Comparison and Combination of Strain and Shear Wave Elastography of Breast Masses for Differentiation of Benign and Malignant Lesions by Quantitative Assessment: Preliminary Study.

OBJECTIVES: To compare the diagnostic performance of strain and shear wave elastography of breast masses for quantitative assessment in differentiating benign and malignant lesions and to evaluate the diagnostic accuracy of combined strain and shear wave elastography. METHODS: Between January and February 2016, 37 women with 45 breast masses underwent both strain and shear wave ultrasound (US) elastographic examinations. The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) final assessment on B-mode US imaging was assessed. We calculated strain ratios for strain elastography and the mean elasticity value and elasticity ratio of the lesion to fat for shear wave elastography. Diagnostic performances were compared by using the area under the receiver operating characteristic curve (AUC). RESULTS: The 37 women had a mean age of 47.4 years (range, 20-79 years). Of the 45 lesions, 20 were malignant, and 25 were benign. The AUCs for elasticity values on strain and shear wave elastography showed no significant differences (strain ratio, 0.929; mean elasticity, 0.898; and elasticity ratio, 0.868; P > .05). After selectively downgrading BI-RADS category 4a lesions based on strain and shear wave elastographic cutoffs, the AUCs for the combined sets of B-mode US and elastography were improved (B-mode + strain, 0.940; B-mode + shear wave; 0.964; and B-mode, 0.724; P < .001). Combined strain and shear wave elastography showed significantly higher diagnostic accuracy than each individual elastographic modality (P = .031). CONCLUSIONS: These preliminary results showed that strain and shear wave elastography had similar diagnostic performance. The addition of strain and shear wave elastography to B-mode US improved diagnostic performance. The combination of strain and shear wave elastography results in a higher diagnostic yield than each individual elastographic modality.

Ultrasonographic features associated with false-negative and false-positive results of extrathyroidal extensions in papillary thyroid microcarcinoma.

PURPOSE: To assess the ultrasonographic features affect accuracy of extrathyroid extension (ETE) evaluation on preoperative ultrasonography (US) in papillary thyroid microcarcinoma (PTMC). METHODS: Of the total patients who underwent thyroid surgery, 516 patients with a tumor measuring less than 1 cm on preoperative US were enrolled in this study. One blinded head and neck radiologist reviewed the preoperative US images to evaluate the US features of PTMC, and the pathologic reports were reviewed. The diagnostic accuracy rates, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, were calculated, and the factors associated with false-negative and false-positive results for ETE were analyzed. RESULTS: The sensitivity, specificity, PPV, NPV, and accuracy for predicting ETE according to sonographic criteria were 32.8%, 87.5%, 51.0%, 76.6%, and 71.7%, respectively. Non-adjacent to the trachea and unilateral lesion on US were significant factors associated with false-negative results. CONCLUSION: Size, shape, and location of PTMC on US are important factors that affect the US results in ETE evaluation.

Risk Factors for False-Negative and False-Positive Results of Magnetic Resonance Computer-Aided Evaluation in Axillary Lymph Node Staging.

PURPOSE: The aims of this study were to investigate the false-negative and false-positive results on magnetic resonance (MR) computer-aided evaluation (CAE) in axillary lymph node (ALN) staging and to evaluate the related factors in patients with invasive breast cancer. METHODS: From July 2011 to May 2014, 103 invasive breast cancer patients who underwent preoperative MR-CAE were included. False MR-CAE results in ALN staging were compared in terms of clinicopathologic features, baseline mammography, and breast ultrasonography. Logistic regression analyses were used to evaluate independent factors related to false results. RESULTS: For MR-CAE, the false-negative and false-positive results of ALN metastasis were 6.8% and 33.3%, respectively. On multivariate analysis, spiculated tumor margin (P = 0.016) and positive lymphovascular invasion (P = 0.020) were associated with false-negative results, and circumscribed tumor margin (P = 0.017) and negative lymphovascular invasion (P = 0.036) were associated with false-positive results for ALN metastasis. CONCLUSIONS: Tumor margin and lymphovascular invasion are the key factors that affect the false MR-CAE results in ALN staging.

Predictive factors for occult contralateral carcinoma in patients with unilateral papillary thyroid microcarcinoma by preoperative ultrasonographic and pathological features.

