Added Value of a New Strain Elastography Technique in Conventional Ultrasound for the Diagnosis of Breast Masses: A Prospective Multicenter Study.

OBJECTIVE: This study aimed to explore the value of elasticity score (ES) and strain ratio (SR) combined with conventional ultrasound in distinguishing benign and malignant breast masses and reducing biopsy of BI-RADS (Breast Imaging Reporting and Data System) 4a lesions. METHODS: This prospective, multicenter study included 910 patients from nine different hospitals. The acquisition and analysis of conventional ultrasound and strain elastography (SE) were obtained by radiologists with more than 5 years of experience in breast ultrasound imaging. The diagnostic sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under curve (AUC) of conventional ultrasound alone and combined tests with ES and/or SR were calculated and compared. RESULTS: The optimal cutoff value of SR for differentiating benign from malignant masses was 2.27, with a sensitivity of 60.2% and a specificity of 84.8%. When combined with ES and SR, the AUC of the new BI-RADS classification increased from 0.733 to 0.824 (p < 0.001); the specificity increased from 48.1% to 68.5% (p < 0.001) without a decrease in the sensitivity (98.5% vs. 96.4%, p = 0.065); and the PPV increased from 52.2% to 63.7% (p < 0.001) without a loss in the NPV (98.2% vs. 97.1%, p = 0.327). All three combinations of conventional ultrasound, ES, and SR could reduce the biopsy rate of category 4a lesions without reducing the malignant rate of biopsy (from 100% to 68.3%, 34.9%, and 50.4%, respectively, all p < 0.001). CONCLUSIONS: SE can be used as a useful and non-invasive additional method to improve the diagnostic performance of conventional ultrasound by increasing AUC and specificity and reducing the unnecessary biopsy of BI-RADS 4a lesions.

Diagnostic and Predictive Values of Strain Ratios in the Regions of Interests in Reference Tissue for Breast Tumor.

PURPOSE: To investigate the diagnostic and predictive value of strain ratios in the regions of interests (ROIs) in reference tissue for breast tumor. PATIENTS AND METHODS: A total of 707 lesions in 665 consecutive patients were examined with B-mode Breast Imaging-Reporting and Data System (BI-RADS) and Ultrasonic elastography (UE). Elasticity score (ES) and strain ratio (SR) in each lesion were calculated. Receiver operating characteristic (ROC) curves were used to assess the diagnostic value of BI-RADS, ES, SR1, SR2, BI-RADS combined with ES (BI-RADS+ES), BI-RADS combined with SR1 (BI-RADS+SR1), and BI-RADS combined with SR2 (BI-RADS+SR2). The sensitivity, specificity, and areas under the ROC curves (Az) were obtained. Scatter plots were generated to demonstrate the correlation between SR1 and SR2. Kruskal-Walls H-test, Mann-Whitney U-test and one-way ANOVA were performed to evaluate SRs and tumor-related variables. Multiple linear regression analysis was carried out to determine variables independently associated with SRs. RESULTS: BI-RADS had high sensitivity and low specificity in the diagnosis of breast tumor. The specificity of BI-BADS combined with ES or SR was even higher. The Az value of BI-RADS+ES or BI-RADS+SRs was higher than that of BI-RADS (P < 0.001). The Az value of ES was higher than those of SR1 and SR2 (P < 0.001), and those of SR1 and SR2 were similar. SR1 and SR2 were highly positively correlated. There was no statistical difference between Az values of BI-RADS+ES, BI-RADS+SR1, and BI-RADS+SR2. Indistinct margin, high histologic grade, histological type, and negative human epidermal growth factor receptor (Her-2) were associated with SR1 and SR2. Progesterone receptor (PR) status and molecular subtype were associated with SR2. Histologic grade and tumor margin were significantly associated with SR1, and tumor margin was associated with SR2. CONCLUSION: SRs in different ROIs in the reference tissue at the same depth showed no different diagnostic value for breast tumor. Both SR1 and SR2 could be useful in assessing the biological characteristics of invasive breast carcinoma.

