Real-time ultrasound elastography in the diagnosis of newly identified thyroid nodules in adults: the ElaTION RCT

Background

Strain and shear wave elastography which is commonly used with concurrent real-time imaging known as real-time ultrasound shear/strain wave elastography is a new diagnostic technique that has been reported to be useful in the diagnosis of nodules in several organs. There is conflicting evidence regarding its benefit over ultrasound-guided fine-needle aspiration cytology alone in thyroid nodules.

Objectives

To determine if ultrasound strain and shear wave elastography in conjunction with fine-needle aspiration cytology will reduce the number of patients who have a non-diagnostic first fine-needle aspiration cytology results as compared to conventional ultrasound-only guided fine-needle aspiration cytology.

Design

A pragmatic, unblinded, multicentre randomised controlled trial.

Setting

Eighteen centres with a radiology department across England.

Participants

Adults who had not undergone previous fine-needle aspiration cytology with single or multiple nodules undergoing investigation.

Interventions

Ultrasound shear/strain wave elastography-ultrasound guided fine-needle aspiration cytology (intervention arm) - strain or shear wave elastography-guided fine-needle aspiration cytology. Ultrasound-only guided fine-needle aspiration cytology (control arm) - routine ultrasound-only guided fine-needle aspiration cytology (the current standard recommended by the British Thyroid Association guidelines).

Main outcome measure

The proportion of patients who have a non-diagnostic cytology (Thy 1) result following the first fine-needle aspiration cytology.

Randomisation

Patients were randomised at a 1 : 1 ratio to the interventional or control arms.

Results

A total of 982 participants (80% female) were randomised: 493 were randomised to ultrasound shear/strain wave elastography-ultrasound guided fine-needle aspiration cytology and 489 were randomised to ultrasound-only guided fine-needle aspiration cytology. There was no evidence of a difference between ultrasound shear/strain wave elastography and ultrasound in non-diagnostic cytology (Thy 1) rate following the first fine-needle aspiration cytology (19% vs. 16% respectively; risk difference: 0.030; 95% confidence interval -0.007 to 0.066; p = 0.11), the number of fine-needle aspiration cytologies needed (odds ratio: 1.10; 95% confidence interval 0.82 to 1.49; p = 0.53) or in the time to reach a definitive diagnosis (hazard ratio: 0.94; 95% confidence interval 0.81 to 1.10; p = 0.45). There was a small, non-significant reduction in the number of thyroid operations undertaken when ultrasound shear/strain wave elastography was used (37% vs. 40% respectively; risk difference: -0.02; 95% confidence interval -0.06 to 0.009; p = 0.15), but no difference in the number of operations yielding benign histology - 23% versus 24% respectively, p = 0.70 (i.e. no increase in identification of malignant cases) - or in the number of serious adverse events (2% vs. 1%). There was no difference in anxiety and depression, pain or quality of life between the two arms.

Limitations

The study was not powered to detect differences in malignancy.

Conclusions

Ultrasound shear/strain wave elastography does not appear to have additional benefit over ultrasound-guided fine-needle aspiration cytology in the diagnosis of thyroid nodules.

Future work

The findings of the ElaTION trial suggest that further research into the use of shear wave elastography in the diagnostic setting of thyroid nodules is unlikely to be warranted unless there are improvements in the technology. The diagnostic difficulty in distinguishing between benign and malignant lesions still persists. Future studies might examine the role of genomic testing on fine-needle aspiration samples. There is growing use of targeted panels of molecular markers, particularly aimed at improving the diagnostic accuracy of indeterminate (i.e. Thy3) cytology results. The application of these tests is not uniform, and their cost effectiveness has not been assessed in large-scale trials.

Study registration

This study is registered as ISRCTN (ISRCTN18261857).

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/19/04) and is published in full in Health Technology Assessment; Vol. 28, No. 46. See the NIHR Funding and Awards website for further award information.

Normalized TSH strategy can improve the initial assessment of thyroid nodules

BACKGROUND

Serum thyrotropin (TSH) has been recommended for the initial assessment of patients with thyroid nodules to exclude functional thyroid nodules (FTN). However, the sensitivity of TSH is very low. The increased level of thyroid peroxidase antibody (TPOAb) is considered to be one of the reasons.

OBJECTIVE

To investigate whether normalized TSH (nTSH) can improve diagnostic efficiency by removing TPOAb interference in the first evaluation of thyroid nodules compared with traditional TSH strategy.

METHODS

Thyroid nodules were retrospectively analysed in 90 patients with FTN and 1038 patients with non-functioning thyroid nodules (non-FTN). The regression coefficient (β) of TPOAb affecting the TSH levels was assessed in patients with thyroid nodules, and then, the nTSH level was calculated based on the following formula: nTSH = TSH-β*TPOAb. We used nTSH levels to initially evaluate the thyroid nodules instead of the traditional TSH values and finally compared the results of the two strategies.

RESULTS

The sensitivity, specificity, accuracy, positive prediction rate (PPV) and negative prediction rate (NPV) of nTSH for accessing FTN were 50.00%, 87.70%, 84.67%, 26.01% and 95.29%, respectively, which were better than the values of 48.90%, 78.70%, 76.33%, 16.60% and 94.67% associated with TSH, respectively (p < 0.001).

CONCLUSION

Serum TPOAb testing is recommended for the first assessment of thyroid nodules. Normalized TSH levels can improve assessment efficiency compared to traditional TSH assessment, increase the specificity and reduce an unnecessary 99mTc-TS test.

Dynamic Perfusion Representation and Aggregation Network for Nodule Segmentation Using Contrast-Enhanced US

Dynamic contrast-enhanced ultrasound (CEUS) imaging has been widely applied in lesion detection and characterization, due to its offered real-time observation of microvascular perfusion. Accurate lesion segmentation is of great importance to the quantitative and qualitative perfusion analysis. In this paper, we propose a novel dynamic perfusion representation and aggregation network (DpRAN) for the automatic segmentation of lesions using dynamic CEUS imaging. The core challenge of this work lies in enhancement dynamics modeling of various perfusion areas. Specifically, we divide enhancement features into the two scales: short-range enhancement patterns and long-range evolution tendency. To effectively represent real-time enhancement characteristics and aggregate them in a global view, we introduce the perfusion excitation (PE) gate and cross-attention temporal aggregation (CTA) module, respectively. Different from the common temporal fusion methods, we also introduce an uncertainty estimation strategy to assist the model to locate the critical enhancement point first, in which a relatively distinguished enhancement pattern is displayed. The segmentation performance of our DpRAN method is validated on our collected CEUS datasets of thyroid nodules. We obtain the mean dice coefficient (DSC) and intersection of union (IoU) of 0.794 and 0.676, respectively. Superior performance demonstrates its efficacy to capture distinguished enhancement characteristics for lesion recognition.

Increased workload without clinical benefit: Results following implementation of the ACR-TIRADS system for thyroid nodules

OBJECTIVE

The ACR-TIRADS system for stratifying thyroid nodule malignancy risk has been widely promoted and implemented. We audited its introduction at a large public hospital in Auckland, New Zealand.

DESIGN

Audit of outcomes following thyroid nodule fine needle aspiration (FNA) before/after ACR-TIRADS.

PATIENTS

Individuals undergoing thyroid FNA 2017-2019.

MEASUREMENTS

From medical records, we obtained details from the pre-FNA ultrasound (nodule size, TIRADS points/levels, radiologist recommendation for FNA), Bethesda (B) cytology classification, histology and post-FNA follow-up.

