Diagnostic utility of real-time ultrasound elastography for prediction of malignancy in solid thyroid nodules

Aim of the work

To study the diagnostic utility of real-time ultrasound elastography (USE) in predicting malignancy in thyroid nodules.

Materials and methods

Forty-five patients with solitary solid thyroid nodules were included in this study. The thyroid nodules were examined by B-mode ultrasound, color flow Doppler ultrasound, and real-time ultrasound elastography (USE). The final diagnosis was obtained from histopathological findings. Tissue stiffness on USE was scored from 1 (low stiffness over the entire nodule) to 6 (high stiffness over the entire nodule and surrounding tissue).

Results

Twenty-eight (62.2%) patients had a final diagnosis of malignancy based on histopathological evidence of malignant thyroid nodules, while 17 (37.8%) were diagnosed as benign nodules. Anteroposterior/transverse (AP/T) diameter more than 1 cm, ill-defined margins and spot micro calcifications were the most predictive conventional ultrasound patterns of malignancy. Elasticity score of 4–6 was highly predictive of malignancy (P < 0.0001), with a sensitivity of 89.3%, a specificity of 88.2% and an accuracy of 88.9%.

Conclusion

Ultrasound elastography is an accurate non invasive tool for evaluating thyroid nodules. It has more appropriate value in the differential diagnosis of thyroid malignancy and enhances the diagnostic assurance of ultrasonographers.     

Comparison analysis between conventional ultrasonography and ultrasound elastography of thyroid nodules

Objective

To compare the effectiveness of conventional ultrasonography and ultrasound elastography in differential diagnosis of thyroid nodular diseases.

Methods

244 patients with 291 thyroid nodules were examined by ultrasonography and ultrasound elastography respectively; the examination results were compared against pathological findings to determine the effectiveness of these two examination methods.

Results

The sensitivity and positive predictive value of conventional ultrasonography is higher than those of ultrasound elastography, but its specificity, accuracy, and negative predictive value is lower than those of the later.

Conclusions

Ultrasound elastography is superior to conventional ultrasonography in differential diagnosis of thyroid nodules. However, ultrasonography is the basis of examination; only on this basis, an additional ultrasound elastography examination could greatly improve the diagnostic rate of thyroid nodular diseases.     

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.     

Can real-time ultrasound elastography using the color score and strain ratio differentiate between benign and malignant solitary thyroid nodules?

Background

Solitary thyroid nodule may represent a multitude of thyroid disorders; therefore, detection of whether these nodules are benign or malignant is crucial for patient’s triage.

Objective

To evaluate the diagnostic performance of the latest generation of real-time ultrasound elastography (USE) in differentiation between benign and malignant solitary thyroid nodules.

Materials and methods

Thirty consecutive patients who were referred for surgical treatment were prospectively examined by real-time USE. Tissue stiffness on real-time USE was determined with light compression using the standard elastography color scoring system according to Rago criteria ranging from 1 (low stiffness over the entire nodule) to 5 (high stiffness over the entire nodule and surrounding tissue). The strain ratio (normal tissue to lesion strain ratio) was calculated. The histopathological examination of these resected nodules was used as the diagnostic standard of reference.

Results

Scores of 1 and 2 with Rago criteria were highly significant seen in benign nodules, whereas, scores of 4 and 5 with Rago criteria were highly significant seen in malignant nodules (p < 0.001) with a sensitivity, specificity and diagnostic accuracy of 78.6%, 78.9% and 78.8% respectively. Additionally, the best strain ratio cut-off value for discrimination between benign and malignant nodules by using receiver operating characteristic analysis was 2.20 (area under the curve of 0.861; p value <0.001) with a consequential sensitivity, specificity and diagnostic accuracy of 85.7%, 90.5% and 88.6% respectively.

Conclusion

Both the color score and the strain ratio are higher in malignant solitary thyroid nodules than those in benign ones. Consequently, real-time USE can be used for the differentiation of benign and malignant solitary thyroid nodules. Eventually, this reduces the number of superfluous surgical procedures on benign thyroid nodules.     

