Sonoelastography in Distinguishing Benign from Malignant Complex Breast Mass and Making the Decision to Biopsy

Objective

To evaluate the additional effect of sonoelastography on the radiologist''s ability for distinguishing benign from malignant complex breast masses and to decide whether to perform biopsy by B-mode US.

Materials and Methods

One hundred eighteen complex breast masses (15 malignant lesions, 103 benign lesions) were included. Five blinded readers independently assessed the likelihood of the malignancy score from 1 to 5 for two data sets (B-mode ultrasound alone and B-mode ultrasound with sonoelastography). Elasticity scores were categorized as 0, 1, or 2 based on the degree and distribution of strain of the echogenic component within complex masses. The readers were asked to downgrade the likelihood of the malignancy score when an elasticity score of 0 was assigned and to upgrade the likelihood of the malignancy score when an elasticity score of 2 was assigned. The likelihood of the malignancy score was maintained as it was for the lesions with an elasticity score of 1. The Az values, sensitivities, and specificities were compared.

Results

The Az value of B-mode ultrasound with sonoelastography (mean, 0.863) was greater than that of B-mode ultrasound alone (mean, 0.731; p = 0.001-0.007) for all authors. The specificity of B-mode ultrasound with sonoelastography (mean, 37.1%) was greater than that of B-mode ultrasound alone (mean, 3.8%; p < 0.001) for all readers. The addition of sonoelastography led to changes in decisions. A mean of 33.6% of benign masses were recommended for follow-up instead of biopsy.

Conclusion

For complex breast masses, sonoelastography allows increase in both the accuracy in distinguishing benign from malignant lesions and the specificity in deciding whether to perform biopsy.     

Incremental value of real-time ultrasound elastography in differentiating breast masses

Aim of the work

To evaluate the value of real-time ultrasound elastography (RTE) in differentiating benign from malignant breast masses.

Materials and methods

This study included, whether palpable or non-palpable, 145 sonographically proven breast masses in 121 patients, imaged by conventional B-mode US, color-flow Doppler US and RTE with histopathological analysis considered as the golden standard reference.

Results

Lesions were differentiated into benign and malignant by conventional B-mode US (79; 45.5% and 66; 54.5%, respectively), RTE (80; 55.2% and 65; 44.8% respectively), and histopathology (82; 56.6% and 63; 43.4%, respectively). The mean difference in the mass size was significant between B-mode US and RTE in malignant masses (P = 0.002), while not significant among benign masses (P = 0.153). The B-mode US depicted sensitivity of 92.06%, specificity of 90.24%, PPV of 87.88%, NPV of 93.67% and accuracy of 91.03%, while the RTE showed sensitivity of 98.41%, specificity of 96.34%, PPV of 95.38%, NPV of 98.75% and accuracy of 97.24%.

Conclusion

Combined use of RTE can complement conventional B-mode US with improving its diagnostic performance in differentiating breast lesions with subsequent reduction in the rate of unnecessary biopsies in benign lesions.     

Diagnostic performance of sonoelastographic Tsukuba score and strain ratio in evaluation of breast masses

The aim of this prospective study was to evaluate the diagnostic performance of the use of strain index ratio by sonoelastography to differentiate between benign and malignant breast lesions.

Real-time ultrasound elastography: Does it improve B-mode ultrasound characterization of solid breast lesions?

Introduction

Elastography is a non-invasive medical imaging technique that detects tumors based on their stiffness (elasticity). Strain images display the relative stiffness of lesions compared with the stiffness of surrounding tissue as cancerous tumors tend to be many times stiffer than the normal tissue, which “gives” under compression. An image in which different degrees of stiffness show as different shades of light and dark is called an elastogram.

Purpose

To prospectively evaluate the sensitivity and specificity of the real-time sonoelastography as compared with B-mode US for distinguishing between benign and malignant solid breast masses. The density of the glandular breast tissue was taken in consideration in addition to the Breast Imaging Reporting and Data System (BI-RADS) categories of the lesions, with biopsy results as the reference standard.

