Estimation of antithyroid drug dose in Graves' disease: value of quantification of thyroid blood flow with color duplex sonography

Association of autoimmune thyroid disease with type 1 diabetes mellitus and its ultrasonic diagnosis and management

As a common hyperglycemic disease, type 1 diabetes mellitus (T1DM) is a complicated disorder that requires a lifelong insulin supply due to the immune-mediated destruction of pancreatic β cells. Although it is an organ-specific autoimmune disorder, T1DM is often associated with multiple other autoimmune disorders. The most prevalent concomitant autoimmune disorder occurring in T1DM is autoimmune thyroid disease (AITD), which mainly exhibits two extremes of phenotypes: hyperthyroidism [Graves' disease (GD)] and hypo-thyroidism [Hashimoto's thyroiditis, (HT)]. However, the presence of comorbid AITD may negatively affect metabolic management in T1DM patients and thereby may increase the risk for potential diabetes-related complications. Thus, routine screening of thyroid function has been recommended when T1DM is diagnosed. Here, first, we summarize current knowledge regarding the etiology and pathogenesis mechanisms of both diseases. Subsequently, an updated review of the association between T1DM and AITD is offered. Finally, we provide a relatively detailed review focusing on the application of thyroid ultrasonography in diagnosing and managing HT and GD, suggesting its critical role in the timely and accurate diagnosis of AITD in T1DM.

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.

Comparison of thyroid blood flow and uptake indices using technetium-99m pertechnetate in patients with graves' disease and euthyroid subjects

Objective: The aim of the present study was to evaluate parameters of early blood flow (EBF) including duration of EBF, perfusion index (PI), uptake indexes 1 and 2 (UI1 and UI2) derived from dynamic thyroid scintigraphy in patients with Graves’ disease (GD), and euthyroid (EI). Maximum instant uptake and maximum uptake of the thyroid gland were also assessed.

Methods: A total of 50 patients with GD and EI were included in this study. Each patient underwent two dynamic scans of 1-minute (20 images at 3 seconds) and 20-minute (20 images at 1 minute) with ^99mTcO4. The time-activity curve of a 1-minute scan was employed to derive EBF parameters; likewise, the time-activity curve of a 20-minute scan was used to determine maximum instant uptake, and the gradient of the curve from the 10th to 20th minute was used to assess maximum uptake.

Results: Values of EBF duration, PI, UI1, UI2, and maximum instant uptake were significantly lower in patients with GD than in those with EI (p<0.05). The calculated gradient of the second half of the curves for all of the patients ranged from 0 to 0.88 and was significantly higher in patients with GD than in those with EI.

Conclusion: Lower values of PI, UI1, UI2 and durations of EBF, along with faster maximum instant uptake in patients with GD in comparison to EI are indicators of a heightened desire for hyper-functioning thyroid glands of patients with GD to absorb ^99mTcO4. Additionally, because of the uprising gradient at the end of the 20-minute time-activity curve, a maximum thyroid uptake of ^99mTcO4 was achieved at more than 20 minutes after the radiopharmaceutical injection.

Role of color Doppler in differentiation of Graves' disease and thyroiditis in thyrotoxicosis

AIM: To evaluate the role of thyroid blood flow assessment by color-flow Doppler ultrasonography in the differential diagnosis of thyrotoxicosis and compare it to technetium pertechnetate thyroid scanning.

METHODS: Twenty-six patients with thyrotoxicosis were included in the study. Clinical history was taken and physical examination and thyroid function tests were performed for all patients. Thyroid autoantibodies were measured. The thyroid glands of all patients were evaluated by gray scale ultrasonography for size, shape and echotexture. Color-flow Doppler ultrasonography of the thyroid tissue was performed and spectral flow analysis of both inferior thyroid arteries was assessed. Technetium99 pertechnetate scanning of the thyroid gland was done for all patients. According to thyroid scintigraphy, the patients were divided into two groups: 18 cases with Graves’ disease and 8 cases with Hashimoto’s thyroiditis. All patients had suppressed thyrotropin. The diagnosis of Graves’ disease and Hashimoto’s thyroiditis was supported by the clinical picture and follow up of patients.

RESULTS: Peak systolic velocities of the inferior thyroid arteries were significantly higher in patients with Graves’ disease than in patients with thyroiditis (P = 0.004 in the right inferior thyroid artery and P = 0.001 in left inferior thyroid artery). Color-flow Doppler ultrasonography parameters demonstrated a sensitivity of 88.9% and a specificity of 87.5% in the differential diagnosis of thyrotoxicosis.

CONCLUSION: Color Doppler flow of the inferior thyroid artery can be used in the differential diagnosis of thyrotoxicosis, especially when there is a contraindication of thyroid scintigraphy by radioactive material in some patients.

Role of ultrasound in thyroid disorders

Thyroid ultrasonography has established itself as a popular and useful tool in the evaluation and management of thyroid disorders, both malignant and benign. Although its use has traditionally been the domain of radiologists, surgeons and endocrinologists are increasingly integrating this technology into their daily clinical and operative practice. This article provides an overview of the relevant uses and indications for ultrasound in various thyroid diseases, describes characteristic ultrasound findings in these diseases, and reviews the relevant literature and guidelines concerning its uses.

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

Thyrotoxicosis with diffuse thyroid disease can be caused by Graves' disease (GD) or destructive thyroiditis (DT). Optimal treatment of the underlying condition requires a prompt and accurate method for the diagnosis of thyrotoxicosis. This study evaluated measurement of the mean peak systolic velocity of the superior thyroid artery (STA-PSV) by ultrasonography in detecting thyrotoxicosis in Japanese patients. We recruited 44 patients with untreated GD, 13 with DT, 55 with treated GD, and 49 subjects without thyroid disease. Blood samples were taken to analyze thyroid function and STA-PSV was measured by ultrasonography. The mean STA-PSV was the highest in the untreated GD group, followed by treated GD patients and then those with DT. Receiver operating characteristic curves of the STA-PSV values demonstrated that the area under the curve required discriminating untreated GD from DT was 0.941. The optimal sensitivity and specificity were 83.7% and 92.3%, respectively, using 45 cm/sec as the cutoff value. In conclusion measurement of STA-PSV by ultrasonography is useful for the diagnosis of thyrotoxicosis in Japanese patients.

Correlation between, clinical, biochemical, color Doppler ultrasound thyroid parameters, and CXCL-10 in autoimmune thyroid diseases

OBJECTIVE

the aim of present study is to determine possible contributions of INF-gamma inducible chemochine CXCL-10 in the thyroid color doppler ultrasound (CDU) parameters typical of autoimmune disorders.

METHODS

we studied a consecutive series of 25 patients with autoimmune thyroid disease and 10 healthy control subjects. All subjects underwent a thyroid CDU examination by the same investigator, who was unaware of the laboratory values at the time of the examination. Moreover, all subjects underwent a clinical evaluation, CXCL-10 and thyroid hormonal assessment.

RESULTS

CXCL-10 levels were significantly higher in patients with autoimmune diseases and as well as in subjects with an increased thyroid vascularization at CDU. Moreover, CXCL-10 levels were significantly (p<0.05) correlated with inferior thyroid arteria peak systolic velocity (ITA-PSV; r = 0.376) and with thyroid volume even after adjustment for confounding factors. No difference was observed between vascular thyroid pattern at CDU and thyroid circulating hormones while, ITA-PSV was significantly associated with TSH (Adj. r = -0.373; p<0.05).

CONCLUSIONS

our data seem to suggest that CXCL-10 could play an important role in the intra-thyroid angiogenesis modulation, explaining, at least partiality, CDU findings typical of thyroid autoimmune diseases. Moreover we confirmed previous reports considering ITA-PSV as the best CDU parameters in the differential diagnosis of thyroid autoimmune disorders.

Reference values for Doppler ultrasound parameters of the thyroid in a healthy iodine-non-deficient population

The aim of this study was to describe normal Doppler parameter values in the thyroid arteries in an iodine-replete region. 165 individuals were randomly selected in a community located in the south-east of Brazil. We obtained a clinical history on each subject and determined serum thyrotropin, antiperoxidase antibodies, thyrotropin receptor antibody (TRAb) and thyroid volumes through ultrasound. Subjects with thyroid disease and those under 20 years of age were excluded. 84 representative subjects (30 men and 54 women) remained. The systolic peak velocity (SPV), resistive index (RI) and pulsatility index (PI) in the superior and inferior thyroid arteries were measured using a 5-12 MHz linear probe. Except for the RI, the distribution of all Doppler parameters was non-gaussian. The median and mean references for the SPV, RI and PI were 24.80 cm s(-1) and 25.85 cm s(-1), 0.60 and 0.62, and 0.98 and 1.04, respectively, for superior thyroid arteries; these reference values for the inferior thyroid artery were 20.92 cm s(-1) and 21.50 cm s(-1), 0.57 and 0.57, and 0.84 and 0.88, respectively (p<0.001). Women had greater SPV values (p<0.01). We have determined reference thyroid Doppler parameter values in our iodine-non-deficient population and prepared tables by sex and age.

Doppler evaluation of pediatric goiter: effect of mandatory iodination

PURPOSE

The aim of this study was to evaluate the hemodynamic status of the thyroid in children with goiter after the use of iodinated dietary salt for 3 years in a region of endemic iodine deficiency.

