A Prospective Study to Evaluate the Reliability of Thyroid Imaging Reporting and Data System in Differentiation between Benign and Malignant Thyroid Lesions

Evaluation of the Efficacy of Thyroid Imaging Reporting and Data Systems Classification in Risk Stratification and in the Management of Thyroid Swelling by Comparing It With Fine-Needle Aspiration Cytology and Histopathological Examination

BACKGROUND

Thyroid nodules are a common clinical challenge, with a significant proportion being cancerous. Fine-needle aspiration cytology (FNAC) is widely used for diagnosis but has limitations. Ultrasound has emerged as a promising tool for distinguishing between benign and malignant nodules. This study aims to compare the diagnostic accuracy of ultrasonography (USG) and FNAC in diagnosing malignant thyroid swelling using postoperative histopathological examinations as the gold standard.

METHOD

A diagnostic accuracy study was conducted over 1.5 years at Rajendra Institute of Medical Sciences, Ranchi, India. A total of 132 patients with thyroid swellings were included. Patients underwent USG and FNAC, and 99 patients subsequently underwent surgery and histopathological examination. Statistical analysis was performed to evaluate the performance of USG and FNAC, including sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

The study encompassed 132 patients, predominantly 94 (71.21%) females. Most patients, i.e., 76 out of 132 (57.58%), were aged 30-50 years, with an average age of presentation at 41 years. Socioeconomic status revealed 120 (90.9%) belonging to Classes II and III. USG and FNAC exhibited sensitivities of 77.4% and 90.3%, specificities of 94.1% and 98.5%, and accuracies of 88.9% and 96.0%, respectively. FNAC demonstrated superior diagnostic performance metrics compared to USG, with higher PPV and NPV, indicating its stronger ability to correctly identify true-positive cases. Ultrasound features and FNAC findings showed significant associations with biopsy results, reaffirming their utility in diagnosing thyroid nodules.

CONCLUSION

FNAC emerged as a highly accurate diagnostic tool for distinguishing between benign and malignant thyroid nodules, outperforming USG. Understanding demographic and clinical characteristics can aid in the timely diagnosis and management of thyroid disorders. Further research is warranted to enhance diagnostic algorithms and optimize patient care in resource-constrained settings.

[Sociodemographic, clinical and ultrasound characterization of thyroid nodule pathology and its association with malignancy in a Colombian high-complexity center]

BACKGROUND AND OBJECTIVE

Thyroid nodules are among the most frequent conditions, with a 10% risk of malignancy. The objective is to describe the frequency of demographic, clinical, and ultrasonographic characteristics of thyroid nodule pathology in adults and to explore the relationship with tumor malignancy.

METHODS

An analytical, retrospective cross-sectional study in adults with thyroid nodules and nodular fine-needle aspiration performed in adult patients from a Colombian reference center between 2009-2019. Data were obtained from the clinical history, descriptive measures of the patient's demographic, clinical, and ultrasound variables were estimated, and their relationship with the malignancy of the tumor was explored.

RESULTS

A total of 445 patients and 515 nodules were included. The median age was 55 years (IQR 44-64), 86.8% of women, and 54.8% had a single lesion. Percentages of 80.2 and 19.8 were benign and malignant nodules, with a median of 15.7mm (IQR 11-25) and 12.7mm (IQR 8.5-18.3), respectively (p<0.001). Hypothyroidism and levothyroxine consumption were higher in those with malignant nodules (p<0.001). The echographic characteristics were statistically different between the nodules. In the malignant ones, there was a higher frequency of solid composition, hypoechogenicity, and irregular margins. In contrast, in the benign ones, the absence of echogenic focus stood out (p<0.001).

CONCLUSION

The ultrasound characteristics are essential to define the risk of malignancy of a thyroid nodule. Therefore, considering the most frequent ones can help in the most appropriate approach to primary care.

Analysis of Thyroid Imaging Reporting and Data System Criteria and Its Correlation With the Pathological Results

Introduction Thyroid nodules are frequently encountered and may be discovered roughly in around 4-8% of individuals by clinical palpation. Aim The present study aims to analyze the Thyroid Imaging Reporting and Data Systems (TIRADS) classification and assess the validity of each criterion in predicting malignancy. Methods A prospective observational study was conducted at Sri Ramachandra Institute of Higher Education and Research from June 2020 to October 2021. Fifty patients who presented to the outpatient clinic with thyroid swelling got an ultrasound (USG) neck performed followed by either fine-needle aspiration cytology (FNAC) or thyroidectomy. They were included in the study and informed consent was obtained from all patients. Results Among 50 patients considered for the study, 36 were females. The mean age for malignant patients is 46 years with a standard deviation (SD) of 15, and for benign lesions is 47 years with an SD of 1. Most of the patients were TIRADS 4, which has a 56.2% risk of malignancy. The pathological results show a significant difference in ACR (American College of Radiology) TIRADS and echogenic foci between FNAC. The present study's solid composition showed a sensitivity of 25% and specificity of 75%, with an odds ratio of 0.90 in picking up malignant nodules. The shape of a nodule taller than wider, a malignant feature, showed a specificity of 92.3%. Punctate echogenic foci showed a sensitivity of 50% and specificity of 76.9% with a statistical significance of p-value 0.048. Conclusion TIRADS scoring avoids unessential invasive techniques for lower TIRADS scores. Certain criteria are more specific in recognizing malignant nodules. Proportional priority shall be given to certain criteria over others, and not all criteria should be considered.

Considerable interobserver variation calls for unambiguous definitions of thyroid nodule ultrasound characteristics

Objective

Thyroid nodule ultrasound characteristics are used as an indication for fine-needle aspiration cytology, usually as the basis for Thyroid Imaging Reporting and Data System (TIRADS) score calculation. Few studies on interobserver variation are available, all of which are based on analysis of preselected still ultrasound images and often lack surgical confirmation.

Methods

After the blinded online evaluation of video recordings of the ultrasound examinations of 47 consecutive malignant and 76 consecutive benign thyroid lesions, 7 experts from 7 thyroid centers answered 17 TIRADS-related questions. Surgical histology was the reference standard. Interobserver variations of each ultrasound characteristic were compared using Gwet's AC1 inter-rater coefficients; higher values mean better concordance, the maximum being 1.0.

Results

On a scale from 0.0 to 1.0, the Gwet's AC1 values were 0.34, 0.53, 0.72, and 0.79 for the four most important features in decision-making, i.e. irregular margins, microcalcifications, echogenicity, and extrathyroidal extension, respectively. The concordance in the discrimination between mildly/moderately and very hypoechogenic nodules was 0.17. The smaller the nodule size the better the agreement in echogenicity, and the larger the nodule size the better the agreement on the presence of microcalcifications. Extrathyroidal extension was correctly identified in just 45.8% of the cases.

Conclusions

Examination of video recordings, closely simulating the real-world situation, revealed substantial interobserver variation in the interpretation of each of the four most important ultrasound characteristics. In view of the importance for the management of thyroid nodules, unambiguous and widely accepted definitions of each nodule characteristic are warranted, although it remains to be investigated whether this diminishes observer variation.

Diagnostic Performance of Various Ultrasound Risk Stratification Systems for Benign and Malignant Thyroid Nodules: A Meta-Analysis

BACKGROUND

To evaluate the diagnostic performance of ultrasound risk-stratification systems for the discrimination of benign and malignant thyroid nodules and to determine the optimal cutoff values of individual risk-stratification systems.

METHODS

PubMed, Embase, SCOPUS, Web of Science, and Cochrane library databases were searched up to August 2022. Sensitivity and specificity data were collected along with the characteristics of each study related to ultrasound risk stratification systems.