Methods

A total of 216 candidate solid lesions (123 benign and 93 malignant) in 188 patients were examined with 2-dimensional ultrasonography, elastosonography and mammography (for 147 patients). The lesions were classified according to the density of the glandular breast tissue into low density group (D1) and a high density group (D2) and were categorized with the BIRADS score. Elastographic images were assigned an elasticity score of 1 to 5 (1–3, benign; 4 and 5, malignant) according to the Multi-Center Team of Study and the strain ratios of the lesions were measured. Concordance between the imaging findings and histopathologic results was documented. Statistical analysis was performed and sensitivity, specificity and positive and negative predictive values for both elastography and conventional sonography were calculated.

Results

Elastography showed less sensitivity but higher specificity than conventional sonography in the differentiation of benign from malignant solid lesions: B-mode sonography had sensitivity of 85.1%, specificity of 93.9%, a positive predictive value of 92.5% and a negative predictive value of 87.8%, compared with the sensitivity of 80.1%, specificity of 97.1%, a positive predictive value of 96.8% and a negative predictive value of 82.1% for elastography. Elastography was superior to B-mode US in diagnosing solid lesions in the low density group (D1) (96.6% vs. 92.4% specificity) and less in the dense glandular tissue (97.8% vs. 95.9% specificity).

Conclusions

Real-time sonoelastography is an useful technique for the characterization of benign and malignant solid lesions as it increases the diagnostic specificity comparable to B-mode ultrasound, particularly in both ACR 1 and 2, thus reducing the false-positive rate.     

Sonoelastography versus dynamic magnetic resonance imaging in evaluating BI-RADS III and IV breast masses

Background

Several clinical studies showed that sonoelastography was useful for the differentiation of benign and malignant breast lesions. Contrast-enhanced MRI has emerged as a promising tool in the detection, diagnosis, and staging of breast cancer.

Aim of work

To study the role of sonoelastography versus dynamic MRI in evaluating BI-RADS III, IV breast masses and detect which modality is of better sensitivity and specificity trying to guide the patient either to follow-up the lesion or proceed to lesion excision.

Subjects and methods

The study included 50 Egyptian patients (age ranged from 32 to 58 years) who presented by breast masses and categorized as BI-RADS III, IV by mammography and ultrasound. Sonoelastography and dynamic MRI were done for all the patients.

Results

Differentiation between BI-RADS III and IV by US elastography had 84% sensitivity and 84% specificity and by MRI had 88% sensitivity and 80% specificity.

Conclusion

Regarding the sonoelastography, it is an easy and cheap modality. The elasticity score is an important parameter for lesion characterization. Combination of morphologic and dynamic MRI studies is very important for the breast lesion evaluation. MRI is more sensitive but less specific than sonoelastography. Finally if we find any suspicious character elicited by either sonoelastography or MRI (BI-RADS IV), lesion excision is recommended.     

Real-time tissue elastography combined with BIRADS-US classification system for improving breast lesion evaluation

Purpose

The purpose of this study was to establish the correlation of prospectively interpreted ultrasound elastography (USE) results with American College of Radiology Breast Imaging Reporting and Data System (BIRADS) assessment and pathologic diagnoses of sonographically visible breast masses and to determine whether USE can improve distinction of benign and malignant lesions.

Patients and methods

Between April 2012 and January 2014, sonoelastography of focal breast lesions was carried out in 410 patients with subsequent histological confirmation. We present data focusing on the sensitivity (SE), specificity (SP) and the positive (PPV) and negative predictive value (NPV) of sonoelastography. In addition we performed an analysis of the diagnostic performance, expressed by the pretest and posttest probability of disease (POD), in BI-RADS-US 3 or 4 lesions as these categories can imply both malignant and benign lesions and a more precise prediction would be a preferable aim.

Results

Sonoelastography demonstrated an improved SP (89.5%) and an excellent PPV (86.8%) compared to B-mode ultrasound (76.1% and 77.2%). Especially in dense breasts ACR III–IV, the SP was even higher (92.8%). In BI-RADS-US 3 lesions, a suspicious elastogram significantly modified the POD from 8.3% to a posttest POD of 45.5%. In BI-RADS-US 4 lesions, we found a pretest POD of 56.6%. The posttest POD changed significantly to 24.2% with a normal elastogram and to 81.5% with a suspicious elastogram.

Conclusions

Real-time tissue elastography may provide additional characterization of breast lesions, improving specificity, particularly for BIRADS 3 and BIRADS 4 lesions.     

Could ultrasonic elastography help the diagnosis of small (≤2 cm) breast cancer with the usage of sonographic BI-RADS classification?

