Does normal thyroid gland by ultrasonography match with normal serum thyroid hormones and negative thyroid antibodies?

Color Doppler ultrasound and real-time elastography in patients with hypothyroidism for the prediction of levothyroxine replacement: a cross-sectional study of 338 patients

AIMS

While hormonal assays are commonly used for thyroid function assessment, Doppler sonography provides valuable information on vascularization and blood flow. This study aimed to examine the potential associations between Doppler parameters and clinical characteristics of hypothyroid patients, such as the autoimmune nature of the disease and adequacy of LT4 replacement.

METHODS

A total of 338 patients with hypothyroidism, primarily caused by autoimmune thyroiditis (AT), were enrolled in this study. Exclusion criteria comprised specific medical conditions, medication history, and nodular abnormalities of the thyroid gland. Patient demographics (age, sex, BMI), treatment parameters (LT4 daily dose), and thyroid hormone levels (TSH, fT4) were recorded.

RESULTS

Among the enrolled patients, 85.2% had autoimmune thyroiditis. Suboptimal levothyroxine (LT4) replacement was observed in 20.1% of patients at the time of enrollment. Patients with autoimmune thyroiditis had increased elastography ratios compared to those without autoimmune disease and present a positive association of elastography ratios with vascularity. In patients without autoimmune thyroiditis, those with suboptimal LT4 replacement had lower total thyroid volume. Patients with suboptimal LT4 replacement had higher peak systolic velocity (PSV) and end-diastolic velocity (EDV) in the inferior thyroid artery and lower resistive index (RI). The severity of hypothyroidism, as indicated by LT4 dose/body mass index (BMI), was negatively correlated with thyroid volume and EDV values of superior and inferior thyroid arteries. PSV of the inferior thyroid artery can predict suboptimal LT4 replacement (sensitivity 81.8%, specificity 42%).

CONCLUSIONS

In situations where obtaining blood tests may be challenging, utilizing color Doppler ultrasound can serve as an alternative method to assess treatment responses and identify patients who require further hormonal examinations.

Effects of COVID-19 vector vaccine on autoantibody profile in reproductive age women

Autoimmune mechanisms have been implicated in the negative effects of vaccines on female reproductive health. This study evaluates the endogenous levels of self-reactive antibodies and ovarian reserve-associated hormones before and after immunization with the domestically developed Gam-COVID-Vac combined vector vaccine to check for possible reproductive sequelae. The prospective study enrolled 120 women aged 18–49, subject to vaccination with Gam-COVID-Vac. Ovarian reserve was assessed prior to vaccination and 90 days after the first component injection. Profiles of specific antibodies to self-antigens, including phospholipids, nuclear antigens, FSH, progesterone, and also thyroid, ovarian, trophoblast, and zona pellucida antigens, were assessed at the same time points by enzyme immunoassay. Overall, the vaccination had no effect on the levels of ovarian reserve-associated hormones and autoantibodies, apart from a transient increase in positivity for antiphosphatidylethanolamine IgM and anti-dsDNA IgG. Seroprevalence of elevated serum autoantibodies constituted 70.8% before and 75% after vaccination. According to the results, immunization with Gam-COVID-Vac does not affect ovarian reserve or autoimmune status, thus being safe for the female reproductive potential.

Testing telediagnostic thyroid ultrasound in Peru: a new horizon in expanding access to imaging in rural and underserved areas

PURPOSE

Thyroid ultrasound is a key tool in the evaluation of the thyroid, but billions of people around the world lack access to ultrasound imaging. In this study, we tested an asynchronous telediagnostic ultrasound system operated by individuals without prior ultrasound training which may be used to effectively evaluate the thyroid and improve access to imaging worldwide.

METHODS

The telediagnostic system in this study utilizes volume sweep imaging (VSI), an imaging technique in which the operator scans the target region with simple sweeps of the ultrasound probe based on external body landmarks. Sweeps are recorded and saved as video clips for later interpretation by an expert. Two operators without prior ultrasound experience underwent 8 h of training on the thyroid VSI protocol and the operation of the telemedicine platform. After training, the operators scanned patients at a health center in Lima. Telediagnostic examinations were sent to the United States for remote interpretation. Standard of care thyroid ultrasound was performed by an experienced radiologist at the time of VSI examination to serve as a reference standard.

RESULTS

Novice operators scanned 121 subjects with the thyroid VSI protocol. Of these exams, 88% were rated of excellent image quality showing complete or near complete thyroid visualization. There was 98.3% agreement on thyroid nodule presence between VSI teleultrasound and standard of care ultrasound (Cohen's kappa 0.91, P < 0.0001). VSI measured the thyroid size, on average, within 5 mm compared to standard of care. Readers of VSI were also able to effectively characterize thyroid nodules, and there was no significant difference in measurement of thyroid nodule size (P = 0.74) between VSI and standard of care.