RESULTS

Sixty-seven studies involving 76,512 thyroid nodules were included in this research. The sensitivity, specificity, diagnostic odds ratios, and area under the curves by K-TIRADS (4), ACR-TIRADS (TR5), ATA (high suspicion), EU-TIRADS (5), and Kwak-TIRADS (4b) for malignancy risk stratification of thyroid nodules were 92.5%, 63.5%, 69.8%, 70.6%, and 95.8%, respectively; 62.8%, 89.6%, 87.2%, 83.9%, and 63.8%, respectively; 20.7111, 16.8442, 15.7398, 12.2986, and 38.0578, respectively; and 0.792, 0.882, 0.859, 0.843, and 0.929, respectively.

CONCLUSION

All ultrasound-based risk-stratification systems had good diagnostic performance. Although this study determined the best cutoff values in individual risk-stratification systems based on statistical assessment, clinicians could adjust or alter cutoff values based on the clinical purpose of the ultrasound and the reciprocal changes in sensitivity and specificity.

The clinical significance of the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) category 5 thyroid nodules: Not as risky as we think?

BACKGROUND

Although the prevalence of thyroid nodules is high, few prove to be malignant. Based on sonographic features, the American College of Radiology Thyroid Imaging Reporting and Data System categorizes malignancy risk of thyroid nodules with associated management recommendations for each category level. Malignancy rates among nodules with a highly suspicious Thyroid Imaging Reporting and Data System category 5 warrant examination in the context of additional risk stratification tools, including cytopathology and molecular testing.

METHODS

All patients who underwent fine-needle aspiration biopsy for Thyroid Imaging Reporting and Data System category 5 nodules from January 2018 to September 2021 in a large integrated academic health system were reviewed. Using the Bethesda System for Reporting Thyroid Cytopathology, categories V and VI were set as malignant. Molecular testing (ThyroSeq version 3; Rye Brook, NY) yielding ≥50% risk of malignancy was deemed positive and correlated with surgical pathology.

RESULTS

A total of 496 Thyroid Imaging Reporting and Data System category 5 nodules were identified. On fine-needle aspiration cytopathology, 61 (12.3%) were malignant. The breakdown included Bethesda System for Reporting Thyroid Cytopathology I, 15 (3%); II, 362 (73%); III, 52 (10.5%); IV, 5 (1%); V, 6 (1.3%); and VI, 55 (11.1%). Of Bethesda System for Reporting Thyroid Cytopathology III/IV nodules with molecular testing (n = 53), 24.5% yielded positive results. In total, 42 (8.5%) nodules underwent surgical resection, most of which were Bethesda System for Reporting Thyroid Cytopathology VI (n = 26, 61.9%). Of excised nodules, 33 (78.6%) nodules were malignant, 6 (14.3%) benign, and 3 (7.1%) noninvasive follicular thyroid neoplasm with papillary-like nuclear features. All Thyroid Imaging Reporting and Data System category 5 nodules with malignant cytology (Bethesda System for Reporting Thyroid Cytopathology V/VI) that underwent surgery were malignant on histopathology. On average, the total Thyroid Imaging Reporting and Data System points were higher in malignant nodules compared with benign (9.3 vs 7.3; P = .015). Moreover, benign nodules more frequently received Thyroid Imaging Reporting and Data System points when the radiologist was unable to determine composition or echogenicity (33% vs 3% among malignant nodules; P = .01).

CONCLUSION

Thyroid Imaging Reporting and Data System category 5 designation in thyroid nodules is associated with a lower risk of malignancy than previously reported. Benign and malignant nodules with Thyroid Imaging Reporting and Data System category 5 designation have discrepancies in certain Thyroid Imaging Reporting and Data System characteristics and individual points assigned, which may offer an opportunity for quality improvement and standardization measures in ultrasound reporting practices.

Correlation of TIRADS and Bethesda Scoring Systems with Final Histopathology of Thyroid Nodules - An Institutional Experience

Fine needle aspiration cytology (FNAC) reduces the number of unnecessary thyroid surgeries for patients with benign nodules and appropriately triages patients with thyroid cancer to appropriate treatment. This was a observational study done on cases presenting with clinical suspicion of thyroid malignancy which underwent ultrasonography followed by FNAC of thyroid nodule. Ultrasonographic characterization of nodules was based on Thyroid Imaging Reporting and Data System (TIRADS) and cytology reporting was based on Bethesda system. All recruited patients underwent thyroidectomy. Pre-operative cytology and ultrasonography features were compared with final histopathology report. In our study, Bethesda system of cytology reporting for thyroid nodules had a better sensitivity, specificity and diagnostic accuracy than TIRADS system of ultrasound reporting. Bethesda system in FNAC had a larger area under the ROC curve (0.91) as compared to ultrasound TIRADS (0.70). Malignancy rate of TIRADS 5 nodules was 97.1% with significant p value (0.022). 100% of Bethesda VI lesions were malignant according to final histopathology report. Ultrasound TIRADS could pre-operatively predict malignancy in 63.6% of indeterminate thyroid nodules which were malignant according to post-operative histopathology. The overall concordance of ultrasound TIRADS, Bethesda system and histopathology was 69.8%. Higher TIRADS and Bethesda scoring among thyroid nodules was associated with increased risk of malignancy. US TIRADS is a good predictor of malignancy in indeterminate thyroid nodules.

The impact of the ultrasound classification on the rate of thyroid surgery indications: a 577 cases series

OBJECTIVES

Nodules of the thyroid gland are common but rarely malignant. Their management can range from simple monitoring to surgery. The use of ultrasound and fine needle aspiration can reduce the rate of unnecessary surgeries. However, there is a risk of false positives and false negatives of malignancy that only pathology can avoid. The objective of this study is to assess the impact of ultrasound classification on the rate of surgical indications.

MATERIAL AND METHODS

Between 2013 and 2017, the ultrasound classification was gradually adopted in our daily practice to become now routine. During this period, we conducted a retrospective study of all the patients who presented to our department for one or more thyroid nodules.

RESULTS

A total of 577 patients were included in the study. We compared two groups, a first where the ultrasound classification was used and a second where this classification was not used. In the end, we found that this classification significantly reduced the surgical indication by 19% while increasing the malignancy detection rate in operated patients by 21%.

CONCLUSIONS

The use of ultrasound classification reduces the indications for surgery while increasing the rate of malignancy in operated patients. The generalization of the use of the ultrasound classification score is strongly recommended in daily practice.

Comparison of diagnostic accuracy and utility of artificial intelligence-optimized ACR TI-RADS and original ACR TI-RADS: a multi-center validation study based on 2061 thyroid nodules

OBJECTIVE

To determine if artificial intelligence-based modification of the Thyroid Imaging Reporting Data System (TI-RADS) would be better than the current American College of Radiology (ACR) TI-RADS for risk stratification of thyroid nodules.

METHODS

A total of 2061 thyroid nodules (in 1859 patients) sampled with fine-needle aspiration or operation were retrospectively analyzed between January 2017 and July 2020. Two radiologists blinded to the pathologic diagnosis evaluated nodule features in five ultrasound categories and assigned TI-RADS scores by both ACR TI-RADS and AI TI-RADS. Inter-rater agreement was assessed by asking another two radiologists to score a set of 100 nodules independently. The reference standard was postoperative pathological or cytopathological diagnosis according to the Bethesda system. Inter-rater agreement was determined using intraclass correlation coefficient (ICC).

RESULTS

AI TI-RADS assigned lower TI-RADS risk levels than ACR TI-RADS (p < 0.001) and had larger area under receiver operating characteristic curve (0.762 vs. 0.679, p < 0.001). The sensitivities of ACR TI-RADS and AI TI-RADS were similar (86.7% vs. 82.2%, p = 0.052), but specificity was higher with AI TI-RADS (70.2% vs. 49.2%, p < 0.001). AI TI-RADS downgraded 743 (48.63%) benign nodules, indicating that 328 (42.3% of 776 biopsied nodules) unnecessary fine-needle aspirations (FNA) could have been avoided. Inter-rater agreement was better with AI TI-RADS than with ACR TI-RADS (ICC, 0.808 vs. 0.861, p < 0.001).

CONCLUSION

AI TI-RADS can achieve meaningful reduction in the number of benign thyroid nodules recommended for biopsy and significantly improve specificity despite a slight decrease in sensitivity.

KEY POINTS

• AI TI-RADS assigned lower TI-RADS risk levels than ACR TI-RADS, showing similar sensitivity but higher specificity. • Half of the benign nodules can be downgraded of which 42.3% of biopsy nodules avoided unnecessary fine-needle aspiration (FNA). • AI TI-RADS had a better overall inter-rater agreement.

The value of neutrophil‐to‐lymphocyte ratio combined with the thyroid imaging reporting and data system in the diagnosis of the nature of thyroid nodules

Objective

The aim of this study was to investigate the diagnostic value of peripheral blood neutrophil‐to‐lymphocyte ratio (NLR) combined with the thyroid imaging reporting and data system (TIRADS) for benign and malignant thyroid nodules.

Methods

A total of 585 adults were enrolled in the study. The receiver operating characteristic curves were used to determine the optimal cut‐off values for NLR and Kwak TIRADS (K‐TIRADS) grades, which were 1.87 and 4a, respectively. Thyroid nodules were scored as follows: NLR–K‐TIRADS score is 2 (both elevated K‐TIRADS grade and NLR), NLR–K‐TIRADS score is 1 (one of these was elevated) and NLR–k‐TIRADS score is 0 (neither were elevated).

Results

The proportions of malignant nodules with NLR‐K‐TIRADS scores of 2, 1 and 0 were 98.59%, 69.62% and 10.19%, and the difference was statistically significant (p < 0.001). In terms of the sensitivity of diagnosis of malignant nodules, NLR‐K‐TIRADS 1 tends to increase relative to K‐TIRADS grades ≥ 4a; in terms of specificity and positive predictive value for the diagnosis of malignant nodules, NLR–K‐TIRADS 2 was significantly higher than K‐TIRADS grades ≥ 4a (all p < 0.05).

Conclusions

NLR combined with K‐TIRADS grades may be a novel method for screening benign and malignant thyroid nodules.

Reproducibility and Interobserver Agreement of Different Thyroid Imaging and Reporting Data Systems (TIRADS)

INTRODUCTION

A number of classification systems (TIRADS) have been developed to estimate the likelihood of malignancy in thyroid nodules, but their reproducibility is yet to be assessed. We evaluated the interobserver variability and diagnostic performance of the TIRADS in Kwak's modification (Kw-TIRADS) and European TIRADS (EU-TIRADS).

METHODS

Two independent specialists, blinded concerning the morphology of the nodules, evaluated ultrasound images of 153 thyroid nodules identified in 149 patients at multiple time points.

RESULTS

The interobserver agreement (Cohen's κ) was 0.52 and 0.67 for Kw-TIRADS and EU-TIRADS, respectively, and rated as substantial. There were strong correlations between Kw-TIRADS and EU-TIRADS for the two observers with Spearman's coefficients of 0.731 (p = 0.00025) and 0.661 (p = 0.0012), respectively. Sensitivity of Kw-TIRADS for the diagnosis of thyroid cancer was 95-92.31% and that of EU-TIRADS was 92.31-89.74%, with specificity of about 60% for both TIRADS.

CONCLUSION

Despite the wide variability in the description of single ultrasonographic features, both Kw-TIRADS and EU-TIRADS may be a useful diagnostic tool in clinical practice.

Update on ACR TI-RADS: Successes, Challenges, and Future Directions, From the AJR Special Series on Radiology Reporting and Data Systems

The American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) is an ultrasound-based risk stratification system (RSS) for thyroid nodules that was released in 2017. Since publication, research has shown that ACR TI-RADS has a higher specificity than other RSSs and reduces the number of unnecessary biopsies of benign nodules compared with other systems by 19.9-46.5%. The risk of missing significant cancers using ACR TI-RADS is mitigated by the follow-up recommendations for nodules that do not meet criteria for biopsy. In practice, after a nodule's ultrasound features have been enumerated, the ACR TI-RADS points-based approach leads to clear management recommendations. Practices seeking to implement ACR TI-RADS must engage their radiologists in understanding how the system addresses the problems of thyroid cancer overdiagnosis and unnecessary surgeries by reducing unnecessary biopsies. This review compares ACR TI-RADS to other RSSs and explores key clinical questions faced by practices considering its implementation. We also address the challenge of reducing interobserver variability in assigning ultrasound features. Finally, we highlight emerging imaging techniques and recognize the ongoing international effort to develop a system that harmonizes multiple RSSs, including ACR TI-RADS.

Comparison of diagnostic performance of the ACR and Kwak TIRADS applying the ACR TIRADS' size thresholds for FNA

OBJECTIVE

To investigate the diagnostic performances and unnecessary fine-needle aspiration (FNA) rates of two point-scale based TIRADS and compare them with a modified version using the ACR TIRADS' size thresholds.

METHODS

Our Institutional Review Board approved this retrospective study and waived the requirement for informed consent. A total of 2106 thyroid nodules 10 mm or larger in size in 2084 patients with definitive cytopathologic findings were included. Ultrasonography categories were assigned according to each guideline. We applied the ACR TIRADS' size thresholds for FNA to the Kwak TIRADS and defined it as the modified Kwak TIRADS (mKwak TIRADS). Diagnostic performances and unnecessary FNA rates were evaluated for both the original and modified guidelines.

RESULTS

Of the original guidelines, the ACR TIRADS had higher specificity, accuracy, and area under the receiver operating characteristic curve (AUC) (63.1%, 68.9%, and 0.748, respectively). When the size threshold of the ACR TIRADS was applied to the Kwak TIRADS, the resultant mKwak TIRADS had higher specificity, accuracy, and AUC (64.7%, 70.3%, and 0.765, respectively) than the ACR TIRADS. The mKwak TIRADS also had a lower unnecessary FNA rate than the ACR TIRADS (54.8% and 56.4%, respectively). The false-negative rate of the Kwak TIRADS was the lowest (1.9%) among all TIRADS.

CONCLUSION

The modified Kwak TIRADS incorporating the size thresholds of the ACR TIRADS showed higher diagnostic performance and a lower unnecessary FNA rate than the original point-scale based TIRADS.

KEY POINTS

• Of the original guidelines, the ACR TIRADS had the highest specificity, accuracy, and area under the receiver operating characteristic curve (AUC) (63.1%, 68.9%, and 0.748, respectively). • When the size threshold of the ACR TIRADS was applied to the Kwak TIRADS, the resultant modified version of Kwak TIRADS had higher specificity, accuracy, and AUC (64.7%, 70.3%, and 0.765, respectively) than the ACR TIRADS. • The false-negative rate of the Kwak TIRADS was the lowest (1.9%) among all TIRADS.

Correlation between Thyroid Imaging Reporting and Data System and Bethesda System of Reporting of Thyroid Cytopathology of Thyroid Nodule: A Single Center Experience

Background:

The incidence of thyroid cancer has been increasing worldwide. Thyroid imaging reporting and data system (TIRADS) has been proposed for risk stratification of thyroid nodules to improve categorical management. Fine needle aspiration cytology based on Bethesda system for reporting of thyroid cytopathology (BSRTC) plays a fundamental role in the evaluation of thyroid nodule microscopically. Both the systems, the TIRADS and the latest revised BSRTC 2017, are widely recommended and practiced all over the world, but the correlation between the two systems has not been established.

Aims and Objectives:

This study was conducted to assess the risk of malignancy (ROM) in the intermediate Bethesda categories of thyroid lesions and their correlation with the corresponding TIRADS categories.

Materials and Method:

It was a prospective cross-sectional study over 1 year including 69 patients aged 18 years or older having solitary thyroid nodules. All cases were triaged using both TIRADS and BSRTC 2017 and the diagnostic performances were compared with subsequent paraffin sections to evaluate ROM. Correlation between TIRADS and BSRTC systems was expressed as kappa value.

Result:

Good concordance was observed between TIRADS and BSRTC systems in the evaluation of benign thyroid nodule lesions (category 2-II). There was discordance in follicular lesions (category 4-IV). The kappa value generated (0.411) revealed moderate agreement between the two risk stratification systems.

Conclusion:

Careful application of both grading systems is essential for the proper segregation of thyroid nodules to facilitate effective clinical and surgical management. However, universally acceptable protocols need to be developed to avoid the heterogeneous approach.

Comparison between Sonographic Features and Fine Needle Aspiration Cytology with Histopathology in the Diagnosis of Solitary Thyroid Nodule

BACKGROUND

High resolution ultrasonography (USG) is the first-line investigation in evaluation of euthyroid nodules. Thyroid imaging reporting and data system (TIRADS) is an USG-based risk stratification system for classifying thyroid nodules. Subjects with high-risk category of TIRADS undergo fine needle aspiration cytology (FNAC) and FNAC findings are reported according to Bethesda classification. Bethesda categories are used for determining risk of malignancy. Data regarding sonographic classification of thyroid nodule and its cytological association with respect to final histopathological diagnosis remains scarcely available in India.

AIMS AND OBJECTIVE

The study evaluated euthyroid nodules for risk of malignancy and compared sonographic features and FNAC (Bethesda classification) findings with histopathology of excised samples.

MATERIAL AND METHODS

This was a single-center observational study on 137 consecutive subjects of solitary euthyroid nodule. All subjects underwent USG according to TIRADS and FNAC where applicable. Surgical biopsy report was used as a gold standard.

RESULTS

The sensitivity, specificity, accuracy, positive predictive and negative predictive value of FNAC were 80%, 90%, 85%, 86%, and 86.6% and TIRADS were 80%, 47.2% 61%, 51.3%, and 77.3%, respectively. FNAC classification was equally sensitive and more specific than TIRADS. Among individual USG parameters, micro-calcification was most sensitive (80%) and specific (86%). Irregular margin and taller-than-wider shape had a specificity of 89% and 92%, respectively. 3 patients (14.28%) with benign cytology and suspicious USG features (specifically TIRADS 4 & 5) undergoing surgery had malignancy in final HPE.

CONCLUSIONS

USG and FNAC are equally sensitive in diagnosing malignant thyroid nodule but FNA is more specific (90%). It's a minimally invasive method which can be used to distinguish malignant from benign lesions with a high degree of accuracy (85%). In patient having high risk feature on USG, a benign cytology needs to be repeat FNAC and they should undergo surgical biopsy for confirmation.

Diagnostic performances and unnecessary US-FNA rates of various TIRADS after application of equal size thresholds

We compared the diagnostic performances and unnecessary FNA rates of several guidelines and modified versions using the size threshold of the ACR TIRADS. Our Institutional Review Board approved this retrospective study and waived the requirement for informed consent and all methods were performed in accordance with the Declaration of Helsinki. A total of 1,384 thyroid nodules in 1,301 patients with definitive cytopathologic findings were included. US categories were assigned according to each guideline. We applied the size threshold suggested by the ACR TIRADS for FNA to the Kwak, ATA and EU guidelines and defined these modified guidelines as the modified Kwak (mKwak), modified ATA (mATA) and modified EU (mEU) guidelines. Diagnostic performances and unnecessary FNA rates of all guidelines were evaluated. Of 1,384 thyroid nodules, 291 (21%) were malignant. Among the original guidelines, the ACR TIRADS had the highest specificity, accuracy, LR and AUC (62.2%, 66%, 2.128 and 0.713). The mKwak, mATA and mEU guidelines had higher specificity, accuracy, LR and AUC (P < 0.001 for all), and fewer unnecessary FNAs, compared with their original guidelines. Among all original and modified guidelines, the mKwak guideline had the highest specificity, accuracy, LR and AUC (64%, 68.6%, 2.389 and 0.75). The unnecessary FNA rate was the lowest with the mKwak guideline (61.1%). The highest sensitivity was observed with the ATA guideline (98.6%). After incorporating the size threshold of the ACR TIRADS to other TIRADS, all guidelines showed higher diagnostic accuracy and lower unnecessary FNA rates than their original versions. The mKwak guideline showed the best diagnostic performances.

Interobserver agreement and efficacy of consensus reading in Kwak-, EU-, and ACR-thyroid imaging recording and data systems and ATA guidelines for the ultrasound risk stratification of thyroid nodules

PURPOSE

To investigate the interobserver agreement (IA) and the impact of consensus reading using four risk stratification systems for thyroid nodules (TN).

METHODS

Four experienced specialists independently rated US images of 80 TN according to the Kwak-TIRADS, EU-TIRADS, ACR TI-RADS, and ATA Guidelines. The cases were randomly extracted from a prospectively acquired database (n > 1500 TN). The observers were blinded to clinical data. This study was divided into two sessions (S1 and S2) with 40 image sets each. After every session, a consensus reading was carried out (C1, C2). Subsequently, the effect of C1 was tested in S2 with 40 new cases followed by C2. Fleiss' kappa (κ) was calculated for S1 and S2 to estimate the IA and learning curves. The results of C1 and C2 were used as reference for diagnostic accuracy calculations.

RESULTS

IA significantly increased (p < 0.01) after C1 with κ values of 0.375 (0.615), 0.411 (0.596), 0.321 (0.569), and 0.410 (0.583) for the Kwak-TIRADS, EU-TIRADS, ACR TI-RADS, and ATA Guidelines in S1 (S2), respectively. ROC analysis (C1 + C2) revealed similar areas under the curve (AUC) for the Kwak-TIRADS, EU-TIRADS, ACR TI-RADS, and ATA Guidelines (0.635, 0.675, 0.694, and 0.654, respectively, n.s.). AUC did not increase from C1 (0.677 ± 0.010) to C2 (0.632 ± 0.052, n.s.). ATA Guidelines were not applicable in five cases.

CONCLUSIONS

IA and diagnostic accuracy were very similar for the four investigated risk stratification systems. Consensus reading sessions significantly improved the IA but did not affect the diagnostic accuracy.

Segmentation and Diagnosis of Papillary Thyroid Carcinomas Based on Generalized Clustering Algorithm in Ultrasound Elastography

Papillary thyroid carcinomas (PTC) are the most common type of thyroid malignant tumors. Existing methods for clustering high-noise ultrasound images tend to degrade the clustering performance. In order to realize accurate segmentation of thyroid nodule in noisy environment, this paper proposes an improved segmentation algorithm based on adaptive fast generalized clustering. Firstly, the parameter balance factor is adaptively determined according to the noise probability of non-local pixels so as to reflect the spatial structure information in the image more accurately. Then, the balance factor is used to effectively combine the linear weighted filtered image in the AFGC algorithm so as to create the adaptive filtered image. Since the filtering degree depends on the probability whether the pixel is noise in the image, the dynamic noise suppression performance of the proposed method can be greatly improved. A large number of qualitative and quantitative experimental results show that the proposed generalized clustering algorithm can obtain more accurate results when clustering images with high noise. It is suitable for intelligent diagnosis of papillary thyroid convolution in clinical examination.

TIRADS Interobserver Variability Among Indeterminate Thyroid Nodules: A Single-Institution Study

OBJECTIVES

A high proportion of cytologically indeterminate, Afirma Gene Expression Classifier "suspicious" thyroid nodules are benign. The Thyroid Imaging Reporting and Data System (TIRADS), was proposed by the American College of Radiology in 2017 to help classify thyroid nodules based on ultrasound characteristics in a standardized fashion to guide management. We aim to determine the interobserver variability of TIRADS classification among cytologically indeterminate and Afirma suspicious nodules.

METHODS

We retrospectively queried cytopathology archives for thyroid fine-needle aspiration specimens obtained between February 2012 and September 2016 with associated (1) indeterminate diagnosis, (2) ultrasound imaging at our institution, (3) Afirma suspicious result, and (4) surgery at our institution. We compared the TIRADS variability of the 3 blinded radiologists using intraclass correlation coefficients.

RESULTS

Our cohort consisted of 127 nodules. Intraclass correlation coefficients can be interpreted as follows: less than 0.4, poor; 0.4 to 0.59, fair; 0.6 to 0.74, good; 0.75 to 1.00, excellent. The intraclass correlation coefficients of the raw TIRADS score and category variability was 0.561 (95% confidence interval [CI]: 0.464-0.651) or fair and 0.547 (95% CI, 0.449-0.640) or fair, respectively. When analyzing composition, echogenicity, shape, margin, and echogenic foci, the ICCs were 0.552 (95% CI, 0.454-0.643), fair; 0.533 (95% CI, 0.432-0.627), fair; 0.359 (95% CI, 0.248-0.469), poor; 0.192 (95% CI, 0.084-0.308), poor; and 0.549 (95% CI, 0.451- 0.641), fair, respectively.

CONCLUSIONS

Our results show that among the subset of cytologically indeterminate and Afirma suspicious nodules, TIRADS interobserver variability was fair. Shape and margin criteria were the biggest sources of disagreement. Large prospective studies are needed to evaluate the interobserver variability of TIRADS in this subset of thyroid nodules.

Diagnostic reliability of the Thyroid Imaging Reporting and Data System (TI-RADS) in routine practice

Purpose

To evaluate the diagnostic reliability of Thyroid Imaging Reporting and Data System (TI-RADS) classifications described by American College of Radiology (ACR) and Kwak et al. by calculating the risk of malignancy, to assess the role of TI-RADS in reducing fine-needle aspiration cytology (FNAC) of benign lesions.

Material and methods

This was a prospective study during the period from December 2017 to August 2018. Thyroid nodules were classified using ACR TI-RADS and TI-RADS proposed by Kwak et al. The TI-RADS categorisations were compared to the final diagnosis obtained by cytopathological/histopathological analysis. The risk of malignancy for each category was calculated. Sensitivity, specificity, and positive and negative predictive values for individual suspicious ultrasound features were also assessed.

Results

We evaluated a total of 127 thyroid nodules. The risk of malignancy was 0% in ACR TR1, 0% in ACR TR2, 6.9% in ACR TR3, 29.2% in ACR TR4, and 80% in ACR TR5 categories. The risk of malignancy for TI-RADS according to Kwak et al. were 0%, 0%, 21.5%, 32.4%, 100% for TI-RADS 2, 3, 4A, 4B, and 4C categories, respectively. Kwak TI-RADS 2 and 3 had higher sensitivity in predicting benignity compared to ACR TR1 and 2 (35.4% vs. 25.9%).

Conclusions

We found TI-RADS classification to be a reliable, non-invasive, and practical method for assessing thyroid nodules in routine practice. TI-RADS can safely avert avoidable FNACs in a significant proportion of benign thyroid lesions.

Inter-observer Variability in the American College of Radiology Thyroid Imaging Reporting and Data System: In-Depth Analysis and Areas for Improvement

The American College of Radiology (ACR) introduced a new standardized system for management of thyroid nodules, the Thyroid Imaging Reporting and Data System (TI-RADS). The purpose of this retrospective study is to evaluate the inter-observer variability in applying TI-RADS in clinical practice without prior dedicated training. We evaluated a total of 180 nodules constituting all consecutive thyroid aspirations performed in the radiology department between January 1, 2014 and June 30, 2014, with exclusion of histologically inadequate samples. Four radiologists, blinded to each other's evaluation and to final pathology results, evaluated all of the nodules based on the TI-RADS lexicon. TI-RADS score and management recommendations were then deduced from the inputted features. Statistical analysis was performed to determine inter-observer agreement among all readers, as well as between each two readers, in all TI-RADS sonographic features and for recommended management per TI-RADS score with multi-user Cohen's κ (Light's κ) and percentage agreement using R. There was fair-to-moderate inter-observer agreement in nodule composition (two-reader κ range: 0.327-0.533) and presence of calcifications (κ range: 0.229-0.527), but poor-to-fair agreement in echogenicity (κ range: 0.141-0.355), shape (κ range: 0.0729-0.513) and margins (κ range: 0.176-0.283). There was fair inter-observer agreement regarding management recommendations (κ range: 0.242-0.359).

The Use of Dynamic Contrast-Enhanced Perfusion MRI in Differentiating Benign and Malignant Thyroid Nodules

To investigate the efficacy of perfusion magnetic resonance imaging (MRI) in benign-malignant differentiation of thyroid nodules. Images from 24 patients with thyroid masses were obtained using dynamic contrast enhanced MRI (DCE-MRI) at 3-T MR. DCE-MRI images were evaluated by post-processing of selected regions of interest (ROIs) on software, thus eliciting quantitative data for each voxel within the ROI. Ktrans, Ve, Kep, iAUC and chi² were calculated automatically. The DCE-MRI values of benign and malignant lesions were then compared. Mean Ktrans and iAUC values in malignant lesions were significantly lower than those in benign lesions (p = 0.028 and 0.049). Ktrans, Kep, and iAUC values in malignant lesions were statistically significantly lower than normal parenchyma values. In contrast to other tissues, the perfusion MRI findings of thyroid masses exhibit a decrease in Ktrans and iAUC values as malignancy increases. Perfusion MRI may be useful in differentiating benign and malignant thyroid nodules once a cut-off value has been determined by other studies.

Correlation between Ultrasound-based TIRADS and Bethesda System for Reporting Thyroid-cytopathology: 2-year Experience at a Tertiary Care Center in India

BACKGROUND

In recent times, high-resolution ultrasound thyroid imaging has paved the way for significant transformation in clinical approach to thyroid nodule. There are several risk stratification systems in thyroid imaging, developed with an aim, not only to reduce the inter-observer variability but also to establish effective communication system. Thyroid image reporting and data system (TIRADS) classification system, which is similar to breast imaging reporting and data system for breast lesion, is the most useful of all. To our knowledge, there is just a handful published research articles available based on Indian population in this regard. In this article, we study the thyroid nodules using high-resolution ultrasound in Indian population and we try to correlate the TIRADS and Bethesda system for reporting thyroid cytopathology.

MATERIALS AND METHODS

This prospective study includes 184 patients studied over a period of 2 years (April 2015-April 2017). Patients having thyroid nodule in B-mode ultrasound and are scheduled to get a fine-needle aspiration cytology (FNAC) done. Bethesda classification of these nodules is tabulated in follow-up period simultaneously. By comparing these data, efficacy of TIRADS in differentiating benign from malignant nodules are assessed finally using accuracy, positive predictive value (PPV), cross-tabulation, and Chi-square tests.

RESULTS

Out of the 117 TIRADS 2 nodules, none turned out to be Bethesda IV or higher, which means none of these nodules turned out to be malignant. The risk of malignancy for TIRADS 2, TIRADS 3, TIRADS 4, and TIRADS 5 was 0, 2.2, 38.5, and 77.8%, respectively. The risk of malignancy percentage in our study is similar to those values obtained in other prominent studies.

CONCLUSION

The probability of a particular nodule being malignant can be effectively inferred from the ultrasound-based TIRADS system with a certain level of confidence. Considering our results and other literature reviews, it be can be safely assumed that FNAC can be at least deferred in patients having TIRADS 2 nodules, which contribute to majority of newly detected cases. In our experience, there is a remarkable correlation exists between TIRADS ultrasound classification and Bethesda cytology, especially for benign nodules.