Role of combined grey scale US and US tissue elastography in differentiating solid thyroid nodules

Background

Ultrasonographic (US) examination is an accurate method for detecting thyroid nodules, but its use in differentiating between benign and malignant thyroid nodules is relatively low. US elastography has been applied to study the hardness/elasticity of nodules to differentiate malignant from benign lesions thus deviating a significant group of patients from unnecessary FNAB.

Objectives

The aim of the study is to evaluate the validity of combined grey scale US and tissue elastography in differentiating benign form malignant solid thyroid nodules.

Methods

The study included 46 selected patients with solid thyroid nodules according to our inclusion and exclusion criteria. The patients underwent surgery for compressive symptoms or suspicion of malignancy on FNA cytology. US features and tissue elastography were scored according to the Rago criteria (1).

Results

On US elastography: all the 31 cases with a final diagnosis of benign nodule had a score of 1–3, while 14 of 15 (94.1%) with a final diagnosis of carcinoma had a score of 4–5, with a sensitivity of 93.3%, a specificity of 100% and an accuracy of 97.8%. Combined US and elastography reveals that hypoechogenicity/score 4–5 was most predictive of malignancy with sensitivity 80% and specificity 100%; and accuracy 93.4%.

Conclusions

US elastography seems to have great potential as a new tool for differentiating solid thyroid nodules and for recommending FNAC. Combined grey scale US features and US elastography added no significant value when compared with US elastography alone. Further prospective studies are needed.     

Neck ultrasonography as preoperative localization of primary hyperparathyroidism with an additional role of detecting thyroid malignancy

Objective

To evaluate and compare the diagnostic performances of high-resolution ultrasonography and ^99mTc-sestamibi scintigraphy for the preoperative localization of abnormal parathyroid glands and to evaluate the ability of US for additional diagnostic roles in detecting thyroid malignancy in patients with pHPT.

Materials and methods

Preoperative localization images of 115 parathyroid adenomas from high-resolution ultrasonography (US) and ^99mTc-sestamibi scintigraphy (SS) were studied from 105 patients, who had undergone parathyroidectomy. Sensitivity, accuracy, and positive predictive value were calculated for the identification of adenomas in lesions and patients for both US and SS, respectively, and US and SS diagnostic performances were compared using generalized estimating equation.

Results

Preoperative imaging by both modalities localized 105 (93.8%) of the 112 parathyroid lesions confirmed at surgery and histology. Sensitivity, accuracy, and positive predictive value were 93.1% and 92.2%, 90.4% and 89.5%, and 96.9% and 96.9% by US and SS, respectively, without any statistically significant differences (P = 0.796, 0.796, 0.879). US found incidental thyroid nodules in 47 patients (47/107, 43.9%), and 7 patients (7/107, 6.5%) were confirmed to have malignancy based on pathology results (all had papillary thyroid carcinoma).

Conclusion

Neck ultrasonography and ^99mTc-sestamibi scintigraphy are complementary methods of the preoperative localization of parathyroid adenomas. Neck ultrasounds add an additional thyroid gland evaluation, and can be useful in the detection of incidental thyroid gland lesions, especially malignant nodules.     

Added value of strain elastosonography in prediction of malignancy in solitary thyroid nodule

Aim and objectives

To evaluate the diagnostic accuracy of elastosonographyin prediction of malignancy in solitary thyroid nodule.

Additional value of qualitative strain ultrasound elastography and strain ratio in predicting thyroid malignancy

Objective

To detect if strain ultrasound elastography and strain ratio have additional value to the conventional grey scale ultrasound in predicting thyroid malignancy.

Shear wave elastography versus real-time elastography on evaluation thyroid nodules: A preliminary study

Objective

To comparatively evaluate shear wave elastography (SWE) and real-time elastography (RTE) in distinguishing malignant from benign thyroid nodules.

Methods

49 patients with 64 focal thyroid nodules were enrolled and underwent SWE and RTE before surgery. SWE elasticity indices (mean, minimum and maximum value of 2-mm region of interest) of nodules were measured. For RTE, elastograms were assessed by Rago criteria and nodules with scores of 4 or 5 were classified as suspicious for malignancy. Surgery histopathologic results were adopted as diagnostic standard.

