Ultrasound-based computer-aided diagnosis for cytologically indeterminate thyroid nodules with different radiologists.

PURPOSE: To evaluate a computer-aided diagnosis (CAD) technique in predicting malignancy for cytologically indeterminate thyroid nodules (TNs) as compared with different experienced radiologists. METHOD: 436 patients with 436 cytologically indeterminate TNs on fine-needle aspiration cytology (FNAC) were included and all were confirmed by surgical pathology. They were retrospectively analyzed with respect to ultrasound (US) characteristics using a commercially available CAD system (AmCAD-UT; AmCad BioMed, Taiwan, China) and reviewed by one junior and one senior radiologists.The CAD system and different experienced radiologists stratified the risk of malignancy using ACR TI-RADS category. The diagnostic performance by different experienced radiologists independently and after consulting the CAD (different experienced radiologists + CAD) and by the CAD alone were compared. RESULTS: The different experienced radiologists showed significantly higher specificities than the CAD system alone. The combination of radiologist and CAD system showed improved diagnostic performance with an AUC (Area under the curve) of 0.740 in the senior radiologist and 0.677 in the junior radiologist, as compared with CAD (AUC: 0.585) alone (all P < 0.05). The combination of senior radiologist and CAD system had the highest diagnostic performance (AUC: 0.740) and specificity (68.9%) compared to the others (all P < 0.05). CONCLUSION: The CAD system may play the potential role as a decision-making assistant alongside radiologists for differential diagnosis of TNs with indeterminate cytology.

A Comparative Analysis of Two Machine Learning-Based Diagnostic Patterns with Thyroid Imaging Reporting and Data System for Thyroid Nodules: Diagnostic Performance and Unnecessary Biopsy Rate.

Background: The risk stratification system of the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) for thyroid nodules is affected by low diagnostic specificity. Machine learning (ML) methods can optimize the diagnostic performance in medical image analysis. However, it is unknown which ML-based diagnostic pattern is more effective in improving diagnostic performance for thyroid nodules and reducing nodule biopsies. Therefore, we compared ML-assisted visual approaches and radiomics approaches with ACR TI-RADS in diagnostic performance and unnecessary fine-needle aspiration biopsy (FNAB) rate for thyroid nodules. Methods: This retrospective study evaluated a data set of ultrasound (US) and shear wave elastography (SWE) images in patients with biopsy-proven thyroid nodules (≥1 cm) from the Shanghai Tenth People's Hospital (743 nodules in 720 patients from September 2017 to January 2019) and an independent test data set from the Ma'anshan People's Hospital (106 nodules in 102 patients from February 2019 to April 2019). Six US features and five SWE parameters from the radiologists' interpretation were used for building the ML-assisted visual approaches. The radiomics features extracted from the US and SWE images were used with ML methods for developing the radiomics approaches. The diagnostic performance for differentiating thyroid nodules and the unnecessary FNAB rate of the ML-assisted visual approaches and the radiomics approaches were compared with ACR TI-RADS. Results: The ML-assisted US visual approach had the best diagnostic performance than the US radiomics approach and ACR TI-RADS (area under the curve [AUC]: 0.900 vs. 0.789 vs. 0.689 for the validation data set, 0.917 vs. 0.770 vs. 0.681 for the test data set). After adding SWE, the ML-assisted visual approach had a better diagnostic performance than US alone (AUC: 0.951 vs. 0.900 for the validation data set, 0.953 vs. 0.917 for the test data set). When applying the ML-assisted US+SWE visual approach, the unnecessary FNAB rate decreased from 30.0% to 4.5% in the validation data set and from 37.7% to 4.7% in the test data set in comparison to ACR TI-RADS. Conclusions: The ML-assisted dual modalities visual approach can assist radiologists to diagnose thyroid nodules more effectively and considerably reduce the unnecessary FNAB rate in the clinical management of thyroid nodules.

Diagnostic Performance Evaluation of Practice Guidelines, Elastography and Their Combined Results for Thyroid Nodules: A Multicenter Study.

The purpose of this multicenter study was to compare the differential diagnostic value of the 2015 American Thyroid Association (ATA) and 2017 American College of Radiology (ACR) practice guidelines and elastography in thyroid nodules. This study also investigated whether the diagnostic value of practice guidelines can be improved, and the unnecessary biopsy rate decreased in combination with elastography. A total of 498 thyroid nodules were evaluated using the ATA and the ACR guidelines. Strain elastography, acoustic radiation force impulse imaging and point-shear wave elastography were used to assess the nodules. The suspicious levels were downgraded or upgraded after combination and unnecessary biopsy rates were calculated, respectively. The diagnostic performance of the practice guidelines was better than that of elastography. The ACR guidelines had a lower unnecessary biopsy rate and similar diagnostic performance compared with the ATA guidelines. The unnecessary biopsy rates significantly decreased when the ACR guidelines were combined with elastography, but the rates did not decrease when the ATA guidelines were combined with elastography.

Conventional ultrasound characteristics, TI-RADS category and shear wave speed measurement between follicular adenoma and follicular thyroid carcinoma.