Thy 3F and 3a malignancy rate, a multisite regional retrospective case series

Introduction The aim of this study was to ascertain the incidence of thyroid cancer for patients categorised as Thy3, 3a or 3f across four tertiary thyroid multidisciplinary centres in the UK. Material and methods This is a retrospective case series examining patients who presented with a thyroid nodule and diagnosed as Thy3, 3a or 3f according to the Royal College of Pathologists modified British Thyroid Association and Royal College of Physicians Thy system. Results In total, 395 patients were included in this study. Of these, 136 turned out to have benign thyroid disease and 24 had micropapillary thyroid carcinomas. The overall rate of thyroid malignancy was 28.8%. For each subcategory, the rate of malignancy was Thy3 24.7.7%, Thy3a 30.4% and Thy3f 29.2. However, the incidence of thyroid malignancy varied considerably between the four centres (Thy 3f 18-54%). Discussion The diagnosis of thyroid cancer is evolving but detection for malignancy for indeterminate nodules remains below 50% for most centres around the world. In 2014, the British Thyroid Association subdivided the original Thy3 category into Thy3a and Thy3f and recommended a more conservative approach to management for Thy3a nodules. Despite this, only two centres yielded a higher conversion rate of malignancy in the new higher graded Thy3f group compared with Thy3a. Conclusion It is debateable whether the new 'Thy3' subcategories are more useful than the original. Local thyroid malignancy rates may also be more useful than national averages to inform treatment decisions.

Effect of Implementing Community of Practice Modified Thyroid Imaging Reporting and Data System on Reporting Adherence and Number of Thyroid Biopsies

RATIONALE AND OBJECTIVES

Thyroid nodules are common in the population, although the rate of malignancy is relatively low (5%-15%). The purpose of this study was to determine if introducing a modified standardized reporting format and management algorithm (Thyroid Imaging Reporting and Data System [TI-RADS]) affects radiologist reporting adherence, number of thyroid biopsies, and other measurable outcomes.

MATERIALS AND METHODS

All thyroid biopsies performed over two 6-month periods were evaluated at a tertiary care hospital with Research Ethics Board approval. The first period was before implementation of TI-RADS and the second was several months after implementation of TI-RADS (using a modified version made through a multidisciplinary collaboration). The number of biopsies performed was determined in each of the two periods as well as the percent of positive malignancy, wait times, and rates of non-diagnostic/unsatisfactory and inconclusive biopsies, which included atypia of undetermined significance (AUS) and follicular lesion of undetermined significance (FLUS).

RESULTS

The average number of biopsies performed prior to implementing modified Kwak's TI-RADS was 74 thyroid biopsies per month and the average number of diagnostic ultrasounds was 271. After the introduction of modified Kwak's TI-RADS, the average number of thyroid biopsies decreased to 60 per month (an 18.9% reduction, P < .05), and the number of diagnostic ultrasound increased to 287 per month (a 5.9% increase from 2016 to 2017). The average wait time for a thyroid biopsy decreased from 5 to 3 weeks (P < .05). There was a slight increase in the rate of positive malignancy results (from 15% to 18%), although it was not statistically significant. The rate of non-diagnostic/unsatisfactory and inconclusive results (including AUS and FLUS) remained unchanged (18% AUS/FLUS/15% non-diagnostic/unsatisfactory before and 17% AUS/FLUS/15% non-diagnostic/unsatisfactory after TI-RADS introduction, P > .05).

CONCLUSIONS

Introduction of a multidisciplinary-approved standardized reporting system with evidence-based management recommendations led to no statistically significant change in the number of diagnostic ultrasounds but a statistically significant reduction in the number of monthly thyroid biopsies and associated reduction in wait times.

Combination of Sonoelastography and TIRADS for the Diagnostic Assessment of Thyroid Nodules

To evaluate the diagnostic performance of elastography alone and combined with Thyroid Imaging Reporting And Data System (TIRADS) for the assessment of non-autonomous thyroid nodules. We included 244 thyroid nodules and analyzed the visual elasticity scores, strain value (SV) and TIRADS classification. Histologic examination revealed 38 malignant (16%) and 206 benign nodules. The SV was lower in malignant nodules than in benign with an optimal cutoff ≤0.225. The visual elasticity scores showed a better diagnostic performance than the SV measurement. The risk for malignancy increased with higher TIRADS category. The sensitivity, specificity, positive predictive value and negative predictive value of TIRADS were superior to sonoelastography. The combination of TIRADS ≥4C and SV ≤0.225 showed the highest odds ratio to predict malignancy. Kwak-TIRADS classification is superior to elastography for the differentiation of benign and malignant thyroid nodules. Our data demonstrate that a high TIRADS class alone is predictive for thyroid carcinoma and the clinical relevance of sonoelastography is negligible.

Use of the ultrasound-based total malignancy score in the management of thyroid nodules

Purpose

The purpose of this study was to validate the role of the total malignancy score (TMS) in identifying thyroid nodules suspicious for malignancy through the sum of their ultrasound features.

Methods

The local ethical committee approved this prospective observational study. We examined 231 nodules in 231 consecutive patients (164 females and 67 males; age range, 20 to 87 years; median age, 59 years; interquartile range, 48 to 70 years) who underwent ultrasound followed by fine-needle aspiration cytology (FNAC). The nodules were further classified using the TMS, which considers ultrasound features (number, echogenicity, structure, halo, margins, Doppler signal, calcifications, and growth), and the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), which considers cytological features. Patients with non-negative nodules (TBSRTC categories III to VI) underwent histological analysis, repeated FNAC, or 2 years of regular ultrasound follow-up. The associations between the final diagnosis, each of the ultrasound features, and the TMS were estimated using the chi-square test, the Mann-Whitney U test, and multivariate logistic regression. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic accuracy of the TMS.

Results

On ultrasound, 47% of the nodules (108 of 231) had a TMS <3, 18% (42 of 231) had a TMS of 3, and 35% (81 of 231) had a TMS >3. The FNAC results of 85% of the nodules (196 of 231) were benign, while 15% (35 of 231) had non-negative results. Hypoechogenicity, solid structure, the presence of microcalcifications, and the number of nodules were independent predictors of the final diagnosis, and the diagnostic accuracy of the TMS was good (area under the ROC curve, 0.82).

Conclusion

The TMS system is simple to use, reliable, easily reproducible, and closely reflects malignancy risk. Based on our results, FNAC could be limited to nodules with a TMS ≥3 without missing any cases of carcinoma.

Use of the Kwak Thyroid Image Reporting and Data System (K-TIRADS) in differential diagnosis of thyroid nodules: systematic review and meta-analysis

PURPOSE

The purpose of this systematic literature review was to assess the usefulness of the Thyroid Image Reporting and Data System (K-TIRADS) classification proposed by Kwak for differentiation of thyroid nodules.

MATERIAL AND METHODS

Four literature databases were searched for relevant articles through early January 2017. A meta-analysis was performed to calculate pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-) and diagnostic odds ratio (DOR). The area under the curve (AUC) from the pooled receiver operating characteristic (ROC) was used to assess the usefulness of this classification for differentiation of thyroid nodules. Meta-analysis was conducted by using meta-analysis software.

RESULTS

We analysed six publications describing 10,926 nodules. Pooled sensitivity, specificity, LR+, LR-, DOR, and AUC for pooled ROC were 0.983 (95 % CI 0.976-0.989), 0.552 (95 % CI 0.542-0.562), 2.666 (95 % CI 1.692-4.198), 0.05 (95 % CI 0.035-0.072), 51.020 (95 % CI 15.241-170.79) and 0.938, respectively.

CONCLUSIONS

Kwak TIRADS has high sensitivity and low specificity. Thus, it is very useful to discard the benign cases and to reduce the number of biopsies.

KEY POINTS

• Routine, adequate standardization of thyroid nodules ultrasound classification is mandatory. • Kwak TIRADS parameters are accurate for differentiating focal thyroid lesions. • Kwak TIRADS system is simple to apply. • Kwak TIRADS system may become a useful diagnostic tool.