RESULTS

Four hundred and twenty-two individuals had 564 FNAs, 163 had surgery and 54 (13%) had cancer in the primary nodule. 37/54 (69%) cancers were papillary thyroid carcinoma (median size 25 mm, 87% ≥10 mm, 61% ≥20 mm). Following ACR-TIRADS introduction, FNA recommendations increased greater than twofold, FNAs performed by 71%-83%, and the monthly rate of FNAs and operations by 60% and 40%, respectively. However, the proportion of cancers/FNA remained similar (9.9% post-TIRADS vs. 8.7% pre-TIRADS). The proportions of FNA results remained stable for B2-B4 categories, but doubled (11% vs. 5%) for B5-B6: 15 FNAs were needed to identify an additional B5/B6 lesion. TIRADS-5 nodules had a higher proportion of B5/B6 (20%) and a lower proportion of B2 (30%) than TIRADS-3 (2%, 57%, respectively) and TIRADS-4 (9%, 56%) nodules. About 5 additional cancers/year were diagnosed, but they were more often small (49% vs. 8% <2 cm, 17% vs. 0% <1 cm).

CONCLUSION

ACR-TIRADS introduction increased workload (FNAs and operations), without increasing the proportion of cancers/FNA. It led to a few more cancers being diagnosed, but many were small and of uncertain clinical significance.

Differentiation of Thyroid Nodules (C-TIRADS 4) by Combining Contrast-Enhanced Ultrasound Diagnosis Model With Chinese Thyroid Imaging Reporting and Data System

Objectives

To establish a contrast-enhanced ultrasound (CEUS) diagnostic schedule by CEUS analysis of thyroid nodules of C-TIRADS 4. To establish a CEUS-TIRADS diagnostic model to differentiate thyroid nodules (C-TIRADS 4) by combining CEUS with Chinese thyroid imaging reporting and data system (C-TIRADS).

Methods

A total of 228 thyroid nodules (C-TIRADS 4) were estimated by CEUS. The arrival time, enhancement degree, enhancement homogeneity, enhancement pattern, enhancement ring, and wash-out time were analyzed in CEUS for all of the nodules. Multivariate factors logistic analysis was performed and a CEUS diagnostic schedule was established. If the nodule had a regular hyper-enhancement ring or got a score of less than 2 in CEUS analysis, CEUS-TIRADS subtracted 1 category. If the nodule got a score of 2 in the CEUS schedule, the CEUS-TIRADS category remained the same as before. If the nodule got a score of more than 2 in the CEUS schedule, CEUS-TIRADS added 1 category. When it reflected an absent enhancement in CEUS, the nodule was judged as CEUS-TIRADS 3. All of the C-TIRADS 4 nodules were re-graded by CEUS-TIRADS. We then compare the diagnosis performance of C-TIRADS, CEUS, and CEUS-TIRADS by sensitivity, specificity, and accuracy.

Results

Among the 228 C-TIRADS 4 nodules, 69 were determined as C-TIRADS 4a, 114 were C-TIRADS 4b, and 45 were C-TIRADS 4c. The sensitivity, specificity, and accuracy of C-TIRADS were 93.1%, 55.3%, and 74.6% respectively. The area under the curve was 0.753. Later arrival time, hypo-enhancement, heterogeneous enhancement, centripetal enhancement, and rapid washout were risk factors of malignancy in multivariate analysis. The sensitivity, specificity, and accuracy of CEUS were 78.7%, 87.5%, and 83.3% respectively. The area under the curve was 0.803. By CEUS-TIRADS diagnostic model combining CEUS with C-TIRADS, a total of 127 cases were determined as malignancy (111 were malignant and 16 were benign) and 101 were diagnosed as benign ones (5 were malignant and 96 were benign). The sensitivity, specificity, and accuracy of CEUS-TIRADS were 95.7%, 85.7%, and 92.1% respectively. The area under the curve was 0.916. The diagnostic performance of CEUS-TIRADS was significantly better than CEUS and C-TIRADS. The difference was statistically significant (P<0.05).

Conclusions

The diagnostic schedule of CEUS could get better diagnostic performance than US in the differentiation of thyroid nodules. The CEUS-TIRADS combining CEUS analysis with C-TIRADS could make up for the deficient sensibility of C-TIRADS, showing a better diagnostic performance than US and CEUS.

"Double-Flash": An Innovative Method to Diagnose Papillary Thyroid Microcarcinomas

The aim of the study was to investigate the diagnostic ability of an innovative method called "Double-Flash" during contrast-enhanced ultrasound (CEUS) examination in papillary thyroid microcarcinomas. A total of 43 nodules measuring <10 mm and with definite pathology confirmed by surgery or fine-needle aspiration biopsy (FNAB) were included in this study. The bottom of "Flash" was pressed in the 40th and 60th seconds, respectively, defined as "Double-Flash." The curve of reperfusion was evaluated and the diagnostic value of "Double-Flash" was compared with that of CEUS. Pathologic results obtained by surgery or FNAB revealed there were 27 malignant and 16 benign nodules. The sensitivity, specificity and accuracy of CEUS were 70.0%, 53.8% and 65.1%. With "Double-Flash," the sensitivity, specificity and accuracy were 92.3%, 82.3% and 88.4%, respectively. The difference was statistically significant. Higher diagnostic ability is obtained with "Double-Flash." The parameter based on the new method could improve the diagnostic performance of quantitative diagnosis in CEUS. The change in the perfusion curve after "Flash" may be a strong indicator of malignancy.

The combination of ATA classification and FNA results can improve the diagnostic efficiency of malignant thyroid nodules

PURPOSE

To determine the diagnostic efficiency of the ATA classification and ultrasound-guided fine-needle aspiration (FNA) results in identifying the risk factors of malignancy, we analyzed the thyroid nodules of patients who underwent thyroidectomy and compared preoperative ATA classifications with FNA results.

METHODS

We retrospectively analyzed 274 nodules of 196 patients who underwent ultrasonography, FNA and thyroidectomy. Histopathological findings of thyroid nodules were considered as the Au standard in the analysis of the diagnostic efficiency of the ATA classification and FNA results. Univariate analysis and binary multivariate logistic regression analysis were applied to identify the ultrasound features associated with malignancy.

RESULTS

The overall malignancy rate of 274 nodules was 41.6%. The areas under the ROC curves (AUCs) for the ATA classification and FNA results were 0.88 and 0.878, respectively (P < 0.001). The sensitivity and specificity of the ATA classification were 86 and 86.9%, whereas those of FNA results were 68.5 and 91.4%, respectively. The specificity (98.7%) and sensitivity (94.3%) increased after the combined use of the ATA classification and FNA results. Taller-than-wide shape, microcalcifications, hypoechogenicity and irregular margins were independent risk factors for malignancy. Microcalcifications had the highest OR (7.58), and taller-than-wide shape had the highest specificity in BSRTC I, II, III and IV cytology.

CONCLUSION

The diagnostic efficiency of the ATA classification and FNA results in identifying malignant nodules was high, and the use of both criteria improved the diagnostic accuracy. Taller-than-wide shape, microcalcifications, hypoechogenicity and irregular margins were independent risk factors for malignancy.

Examination of Malignant Findings of Thyroid Nodules Using Thyroid Ultrasonography

Background

It is important to distinguish benign thyroid nodules from malignant thyroid nodules. Hence, this study aimed to determine the characteristics of patients with thyroid cancer using thyroid ultrasonography.

Methods

We retrospectively examined the ultrasonographic findings of 327 patients with 457 thyroid nodules (age: 59.9 ± 14.3 years; sex, n (%): female 242 (74.0%)) at a single center from 2014 to 2016. Ultrasonography was used to determine the nodule size, shape, border, internal echogenicity, presence of coarse calcifications and microcalcifications within the nodule, internal blood flow and whether the nodule was solid or contained cystic structures. Thyroid fine needle aspiration cytology (FNAC) was performed in all patients. The ultrasonographic findings were compared between patients with benign nodules and those with papillary thyroid carcinoma (PTC). Furthermore, in the analysis of anti-thyroglobulin (Tg) antibody-negative patients with single nodules, values of serum Tg/nodule volume were calculated and compared between patients with benign nodules and those with PTC.

Results

There were 298 (65.2%) benign nodules, 33 (7.2%) PTCs and 126 (27.6%) others (104 follicular neoplasms, 19 masses of undetermined significance and three other malignant tumors). The nodules diagnosed as PTC had significantly lower internal echogenicity (P < 0.01), more microcalcifications (P < 0.01) and comprised more nodules rich in blood flow (P < 0.05) than benign nodules. Solid nodules were found significantly more in the PTC group (P < 0.01). The serum Tg/nodule volume ratio was significantly higher in the PTC group (P < 0.05).

Conclusions

Findings suggestive of PTC were found from images obtained using thyroid ultrasonography. In the diagnosis of PTC, the frequency of FNAC examinations should be reduced as this method is costly and invasive.

Contrast-enhanced ultrasound for the differential diagnosis of thyroid nodules: An updated meta-analysis with comprehensive heterogeneity analysis

The diagnostic accuracy of contrast-enhanced ultrasound (CEUS) for distinguishing malignant thyroid nodules from benign thyroid nodules remains controversial. This meta-analysis was performed to evaluate the overall diagnostic value of CEUS for the characterization of thyroid nodules. Relevant studies were identified by searching PubMed, Embase and the Cochrane Library until August 1th 2019 to assess the overall diagnostic accuracy of CEUS. 37 eligible studies were included in the present meta-analysis. The pooled sensitivity, specificity, positive likelihood rate, negative likelihood rate and diagnostic odds ratio of CEUS were 0.87, 0.83, 5.38, 0.17 and 38.94, respectively, with the AUC of 0.9263. Subgroup analysis showed the heterogeneity was greatly reduced in small nodules group (≤ 1 cm) (I2 = 0.0%), while heterogeneity was still observed in the group of variable sizes group (I2 = 69.5%). However, meta-regression analysis revealed that only diagnostic criterion was the major source of heterogeneity (p = 0.0259). The risk of publication bias was negligible (p = 0.35). CEUS exhibited high accuracy for the identification of thyroid nodules and might provide additional perfusion information for the current US imaging reporting systems.

Effectiveness evaluation of computer-aided diagnosis system for the diagnosis of thyroid nodules on ultrasound: A systematic review and meta-analysis

BACKGROUND

More and more automated efficient ultrasound image analysis techniques, such as ultrasound-based computer-aided diagnosis system (CAD), were developed to obtain accurate, reproducible, and more objective diagnosis results for thyroid nodules. So far, whether the diagnostic performance of existing CAD systems can reach the diagnostic level of experienced radiologists is still controversial. The aim of the meta-analysis was to evaluate the accuracy of CAD for thyroid nodules' diagnosis by reviewing current literatures and summarizing the research status.

METHODS

A detailed literature search on PubMed, Embase, and Cochrane Libraries for articles published until December 2018 was carried out. The diagnostic performances of CAD systems vs radiologist were evaluated by meta-analysis. We determined the sensitivity and the specificity across studies, calculated positive and negative likelihood ratios and constructed summary receiver-operating characteristic (SROC) curves. Meta-analysis of studies was performed using a mixed-effect, hierarchical logistic regression model.

RESULTS

Five studies with 536 patients and 723 thyroid nodules were included in this meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio (DOR) for CAD system were 0.87 (95% confidence interval [CI], 0.73-0.94), 0.79 (95% CI 0.63-0.89), 4.1 (95% CI 2.5-6.9), 0.17 (95% CI 0.09-0.32), and 25 (95% CI 15-42), respectively. The SROC curve indicated that the area under the curve was 0.90 (95% CI 0.87-0.92). The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and DOR for experienced radiologists were 0.82 (95% CI 0.69-0.91), 0.83 (95% CI 0.76-0.89), 4.9 (95% CI 3.4-7.0), 0.22 (95% CI 0.12-0.38), and 23 (95% CI 11-46), respectively. The SROC curve indicated that the area under the curve was 0.96 (95% CI 0.94-0.97).

CONCLUSION

The sensitivity of the CAD system in the diagnosis of thyroid nodules was similar to that of experienced radiologists. However, the CAD system had lower specificity and DOR than experienced radiologists. The CAD system may play the potential role as a decision-making assistant alongside radiologists in the thyroid nodules' diagnosis. Future technical improvements would be helpful to increase the accuracy as well as diagnostic efficiency.

Retrospective Application of the 2015 American Thyroid Association Guidelines for Ultrasound Classification, Biopsy Indications, and Follow-up Imaging of Thyroid Nodules: Can Improved Reporting Decrease Testing?

INTRODUCTION

Thyroid ultrasound has been widely used to determine which nodules need further investigation. The goal of this study is to determine if using an ultrasonographic features checklist based on 2015 American Thyroid Association (ATA) guidelines can improve reporting and decrease unnecessary further testing.

METHODS

In this retrospective study, ultrasonographic images of all nodules biopsied at our institution in 2014 and 2015 were reviewed by radiologists blinded to fine needle aspiration (FNA) biopsy result using a checklist. The checklist was prepared based on 2015 ATA guidelines. The ultrasonographic characteristics of thyroid nodules were compared with the result of biopsy to determine positive predictive value (PPV), negative predictive value (NPV), sensitivity, and specificity for predicting malignancy. Radiologists also made an overall recommendation on need for FNA.

RESULTS

A total of 425 thyroid nodule ultrasound scans were reviewed by radiologists. Biopsy results of 31 nodules were malignant and 394 were non-malignant. Malignant nodules showed higher frequency of solid composition, hypoechoechogenicity, and cervical lymph node involvement compared to benign nodules. Solid nodule composition had the highest PPV (13%) and NPV (94.7%). Extra-thyroid extension had the highest specificity (90.1%). Lesion vascularity had the highest sensitivity (83.8%), followed by hypoechogenicity (65.6%). Overall, the checklist had a positive predictive value of 9%, negative predictive value of 97.5%, sensitivity of 96.8%, and specificity of 11.14%. Radiologists determined that 10% of the nodules were very low-risk and did not require FNA.

CONCLUSION

Using a checklist based on 2015 ATA guideline thyroid nodule ultrasonographic features is a sensitive tool with high NPV to predict benign thyroid nodule, thereby preventing unnecessary FNAs.

Follow-up of Benign Thyroid Nodules—Can We Do Less?

Objective

To determine the incidence of malignancy, follow-up ultrasound (US), and repeat fine needle aspiration (FNA) in thyroid nodules that have been previously biopsied as benign.

Methods

This is a retrospective, descriptive study of benign thyroid nodules evaluated by US between 2010-2011. We determined the frequency of follow-up ultrasounds and FNAs, mean years of follow-up, interval between follow-up US, change in nodule size, reasons for repeat FNA (rFNA), frequency of thyroidectomy, and thyroid malignancy during 5 years of follow-up.

Results

A total of 733 benign thyroid nodules were reviewed in 615 patients. Mean years of US follow-up was 3.47 ± 1.65 years; 275 (37.5%) had no follow-up US; 109 (14.9%) had 1 follow-up US; 93 (12.7%) had 2 follow-up US; and 256 (34.9%) had 3 or more follow-up US. Assessment of thyroid nodule size showed that 215 (28.8%) nodules decreased in size, 145 (19.4%) increased in size by less than 50%, and 91 (12.1%) increased in size by more than 50%. Of the 733 nodules, 17 nodules (2.3%) underwent thyroidectomy for which the pathology result of 9 (1.2%) showed malignancy, and 65 (8.9%) thyroid nodules underwent rFNA. When applying the 2015 recommendations for repeat FNA, 35% were done unnecessarily.

Conclusion

In our sample of initially benign thyroid nodules, only 9 patients (1.2%) had pathology-proven malignancy after a mean follow-up of 3.5 years. Over 30% of patients had more than 3 rUSs. Decreased interval and frequency of rUS should be considered in future guidelines for thyroid management.

Diagnostic value of ultrasonography and TI-201/Tc-99m dual scintigraphy in differentiating between benign and malignant thyroid nodules

PURPOSE

To evaluate the performance of ultrasonography (US) and TI-201/Tc-99m dual (Tl/Tc) scintigraphy in differentiating between benign and malignant thyroid nodules.

METHODS

Eighty-six patients diagnosed to have a thyroid tumor on postoperative histopathologic examination between June 2009 and February 2017 were included in this retrospective study. A radiologist reviewed the US and Tl/Tc scintigraphy reports along with all available clinical and histopathologic information. On Tl/Tc scintigraphy, a nodule in which uptake was higher in the delayed phase than in the surrounding parenchyma was defined as a delayed accumulation pattern and a nodule in which uptake was higher in the delayed phase than in the early phase was defined as a persistent pattern. The Tl/Tc scintigraphy images were evaluated in a blinded manner to assess reproducibility. A statistical analysis was performed to identify features associated with malignancy. Interobserver variability was calculated using the κ statistic.

RESULTS

US had higher sensitivity (81.2%), specificity (88.2%), and positive (96.6%) and negative (53.6%) predictive values than Tl/Tc scintigraphy. An ill-defined margin and microcalcification were independent predictors of a malignant thyroid nodule on multivariate logistic regression (P = 0.003 and P = 0.014, respectively). The persistent pattern had high specificity (85.7%) equivalent to that of US but had lower sensitivity (34.7%). The κ values for the delayed accumulation and persistent patterns were 0.66-0.78 and 0.32-0.50, respectively.

CONCLUSIONS

An ill-defined margin and microcalcification on US were independent predictors of a malignant thyroid nodule. A persistent pattern seen on Tl/Tc scintigraphy could contribute to the differential diagnosis.

Significance of contrast-enhanced ultrasonography in differential diagnosis of thyroid nodules

The present study was aimed to compare the application values between 2-dimensional color Doppler ultrasonography (2DUS) and contrast-enhanced ultrasonography (CEUS) in the differential diagnosis of thyroid malignant nodules.A total of 124 patients suspectedly diagnosed with malignant thyroid nodules under conventional gray-scale ultrasonography were recruited in this study. All enrolled patients were examined by both 2DUS and CEUS.A total of 153 nodules (94.44%) and 45 cases (90.00%) with malignant nodules were detected by the CEUS. No significant differences were noted in nodule detection rates between 2DUS and CEUS (χ = 1.170, P = .279; χ = 0.796, P = .372). The aspect ratio, microcalcification, internal echo, borderline, Vmax, resistance index, and total scores of malignant nodules were higher than those of benign nodules (all P < .05) when diagnosed by 2DUS. The peripheral/internal enhancement time, peak intensity, local enhancement, ring enhancement, and total scores of malignant nodules were significantly higher compared with those of benign nodules (all P < .05) by CEUS. Total score of malignant nodules diagnosed by 2DUS was approximately 3.5 and 2.3 points for CEUS. The diagnostic accuracy of 2DUS as observed by area under the curve was 0.821 with the cut-off value of 3.9, the sensitivity was 82.5%, and the specificity was 85.6%. The diagnostic accuracy of CEUS was 0.862 with the cut-off value of 2.8, the sensitivity was 86.7%, and the specificity was 91.3%.Both 2DUS and CEUS are worthy of application values in the differential diagnosis from benign to malignant thyroid nodules.

Simulation of expected childhood and adolescent thyroid cancer cases in Japan using a cancer-progression model based on the National Cancer Registry: Application to the first-round thyroid examination of the Fukushima Health Management Survey

During the 4 years following the nuclear power plant accident of 2011, 39 males and 77 females were diagnosed with or suspected of having cancer based on the first-round thyroid examination of the Fukushima Health Management Survey (FHMS) targeting residents aged <19 years in Fukushima. Prior comparisons between the observed data and Japan's National Cancer Registry (NCR) data suggested that this incidence might be excessive, but such comparisons are problematic because they need not only to adjust index unit (prevalence proportion vs incidence rate), but also examine characteristics (complete enumeration mass screening for the aged 0 to 18 years vs detections in clinical settings for all the residents) and sensitivity of the examinations. The purpose of this study is to build a common model applicable to any region in Japan under nonaccident conditions, and estimate the expected prevalence based on the numbers of subjects surveyed in the FHMS using a simulation of the sensitivity.The cancer-progression model is an extension of Day and Walter's, the parameters of which were estimated by minimizing the weighted root mean squared error between the average age-specific thyroid incident rates from 2001 to 2010 in the NCR and those determined by the model. We estimated expected detectable prevalent cases by the model with their examination-participation proportions and simulated several sensitivities.Median sojourn times were 34 years (males) and 30 years (females) by the model. Simulation results showed that the numbers of observed prevalent cases were within the 95% confidence intervals of the expected prevalent cases with several sensitivities in each gender.We successfully built a cancer-progression model of thyroid cancer based on Japan's NCR data under no accident conditions. It is a tool for comparing the observed prevalence data of examinations and the NCR data, which resolved 3 issues of index unit, the characteristics and sensitivity of the examinations. Simulation results imply that the number of observed thyroid cancer cases can be detected by the FHMS first-round thyroid screening at several sensitivities under no accident conditions.

Breast cancer metastasis to thyroid: a retrospective analysis

Background

Breast cancers metastasizing to thyroid gland are relatively uncommon in clinical practice.

Objective

Retrospective analysis of data from breast cancer patients with thyroid metastasis (TM).

Methods

The US suspected, fine-needle aspiration cytology (FNAC) confirmed TM in breast cancer patients, treated between 2005 and 2015 at our hospital, was retrospectively analyzed. The data were re-evaluated by the pathologist and radiologist who were blinded to the patients' data.

Results

FNAC and immunohistochemistry confirmed the ultrasonography (US) suspected TM in eight breast cancer patients. Clinically both unilateral and bilateral TM was seen, which were symptomless and metachronously (6–121 months) metastasized. Six of eight cases exhibited recurrence/distant metastasis and were treated with chemotherapy/thyroidectomy of which two cases passed away. The remaining two patients had no recurrences/distant metastases and were treated with partial/total thyroidectomy. Post-chemotherapy US showed more homogenous thyroid parenchyma with gathering of calcification that reduced in size, revealing the sensitiveness of TM to chemotherapy.

Conclusion

US was useful in screening TM in breast cancer patients. Both partial and total thyroidectomy was effective in disease free survival of isolated TM cases, with controlled primary condition. TM responded well to chemotherapy in most of the recurrent breast cancer cases with or without distant metastasis.

Partially cystic thyroid nodules in ultrasound-guided fine needle aspiration: Prevalence of thyroid carcinoma and ultrasound features

Partially cystic thyroid nodules (PCTNs) are common on ultrasound (US). However, there are insufficient data on the prevalence of thyroid carcinoma among such nodules. The purpose of this study was thus to evaluate the prevalence and differentiation of partially cystic thyroid cancers in US-guided fine needle aspiration (FNA).A total of 1342 consecutive patients with 1360 thyroid nodules underwent prospective US diagnosis and FNA biopsy. In total, 281 nodules (20.7%) were partially cystic lesions. The nodules were prospectively analyzed based on US features (ie, solid portion positions, shapes, margins, and microcalcifications) and US diagnosis (benign, suspicious, or malignant).Of the 281 partially cystic lesions, 22 nodules (8%) had inadequate FNA results, 14 nodules were diagnosed as malignant, 9 were suspicious for malignancy, and 236 were benign on FNA. Thirteen cancers were confirmed upon surgical histopathology examination or FNA, yielding a 4.6% rate of malignancy. Twelve of these cancers were papillary carcinomas, and 1 was an anaplastic carcinoma. The following individual sonographic characteristics had a statistically significant association with thyroid cancer: nodule composition (solid portion ≥50%, P = .000), eccentric solid portion (P = .001), irregular nodule shape (P = .000), microcalcification (P = .000), and intranodular vascularity (P = .001). The sensitivity, specificity, and accuracy of the US-based diagnoses were 84.6%, 84.0%, and 84.0%, respectively.Fewer than 5% of the partially cystic nodules in this FNA series were malignant. Sonographic characteristics can be used to prioritize nodules for FNA biopsy.