Results

Of the 64 nodules, 19 were papillary thyroid carcinomas and 45 were benign. SWE indices were significantly higher in malignant than benign nodules (P < 0.05). Areas under the ROC curves (AUC) of SWE parameters were 0.840, 0.831 and 0.788, which were not significantly different from that of RTE showed as 0.880 (P = 0.148–0.482). When the most accurate cut-off, 38.3 kPa for mean value was applied to predict malignancy, the diagnostic specificity, sensitivity, accuracy, positive predictive value and negative predictive value of SWE and RTE were 68.4% versus 79.0%, 86.7% versus 84.4%, 81.3% versus 78.1%, 68.4% versus 64.7% and 86.7% versus 83.3%, respectively (P = 0.683–1.000).

Conclusion

SWE as a promising tool can be performed in differentiating thyroid nodules with comparable results to RTE.     

Man to man training: Can it help improve the diagnostic performances and interobserver variabilities of thyroid ultrasonography in residents?

Objective

The purpose of this study was to determine whether the man to man training can improve the diagnostic performances and interobserver variabilities of residents on thyroid ultrasonography.

Materials and methods

A set of 80 quiz cases with ultrasonography images of thyroid nodules (40 benign and 40 malignant on histopathology) were shown to the residents. Residents 1, 2, and 3 had not received the man to man training while Residents 4, 5, 6, and 7 had. The seven residents were asked to fill out one of the ultrasonography features (internal composition, echogenicity, margin, calcification, and shape) and the final assessment (probably benign and suspicious). Thyroid nodules with one or more ultrasonography features including marked hypoechogenicity, microlobulated or irregular margins, microcalcifications, and taller than wide shape were assessed as suspicious nodules. The diagnostic performances of US by the seven residents and interobserver variabilities between the seven residents and a faculty radiologist were calculated.

Results

The sensitivities, negative predictive values, and accuracies of Residents 4, 5, 6, and 7 were higher than those of Residents 1, 2, and 3. The final assessment between Residents 4, 5, 6, and 7 and the faculty radiologist showed almost perfect agreement but that between Residents 1, 2, and 3 and the faculty radiologist showed substantial agreement.

Conclusion

The man to man training is crucial for the residents to show better diagnostic performances and improvement of interobserver variabilities for evaluating thyroid nodules with ultrasonography.     

The value of virtual touch tissue image (VTI) and virtual touch tissue quantification (VTQ) in the differential diagnosis of thyroid nodules

Objectives

To explore the value of virtual touch tissue image (VTI) and virtual touch tissue quantification (VTQ) in the differential diagnosis of thyroid nodules.

Methods

One-hundred and seven patients with 113 thyroid nodules were performed conventional ultrasound and acoustic radiation force impulse (ARFI) elastography. The stiffness of the nodules on virtual touch tissue image (VTI) was graded, and the area ratios (AR) of nodules on VTI images versus on B-mode images were calculated. Shear wave velocity (SWV) within the thyroid nodules were measured using virtual touch tissue quantification (VTQ) technique. The pathological diagnosis as the gold standard draws the receiver-operating characteristic curve (ROC) to find the cut-off point of VTI grades, AR and SWV to predict thyroid cancer.

Results

The difference in VTI grades of malignant and benign nodules was statistically significant (P < 0.05), as well as in AR and SWV. There was no significant difference in the AR of nodules or the SWV of nodules in benign group or in malignant group. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of VTI grades, AR, and SWV in the differential diagnosis of thyroid nodules were calculated. There was no significant difference in diagnostic accuracy among the three methods.

Conclusion

VTI grades, AR of nodules on VTI images versus on B-mode images and SWV within the nodules can help the differential diagnosis of thyroid nodules.     

The clinical value of ultrasound elastography in predicting malignant thyroid nodules

Objective

This study aims to evaluate the clinical value of ultrasound elastography (USE) in providing information on the nature of the thyroid nodules. This was performed using the elastography score and strain ratio in differentiating thyroid benign and malignant nodules and the histopathological examination was used as the diagnostic standard of reference.

Methods

We examined 84 thyroid nodules in 62 patients with ultrasound elastography. