s and decreased significantly over time (p < 0.001). Six months after the therapeutic dose, the mean PSV was 32.95 ± 16.36 cm/s. However, the subjective parameters did not have a significant correlation with the normalization of the thyroid hormones.

CONCLUSION

 Doppler US was useful for monitoring the therapeutic response of GD patients after treatment with radioiodine by evaluating the thyroid volume and peak systolic velocity.

Superb Microvascular Imaging in the Evaluation of Pediatric Graves Disease and Hashimoto Thyroiditis

OBJECTIVES

We aimed to investigate the differences between spectral Doppler and Superb Microvascular Imaging (SMI; Canon Medical Systems, Tokyo, Japan) findings in children with Hashimoto thyroiditis (HT) and Graves disease (GD) compared to healthy control participants.

METHODS

The study included 34 patients with GD, 37 patients with HT, and 22 healthy volunteers. All patients with HT and 11 patients with GD were euthyroid; 23 patients with GD had symptoms of hyperthyroidism and had thyrotropin values of less than 0.5 mIU/L. Thyroid volumes, mean resistive indices, and peak systolic velocities along with vascularity indices (VIs) on Superb Microvascular Imaging were measured.

RESULTS

Patients with GD had a significantly higher mean thyroid volume (P < .001; right lobe, 11.80 mL; left lobe, 9.10 mL) and peak systolic velocity (right, 32.5 cm/s; left, 30 cm/s) with a lower resistive index (right, 0.48%; left, 0.48%) compared to patients with HT (right, 8.78 mL, 20 cm/s, 0.55%; left, 7.41 mL, 20 cm/s, 0.55%, respectively) and also control participants (right, 4.59 mL, 15 cm/s, 0.56%; left, 3.52 mL, 15 cm/s, 0.54%). Patients with GD had a significantly higher median VI (right, 25%; left, 26%) compared to patients with HT (right, 11%; left, 13%) and control participants (right, 8%; left, 8%). When patients with GD were categorized as euthyroid and hyperthyroid based on thyrotropin levels and clinical symptoms, both euthyroid and hyperthyroid patients with GD had significantly higher thyroid volumes compared to patients with HT (P < .001). Hyperthyroid patients with GD had higher thyroid volumes compared to euthyroid patients with GD; however, the difference failed to reach statistical significance. A significant strong positive correlation with the VI and thyrotropin receptor autoantibody levels (r = 0.696) was found. The highest area under the curve was obtained for the right lobe VI (0.885), followed by the left lobe VI (0.872), right lobe volume (0.828), and peak systolic velocity (0.810). The optimal cutoff VI value for distinguishing between HT and GD was 17.35% with sensitivity, specificity, and diagnostic accuracy of 85.3%, 78.4%, and 81.7%, respectively.

CONCLUSIONS

Superb Microvascular Imaging is a new method that can detect subtle vascularity changes with higher accuracy compared to spectral Doppler parameters in distinguishing between HT and GD.

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.

Unexpected cause of fever in a patient with untreated HIV

We report a case of a 27-year-old man with a history of untreated HIV who presented with fever, rash and leg cramps. Initial suspicion was high for an infectious process; however, after an exhaustive evaluation, thyrotoxicosis was revealed as the aetiology of his symptoms. Recent intravenous contrast administration complicated his workup to determine the exact cause of hyperthyroidism. Differentiation between spontaneously resolving thyroiditis and autonomous hyperfunction was paramount in the setting of existing neutropenia and the need for judicious use of antithyroid therapy. The inability to enlist a nuclear scan in the setting of recent iodinated contrast administration prompted alternative testing, including thyroid antibodies and thyroid ultrasound. In this case, we will discuss the diagnostic challenges of thyrotoxicosis in a complex patient, the sequelae of iodine contrast administration, effects of iodine on the thyroid and the predictive value of other available tests.

Doppler indices of superior thyroid artery in clinically euthyroid adults

Context:

Ultrasonography of thyroid gland is a frequently performed investigation. Many of the diffuse thyroid pathologies are associated with altered vascularity. In view of potential applications and scant available data, there is a need to find normal values of Doppler indices of superior thyroid artery (STA).

Aims:

To find the normal range of Doppler indices like mean peak systolic velocity (PSV), resistivity index (RI), and pulsatility index (PI) of STA in clinically euthyroid adult individuals.

Settings and Design:

Prospective cross-sectional observational study.

Materials and Methods:

A study was done in the Department of Radiodiagnosis of a tertiary care hospital, involving clinically euthyroid adult volunteers. Ultrasonography of the thyroid gland with Doppler of bilateral STAs was performed and mean values of PSV, RI, and PI were calculated.

Results:

A total of 208 subjects, with a mean age of 37.7 years, underwent Doppler evaluation of STA; 148 of them were women and 60 were men. The mean PSV obtained was 16.94 ± 5.3 cm/s. Mean PI and RI were 0.93 ± 0.31 and 0.5 ± 0.13, respectively. There was no significant difference in the values obtained among both the genders.