Thyroid Cancer: Ultrasound Imaging and Fine-Needle Aspiration Biopsy

Ultrasound is critical in detection, diagnosis, and management of thyroid nodules. Ultrasound detection of regional nodal metastatic disease is based on abnormal nodal morphology rather than size and is critical to initial surgical and long-term management of thyroid cancer. Fine-needle aspiration biopsy is the gold standard for malignancy diagnosis in thyroid cancer. Thyroglobulin assay of nodal aspirates improves accuracy in diagnosis of metastases. Reporting lexicons assign risk levels to thyroid nodules with the goal of improving and standardizing patient management. Surveillance ultrasound in papillary microcarcinomas is being evaluated and compared with surgical management.

Is TSH necessary for initial assessment of thyroid nodules?

OBJECTIVE

The use of thyrotropin (TSH) in the initial assessment of thyroid nodules is inefficient and leads to unnecessary assessment costs. We compared the total costs of thyroid nodule assessment with or without the use of TSH in the initial assessment.

METHODS

A total of 1808 patients with thyroid nodules received TSH, fine-needle aspiration (FNA) and thyroid scintigraphy (TS) assessment, including 83 autonomously functioning thyroid nodule (AFTN) cases and 1725 non-AFTN cases. The total costs of the TSH strategy and non-TSH strategies were compared. The ratio of single-use costs of FNA to TS (C_FNA/TS ) was used as the main outcome measure.

RESULTS

Only when 6·03 ≤ C_FNA/TS ≤ 27·17, the lowest total costs were associated with using the conventional TSH strategy. When C_FNA/TS <6·03 or C_FNA/TS >27·17, the lowest costs were found with FNA and TS, respectively.

CONCLUSION

From the perspective of cost economics, in iodine-sufficient areas, we recommend that the decision on the use of TSH for the initial assessment of thyroid nodules should be based on the testing costs of FNA and TS in that medical unit.

Evaluation of Thyroid Nodules by a Scoring and Categorizing Method Based on Sonographic Features

OBJECTIVES

To assess sonographic features of thyroid nodules associated with malignancy and to establish a scoring and categorizing method based on sonographic features.

METHODS

A total of 2445 patients with 2445 thyroid nodules were included and divided into 2 groups: benign (1493 cases) and malignant (952 cases). First, 10 sonographic features, including shape, border, margin, internal content, echogenicity, microcalcifications, posterior echo, halo, vascularization distribution, and vascularization degree, were defined, and all nodules were retrospectively evaluated. Second, the features associated with malignancy were selected by statistical analysis and were assigned weightings according to their odds ratios. Third, a total score for each nodule was obtained after the assigned weightings of the suspicious features were summed. Fourth, the malignancy rate of each total score was calculated. Then a modified version of the Thyroid Imaging Reporting and Data System (TI-RADS) was established with reference to the American College of Radiology's Breast Imaging Reporting and Data System.

RESULTS

Seven independent features associated with malignancy were a taller-than-wide shape, an obscure border, an irregular margin, solid internal content, marked hypoechogenicity and hypoechogenicity, microcalcifications, and an internal vascularization distribution. The TI-RADS included 5 categories with different malignancy rates: category 3 (<2%), 4A (2%-5%), 4B (5%-50%), 4C (50%-90%), and 5 (≥ 90%).

CONCLUSIONS

A modified version of TI-RADS was established on the basis of the sonographic features with different weightings according to the relative risk of malignancy. This system could be of great use in predicting the nature of thyroid nodules in a quantified and standardized way and also helping clinicians decide on the clinical management.

Focal Lymphocytic Thyroiditis Nodules Share the Features of Papillary Thyroid Cancer on Ultrasound

PURPOSE

It is often difficult to discriminate focal lymphocytic thyroiditis (FLT) or adenomatous hyperplasia (AH) from thyroid cancer if they both have suspicious ultrasound (US) findings. We aimed to make a predictive model of FLT from papillary thyroid cancer (PTC) in suspicious nodules with benign cytologic results.

MATERIALS AND METHODS

We evaluated 214 patients who had undergone fine-needle aspiration biopsy (FNAB) and had shown thyroid nodules with suspicious US features. PTC was confirmed by surgical pathology. FLT and AH were confirmed through more than two separate FNABs. Clinical and biochemical findings, as well as US features, were evaluated.

RESULTS

Of 214 patients, 100 patients were diagnosed with PTC, 55 patients with FLT, and 59 patients with AH. The proportion of elevated thyrotropin (TSH) levels (p=0.014) and thyroglobulin antibody (Tg-Ab) or thyroid peroxidase antibody (TPO-Ab) positivity (p<0.001) in the FLT group was significantly higher than that in the PTC group. Regarding US features, absence of calcification (p=0.006) and "diffuse thyroid disease" (DTD) pattern on US (p<0.001) were frequently seen in the FLT group. On multivariate analysis, Tg-Ab positivity, presence of a DTD pattern on US, and absence of calcification in nodules were associated with FLT with the best specificity of 99% and positive predictive value of 96%. In contrast, a taller than wide shape of nodules was the only variable significant for differentiating AH from PTC.

CONCLUSION

Suspicious thyroid nodules with cytologic benign results could be followed up with US rather than repeat FNAB, if patients exhibit Tg-Ab positivity, no calcifications in nodules, and a DTD pattern on US.

The predictive value of structured ultrasonographic staging for thyroid nodules

BACKGROUND

'R staging' is a new ultrasonographic scoring system developed and used by our specialist head and neck radiologist for reporting sonographic risk of malignancy to those at our thyroid multidisciplinary team meeting. This study aimed to: classify the R staging system, examine its relationship with the eventual histopathological diagnosis and define its clinical utility.

METHODS

The pre-operative ultrasound scans of 78 patients were assigned an R status by our specialist head and neck radiologist. The final histopathology report for each thyroid nodule was used as the 'gold standard' for analysis.

RESULTS

When thyroid nodules were classified as low risk (R stages 1-3) or high risk (R stages 4-5) for malignancy, the sensitivity of R staging was 74.2 per cent and specificity was 80.9 per cent. An R5 status was 100 per cent predictive of malignancy.

CONCLUSION

Our results compare favourably with other suggested ultrasonographic staging systems for thyroid nodules.

A Review on Ultrasound-Based Thyroid Cancer Tissue Characterization and Automated Classification

In this paper, we review the different studies that developed Computer Aided Diagnostic (CAD) for automated classification of thyroid cancer into benign and malignant types. Specifically, we discuss the different types of features that are used to study and analyze the differences between benign and malignant thyroid nodules. These features can be broadly categorized into (a) the sonographic features from the ultrasound images, and (b) the non-clinical features extracted from the ultrasound images using statistical and data mining techniques. We also present a brief description of the commonly used classifiers in ultrasound based CAD systems. We then review the studies that used features based on the ultrasound images for thyroid nodule classification and highlight the limitations of such studies. We also discuss and review the techniques used in studies that used the non-clinical features for thyroid nodule classification and report the classification accuracies obtained in these studies.

Correlation between maximum intensity and microvessel density for differentiation of malignant from benign thyroid nodules on contrast-enhanced sonography

OBJECTIVES

The purpose of this study was to retrospectively evaluate contrast-enhanced sonography for differentiation of benign and malignant thyroid nodules by analyzing the correlation between maximum intensity and microvessel density.

METHODS

From February 2010 to May 2012, 122 patients (85 female and 37 male; mean age ± SD, 45 ± 9.1 years) with thyroid nodules (62 papillary thyroid carcinomas, 30 nodular goiters, and 30 adenomas) that underwent routine thyroid sonography and were diagnosed by surgery were included in this study. Contrast-enhanced sonography was performed, and enhancement patterns were classified into 3 groups: high, equal, and low enhancement. As a time-intensity curve parameter, the correlation of maximum intensity with CD31 and CD34 microvessel density counts was analyzed.