BACKGROUND: The surgical extent and indication for treatment in patients with papillary thyroid microcarcinoma (PTMC) remain a controversial issue. The aim of this study was to investigate the predictive factor for contralateral occult carcinoma in patients with unilateral PTMC by preoperative ultrasonographic and pathological features. METHODS: Of the total patients who underwent thyroidectomy, 455 patients with PTMC confined to one unilateral lobe as diagnosed using preoperative ultrasonography (US) were enrolled in the study. Occult contralateral carcinoma was defined as tumor foci in the contralateral lobe that was not detected preoperatively, but was detected pathologically. All patients underwent preoperative US review to investigate the US features of PTMC such as laterality, location, size, internal component, echogenicity, margin, calcification shape, multifocality, bilaterality, extrathyroidal extension, and location with respect to the trachea. Clinicopathological data were also analyzed. RESULTS: Of the total of 455 patients who underwent total thyroidectomy for preoperatively detected unilateral PTMC, 71 patients (15.6 %) had contralateral occult carcinoma. Clinicopathological characteristics did not significantly differ between patients with and without contralateral occult carcinoma. Multivariate analysis showed that the absence of a well-defined margin and the presence of a probably benign nodule in the contralateral lobe were independent predictive factors for contralateral occult carcinoma in patients with unilateral PTMC in preoperative US images. CONCLUSION: We demonstrated that an absence of a well-defined margin and the presence of a probably benign nodule in the contralateral lobe were independent predictive factors for contralateral occult carcinoma in patients with unilateral PTMC in preoperative US. The prediction of contralateral occult carcinoma in unilateral PTMC using preoperative US features could be useful for determining the optical extent of surgery.

Comparison of mammographic density estimation by Volpara software with radiologists' visual assessment: analysis of clinical-radiologic factors affecting discrepancy between them.

BACKGROUND: Volumetric breast density analysis is useful for quantitative mammographic assessment. However, there are few studies about clinical-radiologic factors contributing to discrepancies in the visual assessment by radiologists. PURPOSE: To compare automated volumetric breast density measurement with BI-RADS breast density category by radiologists' visual assessments and to evaluate the clinical-radiologic factors affecting disagreement between two estimations. MATERIAL AND METHODS: From February 2011 to September 2012, 860 patients (mean age, 54.7 ± 10.2 years) who had undergone digital mammography including fully automated volumetric breast density analysis, were enrolled. The agreement in breast density assessments between two radiologists, and between an experienced radiologist and the automated software were evaluated using a weighted kappa (k) value. Clinical-radiologic factors contributing to disagreement between the results obtained by a radiologist and the automated software were evaluated using univariate and multivariate analysis. RESULTS: Breast density assessments obtained by two different radiologists were in good agreement (weighted k statistics 0.835%; 95% confidence interval [CI], 0.8098-0.8608); breast density assessments obtained by an experienced radiologist versus automated software were in moderate agreement (weighted k statistics 0.799%; 95% CI, 0.7708-0.8263). Univariate analysis identified a difference in bilateral breast density and patient age as two factors that significantly contributed to disagreement between the two approaches (P = 0.0002, P = 0.019). Multivariate analysis only identified a difference in bilateral breast density as a contributing factor. CONCLUSION: The automated volumetric breast density measurement showed good agreement with radiologists' assessment. The difference in bilateral breast density affected the disagreement between results from visual assessment and automated software.

Role of [18F]fluorodeoxyglucose positron emission tomography-computed tomography, sonography, and sonographically guided fine-needle aspiration biopsy in the diagnosis of axillary lymph nodes in patients with breast cancer: comparison of diagnostic performance.

OBJECTIVES: The aim of this study was to compare the diagnostic performance of [(18)F]fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) with that of sonography and sonographically guided fine-needle aspiration (FNA) for determining the preoperative axillary lymph node (ALN) status and to evaluate the factors related to false-negative PET-CT, sonographic, and FNA results in ALN staging of invasive ductal carcinoma. METHODS: From March 2009 to July 2012, 226 patients had a diagnosis of primary breast cancer. Among these patients, 107 constituted the study population after exclusion of transferred patients and patients with breast cancer other than invasive ductal carcinoma. The diagnostic performance of the modalities was compared with pathologic reports. Univariate and multivariate analyses were used to evaluate the relationship between clinicopathologic factors (symptoms, T stage, hormone receptors, and histologic grade), false-negative results, and true-negative results on PET-CT, sonography, and FNA. RESULTS: Of the 107 patients, 45 (42.1%) had positive results on final pathologic analysis of ALNs. Sonographically guided FNA had a significantly higher specificity, positive predictive value, accuracy, and area under the receiver operating characteristic curve than sonography and PET-CT (P < .01). When sonography and PET-CT were combined, the sensitivity was significantly improved (P = .019) compared with sonography alone. When FNA and PET-CT were combined, the sensitivity and negative predictive value were significantly increased compared with each modality (P < .01). CONCLUSIONS: Sonographically guided FNA was found to be an excellent diagnostic tool for preoperative evaluation of the ALN status. To obviate the step of sentinel lymph node biopsy for determining the ALN status, combined evaluation of ALNs by these modalities may be more complementary than the use of a single modality.