CONCLUSION

Thyroid VSI telediagnostic ultrasound demonstrated both excellent visualization of the thyroid gland and agreement with standard of care thyroid ultrasound for nodules and thyroid size evaluation. This system could be deployed for evaluation of palpable thyroid abnormalities, nodule follow-up, and epidemiological studies to promote global health and improve the availability of diagnostic imaging in underserved communities.

Recent recommendations from ATA guidelines to define the upper reference range for serum TSH in the first trimester match reference ranges for pregnant women in Rio de Janeiro

OBJECTIVES

American Thyroid Association (ATA)'s new guidelines recommend use of population-based trimester-specific reference range (RR) for thyrotropin (TSH) in pregnancy. The aim of this study was to determine first trimester TSH RR for a population of pregnant women in Rio de Janeiro State.

SUBJECTS AND METHODS

Two hundred and seventy pregnant women without thyroid illness, defined by National Academy of Clinical Biochemistry, and normal iodine status were included in this sectional study. This reference group (RG) had normal median urinary iodine concentration (UIC = 219 μg/L) and negative anti-thyroperoxidase antibodies (TPOAb). Twin pregnancy, trophoblastic disease and use of drugs or supplements that influence thyroid function were excluded. In a second step, we defined a more selective reference group (SRG, n = 170) by excluding patients with thyroiditis pattern on thyroid ultrasound and positive anti-thyroglobulin antibodies. This group also had normal median UIC. At a final step, a more selective reference group (MSRG, n = 130) was defined by excluding any pregnant women with UIC < 150 μg/L.

RESULTS

In the RG, median, 2.5th and 97.5th percentiles of TSH were 1.3, 0.1, and 4.4 mIU/L, respectively. The mean age was 270 ± 5.0 and the mean body mass index was 25.6 ± 5.2 kg/m2. In the SRG and MSRG, 2.5th and 975th percentiles were 0.06 and 4.0 (SRG) and 0.1 and 3.6 mIU/L (MSRG), respectively.

CONCLUSIONS

In the population studied,TSH upper limit in the first trimester of pregnancy was above 2.5 mIU/L. The value of 3.6 mIU/L, found when iodine deficiency and thyroiditis (defined by antibodies and ultrasound characteristics) were excluded, matches recent ATA guidelines.

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.

Thyroid Ultrasonography in Differentiation between Graves' Disease and Hashimoto's Thyroiditis

OBJECTIVE

Graves' disease and Hashimoto's thyroiditis are the most common causes of hyper and hypothyroidism, respectively. Differentiation of these 2 diseases, if the patient is euthyroid, may sometimes be extremely difficult on the basis of clinical and laboratory findings. The purpose of this study was to determine the sensitivity and specificity of gray scale sonography in differentiation of Graves' disease from Hashimoto's thyroiditis.

METHODS

This study included 149 patients divided into three groups, patients with Graves' disease (34 patients, mean age = 36.8 ± 10.17 years), Patients with Hashimoto's thyroiditis (62 patients, mean age = 33.4 ± 12.16 years) and control group (53 healthy people, mean age = 34.74 ± 16.87 years). Members of all groups were referred to a single radiologist for thyroid sonography for evaluation of thyroid echogenicity pattern.

RESULTS

A total of 117 women and 32 men were examined by sonography. The most common sonographic pattern in Hashimoto and Graves' was homogenous hypo-echogenicity which was observed in 45.2% and 47.1% of cases, respectively. Peripheral hypo-echogenicity pattern was seen in 40.3% of Hashimoto's group with 100% specificity and 40.3% sensitivity. Central-hypoechogenic pattern was observed in 17.6% of Graves' group with 100% and 17.6% specificity and sensitivity, respectively.

CONCLUSION

Our findings indicate that sonography has high specificity but low sensitivity in the diagnosis of either Graves' disease or Hashimoto's thyroiditis. It is therefore not possible to differentiate between these two diseases using sonography alone. Confirmation by laboratory data is also needed.

Correlation of normal thyroid ultrasonography with thyroid tests

BACKGROUND

Thyroid disorders are frequently seen in the community. Thyroid ultrasonography (US) is commonly used in the diagnosis of thyroid diseases. The relationship between heterogeneous echogenicity of thyroid gland and thyroid tests are well known.

METHODS

The aim of this study is to evaluate the correlation of normal US with the thyroid tests. A total of 681 individuals were enrolled in the study. Individuals were separated into two groups as normal (group 1) and hypoechoic (group 2) according to the echogenicity in US. Subjects with nodular thyroid lesions were excluded from the study. Thyroid stimulating hormone (TSH), free T4 (fT4), thyroid peroxidase antibody (TPOAb) and anti-thyroglobulin antibody (TgAb) values were recorded in both groups and thyroid stimulating hormone receptor antibody (TRAb) was recorded in individuals with low TSH.