Interobserver and intermethod variability in data interpretation of breast strain elastography in suspicious breast lesions

Background/aim: Strain elastography has the disadvantage of being operator-dependent. Interobserver variability is observed during image acquisition and interpretation. This study aimed to analyze the interobserver and intermethod variability of strain elastography in image interpretation and evaluate the diagnostic performance combining elasticity score and strain ratio with ultrasonography. Materials and methods: A retrospective study was conducted on 70 breast lesions evaluated with B-mode ultrasonography and strain elastography. B-mode ultrasonography findings, elasticity scores, and strain ratio values were evaluated using static images by two radiologists. BI-RADS assessment of the lesions and the decision of both observers as to whether the biopsy was required using B-mode ultrasonography, and the combined ultrasonography+elasticity score, and the combined ultrasonography+elasticity score+strain ratio were compared with the histopathological results. Also, the interobserver agreement was analyzed for all the combinations. Results: There was very good agreement (weighted κ = 0.865) between the observers for the elasticity scores. Very good agreement was observed between the observers for BI-RADS assessments using the combined ultrasonography+elasticity score and the combined ultrasonography+elasticity score+strain ratio (weighted κ = 0.848, and 0.902, respectively). Area under the curve of B-mode ultrasonography, the combined B-mode ultrasonography+elasticity score, and the combined B-mode ultrasonography+elasticity score+strain ratio, were calculated as 0.859, 0.866, and 0.916 for observer 1, and 0.851, 0.829, and 0.916 for observer 2, respectively. There were no statistically significant differences between the observers' diagnostic performances in any of the combinations (P = 0.703, 0.067, and 0.972, respectively). Conclusion: In the evaluation and further assessment of breast lesions, semiquantitative strain ratio calculation may help improve diagnostic accuracy by reducing interpretational variety, when used together with B-mode ultrasonography and elasticity scoring, especially for inexperienced individuals.

Added value of strain elastography in the characterisation of breast lesions: A prospective study.

BACKGROUND: Elastography is a new promising ultrasonographic technique which is used to differentiate benign and malignant breast lesions based on the stiffness of the lesion. PURPOSE: To determine the role of strain elastography in characterisation of breast lesions and to compare the diagnostic performances of strain elastography and conventional ultrasound (US). METHODS: In total, 113 breast lesions in 100 women were prospectively evaluated by US and strain elastography followed by the histopathological examination. Elastography score based on the Tsukuba colour scale and strain ratio were determined for each lesion. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value were calculated for each modality and the diagnostic performances were compared. The best cut-off point was calculated for each of the elastography parameters using the receiver operator curve analysis. RESULTS: Out of the 113 lesions, 40 were malignant (35.4%) and 73 were benign (64.6%). The area under the curve for elastography score showed significant difference with that of US: 0.98 versus 0.90 (Difference = 0.08, p =0.02). The elastography parameters were more specific as compared to US (ES-95 and SR-93% vs. 63%, p < 0.05) with a high negative predictive value. The combined use of elastography and US gave better results with 95% sensitivity, 94% specificity, 94% accuracy and negative predictive value reaching 97%. CONCLUSION: Strain elastography is a useful adjunct to conventional ultrasonography. The combined use of strain elastography and ultrasound improves the characterisation of breast lesions and helps in down-staging of assigned BI-RADS category, thereby avoiding unnecessary biopsies. ES is the most useful elastography parameter to differentiate between benign and malignant breast lesions.

Can Strain Elastography Predict Malignancy of Soft Tissue Tumors in a Tertiary Sarcoma Center?

This study aims to investigate the ability of ultrasound strain elastography as an adjunct to predict malignancy in soft tissue tumors suspect of sarcoma or metastasis in a tertiary reference center for sarcoma. A total of 137 patients were included prospectively. Patients were referred on the basis of clinical or radiological suspicion of malignant soft tissue tumor. All patients had previously undergone diagnostic imaging (MRI, CT or PET-CT). After recording strain elastography cine loops, ultrasound guided biopsy was performed. Three investigators, who were blinded to final diagnosis, reviewed all elastograms retrospectively. For each elastogram, a qualitative, visual 5-point score was decided in consensus and a strain ratio was calculated. Final pathology obtained from biopsy or tumor resection served as gold standard. Eighty-one tumors were benign, and 56 were malignant. t-tests showed a significant difference in mean visual score between benign and malignant tumors. There was no significant difference in mean strain ratio between the two groups. Strain elastography may be a valuable adjunct to conventional B-mode ultrasound, perhaps primarily in primary care, when considering whether to refer to a sarcoma center or to biopsy, although biopsies cannot reliably be ruled out based on the current data.