Sonographic appearance of a neuroendocrine tumor arising in the axilla: case report and literature review.

Neuroendocrine tumors (NETs) are tumors that originate from neuroendocrine cells throughout the body. NETs are most commonly found in the appendix, followed by the rectum, ileum, lungs, and bronchi. NETs arising in soft tissues are rare. Here we describe the sonographic appearance of a NET in the axilla.

Comparison of sonographically guided core needle biopsy and excision in breast papillomas: clinical and sonographic features predictive of malignancy.

OBJECTIVES: The aim of this study was to evaluate the clinical factors and sonographic features of benign papillomas of the breast proven by sonographically guided 14-gauge core needle biopsy and their upgrade or malignancy rate after sonographically guided vacuum-assisted excision or surgical excision. METHODS: We reviewed the medical records of patients who underwent core needle biopsy from July 2005 to December 2011. We evaluated 39 benign papillomas without atypia in 34 patients. The papillomas were diagnosed by core needle biopsy and underwent surgical or vacuum-assisted excision. After core needle biopsy, imaging-histologic correlation was performed to determine concordance. The upgrade and malignancy rates were assessed after surgical or vacuum-assisted excision, and associated clinical and radiologic factors, including patient age, lesion size, distance from the nipple, sonographic features, and American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) category were evaluated. RESULTS: Three lesions (7.7 %) among 39 papillomas were upgraded to papilloma with atypia after surgical excision. There was no malignancy after excision. The upgrade rates for BI-RADS categories 3, 4a, 4b, and 4c were 0%, 6.9%, 0%, and 20%, respectively. There were no significant differences in the upgrade to papilloma with atypia in terms of the presence of symptoms, lesion size, distance from the nipple, BI-RADS category, or imaging-histologic correlation. CONCLUSIONS: Prediction of papilloma with atypia, not malignancy, was challenging because there were no associated clinical or radiologic factors to predict papilloma with atypia before excision. However, there was no malignancy after excision. Therefore, intensive surveillance is preferable to immediate surgical excision for benign papillomas diagnosed on core needle biopsy.

Sonographic findings of axillary masses: what can be imaged in this space?

The diagnosis of axillary masses can be challenging because various tumors can develop in parts of the axilla other than lymph nodes, even though we frequently encounter axillary masses in daily practice. These lesions include soft tissue masses associated with nontumorous conditions (accessory breast tissue and chronic granulomatous inflammation) and benign and malignant tumorous conditions (lipomas, epidermal inclusion cysts, lymphangiomas, fibroadenomas, schwannomas, malignant neuroendocrine tumors, and lymph node-associated diseases). In this pictorial essay, we display commonly encountered sonographic findings of various axillary lesions to assist in the differential diagnosis of axillary masses.

Agenesis of a submandibular gland with compensatory pseudotumoral hypertrophy of the contralateral gland: sonographic findings.

Agenesis of a submandibular gland with compensatory hypertrophy of the contralateral gland is an extremely rare disorder. Most reported cases of unilateral submandibular agenesis have been asymptomatic without any associated facial anomalies. We report a case of submandibular gland hypertrophy mimicking a mass that was detected incidentally. The absence of the contralateral submandibular gland and associated contralateral sublingual gland hypertrophy was confirmed by typical imaging findings.

Radiomic models based on magnetic resonance imaging predict the spatial distribution of CD8+ tumor-infiltrating lymphocytes in breast cancer.