Objectives

To evaluate the additive value of ultrasound strain elastography (USE) to BI-RADS for the differentiation of benign and malignant breast small lesions.

Methods

Breast masses (≤2 cm) with histological diagnosis examined by ultrasonography and USE in our department from April 2004 to December 2009 were reviewed. Conventional B-mode ultrasound findings were classified according to the BI-RADS classification. USE findings were classified according to the 5-point scale. Histological diagnosis was used as the reference standard.

Results

401 (246 benign (61.3%), 155 malignant (38.7%)) from 370 consecutive patients were included in the study. Sensitivity and specificity were 90.3%, 68.3% for BI-RADS; 72.3%, 91.9% for USE. The sensitivity of BI-RADS was better than that of USE (P < 0.05), while the specificity of USE was better than that of BI-RADS (P < 0.05). A revised BI-RADS combined with USE results was proposed in this study. Sensitivity and specificity were 83.9% and 87.8% for revised BI-RADS. The diagnostic performance of revised BI-RADS was better than BI-RADS (P < 0.05).

Conclusions

USE could give BI-RADS some help in the differentiation of benign and malignant breast small lesions. The addition of elastography to BI-RADS could improve the diagnostic performance in <2 cm lesions.     

Diagnosis of solid breast lesions by elastography 5-point score and strain ratio method

Purpose

To compare the diagnostic performance of 5-point scoring system and strain ratio by sonoelastography in the assessment of solid breast lesions.

Material and methods

One hundred and eighty-seven solid masses in 155 patients were scanned by two-dimensional ultrasonography and sonoelastography. Elasticity scores were determined with a 5-point scoring method, and the strain ratio was based on the comparison of the average strain measured in the lesion with the adjacent breast tissue in the same depth. Pathological results were taken as gold standards to compare the diagnostic efficacy of two methods with clinical diagnostic test and receiver operating characteristic (ROC) curves.

Results

Among 187 lesions, 130 were benign and 57 were malignant. The mean scores (1.62 ± 0.69 vs 4.07 ± 0.26, P < 0.05) and strain ratios (2.06 ± 1.27 vs 6.66 ± 4.62, P < 0.05) were significantly higher of malignant than benign lesions. The area under the curve for the 5-point scoring system and for strain ratio-based elastographic analysis was 0.892 and 0.909, respectively (P > 0.05). For 5-point scoring, sonoelastography had 84.2% sensitivity, 84.6% specificity, 84.5% accuracy, 70.6% positive predictive value and 92.4% negative predictive value. When a cutoff point of 3.06 was used, sensitivity, specificity, accuracy, positive and negative predictive values were 87.7%, 88.5%, 88.2%, 76.9% and 94.3%, respectively for the strain ratio (P > 0.05).

Conclusions

The 5-point scoring system and strain ratio has similar diagnostic performance, and the strain ratio could be more objective to differentiate the masses when those masses were difficult to be judged by using 5-point scoring system in sonoelastographic images.     

Role of supersonic shear wave imaging quantitative elastography (SSI) in differentiating benign and malignant solid breast masses

Purpose

To evaluate sensitivity and specificity of supersonic shear wave imaging quantitative elastography (SSI) for distinguishing benign and malignant solid breast masses.

Materials and methods

100 patients with small solid breast masses, were included. The lesions were classified according to the BIRADS (Breast Imaging and Reporting Data System) by SSI. Measurement of the kilopascals (kPa) in different areas of the examined region of interest (ROI) was performed. Ultrasound-guided Tru-cut needle biopsy with an 18-gauge needle was done in all cases.

Results

From the malignant lesions (according to histopathological data), 15% were classified as BIRADS 4 and 85% as BIRADS 5 by SSI. Of the benign lesions, 98%, were classified as BIRADS 3% and 2% as BIRADS 4. According to the histological data, 100% of the lesions with a score of 5 (by SSI) were malignant and 100% of the lesions with a score of 3 were benign. 10% of the lesions with a score of 4 were benign and 90% were malignant. The mean elasticity values were significantly higher for malignant lesions than for benign lesions.

Conclusions

SSI has high sensitivity and specificity in the differentiation of benign and malignant solid breast masses.     

Characterization and guided-procedures of breast suspicious microcalcifications: can MicroPure ultrasound do it?

Objective

To assess the diagnostic value of high-frequency (MicroPure) ultrasound in evaluating suspicious microcalcifications and to determine its capability in biopsy guidance.