Can strain elastography be used in reclassification of indeterminate breast lesions in BIRADS lexicon?: A prospective study.

PURPOSE: To evaluate the role of strain elastography (SE) in reclassification of indeterminate breast lesions placed under BIRADS 3 and 4 categories by conventional ultrasound (US) parameters so as to recourse biopsy only for suspicious stiffer lesions. METHODS: 113 breast lesions in 100 women assigned as BIRADS category 3 and 4 on US parameters were prospectively evaluated by SE followed by histo-pathological examination. Strain ratio (SR) and Elastography Score (ES) were determined for each lesion. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each modality and diagnostic performance were compared. The best cut-off point was calculated for each of the elastography parameter using the receiver operator curve analysis (ROC). RESULTS: Out of the 113 lesions, 40 were malignant (35.4%) and 73 were benign (64.6%). A statistically significant difference was observed in the AUC for ES and conventional US: 0.98 vs 0.90 (Difference = 0.08, P = 0.02). Elastography parameters were more specific as compared to US (ES-94.5 & SR-93.2% vs 63%, P < 0.05) with high NPV. SE performed better in BIRADS 4 category lesions. On the basis of elastography parameters, 85% of BIRADS 4 category lesions were correctly predicted as benign with overall sensitivity, specificity and diagnostic accuracy of elastography being 97%, 84.6% and 91.9%. Among BIRADS 3 category lesions, 97% were correctly predicted as benign and 50% lesions were correctly predicted as malignant with a sensitivity of 50%, specificity of 97.8% and diagnostic accuracy of 94%. CONCLUSION: Strain elastography is a useful adjunct to conventional ultrasonography for the assessment of indeterminate breast lesions and may help in avoiding unnecessary follow ups and biopsies. Elastography score is a better parameter as compared to strain ratio.

[Diagnostic value of ultrasonic elastic strain ratio and elasticity score for thyroid micronodules of TI-RADS 4].

Objective: To investigate diagnostic value of ultrasonic elastic strain ratio and elasticity score for thyroid micronodules of TI-RADS 4. Method: In total, 211 consecutive patients with 225 thyroid micronodules were enroled in the study, all the nodules were evaluated by TI-RADS criteria before and all of them were examined by elastic imaging. We set the histology as the reference standard. The elastic strain ratio and elasticity score values, as well as their diagnostic threshold and efficiency, were compared and analyzed by the receiver operating characteristic(ROC) curve. Result: Statistically significant differences(P<0.05) in both elastic strain ratio and elasticity score values were detected among the thyroid microcarcinoma and benign groups. The area under the ROC curve of elastic strain ratio was significantly greater than that of elasticity score(0.935 and 0.825, respectively; P<0.05). Using elastic strain ratio ≥3.45 and elasticity score ≥3.00 as diagnostic threshold values, the diagnostic sensitivity, specificity, and accuracy of elastic strain ratio for differentiating benign and malignant nodules were 86.51%, 90.32%, and 87.56%, respectively, whereas those of elasticity score were 80.98%, 79.03% and 80.44%, respectively. Conclusion: Ultrasonic elastic strain ratio and elasticity score have very high diagnostic value for the thyroid micronodules of TI-RADS 4, and strain ratio has more advantages.

Breast strain elastography: Observer variability in data acquisition and interpretation.

OBJECTIVE: To analyze the observer reproducibility of breast strain elastography in elasticity image acquisition and elasticity image interpretation. METHODS: This was an institutional ethics committee approved prospective study. One hundred twenty-four breast lesions in 118 women (mean age 45.39 ±â€¯12.97 years old, range 21-77 years old) were examined with strain elastography by two blinded radiologists in turn. Three blinded observers separately reviewed and recorded the elasticity score of each lesion obtained by the two performers. The interobserver reproducibility of elasticity image acquisition between the two performers, the interobserver and intraobserver reproducibility of elasticity image interpretation among observers were evaluated. The diagnostic performance of strain elastography was compared between the two performers. RESULTS: Fifty-three lesions were malignant and 71 were benign. The interobserver kappa value was 0.438 for the elasticity score between the two performers. Between the three observers, the overall interobserver and intraobserver kappa value was 0.365 and 0.655, respectively. There was no significant difference of the area under the receiver operator characteristic curve (Az) value for the elasticity score between performer 1 and 2 (P = 0.143). CONCLUSIONS: Our results suggested moderate interobserver reproducibility in breast strain elasticity image acquisition, poor interobserver and good intraobserver agreement in image interpretation.