Infiltration of CD8+ T cells and their spatial contexture, represented by immunophenotype, predict the prognosis and therapeutic response in breast cancer. However, a non-surgical method using radiomics to evaluate breast cancer immunophenotype has not been explored. Here, we assessed the CD8+ T cell-based immunophenotype in patients with breast cancer undergoing upfront surgery (n = 182). We extracted radiomic features from the four phases of dynamic contrast-enhanced magnetic resonance imaging, and randomly divided the patients into training (n = 137) and validation (n = 45) cohorts. For predicting the immunophenotypes, radiomic models (RMs) that combined the four phases demonstrated superior performance to those derived from a single phase. For discriminating the inflamed tumor from the non-inflamed tumor, the feature-based combination model from the whole tumor (RM-wholeFC) showed high performance in both training (area under the receiver operating characteristic curve [AUC] = 0.973) and validation cohorts (AUC = 0.985). Similarly, the feature-based combination model from the peripheral tumor (RM-periFC) discriminated between immune-desert and excluded tumors with high performance in both training (AUC = 0.993) and validation cohorts (AUC = 0.984). Both RM-wholeFC and RM-periFC demonstrated good to excellent performance for every molecular subtype. Furthermore, in patients who underwent neoadjuvant chemotherapy (n = 64), pre-treatment images showed that tumors exhibiting complete response to neoadjuvant chemotherapy had significantly higher scores from RM-wholeFC and lower scores from RM-periFC. Our RMs predicted the immunophenotype of breast cancer based on the spatial distribution of CD8+ T cells with high accuracy. This approach can be used to stratify patients non-invasively based on the status of the tumor-immune microenvironment.

US-guided diffuse optical tomography for breast lesions: the reliability of clinical experience.

PURPOSE: To prospectively assess the reliability of US-guided diffuse optical tomography (US-DOT) using interobserver agreement for the diagnosis of breast lesions with individual real-time imaging and to assess the interobserver agreement of conventional sonography (US) combined with US-DOT for differentiation between benignity and malignancy breast lesions. MATERIALS AND METHODS: An Institutional Review Board approved this study, and all subjects provided written informed consent. 122 breast lesions in 111 patients evaluated with US-guided core biopsy were included. Assessments with US and US-DOT for cases subjected to biopsy were obtained by two radiologists using individual real-time imaging prior to biopsy and were prospectively recorded by each performer. With DOT, the total haemoglobin concentration (THC) for each breast lesion was measured. Histopathological results from US-guided biopsies were used as a reference standard. To assess measurement interobserver agreement, the intraclass correlation coefficient (ICC) and the Bland-Altman plot were used for THC in US-DOT and the kappa values and ROC analysis were used to evaluate the diagnostic performances of the US BI-RADS final assessment in US and combined US and US-DOT. RESULTS: Of 122 US-guided core biopsied lesions, 83 (68.0%) were diagnosed as benign, and 39 (32.0%) as malignant. Excellent correlation was seen in the THC in US-DOT (ICC score 0.796; 95% confidence interval, 0.708-0.857). The interobserver agreement in BI-RADS final assessment with US and US-DOT (almost perfect; κ = 0.8618) was improved compared with that of US (substantial agreement, κ = 0.6574). However, the overall areas under the ROC curve did not show significant differences between US and combined US and US-DOT, 0.8894 and 0.8975, respectively (P = 0.981). CONCLUSIONS: The reliability of THC in US-DOT showed excellent correlation in overall real-time performance. Although the inter-observer agreement for BI-RADS final assessment of US was improved by using US-DOT, the performances of radiologists with respect to the characterization of breast masses as benign or malignant were not significantly improved with US-DOT.

Breast ultrasonography in young Asian women: analyses of BI-RADS final assessment category according to symptoms.

BACKGROUND: Breast ultrasound is the major imaging modality in young women because it incurs no radiation exposure and dense breast tissue, which is common in young women, yields a high rate of false-negative results on mammography. PURPOSE: To investigate the cancer rates of the sonographic BI-RADS categorization and histopathologic results according to the presence of symptoms in young Asian women. MATERIAL AND METHODS: We included 811 young women under 30 years of age who underwent a breast ultrasound during the study period. The mean age of all subjects was 24.5 years (range 11-29 years). Histopathologic results were compared with the results after application of the BI-RADS categorization. RESULTS: Sonographic findings were classified as category 1 (n=192), category 2 (n=81), category 3 (n=399), category 4 (n=134), and category 5 (n=5). The cancer rates for category 1, 2, 3, 4, and 5 were 0, 0, 0.3, 6.3, and 100% in the symptomatic group, respectively. For the asymptomatic group, the cancer rates were 0, 0, 0, 8.7, and 100%, respectively. More cancers were found in high-risk women (22.2%, 4/18) than in non-high-risk women (1.4%, 11/793). CONCLUSION: BI-RADS categorization was helpful for predicting the probability of malignancy in young Asian women.

Sonographic appearance of a schwannoma mimicking an axillary lymphadenopathy.