Thyroid Imaging Reporting and Data System (TIRADS) in Stratifying Risk of Thyroid Malignancy at The Medical City

Objective

To determine the accuracy of Thyroid Imaging Reporting and Data System (TIRADS) in detecting thyroid malignancy, determine risk of malignancy in each TIRADS category and determine the ultrasound characteristics associated with malignancy.

Methodology

This is a retrospective cross-sectional study involving patients who underwent ultrasound, thyroid fine needle aspiration biopsy (FNAB) and thyroidectomy at The Medical City from January 2014 to December 2015. Ultrasound reports were retrieved and reviewed by two radiologists on separate occasions who were blinded to the cytopathology and histopathology results. The histopathology reports were correlated with ultrasound features to determine features associated with malignancy. Stata SE 12 was used for data analysis. TIRADS sensitivity, specificity, positive predictive values and negative predictive values and accuracy were calculated.

Results

149 patients with thyroid nodules were included. Solid composition is the ultrasound feature predictive of malignancy with adjusted OR 4.912 (95% Cl 1.3257 to 18.2011, p=0.017). The risk of malignancy for TIRADS categories 3, 4a, 4b, 4c and 5 were 12.50%, 12.82%, 26.19%, 53.70% and 66.67%, respectively. The Crude OR (95% CI) for TIRADS 4a, 4b, 4c and 5 were 1.03 (0.10 to 10.23), 2.48 (0.27 to 22.54), 8.12 (0.93 to 70.59) and 14.0 (0.94 to 207.60), respectively. The sensitivity, specificity, PPV, NPV and accuracy of TIRADS in relation to surgical histopathology report were 98.00%, 7.07%, 34.75%, 87.50%, and 53% respectively in TIRADS categories 4 and 5.

Conclusion

This study showed that a solid nodule is the most frequent ultrasound feature predictive of thyroid malignancy. Higher TIRADS classification is associated with higher risk of thyroid malignancy. TIRADS is a sensitive classification in recognizing patients with thyroid cancer.

Size of thyroid carcinoma by histotype and variants: A population-based study in a mildly iodine-deficient area

BACKGROUND

Data relating the size of thyroid cancer with histological types and variants are scarce.

METHODS

All incident thyroid cancer diagnosed between 2003 and 2012 in a mildly iodine-deficient area were derived from a population-based tumor registry. Undifferentiated/anaplastic thyroid cancer and incidental cases were excluded. Major diameter of thyroid cancer, as assessed by pathological examination, was stratified in classes: ≤10 mm; 11-20 mm; 21-40 mm; and >40 mm. For each class, absolute and relative frequencies of histological types were calculated.

RESULTS

Tumors >20 mm were more frequent among follicular thyroid carcinoma (FTC) and Hürthle cell carcinoma than in other histotypes, with median size of 22.50 mm (95% confidence interval [CI] 16.71-28.29) and 25.00 mm (95% CI 17.04-32.96) in FTC and Hürthle cell carcinoma, respectively. Odds ratio for tumors >20 mm was significant for FTC and Hürthle cell carcinoma only (P < .0001).

CONCLUSION

Among the histotypes and variants of differentiated thyroid cancer, FTC and Hürthle cell carcinoma are characterized by the largest size.

An Atypical Presentation of Congenital Pulmonary Airway Malformation (CPAM): A Rare Case with Antenatal Ultrasound Findings and Review of Literature

BACKGROUND

Congenital pulmonary airway malformation (CPAM) is a relatively rare congenital anomaly with a wide spectrum of ultrasound features depending on the specific variety of CPAM. Antenatal ultrasound is a valuable, safe, nonionizing, cost-effective, widely available and easily reproducible imaging tool and is indispensable in the diagnosis of CPAM. In this paper, we aimed to report an atypical imaging presentation of CPAM type II in the second trimester, extensively involving all lobes of the left lung.

CASE REPORT

A 25-year-old G1P0A0 woman with a gestational age of around 22 weeks was referred for an anomaly scan. The antenatal ultrasound scan showed a single, live, intrauterine foetus corresponding to a gestational age of around 22 weeks and 4 days. There were multiple, anechoic structures noted within the pulmonary tissue in the left hemithorax, each measuring around 3 to 4 mm in diameter. The lesion was extending from the left lower lobe up to the apical (apicoposterior) segment of the left upper lobe. The ultrasound diagnosis of congenital pulmonary airway malformation type II was made. After explaining the condition and the poor prognosis to the patient, an informed consent was obtained after she opted for medical termination of pregnancy.

CONCLUSIONS

Congenital pulmonary airway malformation (CPAM) is an uncommon foetal anomaly with a very wide range of ultrasound appearances depending on the specific type of CPAM. CPAM also has a wide spectrum of differential diagnoses and a variable prognosis. Antenatal ultrasound should always be the primary mode of diagnosis in CPAM.

The utility of thyroid ultrasonography in the management of thyroid nodules

BACKGROUND

Ultrasonography for thyroid nodules is one of the most common imaging tests performed in the general population. Details from ultrasound reports guide biopsies and surgery. This study quantifies the completeness of these reports based on Thyroid Imaging and Reporting System (TI-RADS) criteria and considers their utility in predicting malignant disease.

METHODS

We retrospectively reviewed ultrasound reports for 329 thyroidectomy patients and extracted data elements using the TI-RADS criteria: nodule size, echogenicity, margins, vascularity, solid/cystic composition and the presence or absence of microcalcifications and the halo sign. We assessed the reports to determine whether individual or multiple criteria were associated with malignancy.

RESULTS

More than 97% of reports document nodule size; however, more than 90% of the reports noted only 3 or fewer of the 6 remaining TI-RADS criteria. The presence of microcalcifications was the most sensitive marker of malignancy (> 90%), whereas the documentation of irregular margins was the most specific indicator of malignancy (88%). Overall it was clear that microcalcifications, hypoechogenicity, irregular margins and solid nodules were significantly more likely to be found in malignant neoplasms; their absence predicted benign disease. Because so few reports consistently documented all criteria, the overall ability of thyroid ultrasonography to discriminate between lowerand higher-risk nodules is limited.

CONCLUSION

Although the accuracy of thyroid ultrasonography is good, few ultrasound reports contain the necessary information, as defined by TI-RADS, to predict malignancy and guide management. When reported, microcalcifications and/or irregular margins are the best predictors of malignancy.

Computer-aided diagnosis of malignant or benign thyroid nodes based on ultrasound images

The objective of this study is to evaluate the diagnostic value of combination of artificial neural networks (ANN) and support vector machine (SVM)-based CAD systems in differentiating malignant from benign thyroid nodes with gray-scale ultrasound images. Two morphological and 65 texture features extracted from regions of interest in 610 2D-ultrasound thyroid node images from 543 patients (207 malignant, 403 benign) were used to develop the ANN and SVM models. Tenfold cross validation evaluated their performance; the best models showed accuracy of 99% for ANN and 100% for SVM. From 50 thyroid node ultrasound images from 45 prospectively enrolled patients, the ANN model showed sensitivity, specificity, positive and negative predictive values, Youden index, and accuracy of 88.24, 90.91, 83.33, 93.75, 79.14, and 90.00%, respectively, the SVM model 76.47, 90.91, 81.25, 88.24, 67.38, and 86.00%, respectively, and in combination 100.00, 87.88, 80.95, 100.00, 87.88, and 92.00%, respectively. Both ANN and SVM had high value in classifying thyroid nodes. In combination, the sensitivity increased but specificity decreased. This combination might provide a second opinion for radiologists dealing with difficult to diagnose thyroid node ultrasound images.

Diagnostic accuracy of Thyroid Imaging Reporting and Data System in the prediction of malignancy in nodules with atypia and follicular lesion of undetermined significance cytologies

OBJECTIVE

Thyroid Imaging Reporting and Data System (TIRADS) is a simple and reliable reporting system for the prediction of malignancy. We aimed to determine the role of TIRADS in the prediction of malignancy in subcategories of Bethesda Category III, atypia of undetermined significance (AUS) and follicular lesion of undetermined significance (FLUS).