Value of ultrasound elastography in diagnosis of cervical tuberculous lymphadenopathy / 第二军医大学学报

Objective To analyze and compare the ultrasound elastography (UE) features of various types of cervical tuberculous lymphadenopathy (CTL), and to investigate the value and limitation of UE in diagnosis of CTL. Methods A total of 70 CTL patients confirmed by pathology or diagnostic treatment who were admitted to Shanghai Pulmonary Hospital affiliated to Tongji University from Jul. 2017 to Mar. 2018 were enrolled, and the images of conventional ultrasound and UE of the largest lymph nodes in each patient were retrospectively analyzed. According to the conventional ultrasound classification criteria of tuberculous lymphadenopathy, the lesions were divided into acute inflammatory type (type), caseous necrotic type (typeⅡ), cold abscess type (type III) and healing calcification type (type ). The elasticity score and strain ratio of various types of CTL lesions were summarized and compared. Results There were 24 (34.29%) typeCTL lesions, 28 (40.00%) typeⅡ, 12 (17.14%) type III, and 6 (8.57%) type . The hardness of CTL lesions of typeand typeⅡ was high, with the elastic score being 3-4 (47/52, 90.38%) and the strain ratio being 3-5; the hardness of type III was the lowest, with the elastic score being 1-2 (10/12, 83.33%) and the strain ratio2; the hardness of type was the highest, with the elastic score being 4-5 (6/6, 100.00%) and the strain ratio5. There were significant differences in elastic score and strain ratio among the four type CTL lesions (H＝30.756, F＝23.177; both P0.001). Pairwise comparison showed that except for the differences between typeand typeⅡ lesions, there were significant differences in elastic scores and strain ratios between the four type CTL lesions (P0.05). Conclusion The value of UE in the diagnosis of CTL is limited. It may play some roles in determining whether there is an obvious granuloma formation in typelesions and the tension of type III lesions.

Value of different ultrasound elastography techniques in patients with venous malformations prior to and after sclerotherapy.

AIM: Comparison of different ultrasound elastography techniques for detection of changes after sclerotherapy within venous malformations. MATERIAL AND METHODS: In patients with venous malformations sonography was executed at exactly the same position prior to and after ethanol-gel sclerotherapy. Both examinations included B-Mode, vascular sonography with Color-Coded Duplex Sonography, and additional sonography with different elastography techniques (strain, qualitative and quantitative Acoustic Radiation Force Impulse (ARFI) elastography) with a linear transducer (6-9 MHz). Qualitative elastograms were read in consensus and scored. Differences of elasticity scores were statistically analyzed, p-values <0.05 were regarded significant. RESULTS: Elasticity scores of strain and qualitative ARFI elastography in 25 patients (21 females, averagely 24.4 years old) were comparable before treatment (p = 0.69). After therapy qualitative ARFI scores changed significantly compared to pre-treatment scores (p = 0.0017), whereas strain elastography scores revealed no significant changes (p = 0.13). Quantitative ARFI values obtained after sclerotherapy within the venous malformations were significantly higher compared to pre-treatment values (p = 0.049), and significantly higher to values obtained in surrounding tissue (p = 0.030). Comparison of pre- and post-treatment ARFI values of the surrounding tissue was not significant (p = 0.67). CONCLUSION: Elasticity scores of qualitative ARFI elastography reliably detect ethanol-gel induced changes in venous malformations. Quantitative ARFI may be a tool for therapy planning, and for monitoring sclerotherapy outcome as well as the effect of sclerosing agents on malformation and surrounding tissue in patients with venous malformations.