RESULTS

On contrast-enhanced sonography, most patients with papillary thyroid carcinomas showed a heterogeneous low enhancement pattern, whereas most patients with nodular goiters showed an equal enhancement pattern, and patients with adenomas showed a high enhancement pattern. The detection of papillary thyroid carcinomas with low enhancement had sensitivity of 96.8%, specificity of 95.0%, and accuracy of 95.9%. Compared with the papillary thyroid group, the mean microvessel density counts were significantly higher in the nodular goiter and adenoma groups (P< .05). We also found that the maximum intensity was significantly associated with CD31 and CD34 counts (CD31, r = 0.963; P < .01; CD34, r = 0.968; P < .01).

CONCLUSIONS

Maximum intensity has a significant relationship with microvessel density. Contrast-enhanced sonography is a practical and convenient means for differentiating benign from malignant thyroid nodules.

Thyroid nodules with macrocalcification: sonographic findings predictive of malignancy

PURPOSE

To analyze which sonographic features of thyroid nodules with macrocalcifications were predictable of thyroid malignancy.

MATERIALS AND METHODS

We reviewed sonographic findings of 854 macrocalcified thyroid nodules in patients who underwent fine needle aspiration biopsy between December 2009 and January 2011. There were 171 non-diagnostic aspirations, 34 nodules with category 3, 4, 5 based on Bethesda system, which were not confirmed by surgery, and these nodules were excluded from the analysis. Sonographic characteristics of the macrocalcifications including its thickness, interruption, and existence of soft tissue rim outside the macrocalcification were analyzed. Other sonographic characteristics of nodules such as shape, margin, composition, echo pattern, vascularity, and underlying parenchymal echogenicity were also evaluated. The correlation of sonographic features with cytopathologic results and the diagnostic performance of sonographic features for the prediction of malignancy were analyzed.

RESULTS

Among 649 nodules, 179 (27.6%) nodules were malignant and 470 (72.4%) nodules were benign. Among the features of the macrocalcification, interruption, irregular thickness, or the presence of soft tissue outside calcification rim were associated with malignancy (p<0.001). A high sensitivity and negative predictive values for the prediction of malignancy was found in sonographic characteristics of irregular thickness (92.2% and 91.0%, respectively) and the presence of soft tissue (88.5% and 88.8%, respectively).

CONCLUSION

Sonographic characteristics of macrocalcification such as interruption, irregular thickness and the presence of soft tissue rim were associated with malignancy in thyroid nodules with macrocalcifications.

Diagnostic performances of various gray-scale, color Doppler, and contrast-enhanced ultrasonography findings in predicting malignant thyroid nodules

BACKGROUND

Ultrasonography is the most frequently used clinical tool for the identification, assessment, and follow-up of thyroid nodules. The purpose of this research was to evaluate the value of diagnostic ultrasonography indicators, to obtain rankings of the most valuable indicators in the differential diagnosis of thyroid nodules, and to analyze the optimal diagnostic points and clinical values.

METHODS

One hundred forty-four patients with 172 thyroid nodules underwent preoperative ultrasonography examinations, including gray-scale ultrasonography (GSUS), color Doppler ultrasonography (CDUS), and contrast-enhanced ultrasonography (CEUS). Fourteen indicators of thyroid nodules on GSUS, CDUS, and CEUS were selected to evaluate all thyroid nodules. The differences between the benign and malignant thyroid nodules in all indicators were analyzed by the chi-squared test; the diagnostic ultrasonography values were obtained by logistic regression; and the optimal diagnostic points were explored by receiver operating characteristic curve analysis.

RESULTS

Of the 172 thyroid nodules that were surgically removed, 78 were benign and 94 were malignant. Ten indicators of GSUS and CEUS showed significant differences between the benign and malignant nodules (p<0.05), whereas four CDUS indicators had no value. The rankings of the valuable indicators were obtained according to their odds ratios (ORs). The top four indicators were ring enhancement and homogeneity of enhancement on CEUS, and microcalcification and halo on GSUS. These indicators were the most valuable, with ORs of greater than 20 in the differential diagnosis of benign and malignant thyroid nodules. The other six indicators-the relative arrival time of the nodule on CEUS, interior echogenicity on GSUS, peak interior echogenicity on CEUS, shape on GSUS, peak peripheral echogenicity on CEUS, and orientation on GSUS-were also valuable, with ORs less than 20. The areas under the receiver operating characteristic curves for GSUS, CEUS, and the combination of GSUS and CEUS in the diagnosis of thyroid nodules were 0.936, 0.910, and 0.966, respectively. Five positive features of the 10 valuable indicators on GSUS and CEUS defined the cut-off for the diagnosis of malignant thyroid nodules, with a sensitivity of 89.4% (84/94), specificity of 93.6% (73/78), and accuracy of 91.3% (157/172).

CONCLUSIONS

The ring enhancement and homogeneity of enhancement of thyroid nodules on CEUS and the microcalcification and halo on GSUS were the four most valuable indicators in the differential diagnosis of thyroid nodules. Conjoint analysis of specific features of thyroid nodules on GSUS and CEUS could enhance the diagnostic value of thyroid nodules.

Cellular calcium dynamics in lactation and breast cancer: from physiology to pathology

Breast cancer is the second leading cause of cancer mortality in women, estimated at nearly 40,000 deaths and more than 230,000 new cases diagnosed in the U.S. this year alone. One of the defining characteristics of breast cancer is the radiographic presence of microcalcifications. These palpable mineral precipitates are commonly found in the breast after formation of a tumor. Since free Ca(2+) plays a crucial role as a second messenger inside cells, we hypothesize that these chelated precipitates may be a result of dysregulated Ca(2+) secretion associated with tumorigenesis. Transient and sustained elevations of intracellular Ca(2+) regulate cell proliferation, apoptosis and cell migration, and offer numerous therapeutic possibilities in controlling tumor growth and metastasis. During lactation, a developmentally determined program of gene expression controls the massive transcellular mobilization of Ca(2+) from the blood into milk by the coordinated action of calcium transporters, including pumps, channels, sensors and buffers, in a functional module that we term CALTRANS. Here we assess the evidence implicating genes that regulate free and buffered Ca(2+) in normal breast epithelium and cancer cells and discuss mechanisms that are likely to contribute to the pathological characteristics of breast cancer.

Effect of complex wavelet transform filter on thyroid tumor classification in three-dimensional ultrasound

Ultrasonography has great potential in differentiating malignant thyroid nodules from the benign ones. However, visual interpretation is limited by interobserver variability, and further, the speckle distribution poses a challenge during the classification process. This article thus presents an automated system for tumor classification in three-dimensional contrast-enhanced ultrasonography data sets. The system first processes the contrast-enhanced ultrasonography images using complex wavelet transform-based filter to mitigate the effect of speckle noise. The higher order spectra features are then extracted and used as input for training and testing a fuzzy classifier. In the off-line training system, higher order spectra features are extracted from a set of images known as the training images. These higher order spectra features along with the clinically assigned ground truth are used to train the classifier and obtain an estimate of the classifier or training parameters. The ground truth tells the class label of the image (i.e. whether the image belongs to a benign or malignant nodule). During the online testing phase, the estimated classifier parameters are applied on the higher order spectra features that are extracted from the testing images to predict their class labels. The predicted class labels are compared with their corresponding original ground truth to evaluate the performance of the classifier. Without utilizing the complex wavelet transform filter, the fuzzy classifier demonstrated an accuracy of 91.6%, while utilizing the complex wavelet transform filter, the accuracy significantly boosted to 99.1%.

Thyroid nodule management: clinical, ultrasound and cytopathological parameters for predicting malignancy

Although fine-needle aspiration cytology is considered to be the reference method for evaluating thyroid nodules, the results are inaccurate in approximately 10-30% of cases. Several studies have attempted to predict the risk of malignancy in thyroid nodules based on age, nodularity, thyrotropin values, thyroid autoimmune disease, hot/cold nodule status, and ultrasound parameters. However, no consensus has been found, and none of these parameters has significantly affected patient management. The management of indeterminate thyroid nodules and re-biopsies of nodules with initially benign cytological results remain important and controversial topics of discussion. The Bethesda cytological system and several studies on the use of molecular markers to predict malignancy from cytological samples of thyroid nodules need further clarification. More in-depth discussions among and continuous education of the specialists involved in treating thyroid disease are necessary to improve the management of these patients. This review aims to examine the clinical, laboratory, ultrasound, and scintigraphic parameters that can be used for thyroid nodule management.