Subjects and methods

Sixty-two cases with suspicious microcalcifications detected on mammographic examination had been re-evaluated by MicroPure US. The studied cases underwent true cut tissue/surgical excision biopsy. Histopathology revealed 25 benign and 37 malignant lesions and was considered the gold standard of reference.

Results

Malignant microcalcifications were easier to be visible at MicroPure US, as they were detected in 86.5% (n = 32/39) compared to only 68% (n = 17/25) of the benign lesions. US depicted more breast masses associated with malignant microcalcifications in 78% (n = 29/37) than those associated with benign ones seen in 36% (n = 9/25).Visibility of suspicious microcalcifications at US was aided by preliminary mammogram. Given known mammography location of these microcalcifications had made their visualization accessible by MicroPure US in 79% (n = 49) of the cases.

Conclusion

MicroPure ultrasound cannot discriminate benign from malignant breast microcalcifications. MicroPure can be useful in detecting clustered microcalcifications that are not accessible by B-mode ultrasound; provided knowledge of their mammographic location and thus can provide better guidance for pre-surgical wire localization and ultrasound-guided biopsies.     

Differentiating benign from malignant solid breast lesions: Combined utility of conventional ultrasound and contrast-enhanced ultrasound in comparison with magnetic resonance imaging

Objective

To prospectively evaluate the diagnostic efficacy of conventional ultrasound (US), contrast-enhanced US (CEUS), the combined use of two modalities, and magnetic resonance imaging (MRI) in the differentiation of focal solid breast lesions.

Materials and methods

61 patients with BI-RADS category 3–5 breast lesions detected at conventional US underwent CEUS and MRI. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of conventional US, CEUS, combination of two modalities and MRI for discrimination between benign and malignant breast lesions.

Results

Tissue specimens of 61 breast lesions were obtained either from surgical resection (n = 46) or from needle biopsy (n = 15). Histopathologic diagnosis revealed 28 benign and 33 malignant lesions. The diagnostic performance of conventional US and CEUS in differentiating benign from malignant breast lesions showed no significant difference (P = 0.741). The combination of two modalities significantly improved the diagnostic accuracy compared with either conventional US or CEUS alone (P = 0.031 and P = 0.012, respectively). The area under the ROC curve (A_z) value for the combined use of two modalities for discrimination between benign and malignant breast lesions was 0.94, and that for MRI was 0.91, whereas no statistical difference was found between them (P = 0.296).

Conclusion

The combined use of conventional US and CEUS has a better diagnostic performance than either method alone and displays good agreement with MRI in the differentiation capability for benign and malignant breast lesions.     

Added value of Virtual Touch IQ shear wave elastography in the ultrasound assessment of breast lesions

Purpose

To determine the diagnostic performance of Acoustic Radiation Force Impulse (ARFI) Virtual Touch IQ shear wave elastography in the discrimination of benign and malignant breast lesions.

Materials and methods

Conventional B-mode and elasticity imaging were used to evaluate 110 breast lesions. Elastographic assessment of breast tissue abnormalities was done using a shear wave based technique, Virtual Touch IQ (VTIQ), implemented on a Siemens Acuson S3000 ultrasound machine. Tissue mechanical properties were interpreted as two-dimensional qualitative and quantitative colour maps displaying relative shear wave velocity. Wave speed measurements in m/s were possible at operator defined regions of interest. The pathologic diagnosis was established on samples obtained by ultrasound guided core biopsy or fine needle aspiration.

Results

BIRADS based B-mode evaluation of the 48 benign and 62 malignant lesions achieved 92% sensitivity and 62.5% specificity. Subsequently performed VTIQ elastography relying on visual interpretation of the colour overlay displaying relative shear wave velocities managed similar standalone diagnostic performance with 92% sensitivity and 64.6% specificity. Lesion and surrounding tissue shear wave speed values were calculated and a significant difference was found between the benign and malignant populations (Mann–Whitney U test, p < 0.0001). By selecting a lesion cut-off value of 3.31 m/s we achieved 80.4% sensitivity and 73% specificity. Applying this threshold only to BIRADS 4a masses, we reached overall levels of 92% sensitivity and 72.9% specificity.

Conclusion

VTIQ qualitative and quantitative elastography has the potential to further characterise B-mode detected breast lesions, increasing specificity and reducing the number of unnecessary biopsies.     