Application of Real-time Ultrasound Elastography for Preoperative Staging of Rectal Cancer / 中国医科大学学报

Objective To explore the role of real-time ultrasound elastography (RUE) in the staging of rectal cancer.Methods We retrospectively analyzed 41 cases of rectal cancer by both double plane transrectal conventional ultrasonography (CU) and RUE and comparatively assessed elasticity scores and strain ratios (SR) of the tumor along with postoperative pathological staging results.Results The accuracy of CU for preoperative staging of rectal tumors was 80.49％.There were significant differences between the elasticity scores and strain ratios of the T1 stage and T2,T3,and T4 stages,and also in elasticity scores and strain ratios of the T4 stage and T2 and T3 stages of rectal cancer by using RUE (P ＜ 0.05).Taking the elasticity score of 3 points as the optimal ritical value in the diagnosis of the T1 stage of rectal cancer,the sensitivity,specificity,positive predictive value,and negative predictive value were 66.67％,96.88％,85.71％,and 91.18％ respectively.Condusion Endorectal RUE can assess the elastic stiffness of rectal cancer,and it helps in the preoperative staging of rectal cancer.

A multicenter study to confirm further diagnostic value of strain ratio method giving to 5-point scoring by elastography for differentiation of breast lesions / 中华超声影像学杂志

Objective To confirm whether strain ratio should be added after evaluation of lesions with 5-point elasticity scoring for differentiating breast lesions on ultrasonic elastography(UE).Methods Eight hundred and forty-six consecutive female patients with 1 071 breast lesions were recruited into a multicenter retrospective study,which involved 8 centers across China.All the patients underwent the UE procedure and the strain ratios were calculated.The sensitivity,specificity,accuracy,PPV and NPV were calculated for each of the two evaluation systems and the areas under the ROC curve were compared.Results The strain ratios of 559 benign lesions(2.7±1.4)and 512 malignant lesions(8.1±5.9)were significantly different (P<0.001).When the cutoff point was 3.03,strain ratio method had 81.6% sensitivity,89.7% specificity,81.7% accuracy,80.2% PPV and 84.2% NPV.The areas under the ROC curve with the strain ratio method and 5-point scoring method were 0.865 and 0.862,respectively(P =0.622).For the lesions with elasticity score 3 and 4,the areas under the ROC curve of the two Methods were 0.71 1 and 0.629, respectively(P = 0.020).Conclusions Although the two UE Methods have similar diagnostic performance,separate calculation of the strain ratios seems compulsory,especially for the lesions with elasticity score 3 and 4.

Real-Time Elastography and Contrast-Enhanced Ultrasonography in the Evaluation of Testicular Masses: A Comparative Prospective Study.

This study investigates the usefulness of contrast-enhanced ultrasound (CEUS) and real-time elastography (RTE) for the characterization of testicular masses by comparing pre-operative ultrasound findings with post-operative histology. Sixty-seven patients with 68 sonographically detected testicular masses underwent B-mode, color-coded Doppler sonography (CCDS), CEUS and RTE according to defined criteria. For RTE, elasticity score (ES), difference of elasticity score (D-ES), strain ratio (SR) and size quotient (Qsize) were evaluated. Histopathologically, 54/68 testicular lesions were neoplastic (47 malignant, 7 benign). Descriptive statistics revealed the following results (neoplastic vs. non-neoplastic) for sensitivity, specificity, positive predictive value, negative predictive value and accuracy, respectively: B-mode, 100%, 43%, 87%, 100%, 88%; CCDS 81%, 86%, 96%, 55%, 82%; CEUS 93%, 85%, 96%, 73%, 91%; ES 98%, 25%, 85%, 75%, 85%; D-ES 98%, 50%, 90%, 83%, 89%; SR 90%, 45%, 86%, 56%, 81%; and Qsize 57%, 83%, 94%, 28%, 61%. B-mode with CCDS remains the standard for assessing testicular masses. In characterization of testicular lesions, CEUS clearly outperformed all other modalities. Our study does not support the routine use of RTE in testicular ultrasonography because of its low specificity.

Sonoelastographic strain ratio: how does the position of reference fat influence it?

PURPOSE: The purpose of this study was to evaluate how the reference fat position influenced the calculation of the sonoelastographic strain ratio. METHODS: Three hundred fifty-eight breast masses (256 benign lesions and 102 malignant lesions) in 300 women (mean age 47.4 years; age range 17-82 years) who had been scheduled for a percutaneous needle biopsy or surgical excision were examined using B-mode ultrasonography and elastography. The sonoelastographic strain ratio was calculated twice per lesion; once by dividing the strain value of the fat near the mass by that of the mass (FLR 1) and once by dividing the strain value of the subcutaneous fat by that of the mass (FLR 2). RESULTS: Most (91.9 %) showed a difference of less than 0.5 between FLR 1 and FLR 2 values. Regardless of the position of reference fat, there was no statistically significant difference between the FLR 1 and FLR 2 values (p value = 0.077 and 0.0825, respectively). According to the pathology of the lesion, a difference between FLR 1 and FLR 2 less than 0.5 occurred in 95.3 % of the benign lesions and 84 % of the malignant lesions (p < 0.001). CONCLUSIONS: The sonoelastographic strain ratio was not significantly affected by the position of reference fat.