ThyroScreen system: high resolution ultrasound thyroid image characterization into benign and malignant classes using novel combination of texture and discrete wavelet transform

Using right equipment and well trained personnel, ultrasound of the neck can detect a large number of non-palpable thyroid nodules. However, this technique often suffers from subjective interpretations and poor accuracy in the differential diagnosis of malignant and benign thyroid lesions. Therefore, we developed an automated identification system based on knowledge representation techniques for characterizing the intra-nodular vascularization of thyroid lesions. Twenty nodules (10 benign and 10 malignant), taken from 3-D high resolution ultrasound (HRUS) images were used for this work. Malignancy was confirmed using fine needle aspiration biopsy and subsequent histological studies. A combination of discrete wavelet transformation (DWT) and texture algorithms were used to extract relevant features from the thyroid images. These features were fed to different configurations of AdaBoost classifier. The performance of these configurations was compared using receiver operating characteristic (ROC) curves. Our results show that the combination of texture features and DWT features presented an accuracy value higher than that reported in the literature. Among the different classifier setups, the perceptron based AdaBoost yielded very good result and the area under the ROC curve was 1 and classification accuracy, sensitivity and specificity were 100%. Finally, we have composed an Integrated Index called thyroid malignancy index (TMI) made up of these DWT and texture features, to facilitate distinguishing and diagnosing benign or malignant nodules using just one index or number. This index would help the clinicians in more quantitative assessment of the thyroid nodules.

Impact of screening with thyroid ultrasonography in myasthenia gravis patients

OBJECTIVES

This study was conducted to screen thyroid abnormality evaluated with ultrasonography (US) in patients with myasthenia gravis (MG) and investigate further when malignancy is suspected.

METHODS

Thyroid screening using US was conducted in 162 patients with MG. In cases where malignancy was suspected, further investigations were performed.

RESULTS

Abnormal US findings were detected in 125 of 162 patients with MG (72 patients with nodules, 74 patients with cysts, 27 patients with diffuse findings such as enlargement, atrophy, a hypoechoic pattern or a heterogenous echoic pattern, and 28 patients with calcification). From among these 125 subjects, 30 patients underwent further examinations such as needle aspiration cytology. As a result, six patients (3.7% of 162 cases) were positive for papillary carcinoma. The size of the carcinoma in three patients was <10 mm, yet the stage of thyroid carcinomas was high (stage III or IVa) in all six cases.

CONCLUSIONS

Our data suggest that the prevalence of thyroid carcinoma in cases of MG may be higher than that of the general population. Furthermore, in patients with MG, there is a possibility that the stage of the carcinoma is higher even when the carcinoma is of a very small size. Patients with MG, when diagnosed, should be advised to undergo US screening of the thyroid because most cases of thyroid carcinoma are highly curable.

Non-invasive automated 3D thyroid lesion classification in ultrasound: a class of ThyroScan™ systems

Ultrasound-based thyroid nodule characterization into benign and malignant types is limited by subjective interpretations. This paper presents a Computer Aided Diagnostic (CAD) technique that would present more objective and accurate classification and further would offer the physician a valuable second opinion. In this paradigm, we first extracted the features that quantify the local changes in the texture characteristics of the ultrasound off-line training images from both benign and malignant nodules. These features include: Fractal Dimension (FD), Local Binary Pattern (LBP), Fourier Spectrum Descriptor (FS), and Laws Texture Energy (LTE). The resulting feature vectors were used to build seven different classifiers: Support Vector Machine (SVM), Decision Tree (DT), Sugeno Fuzzy, Gaussian Mixture Model (GMM), K-Nearest Neighbor (KNN), Radial Basis Probabilistic Neural Network (RBPNN), and Naive Bayes Classifier (NBC). Subsequently, the feature vector-classifier combination that results in the maximum classification accuracy was used to predict the class of a new on-line test thyroid ultrasound image. Two data sets with 3D Contrast-Enhanced Ultrasound (CEUS) and 3D High Resolution Ultrasound (HRUS) images of 20 nodules (10 benign and 10 malignant) were used. Fine needle aspiration biopsy and histology results were used to confirm malignancy. Our results show that a combination of texture features coupled with SVM or Fuzzy classifiers resulted in 100% accuracy for the HRUS dataset, while GMM classifier resulted in 98.1% accuracy for the CEUS dataset. Finally, for each dataset, we have proposed a novel integrated index called Thyroid Malignancy Index (TMI) using the combination of FD, LBP, LTE texture features, to diagnose benign or malignant nodules. This index can help clinicians to make a more objective differentiation of benign/malignant thyroid lesions. We have compared and benchmarked the system with existing methods.

Cost-effective and non-invasive automated benign and malignant thyroid lesion classification in 3D contrast-enhanced ultrasound using combination of wavelets and textures: a class of ThyroScan™ algorithms

Ultrasound has great potential to aid in the differential diagnosis of malignant and benign thyroid lesions, but interpretative pitfalls exist and the accuracy is still poor. To overcome these difficulties, we developed and analyzed a range of knowledge representation techniques, which are a class of ThyroScan™ algorithms from Global Biomedical Technologies Inc., California, USA, for automatic classification of benign and malignant thyroid lesions. The analysis is based on data obtained from twenty nodules (ten benign and ten malignant) taken from 3D contrast-enhanced ultrasound images. Fine needle aspiration biopsy and histology confirmed malignancy. Discrete Wavelet Transform (DWT) and texture algorithms are used to extract relevant features from the thyroid images. The resulting feature vectors are fed to three different classifiers: K-Nearest Neighbor (K-NN), Probabilistic Neural Network (PNN), and Decision Tree (DeTr). The performance of these classifiers is compared using Receiver Operating Characteristic (ROC) curves. Our results show that combination of DWT and texture features coupled with K-NN resulted in good performance measures with the area of under the ROC curve of 0.987, a classification accuracy of 98.9%, a sensitivity of 98%, and a specificity of 99.8%. Finally, we have proposed a novel integrated index called Thyroid Malignancy Index (TMI), which is made up of texture features, to diagnose benign or malignant nodules using just one index. We hope that this TMI will help clinicians in a more objective detection of benign and malignant thyroid lesions.

Automated benign & malignant thyroid lesion characterization and classification in 3D contrast-enhanced ultrasound

In this work, we present a Computer Aided Diagnosis (CAD) based technique for automatic classification of benign and malignant thyroid lesions in 3D contrast-enhanced ultrasound images. The images were obtained from 20 patients. Fine needle aspiration biopsy and histology confirmed malignancy. Discrete Wavelet Transform (DWT) and texture based features were extracted from the thyroid images. The resulting feature vectors were used to train and test three different classifiers: K-Nearest Neighbor (K-NN), Probabilistic Neural Network (PNN), and Decision Tree (DeTr) using ten-fold cross validation technique. Our results show that combination of DWT and texture features in the K-NN classifier resulted in a classification accuracy of 98.9%, a sensitivity of 98%, and a specificity of 99.8%. Thus, the preliminary results of the proposed technique show that it could be adapted as an adjunct tool that can give valuable second opinions to the doctors regarding the nature of the thyroid nodule. The technique is cost-effective, non-invasive, fast, completely automated and gives more objective and reproducible results compared to manual analysis of the ultrasound images. We however intend to establish the clinical applicability of this technique by evaluating it with more data in the future.

Thyroid Nodules in Children: A Single Institution's Experience

Thyroid nodules in children are uncommon but often present an increased risk of malignancy in comparison to their adult counterpart. Multiple diagnostic modalities are frequently employed to characterize these nodules including ultrasound, radionuclide scans, fine needle aspiration (FNA), thyroid function tests, and evaluation of patient demographics. We chose to evaluate if any of these modalities influence treatment or signify a tendency for a nodule to represent a malignant lesion. A retrospective review of patients <21 years of age who underwent partial or total thyroidectomy from 2004 to 2009 was performed (IRB no. 4695). Other than an FNA indicating a malignancy, there does not appear to be any value to extensive preoperative imaging, nor can patient risk be stratified based upon age. We conclude that there is minimal utility in an extensive preoperative workup in a child with a thyroid nodule.