Can ultrasound elastography distinguish metastatic from reactive lymph nodes in patients with primary head and neck cancers?

Objectives

The purpose of this study was to evaluate the diagnostic utility of real-time elastography (RTE) in differentiating between reactive and metastatic cervical lymph nodes (LN) in patients with primary head and neck cancer in comparison with the conventional B mode and power Doppler parameters.

Methods

A total of 127 lymph nodes in 78 patients with primary head and neck cancer were examined by B-mode sonography, power Doppler ultrasound and elastography. Elastographic patterns were determined on the distribution and percentage of the lymph node area with low elasticity (hard), with pattern 1 being an absent or very small hard area to pattern 5, a hard area occupying the entire lymph node. Patterns 3–5 were considered metastatic. Ultrasound guided aspiration cytology was done for 57 lymph nodes. Excision biopsy was done for 52 lymph nodes. Eighteen lymph nodes responded to conservative treatment, and were considered reactive.

Results

The majority (85.3%) of the metastatic lymph nodes had elastography pattern 3–5. This finding was observed in only 5% of the benign lymph nodes (P < 0.001). The elastography pattern had sensitivity of 85.3%, specificity of 95.5%, PPV of 97.2%, NPV of 78.1% and overall accuracy of 88.9% in differentiation between benign and malignant lymph nodes. On the other hand, for the B mode criteria, the best accuracy was given to abnormal hilum (83%). The accuracy of power Doppler ultrasound pattern was 70.8%.

Conclusions

The accuracy of sonoelastography is higher than usual B mode and power Doppler ultrasound parameters in differentiation between benign and malignant nodes. The integration of lymph node sonoelastography in the follow up of patients with known head and neck cancer may reduce the number of biopsies.     

Diagnostic performance of qualitative shear-wave elastography according to different color map opacities for breast masses

Purpose

To compare the diagnostic performance of qualitative shear-wave elastography (SWE) according to three different color map opacities for breast masses

Materials and methods

101 patients aged 21–77 years with 113 breast masses underwent B-mode US and SWE under three different color map opacities (50%, 19% and 100%) before biopsy or surgery. Following SWE features were reviewed: visual pattern classification (pattern 1–4), color homogeneity (E_homo) and six-point color score of maximum elasticity (E_col). Combined with B-mode US and SWE, the likelihood of malignancy (LOM) was also scored. The area under the curve (AUC) was obtained by ROC curve analysis to assess the diagnostic performance under each color opacity.

Results

A visual color pattern, E_homo, E_col and LOM scoring were significantly different between benign and malignant lesions under all color opacities (P < 0.001). For 50% opacity, AUCs of visual color pattern, E_col, E_homo and LOM scoring were 0.902, 0.951, 0.835 and 0.975. But, for each SWE feature, there was no significant difference in the AUC among three different color opacities. For all color opacities, visual color pattern and E_col showed significantly higher AUC than E_homo. In addition, a combined set of B-mode US and SWE showed significantly higher AUC than SWE alone for color patterns, E_homo, but no significant difference was found in E_col.

Conclusion

Qualitative SWE was useful to differentiate benign from malignant breast lesion under all color opacities. The difference in color map opacity did not significantly influence diagnostic performance of SWE.     

Can diffusion weighted imaging distinguish between benign and malignant solid or predominantly solid gynecological adnexal masses?

Objective

To determine the benefit of DWI in diagnosis of benign and malignant solid or predominantly solid gynecological adnexal or ovarian masses.

Material and Methods

This study is carried out on 23 patients with histologically proven solid or predominantly solid adnexal or ovarian masses out of which 5 cases (21.8%) have benign and 18 cases (78.2%) have malignant neoplasms. Among these 19 cases (82.6%) have unilateral disease and 4 cases (17.4%) have bilateral disease which was metastatic ovarian carcinoma.

Result

On DWI, high signal intensity is noted in malignant lesion more frequently than in benign lesion. (P < 0.001) in adnexal lesions, while in ovarian lesions (P = 0.001).The differentiation between benign and malignant adnexal lesions revealed no significant difference in the apparent diffusion coefficient (ADC) value (P = 0.22).

Conclusion

DWI is a helpful tool in differentiation between predominantly solid and solid benign and malignant adnexal lesions because there is an increased frequency of higher signal intensity (diffusion restriction) in malignant lesions.     