RESULTS

86.1% of individuals in group 1 had normal TSH, 93.7% had normal thyroid antibodies and in 77.6% of individuals, all thyroid tests performed were normal. In the 6.9% of the group 2, all reviewed thyroid tests were normal (P<0.001).

CONCLUSIONS

Our study shows that US is correlated with normal thyroid function tests and is a valuable tool in the prediction of normal thyroid function.

Analysis of tissue surrounding thyroid nodules by ultrasound digital images

Since US is not easily reproducible, the digital image analysis (IA) has been proposed so that the image evaluation is not subjective. In fact, IA meets the criteria of objectivity, accurateness, and reproducibility by a matrix of pixels whose value is displayed in a gray level. This study aims at evaluating via IA the tissue surrounding a thyroid nodule (backyard tissue, BT) from goitres with benign (b-BT) and malignant (m-BT) lesions. Sixty-nine US images of thyroid nodules surrounded by adequate thyroid tissue was classified as normoechoic and homogeneous were enrolled as study group. Forty-three US images from normal thyroid (NT) glands were included as controls. Digital images of 800 × 652 pixels were acquired at a resolution of eight bits with a 256 gray levels depth. By one-way ANOVA, the 43 NT glands were not statistically different (P = 0.91). Mean gray level of normal glands was significantly higher than b-BT (P = 0.026), and m-BT (P = 0.0001), while no difference was found between b-BT and m-BT (P = 0.321). NT tissue boundary external to the nodule was found at 6.0 ± 0.5 mm in cancers and 4.0 ± 0.5 mm in benignancies (P = 0.001). These data should indicate that the tissue surrounding a thyroid nodule may be damaged even when assessed as normal by US. This is of interest to investigate the extranodular effects of thyroid tumors.

One in five subjects with normal thyroid ultrasonography has altered thyroid tests

The relation between thyroid ultrasonography and laboratory, and the relationship of thyroid volume with clinical and anthropometric parameters, are not well clarified. Aim of the study was to investigate normal and hypoechoic-inhomogeneous not nodular thyroid gland in predicting thyroid tests, and to assess the correlation of thyroid volume with several clinical parameters. The series included 434 subjects (244 with normal thyroid ultrasonography, and 190 with hypoechoic-inhomogeneous thyroid) at their first evaluation. Subjects with normal ultrasonography and skewed tests were re-evaluated after one year. All subjects with normal ultrasound showed normal free-T₄, while TSH was elevated in 9.8% of cases and thyroid antibodies were positive in another 9.8%. In patients with hypoechoic-inhomogeneous thyroid, free-T₄ was low in 33.2%, TSH was elevated in 78.4% and thyroid antibodies were positive in 76.3%. Normal ultrasonography matched with normal tests in 81.1% of cases while hypoechoic-inhomogeneous thyroid in 9.5% (p<0.001). The re-evaluation of tests showed no significant difference. In subjects with both normal ultrasonography and tests, thyroid volume was correlated with age (p=0.001), weight (p=0.003), BMI (p=0.04), body surface area (p=0.002). Thyroid laboratory assessment was different between subjects with ultrasonographically normal or hypoechoic-inhomogeneous thyroid. Thyroid volume of thyroid diseases-free subjects was correlated with age, weight, BMI and body surface area, and this should be of interest to investigate the references of normality of thyroid size.

Low concordance between positive antibodies to thyroperoxidase and thyroid ultrasound autoimmune pattern in pregnant women

The diagnostic and prognostic role of thyroid ultrasound (TUS) in pregnant women positive for antibodies to thyroperoxidase (TPOAb) is unclear. The aim of our study was to compare the relation of ultrasound thyroid texture to the thyroid laboratory tests in pregnant women and controls. Using a semi-quantitative assessment we compared TUS in two groups of women with positive TPOAb and/or with thyroid dysfunction (TSH out of 0.06-3.67 mIU/L): 186 women in 1(st) trimester of pregnancy recruited from universal screening and 67 asymptomatic age-comparable non-pregnant non-postpartum women recruited from screening of general population (controls). Women with previous history of thyroid diseases were excluded. Only 64/131 (48.9 %) of TPOAb-positive pregnant women were TUS-positive (TUS with autoimmune pattern) in comparison with 35/49 (71.4 %) TPOAb-positive controls (p <0.011). Pregnant women had more often TSH >10.0 mIU/L if they were TPOAb-positive/TUS-positive as compared to those TPOAb-positive/TUS-negative (8/64 (12.5 %) vs. 0/67 (0 %), p = 0.009). The prevalence of preterm deliveries among TPOAb-positive women was significantly lower if TPOAb-positivity was not accompanied by TUS-positivity (2/67 (3.0 %) vs. 10/64 (15.6 %) in TPOAb-positive/TUS-positive women, p = 0.028). In conclusion, nearly half of the TPOAb-positive pregnant women did not have an autoimmune pattern in TUS. Normal TUS image in TPOAb-positive pregnant women might be a protective factor for preterm delivery.