Conclusion:

Mean values of Doppler indices of STA in euthyroid individuals have been found in this study.

Guidelines for the treatment of childhood-onset Graves' disease in Japan, 2016

Purpose behind developing these guidelines: Over one decade ago, the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2006” (Japan Thyroid Association (JTA)) were published as the standard drug therapy protocol for Graves’ disease. The “Guidelines for the Treatment of Childhood-Onset Graves’ Disease with Antithyroid Drug in Japan, 2008” were published to provide guidance on the treatment of pediatric patients. Based on new evidence, a revised version of the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2006” (JTA) was published in 2011, combined with the “Handbook of Radioiodine Therapy for Graves’ Disease 2007” (JTA). Subsequently, newer findings on pediatric Graves’ disease have been reported. Propylthiouracil (PTU)-induced serious hepatopathy is an important problem in pediatric patients. The American Thyroid Association’s guidelines suggest that, in principle, physicians must not administer PTU to children. On the other hand, the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2011” (JTA) state that radioiodine therapy is no longer considered a “fundamental contraindication” in children. Therefore, the “Guidelines for the Treatment of Childhood-Onset Graves’ Disease with Antithyroid Drug in Japan, 2008” required revision.

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.

Cutoff value of thyroid uptake of (99m)Tc-pertechnetate to discriminate between Graves' disease and painless thyroiditis: a single center retrospective study

Thyroid uptake of (99m)Tc-pertechnetate is a useful way to determine the cause of thyrotoxicosis. In daily clinical practice, (99m)Tc-pertechnetate uptake is used to discriminate between Graves' disease and painless thyroiditis when clinical information is not enough to make the distinction. However, since the optimal cutoff value of (99m)Tc-pertechnetate uptake has not yet been elucidated, our aim was to determine this value. We recruited patients with thyrotoxicosis in whom (99m)Tc-pertechnetate uptake was measured in clinical settings between 2009 and 2013. Three experienced endocrinologists (who were blinded to the value of (99m)Tc-pertechnetate uptake and initial treatment) diagnosed the cause of thyrotoxicosis based on thyrotropin, free triiodothyronine, free thyroxine, and thyrotropin receptor antibody levels, and by ultrasound findings and using images of thyroid uptake of (99m)Tc-pertechnetate without the actual values. Ninety-four patients diagnosed as having Graves' disease or painless thyroiditis were finally included. According to the diagnosis, the optimal cutoff value of (99m)Tc-pertechnetate uptake was determined by receiver operating characteristics analysis. A cutoff value of 1.0% provided optimal sensitivity and specificity of 96.6% and 97.1%, respectively. Then, its validity was confirmed in 78 patients with confirmed Graves' disease or painless thyroiditis diagnosed at another institute. Applying this cutoff value to the patients with thyrotoxicosis revealed positive and negative predictive values for Graves' disease of 100% and 88.9%, respectively. In conclusion, a cutoff value for (99m)Tc-pertechnetate uptake of 1.0% was useful to discriminate between Graves' disease and painless thyroiditis.

The value of the mean peak systolic velocity of the superior thyroidal artery in the differential diagnosis of thyrotoxicosis

Purpose:

The aim of this study was to validate the superior thyroidal artery mean peak systolic velocity (STA-mPSV) as an alternative to other diagnostic parameters in the differentiation of the causes of thyrotoxicosis in Korean patients.

Methods:

This study was conducted with newly diagnosed and untreated thyrotoxic patients. Forty patients were diagnosed with Graves disease (GD) and 20 patients with destructive thyroiditis (DT). Another 60 healthy subjects without thyroid disease participated as the control group. Blood samples were taken to evaluate the thyroid function and thyroid autoantibodies (TRAb). Twenty-four hour radioactive iodine uptake (RAIU) scanning was performed to confirm GD or DT. The STA-mPSV was measured using color Doppler ultrasonography.

Results:

The STA-mPSV was significantly higher in the untreated GD group than in the DT group (GD, 78.96±29.04 cm/sec; DT, 29.97±14.67 cm/sec; control, 17.55±4.99 cm/sec; P<0.001). The area under the curve (AUC) of the STA-mPSV for the differential diagnosis of untreated GD and DT was 0.9506 (optimal cutoff value, 41.3 cm/sec; sensitivity, 95%, 38/40; specificity, 85%, 17/20) in the receiver operating characteristic analysis. The AUC values of the STA-mPSV, RAIU, and TRAb were 0.9506, 1, and 0.9988, respectively (P=0.159).

Conclusion:

In clinical practice, the STA-mPSV has a diagnostic value similar to that of the TRAb and 24-hour RAIU in the differential diagnosis of newly diagnosed Korean thyrotoxic patients.