Schwannomas are benign nerve sheath tumors derived from Schwann cells and are the most common type of peripheral nerve tumor. Schwannomas occur mainly in the extremities, trunk, and head and are rarely manifested in the axilla. Although various solid tumors can develop in the axilla, only a few cases of schwannoma in the axillary cavity have been reported. Herein, we describe the sonographic appearance of a schwannoma arising from the brachial plexus in the axilla.

Malignancy risk of thyroid nodules with nonshadowing echogenic foci.

PURPOSE: This study was conducted to determine the malignancy risk and diagnostic value of various types of nonshadowing echogenic foci (NEF) in the risk stratification of thyroid nodules. METHODS: A total of 1,018 consecutive thyroid nodules (≥1 cm) with final diagnoses were included. The presence of NEF was determined and types of NEF were classified according to the presence of a comet tail artifact (CTA), location, and size through a prospective evaluation. The associations with malignancy, malignancy risk, and diagnostic value of various types of NEF were assessed. RESULTS: Intrasolid punctate NEF without CTA was the only type of NEF that was an independent predictor of malignancy (P<0.001). The malignancy risk of intrasolid punctate NEF without CTA was substantially higher in solid hypoechoic nodules than in isoechoic or nonsolid nodules (71.3% vs. 9.2%, P<0.001). In solid hypoechoic nodules, slightly increased sensitivity (70.8% vs. 67.9%) for malignancy and a similar malignancy risk (71.4% vs. 71.3%) were observed for intrasolid punctate NEF (with or without CTA) and intrasolid punctate NEF without CTA, respectively. NEF with CTA at the margin of the cystic component was not associated with malignancy or benignity in nonsolid nodules (P>0.05). CONCLUSION: Intrasolid punctate NEF without CTA was the only independent predictor of malignancy. However, solid hypoechoic nodules with intrasolid punctate NEF should be classified as high-suspicion nodules regardless of coexisting CTA. Other types of NEF had no added value for detecting malignancy compared to intrasolid punctate NEF without CTA.

Axillary lymph node metastasis: CA-15-3 and carcinoembryonic antigen concentrations in fine-needle aspirates for preoperative diagnosis in patients with breast cancer.

PURPOSE: To assess whether concentrations of the tumor markers breast cancer antigen 15-3 (CA-15-3) and carcinoembryonic antigen (CEA) in fine-needle aspirates (FNAs) differ between benign and malignant lymph nodes and whether FNA concentrations of the tumor markers can improve the sensitivity of axillary lymph node (ALN) FNA in patients with breast cancer. MATERIALS AND METHODS: An Institutional Review Board approved this study. All subjects gave written informed consent. Ultrasonographically (US)-guided FNA was performed for 134 ALNs in 134 women (mean age, 49.6 years; range, 28-92 years) with breast cancer. Immediately after obtaining an FNA cytology specimen, the needle was rinsed with 1 mL of normal saline solution. CEA and CA-15-3 concentrations were measured in the washout. Of the 134 ALNs, 86 were malignant and 48 were benign. Sensitivity of FNA cytology alone was compared with the sensitivity of FNA cytology and CEA and CA-15-3 FNA concentrations. RESULTS: Patients with a positive metastatic diagnosis had significantly higher FNA concentrations of CEA and CA-15-3 than did those with a negative diagnosis (both P = .02). FNA cytology sensitivity was 87.2%, and the combined sensitivity of FNA cytology and FNA tumor marker concentrations was 96.5% (P = .01). CONCLUSION: Evaluation of CEA and CA-15-3 concentrations in FNA could be helpful for the preoperative diagnosis of ALN metastasis in patients with breast cancer. (c) RSNA, 2010.

Diagnostic approach for evaluation of lymph node metastasis from thyroid cancer using ultrasound and fine-needle aspiration biopsy.