METHODS

Sixty-six children between 7 and 12 years of age were included in the study. Three groups were constituted according to sonographically measured thyroid volume and urinary iodine excretion levels. Group 1 included 11 children with thyroid volumes greater than the 97th percentile according to age and sex criteria suggested by the World Health Organization International Council for Control of Iodine Deficiency Disorders and urinary iodine level lower than 100 microg/l. Group 2 included 30 children with thyroid volumes greater than the 97th percentile and urinary iodine level equal to or higher than 100 microg/l. The control group included 25 children who had normal thyroid volume and urinary iodine level. All children were examined by thyroid duplex sonography. Peak systolic velocity (PSV) and resistance index (RI) were measured in the inferior thyroid artery bilaterally.

RESULTS

PSV in group 1 was significantly higher than in group 2 and in the control group (P < 0.05 and P < 0.01, respectively). There was no significant difference between the PSV of group 2 and the control group. The RI in groups 1 and 2 was significantly lower than in the control group (P < 0.01 and P < 0.01, respectively). There was no significant difference between the RIs of group 1 and group 2.

CONCLUSIONS

These findings suggest an effect of iodination on thyroid hemodynamics before the size of the hyperplastic thyroid returned to normal, in keeping with normalization of the urinary iodine level.

Power Doppler ultrasound imaging for quantification of urinary bladder neck blood flow changes

This study was designed to evaluate power Doppler imaging for assessment of urinary bladder neck blood flow in comparison with laser Doppler flowmetry (LDF) in an animal model. Transrectal power Doppler ultrasound (US) and LDF of the urinary bladder neck were performed in three anesthetized pigs during comparative cystometry. Normal saline (NaCl) was used for the first run, followed by a second run with 0.2 mol/L potassium chloride (KCl). Standardized sonographic equipment settings (Acuson Sequoia 512); MountainView, CA) were used for power Doppler imaging. Computer-assisted calculation of color pixel density (CPD) of power Doppler images was performed using Scion Image) software image analysis. Tissue perfusion units (TPU) were measured using a BLF21 laser Doppler flowmeter (Transonic Systems Inc., Ithaca, NY, USA). The power Doppler results were compared with the findings obtained by LDF. NaCl filling resulted in a mean CPD increase at the bladder neck from 18.65 (+/- 1.78) at empty bladder to 37.8 (+/- 1.84) at 100 mL and to 88.32 (+/- 1.35) at full bladder capacity (C(max)) of 270 mL, respectively. With KCl filling, a mean CPD increase from 18.65 (+/- 1.78) to 59.63 (+/- 0.5) at 100 mL and 110.82 (+/- 2.98) at full bladder capacity (270 mL) was observed. The CPD increase was significantly higher for KCl than with NaCl (p < 0.001). With NaCl filling, bladder neck blood flow increased from 22 TPU (empty) to 46 TPU (100 mL) and 62.5 TPU at C(max), compared to 22 TPU, 50 TPU and 102.5 TPU with KCl. CPD and TPU measurements showed a strong correlation at p = 0.01. In conclusion, transrectal power Doppler US image quantification is a feasible and accurate method for assessing blood flow changes in the urinary bladder neck.

Variability of thyroid blood flow Doppler parameters in healthy women

The purpose of this study was to estimate variability of flow Doppler parameters in the superior thyroid artery (STHA) during the menstrual cycle in young women and to explore the influence of endogenous 17-b-estradiol (E2) and progesterone (PRG) on the velocity waveform. The plasma concentration of these hormones was correlated with flow velocities, pulsatility index (PUI), resistance index (RI) and acceleration index (accI) and time (accT), which were measured with color-coded duplex sonography 8 times during the cycle in 14 healthy women (age range: 23 to 25 years). Coefficient of variation (CV), interclass correlation (ICC), repeatability (repC) and pooled Pearson correlation (r) coefficients were used to estimate the variability of the parameters. The highest variability was found for accI and accT: CV = 48% and 31%; ICC = 0.51 and 0.45; repC = 2.8 and 95; r = 0.37 and 0.4, respectively. The CV for flow velocities varied from 25% to 26%, ICC from 0.53 to 0.56, repC from 8 to 17 and r has a value of 0.46. The respective values for RI and PUI were: 11%, 18%; 0.48, 0.55; 0.15, 0.48; and 0.46, 0.48. The diastolic blood pressure decreased significantly by 7 mmHg (p < 0.01) in the luteal phase, whereas other physiological variables were stable during the cycle. Although the fluctuations of the flow parameters during the cycle were not statistically significant, a weak linear correlation between flow velocities and concentration of E2 was found; for mean velocity r = 0.16, p < 0.05. Impedance indices showed an increasing trend in the luteal phase, along with increase of the pulse pressure index (PPI). The results showed that variability of the flow parameters in the STHA is substantial and that higher flow velocities are associated with increase of plasma concentration of 17-b-estradiol during the menstrual cycle in young women.