Therapeutic effectiveness of potassium iodine in drug-naïve patients with Graves' disease: a single-center experience

Iodine is beneficial against Graves' thyrotoxicosis, though its effects are short-lived. However, its long-term effectiveness as an initial therapy has not been fully elucidated. Here, we compared the effects of potassium iodine (KI) and methimazole (MMI) in Graves' thyrotoxicosis and on thyrotropin receptor antibody (TRAb) levels. Between 2008 and 2011, 293 patients with untreated Graves' disease visited the outpatient clinic of Juntendo University. Of these, 227 patients were treated with MMI and 30 treated with KI as the initial therapy. To compare the effects of KI and MMI, we identified patients with similar probabilities of receiving MMI or KI using propensity score (PS) analysis based on the observed clinical features. PS matching created 20 matched pairs of patients with Graves' disease treated with MMI and KI. The baseline characteristics of post-matched patients treated with MMI were comparable to those treated with KI (FT3; 7.16 ± 2.30, 6.56 ± 1.85 pg/ml, FT4; 2.57 ± 0.79, 2.49 ± 0.70 ng/dl, respectively). The initial dose of MMI was 14.0 ± 8.2 mg/day and that of KI was 53.6 ± 11.7 mg/day. Three patients of the KI group did not respond to the monotherapy, requiring the inclusion of antithyroid drugs. One patient on MMI developed moderate skin eruption, but continued the treatment. Patients who continued the initial treatment showed significant and comparable reductions in FT4, FT3 and TRAb by MMI as well as by KI at the end of 12-month treatment. Although patients were limited to mild untreated Graves' disease thyrotoxicosis, KI offers a possible alternative initial treatment for this condition.

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.

An evaluation of thyrotoxic autoimmune thyroiditis patients with triplex Doppler ultrasonography

OBJECTIVE

This study aimed to investigate the usefulness of blood flow parameters obtained from STA and CCA with Triplex Doppler ultrasonography (TDU) on patients with thyrotoxicosis.

MATERIALS AND METHODS

This cross-sectional study included consecutive 24 patients with thyrotoxicosis and 18 healthy controls. The thyroid gland blood flow parameters were evaluated with TDU.

RESULTS

The thyroid volumes and FT3, TRAb, 4-h and 24-h radioactive iodine uptake (RAIU) levels of Group 1 were significantly high compared to those of Group 2. The thyroid volumes and FT3, FT4 and TSH levels of both Group 1 and Group 2 showed a statistically significant difference compared to Group 3. STA-PSV values for Group 1, Group 2 and Group 3 were 138 cm/s, 54 cm/s and 37 cm/s, respectively. STA-EDV values for these groups were 60 cm/s, 25 cm/s and 15 cm/s, respectively. PSVR values for these groups were 1.01, 0.45, 0.34 cm/s, respectively. EDVR values for these groups were 1.29, 0.70 and 0.49 cm/s, respectively. In Group 1, STA-PSV, STA-EDV, PSVR and EDVR values were significantly high compared to those of Group 2. RAIU levels showed a significant positive correlation with the STA-PSV, STA-EDV and PSVR.

CONCLUSION

The thyroid gland blood flow parameters may be used in clinical diagnosis of patients with thyrotoxicosis.

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.

Mean peak systolic velocity of the superior thyroid artery is correlated with radioactive iodine uptake in untreated thyrotoxicosis

OBJECTIVE

To evaluate the correlation between mean superior thyroid artery peak systolic velocity (STA-PSV) and radioactive iodine uptake (RAIU) in Chinese patients with untreated thyrotoxicosis, using retrospectively and prospectively collected data.

METHODS

Patients with untreated thyrotoxicosis (n = 220) and euthyroid control subjects (n = 30) underwent thyroid function, thyroid autoantibody and thyroid ultrasonography tests. Mean STA-PSV was measured by ultrasonography. RAIU tests identified 168 patients with Graves' disease and 52 with destructive thyroiditis. Linear correlation of mean STA-PSV with 3-h and 24-h RAIU, and sensitivity, specificity and receiver operating characteristic (ROC) curves for mean STA-PSV in the differential diagnosis of Graves' disease and destructive thyroiditis were calculated.

RESULTS

Mean STA-PSV was significantly higher in Graves' disease than in destructive thyroiditis. Mean STA-PSV correlated positively and significantly with 3-h and 24-h RAIU. Area under the ROC curve of mean STA-PSV for the differential diagnosis of Graves' disease and destructive thyroiditis was 0.825 (optimum cut-off value of mean STA-PSV, 45.25 cm/s; sensitivity, 80.4%; specificity, 81.4%).

CONCLUSIONS

Detection of mean STA-PSV by ultrasonography agrees with RAIU and is useful for the differential diagnosis of thyrotoxicosis in Chinese patients.