Changes in spastic muscle stiffness after botulinum toxin A injections as part of rehabilitation therapy in patients with spastic cerebral palsy.

OBJECTIVE: To investigate changes in stiffness in the gastrocnemius (GCM) muscle following rehabilitation therapy and botulinum toxin type A (BTX-A) injections in patients with spastic cerebral palsy (CP). METHODS: The study included 16 children with spastic CP (Group 1) and 17 healthy children (Group 2). The children with CP received BTX-A injections and underwent rehabilitation therapy. The GCM and soleus muscles of the CP group were evaluated according to the modified Ashworth scale (MAS). The thicknesses of the muscles were measured, and the elasticity score (ELX 2/1) index was calculated. RESULTS: The ELX 2/1 indices of the gastromedialis (GM) and gastrolateralis (GL) were significantly higher in Group 1 than in Group 2 (p < 0.05). The ELX 2/1 indices in the GM and GL muscles in the CP group were found to have decreased 4 weeks after the procedure (p < 0.05). Furthermore, the mean MAS score of the ankle decreased, from 3.4 to 2.6 (p < 0.05). GM ELX 2/1 in Group 1 (post-treatment) was significantly different from Group 2 (p < 0.05). CONCLUSIONS: The combined use of clinical scales and sonoelastography can provide valuable information for determining structural changes in the GCM muscle following rehabilitation therapy and BTX-A injections.

Diagnostic value of elastosonography for thyroid microcarcinoma.

OBJECTIVE: To assess the diagnostic value of elastosonography for thyroid microcarcinoma (TMC), particularly with regard to elasticity score (ES) and strain ratio (SR). METHODS: Conventional ultrasound and elastosonography were performed for 487 thyroid micronodules before surgery. We set the histology as the reference standard. The ES and SR values, as well as their diagnostic threshold and efficiency, were compared and analyzed by the receiver-operating characteristic (ROC) curve. Additional comparisons between TMC patients with and without extracapsular extension were also performed. RESULTS: Statistically significant differences (P<0.05) in both ES and SR values were detected among the TMC and benign groups. The area under the ROC curve of SR was significantly greater than that of ES (0.956 and 0.844, respectively; P<0.05). Using ES⩾3 and SR⩾3.65 as diagnostic threshold values, the diagnostic sensitivity, specificity, and accuracy of ES for differentiating benign and malignant nodules were 79.9%, 72.3%, and 80.5%, respectively, whereas those of SR were 86.6%, 85.3%, and 89.4%, respectively. The maximum diameter, microcalcification status, aspect ratio, bilateral cervical lymph node metastasis, and SR values of nodules with extracapsular extension (A1 subgroup) were greater than those of nodules without extracapsular extension (A2 subgroup). CONCLUSIONS: Elasticity imaging technology not only can help differentiate between benign and malignant thyroid micronodules but also allow SR values to provide accurate and objective information on tissue hardness and to predict TMC extracapsular extension or even bilateral cervical lymph node metastasis.

Ultrasound elastography in the differential diagnosis of benign and malignant cervical lesions.