The purpose of the study was to explore the differences of conventional ultrasound characteristics, thyroid imaging reporting and data system (TI-RADS) category and shear wave speed (SWS) measurement between follicular adenoma (FA) and follicular thyroid carcinoma (FTC). Twenty-eight FTCs and 67 FAs proven by surgery were retrospectively included for analysis. Conventional ultrasound and point-shear wave elastography (p-SWE) were performed in all of the included patients. The ultrasound features, American Thyroid Association (ATA) TI-RADS category and American College of Radiology (ACR) TI-RADS category, SWS measurement were compared between the two groups. Receiver operating characteristic (ROC) curve was performed and area under ROC curve (AUC) was obtained for significant features. There were no statistical differences in mean age (46.9±15.7years vs. 48.6±13.6years, P = 0.639), gender (9 males, 32.1% vs. 18 males, 29.0%, P = 0.766) and mean diameter (28.3±16.2 mm vs. 33.8±11.9 mm, P = 0.077) between FTCs and FAs. Hypoechogenicity, lobulated or irregular margin, macrocalcification were more common in FTCs than FAs (all P < 0.05). Mean SWS of FTCs (2.29±0.64 m/s) was slightly higher than that of FAs (1.94±0.68 m/s) (P = 0.023). The AUCs were 0.655, 0.744, and 0.744 with the cut-off SWS≥1.89 m/s, ACR TI-RADS category 4 and intermediate suspicion of ATA TI-RADS category. The sensitivity and AUC were 82.1% and 0.812 with combined ultrasound features of hypoechogenicity, lobulated or irregular margin and macrocalcification. In Conclusion, SWS measurement and TI-RADS categories were useful for the identification of FTCs from FAs.

Suspicious ultrasound and clinicopathological features of papillary thyroid carcinoma predict the status of TERT promoter.

PURPOSE: To investigate the value of ultrasound (US) and clinicopathological features of papillary thyroid cancer (PTC) in predicting Telomerase Reverse Transcriptase (TERT) promoter mutations. METHODS: Preoperative US images of 351 surgically confirmed PTCs were evaluated in terms of PTCs size and US features. The basic clinicopathological features were also retrieved. Univariate and multivariate analyses were performed to identify the risk factors for TERT promoter mutations. A scoring system was developed based on the cumulative number of risk factors. The area under the receiver operating characteristic curve (AUC) and cut-off value were calculated to evaluate the diagnostic performance of the scoring system for predicting TERT promoter mutations. RESULTS: TERT promoter mutations were found in 4.84% (17/351) of patients with PTCs. Patient age >50 years (OR: 6.244, P = 0.006), multifocality (OR: 21.071, P = 0.022), taller-than-wide shape (OR: 4.934, P = 0.029), microlobulated margin (OR: 4786, P = 0.032), and capsule contact or involvement (OR: 4.668, P = 0.030) were independent risk factors for TERT promoter mutations. TERT promoter mutations were relevant to more suspicious US and clinicopathological features than TERT promoter wild-type PTC (median, 4 vs. 1, P < 0.001). The cut-off value was 2.5 and the associated AUC was 0.908 (P < 0.001). CONCLUSIONS: The probability of TERT promoter mutations increases along with the suspicious US features and clinicopathological characteristics, which may help to recognize patients who deserve a different approach, in terms of management and follow-up, in view of the worst outcome associated to this mutation.

[Bacteriological examination on needle biopsy specimens of cavity and tuberculoma after a short course chemotherapy in initially sputum positive pulmonary tuberculosis patients].

OBJECTIVE: To evaluate the therapeutic effect of a short course chemotherapy on initially sputum positive cavitary pulmonary tuberculosis or tuberculoma by bacteriological examination of specimens through percutaneous lung biopsy after the chemotherapy. METHODS: Eighty-three cases of initially sputum positive pulmonary tuberculosis with cavities or tuberculoma were included from Jan. 2002 and May. 2004. The patients finished a course of chemotherapy (2HREZ/4HR), and the sputum was converted to smear-negative and culture-negative, but cavities or tuberculoma remained on the chest X-ray. Lung specimens were obtained from the wall or content of the cavity or from the tuberculoma by CT-guided percutaneous lung biopsy for bacteriological examination within one month after the course. RESULTS: All the needle biopsy specimens were smeared and cultured for Mycobacterium tuberculosis. Eight cases (8/83, 9.6%) showed positive results: 3 were smear-positive and culture-positive, and 5 smear-negative but culture-positive. Drug susceptibility test showed that 7 of them were drug-sensitive and the remaining 1 was resistant to rifampin and isoniazid. After follow-up of 24 months, 6 of them converted to sputum smear-positive. CONCLUSION: Our study showed that 90.4% (75/83) of the tuberculosis cases achieved real bacteriological negative result on biopsies after a short course chemotherapy, and the bacteriological positive cases on biopsy experienced 75.0% (6/8) sputum bacteriological recurrence. The result suggests that the evaluation criteria with sputum on therapeutic effect of pulmonary tuberculosis needs to be reassessed.