Value of mammography and combined grey scale ultrasound and ultrasound elastography in the differentiation of solid breast lesions

Aim of the work

The aim of this work was to evaluate the value of ultrasound elastography (UE) in differentiating benign versus malignant solid breast lesions discovered in mammography and compare it with grey scale ultrasound (US) and mammography.

Methods

From May 2011 to May 2013, 114 solid lesions from 100 consecutive patients discovered during mammography were categorized into benign or malignant by mammography and US and further analyzed with UE. The diagnostic results of the cases were compared with histopathologic findings.

Results

Of 114 lesions, 33 were histologically malignant, and 81 were benign. UE was the most specific (95.1%) of the 3 modalities. The accuracy (81.7%) of UE was equal to mammography and was higher than those of US (82.5% and 71.9%, respectively). A combination of UE and US had the best sensitivity (90.9%) and accuracy (93.8%).

Conclusions

Ultrasound elastography is useful for breast lesion characterization and is an easier and cheaper method and more specific than mammography or US alone, but it is operator dependent. When combined with US, detection accuracy can be greatly improved and the combination potentially could reduce unnecessary biopsy.     

US screening for detection of nonpalpable locoregional recurrence after mastectomy

Purpose

To assess the value of screening ultrasonography (US) in the detection of nonpalpable locoregional recurrence following mastectomy for breast cancer and to describe the US appearances of occult recurrent cancers.

Materials and methods

During a 36-month period, 1180 consecutive US screenings were performed for mastectomy sites and ipsilateral axillary fossae in 468 asymptomatic women who had undergone mastectomy for breast cancer. All US results were divided into three groups: negative findings, probably benign nodules, and suspicious for malignant nodules. The final diagnoses were based on pathology results and clinical or sonographic follow-up for more than 12 months. The diagnostic performance of US for detecting nonpalpable locoregional recurrence was assessed. The US appearances of occult recurrent cancers were retrospectively reviewed.

Results

Of the 468 patients assessed, 19 (4.1%) showed “suspicious for malignant nodules”; of these lesions, 10 were malignant. One false-negative case was identified. The sensitivity and specificity were 90.9% and 98.0%, respectively. A biopsy positive predictive value of 52.6% was observed. Cancer detection rates were 2.1% with US screenings of mastectomy sites and ipsilateral axillary fossae. The common US features of occult recurrences at the mastectomy sites were irregular shaped, not-circumscribed marginated, and hypoechoic masses with intratumoral vascularities. The most common location was within the deep muscle layer.

Conclusion

Although locoregional recurrence infrequently occurs after mastectomy for breast cancer, screening US enables detection of nonpalpable cancer before it can be detected by clinical examination. Routine follow-up US can be advocated for early detection of nonpalpable locoregional recurrent cancer.     

Comparison of muscle-to-nodule and parenchyma-to-nodule strain ratios in the differentiation of benign and malignant thyroid nodules: Which one should we use?

Objective

The aim of this study is to investigate the diagnostic accuracy of muscle-to-nodule strain ratio (MNSR) in the differentiation of benign and malignant thyroid nodules and to see if there was a difference between MNSR and parenchyma-to-nodule strain ratios (PNSR) in diagnosis.

Methods

A total of 106 consecutive patients (88 women and 18 men; age range 19–79 years) with thyroid nodules were prospectively examined using ultrasound and sonoelastography before the fine-needle aspiration biopsy. The mean MNSR and PNSR were calculated for each nodule and the elasticity score was determined according to four-point scoring system.

Results

According to the four-point scoring system, 44 of the 83 benign nodules had a score of one or two while 22 of the 23 malignant nodules had a score of three or four (p < 0.001). Using ROC analysis, the best cutoff point for MNSR 1.85 and for PNSR 3.14 was calculated. The sensitivity and specificity for the MNSR were 95.6%, 92.8%, respectively; for the PNSR were 95.6%, 93.4%, respectively, when the best cutoff points were used (p < 0.001). The κ value for the PNSR and MNSR methods was 0.87, which indicated an almost perfect agreement (p < 0.001).

Conclusions

Sonoelastography has a high diagnostic accuracy in the differentiation of benign and malignant thyroid nodules. There was no significant difference between MNSR and PNSR in the differentiation of benign and malignant thyroid nodules. Therefore, we think that MNSR could safely be used in situations where PNSR could not be used.