OBJECTIVES: This study aimed to evaluate the clinical value of ultrasound elastography in the differential diagnosis of benign and malignant cervical lesions and to compare the accuracy of the elasticity score and strain ratio in differentiating cervical lesions. METHODS: B-mode sonography and ultrasound elastography were performed on 84 cervical lesions (40 benign and 44 malignant) in 84 patients. All of the images were obtained transvaginally. The elasticity score was determined by a 5-point scoring method. Calculation of the strain ratio was based on a comparison of the average strain measured in the lesion with the adjacent tissue of the same depth, size, and shape. The findings were compared with histopathologic results. With the use of receiver operating characteristic curves, the diagnostic value of the elasticity score and strain ratio methods was determined. RESULTS: The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the elasticity score in the differential diagnosis of cervical lesions were 81.8%, 85.0%, 83.3%, 85.7%, and 81.0%, respectively, whereas those of the strain ratio were 90.9%, 90.0%, 90.5%, 90.9%, and 90.0%. A strain ratio cutoff value of 4.525 was used as a standard to distinguish benign from malignant lesions. The strain ratio values of malignant lesions were much higher than those of benign lesions (range, 4.85-8.91 versus 0.62-4.50). The differences were statistically significant (P < .01). CONCLUSIONS: Ultrasound elastography is a promising technique that is easy and rapid to perform and can help identify cervical lesions that are likely to be malignant. It is obvious that the strain ratio yielded better results than the elasticity score. Both methods are semiquantitative, but quantification of the strain ratio is finer than that of the elasticity score.

Real-time ultrasound elastography for differentiation of benign and malignant thyroid nodules: a meta-analysis.

OBJECTIVES: The clinical challenge of managing thyroid nodules nowadays is to diagnose the minority of malignant disease. Real-time ultrasound elastography, which can measure tissue elasticity, is used as a complement to conventional sonography for improving the diagnosis of thyroid tumors. There are 2 common criteria for evaluating an elastogram: the elasticity score and strain ratio. This meta-analysis was performed to expand on a previous meta-analysis to assess the diagnostic power of ultrasound elastography in differentiating benign and malignant thyroid nodules for elasticity score and strain ratio assessment. METHODS: The MEDLINE, EMBASE, PubMed, and Cochrane Library databases up to January 31, 2013, were searched. The pooled sensitivity, specificity, and summary receiver operating characteristic curve were obtained from individual studies with a random-effects model. The extent and sources of heterogeneity were explored. RESULTS: A total of 5481 nodules in 4468 patients for elasticity score studies and 1063 nodules in 983 patients for strain ratio studies were analyzed. The overall mean sensitivity and specificity of ultrasound elastography for differentiation of thyroid nodules were 0.79 (95% confidence interval [CI], 0.77-0.81) and 0.77 (95% CI, 0.76-0.79) for elasticity score assessment and 0.85 (95% CI, 0.81-0.89) and 0.80 (95% CI, 0.77-0.83) for strain ratio assessment, respectively. The areas under the curve for the elasticity score and strain ratio were 0.8941 and 0.9285. CONCLUSIONS: These results confirmed those obtained in the previous meta-analysis. Ultrasound elastography has high sensitivity and specificity for identification of thyroid nodules. It is a promising tool for reducing unnecessary fine-needle-aspiration biopsy.

Computer-assisted assessment of ultrasound real-time elastography: initial experience in 145 breast lesions.

PURPOSE: To develop and evaluate a computer-assisted method of quantifying five-point elasticity scoring system based on ultrasound real-time elastography (RTE), for classifying benign and malignant breast lesions, with pathologic results as the reference standard. MATERIALS AND METHODS: Conventional ultrasonography (US) and RTE images of 145 breast lesions (67 malignant, 78 benign) were performed in this study. Each lesion was automatically contoured on the B-mode image by the level set method and mapped on the RTE image. The relative elasticity value of each pixel was reconstructed and classified into hard or soft by the fuzzy c-means clustering method. According to the hardness degree inside lesion and its surrounding tissue, the elasticity score of the RTE image was computed in an automatic way. Visual assessments of the radiologists were used for comparing the diagnostic performance. Histopathologic examination was used as the reference standard. The Student's t test and receiver operating characteristic (ROC) curve analysis were performed for statistical analysis. RESULTS: Considering score 4 or higher as test positive for malignancy, the diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 93.8% (136/145), 92.5% (62/67), 94.9% (74/78), 93.9% (62/66), and 93.7% (74/79) for the computer-assisted scheme, and 89.7% (130/145), 85.1% (57/67), 93.6% (73/78), 92.0% (57/62), and 88.0% (73/83) for manual assessment. Area under ROC curve (Az value) for the proposed method was higher than the Az value for visual assessment (0.96 vs. 0.93). CONCLUSION: Computer-assisted quantification of classical five-point scoring system can significantly eliminate the interobserver variability and thereby improve the diagnostic confidence of classifying the breast lesions to avoid unnecessary biopsy.