OBJECTIVE: The purpose of our study was to investigate ultrasound criteria to determine the most accurate criterion to differentiate metastatic from benign lymph nodes on ultrasound and to evaluate the frequency of metastasis according to the cytology results. MATERIALS AND METHODS: One hundred eighteen consecutive patients with thyroid malignancy underwent fine-needle biopsy of suspicious lymph nodes. We investigated the diagnostic performance of each ultrasound feature (loss of fatty hilum, presence of cystic change or calcification, hyperechogenicity, and round shape) and ultrasound criteria 1 and 2. We considered criterion 1 to be if one of the aforementioned malignant ultrasound findings was present and criterion 2 to be if one of the aforementioned malignant ultrasound findings, excluding the loss of fatty hilum, was present. Cytology results were divided into metastasis, macrophages without malignant cells, cell paucity, and negative for malignancy, and we evaluated the frequency of metastasis. RESULTS: There were 91 metastatic and 27 benign nodes. The area under the receiver operating characteristic curve value of criterion 2 was significantly higher than that of criterion 1. The frequency of metastasis was highest with a cytologic result of metastasis (95.8%), followed by macrophages without malignant cells (87.5%), cell paucity (71.4%), and negative for malignancy (34.4%). CONCLUSION: The most accurate ultrasound criterion to differentiate metastatic from benign lymph nodes was ultrasound criterion 2 (any suspicious ultrasound features except for loss of fatty hilum), and we should not neglect lymph nodes with suspicious ultrasound features, even if they do not contain malignant cells on cytology.

Communication between spaces formed by fasciae of male external genitalia and perineum: computed tomographic cadaveric study and clinical significance.

OBJECTIVE: The purposes were to evaluate the communication and the extent of the spaces formed by fasciae of the male external genitalia and the perineum and to correlate the spaces with clinical observations regarding anatomic progression of diseases. MATERIALS AND METHODS: Multi-detector row computed tomography (CT) was performed through the perineum and the pelvis of 5 fresh cadavers injected with contrast material in the space between dartos and Buck fasciae of the penis. Two of the 5 cadavers, injected with the contrast material mixed with blue ink, were dissected to confirm the observations made on multi-detector row computed tomography. Computed tomographic images of 11 patients with diseases involving the potential spaces formed by the fasciae of the male genitalia and the perineum were correlated with observations made on CT of the cadavers. RESULTS: The contrast material filling the scrotal cavity extended posteriorly in the perineum, remained far below the urogenital diaphragm, and reached superiorly to the potential space along Scarpa fascia in all cadavers. At cadaveric dissection, the ink-stained spaces were confined by the fascial planes involving Colles, Buck, dartos, and Scarpa fasciae. Spread of disease in the 11 patients (6 patients with localized genital edema, 4 with Fournier gangrene, and 1 with bulbous urethral rupture) was confined in the spaces demonstrated on CT images of the cadavers. CONCLUSIONS: Free communication and disease spread occur within the confines of the superficial perineal, scrotal, penile, and abdominal wall spaces formed by Colles, Buck, dartos, and Scarpa fasciae.

Giant cell tumor of a tendon sheath mimicking an axillary lymph node.

A giant cell tumor of the tendon sheath (GCTTS) is 1 of the most common soft-tissue tumors of the hand and wrist, while the 2nd most frequent site is the ankle-foot complex. Although various solid tumors can develop in the axilla, GCTTS has not yet been reported. We describe the sonographic appearance of GCTTS in the axilla.

Diagnostic Performance of a Combination of Shear Wave Elastography and B-Mode Ultrasonography in Differentiating Benign From Malignant Thyroid Nodules.

OBJECTIVES: This study was conducted to compare clinicopathologic and radiologic factors between benign and malignant thyroid nodules and to evaluate the diagnostic performance of shear wave elastography (SWE) combined with B-mode ultrasonography (US) in differentiating malignant from benign thyroid nodules. METHODS: This retrospective study included 92 consecutive patients with 95 thyroid nodules examined on B-mode US and SWE before US-guided fine-needle aspiration biopsy or surgical excision. B-mode US findings (composition, echogenicity, margin, shape, and calcification) and SWE elasticity parameters (maximum [Emax], mean, minimum, and nodule-to-normal parenchymal ratio of elasticity) were reviewed and compared between benign and malignant thyroid nodules. The diagnostic performance of B-mode US and SWE for predicting malignant thyroid nodules was analyzed. The optimal cutoff values of elasticity parameters for identifying malignancy were determined. Diagnostic performance was compared between B-mode US only, SWE only, and the combination of B-mode US with SWE. RESULTS: On multivariate logistic regression analysis, age (odds ratio [OR], 0.90; P=0.028), a taller-than-wide shape (OR, 11.3; P=0.040), the presence of calcifications (OR, 15.0; P=0.021), and Emax (OR, 1.22; P=0.021) were independent predictors of malignancy in thyroid nodules. The combined use of B-mode US findings and SWE yielded improvements in sensitivity, the positive predictive value, the negative predictive value, and accuracy compared with the use of B-mode US findings only, but with no statistical significance. CONCLUSION: When SWE was combined with B-mode US, the diagnostic performance was better than when only B-mode US was used, although the difference was not statistically significant.