DESIGN & PATIENTS

A total of 461 nodules with AUS cytology in 450 patients and 179 nodules with FLUS cytology in 168 patients were included. Ultrasonography (US) features and postoperative histopathology results were documented. Every suspicious US feature was scored as 1 and 0 according to the presence or not, respectively. TIRADS category of each nodule was determined.

RESULTS

In AUS subcategory, histopathologically malignant nodules had significantly different TIRADS categories compared to benign nodules (P = 0·001), but this was not the case in FLUS subcategory (P = 0·121). In AUS group, malignant nodules had significantly higher prevalance of microcalcification, hypoechogenicity and anteroposterior/transverse ratio than benign ones (P < 0·001, P < 0·001 and P = 0·003, respectively) and TIRADS categories of 4c and 5 were more frequent in malignant nodules (P < 0·05). Microcalcification, hypoechogenicity and TIRADS were found to be associated with malignancy in multivariate logistic regression analysis in this subcategory. TIRADS category ≥4c was associated with malignancy (AUC ± SE: 0·584 ± 0·028). In FLUS subcategory, there was no significant difference between histopathologically malignant and benign nodules with respect to suspicious US features (P > 0·05, all).

CONCLUSION

TIRADS seems to be useful in predicting malignancy and planning further management in the AUS subcategory, but not quite so in the FLUS subcategory.

A Recurrent Case of Pentalogy of Cantrell: A Rare Case with Sonological Findings and Review of Literature

BACKGROUND

Pentalogy of Cantrell (POC) is an extremely rare and complex congenital anomaly. Ultrasound is a valuable, safe, nonionizing, cost effective, widely available, and easily reproducible imaging tool and is indispensible in the diagnosis of POC. Despite the rarity of POC, it is imperative for a radiologist to be aware of its wide spectrum of presentation on ultrasound in first trimester of gestation. Most reported cases in literature till now have been sporadic. In this paper, we aimed to report for the first time in literature, a recurrent case of POC detected in the first trimester in a mother whose previous pregnancy also was terminated in the second trimester medically due to the ultrasound diagnosis of POC. We also discuss the role of ultrasound and other imaging modalities in a case of POC as well as the differential diagnoses which can mimic POC.

CASE REPORT

A 23-year-old G2P0A1 (Gravida2, para0, abortion1) woman with a gestational age of around 12 weeks was referred for a routine first trimester ultrasound scan. The antenatal ultrasound scan showed a single, live, intrauterine gestation corresponding to a gestational age of 11 weeks and 5 days. The fetal heart was visualized outside the chest through a defect in the lower sternum in association with anterior diaphragmatic and ventral abdominal wall defects suggestive of thoraco-abdominal variety of ectopia cardis. There was a membrane covered, midline, abdominal wall defect at the base of the umbilical cord insertion containing the herniated abdominal organs including the liver, bowel loops and the ectopic cardia. There was a breach in the normal outline of the lower sternum indicating a sternal deficiency. The fetal pericardium was absent. The nuchal translucency was grossly increased. Pentalogy of Cantrell was diagnosed on ultrasound and the patient was explained about the poor prognosis of this condition. An informed consent was obtained after she opted for medical termination of pregnancy. The autopsy confirmed all the above mentioned ultrasound features.

CONCLUSIONS

Pentalogy of Cantrell (POC) is an extremely rare and complex syndrome of numerous fetal anomalies but should always be borne in the mind during the ultrasound evaluation of either of an omphalocele, ectopia cordis, distal sternal defect, pericardial defect, anterior diaphragmatic defect or intracardiac anomalies. Ultrasound is a valuable, safe, nonionizing, cost effective, widely available, and easily reproducible imaging tool for diagnosis of POC. Ultrasound should always be the primary mode of diagnosis in POC because although Magnetic resonance imaging (MRI) can help in better delineation of fetal anomalies, it does not significantly alter the course of the pregnancy or the management of POC.

Bayesian analysis of high-resolution ultrasonography and guided fine needle aspiration cytology in diagnosis of palpable thyroid nodules

INTRODUCTION

To evaluate diagnostic accuracy of high-resolution ultrasonography in differentiation of benign and malignant thyroid nodules in comparison to results of guided fine needle aspiration cytology based on the Bayes rule.

OBJECTIVE

To assess the validity of ultrasonography results of thyroid nodules in comparison to guided fine needle aspiration cytology findings.

METHODS

This study was done on randomly chosen 80 patients presented with palpable thyroid nodules, undergone real-time sonographic evaluation of thyroid nodules to characterize features, internal consistency, margins, echotexture, calcification, peripheral lucent halo and vascularity. Ultrasonography guided fine needle aspiration cytology studies of thyroid nodules were done.

RESULTS

Palpable thyroid nodules were highly prevalent in fourth and fifth decades of life with female-male ratio, 4:1. Solid internal consistency was demonstrated by 75% malignant nodules. Hypoechogenicity and intra-nodular micro-calcifications were observed in 92% malignant nodules; 83% malignant nodules had intra-nodular vascularity and absence of peripheral halo. The pre-test prevalence of malignant nodules in the targeted population was 17.5%. As type I error, 2.5% false-positive cases and as type II error, 5.0% false-negative cases were detected. Values of sensitivity and specificity of the ultrasonography test were 71.43 and 96.97%, respectively.

CONCLUSION

Malignant thyroid nodules demonstrated ultrasonography characteristics of hypoechoic texture, intra-nodular micro-calcifications, solid consistency, internal vascularity and absence of peripheral halo. The ultrasonography test has 92.5% diagnostic accuracy to differentiate malignant from benign lesions in comparison to the gold standard fine needle aspiration cytology test.

A Classic Case of Subcutaneous Cysticercosis: A Rare Case with Sonological Findings and Review of Literature

Background

Cysticercosis is a parasitic infection caused by the larval stages of the pork tapeworm, Taenia solium. The subcutaneous form of the disease is a relatively rare clinical entity. Despite its rarity, it is imperative for a radiologist to be aware of this subcutaneous form of the disease and its various radiological patterns while evaluating any subcutaneous swelling. In this paper, we aimed to describe a typical case of ‘subcutaneous cysticercosis involving the left anterior chest wall’ with high resolution ultrasound findings. We also discussed the role of other imaging modalities in a case of subcutaneous cysticercosis. To the best of our knowledge, our case is only the second documented case report of sonological evaluation of subcutaneous cysticercosis involving the left anterior chest wall and the first case with high resolution ultrasound images of the lesion.

Case Report

An 11-year-old male presented with a painless, subcutaneous swelling over the left anterior chest wall for the last 2 months. High resolution ultrasound showed a well-defined, thin-walled, cystic lesion with an eccentric, echogenic focus in the subcutaneous plane. On change of the posture of the patient, this focus showed mobility. The hypoechoic area surrounding this cyst showed significant exudative fluid collection with diffuse, floating echoes and thin, incomplete internal septations. The adjacent soft tissues were thickened and irregular, suggestive of edema. This was followed by an excision biopsy. Histopathological examination revealed cysticercus cellulose parasite with an extensive mixed inflammatory cell infiltrate in the surrounding tissue. The patient was also administered oral antihelminthic therapy. Repeat ultrasound examination at the end of this management regimen showed complete healing with no e/o any remnant or recurrent cystic lesion, abscess or edema in the subcutaneous plane.

Conclusions

Subcutaneous cysticercosis is a relatively rare form of cysticercosis but should always be born in mind during the evaluation of subcutaneous swellings. High resolution ultrasound is a valuable, safe, nonionizing, cost-effective, widely-available, and easily-reproducible imaging tool for diagnosis of subcutaneous cysticercosis. There is a wide spectrum of ultrasound patterns of subcutaneous cysticercosis. In classic cases with a cyst containing a scolex within and with a surrounding abscess, high resolution ultrasound should always be the primary mode of diagnosis, thus avoiding unnecessary fine needle aspiration cytologies.