A retrospective study of thyroid structural abnormalities in alopecia patients

BACKGROUND

Thyroid dysfunction is classically associated with alopecia. Studies focusing on manual thyroid examinations, with ultrasonography of palpable abnormalities, in alopecia patients are lacking.

OBJECTIVE

To examine the clinical utility of manual and sonographic evaluation of the thyroid in alopecia patients.

METHODS

A retrospective chart review was performed among patients diagnosed with alopecia.

RESULTS

We found that 20.2% (74/367) of manual thyroid exams performed were deemed abnormal and 78.8% (41/52) of patients who had an ultrasound had an abnormal finding. Twenty two of the 74 patients did not obtain the requested ultrasound. Non-scarring alopecia was associated with 36 of 41 patients with abnormal ultrasounds (Telogen effluvium 29.3%, Androgenetic alopecia 27.8%, Alopecia areata 24.4%, and Traction alopecia 9.8%). No one specific structural abnormality was associated with a specific hair loss type. Of note, 78% (32/41) of patients with an abnormal ultrasound exam had normal thyroid function tests and only 9/41 (22%) patients had both.

LIMITATIONS

THESE INCLUDE: a retrospective study design, small sample size, use of multiple sites for laboratory and sonographic thyroid evaluation, and a high attrition rate for ultrasound evaluation.

CONCLUSIONS

This study revealed that the manual examination of the thyroid in alopecia patients may identify additional thyroid abnormalities not detected with serologic evaluation alone. Further prospective studies are required to evaluate the necessity and significance of manual thyroid palpation and subsequent ultrasound studies in this patient population.

Predicting malignancy in thyroid nodules: molecular advances

Over the last several years, a clearer understanding has developed of the genetic alterations underlying thyroid carcinogenesis. This knowledge can be used to tackle 1 of the challenges facing thyroidologists: management of the indeterminate thyroid nodule. Despite the accuracy of fine-needle aspiration cytology, many patients undergo surgery to diagnose malignancy and better diagnostic tools are required. A number of biomarkers have recently been studied and show promise in this setting. In particular, BRAF, RAS, PAX8-PPARγ, microRNAs, and loss of heterozygosity have each been demonstrated as useful molecular tools for predicting malignancy and can potentially guide decisions regarding surgical management of nodular thyroid disease. This review summarizes the current literature surrounding each of these markers, highlights our institution's prospective analysis of these markers, and describes the subsequent incorporation of molecular markers into a management algorithm for thyroid nodules.

Ultrasound-guided fine-needle aspiration biopsy in unselected consecutive patients with thyroid nodules

The objective was to analyze the results of UG-FNAB, performed in unselected consecutive patients with thyroid nodules. Methods. The UG-FNAB records were analyzed in this retrospective study. Indication for biopsy was the presence of at least one nodule detected by ultrasound. Results. 330 patients at mean age ± SD 48.4 ± 11.2 years; women/men = 12.8/1 were analyzed. From the total 596 nodules found 546 (91.6%) were investigated with 1231 punctures (2.3 per nodule and 3.7 per patient). Benign solitary nodules had 42.7%, multinodular goiter (MNG) 44.8%, inconclusive 4.8%, and others 2.1% and malignant nodules 5.5% of the patients (6.6% of solitary and 5.1% of MNG patients). The risk for a separate nodule in MNG to be malignant was 2.7%. Conclusions. UG-FNAB is a safe and reliable diagnostic approach for thyroid nodules. It is the method of choice for hypo- and isoechoic not purely cystic solitary nodules, regardless of the nodule size. In MNG, its positive predictive value and diagnostic accuracy are lower. The final decision for regular US monitoring, UG-FNAB of the dominant nodule, multipuncture UG-FNAB or surgical exploration is one of complex appraisal. We consider UG-FNAB appropriate for most nodules in MNG, according to the above mentioned criteria.

Value of ultrasound and cytological classification system to predict the malignancy of thyroid nodules with indeterminate cytology

Although fine-needle aspiration cytology is considered the gold standard for evaluating thyroid nodules, in about 10-30% of the cases, cytology is indeterminate. This study aimed to determine the value of cytological classification system and ultrasound (US) to predict malignancy in indeterminate thyroid nodule. This retrospective analysis enrolled 80 patients surgically treated at a single center, 75% (60) with benign vs. 25% (20) with malignant lesions at final histology. The clinical, scintigraphic, sonographic, and cytological classification (Bethesda) variables were analyzed in these selected cases of indeterminate cytology, and a prediction model was designed after the multivariate analysis. There was a 25% prevalence of malignancy (20/80). There were no differences in gender, serum thyroid-stimulating hormone and FT4 levels, thyroid auto-antibodies, thyroid dysfunction, and scintigraphic results between benign and malignant nodule groups. The border irregularity in sonographic study was at increased risk for malignancy. The cytological analysis based on Bethesda System (category IV) was an independent predictor for malignancy in indeterminate thyroid nodules. After the multivariate analysis, the model obtained showed border irregularity and Bethesda System category IV as predictive factors of malignancy in indeterminate thyroid nodules, featuring 76.9% of accuracy. This study confirmed a significant increase of risk for malignancy in thyroid nodules with indeterminate cytology showing Bethesda System category IV and suspicious features at US. These findings enhance our current limited predictive armamentarium and can be used to guide surgical decision making.

Role of ultrasound, clinical and scintigraphyc parameters to predict malignancy in thyroid nodule

Background

This study aimed to evaluate clinical, laboratory, ultrasound (US) and scintigraphyc parameters in thyroid nodule and to develop an auxiliary model for clinical application in the diagnosis of malignancy.

Methods

We assessed 143 patients who were surgically treated at a single center, 65% (93) benign vs. 35% (50) malignant lesions at final histology (1998-2008). The clinical, laboratory, scintigraphyc and US features were compared and a prediction model was designed after the multivariate analysis.

Results

There were no differences in gender, serum TSH and FT4 levels, thyroid auto-antibodies (TAb), thyroid dysfunction and scintigraphyc results (P = 0.33) between benign and malignant nodule groups. The sonographic study showed differences when the presence of suspected characteristics was found in the nodules of the malignant lesions group, such as: microcalcifications, central flow, border irregularity and hypoechogenicity. After the multivariate analysis the model obtained showed age (>39 years), border irregularity, microcalcifications and nodule size over 2 cm as predictive factors of malignancy, featuring 81.7% of accuracy.

Conclusions

This study confirmed a significant increase of risk for malignancy in patients of over 39 years and with suspicious features at US.

Characterization of single thyroid nodules by contrast-enhanced 3-D ultrasound

High-resolution ultrasonography (HRUS) has potentialities in differential diagnosis between malignant and benign thyroid lesions, but interpretative pitfalls remain and accuracy is still poor. We developed an image processing technique for characterizing the intra-nodular vascularization of thyroid lesions. Twenty nodules (10 malignant) were analyzed by three-dimensional (3-D) contrast-enhanced ultrasound imaging. The 3-D volumes were preprocessed and skeletonized. Seven vascular parameters were computed on the skeletons: number of vascular trees (NT); vascular density (VD); number of branching nodes (or branching points) (NB); mean vessel radius (MR); 2-D (DM) and 3-D (SOAM) tortuosity; and inflection count metric (ICM). Results showed that the malignant nodules had higher values of NT (83.1 vs. 18.1), VD (00.4 vs. 0.01), NB (1453 vs. 552), DM (51 vs. 18), ICM (19.9 vs. 8.7) and SOAM (26 vs. 11). Quantification of nodular vascularization based on 3-D contrast-enhanced ultrasound and skeletonization could help differential diagnosis of thyroid lesions.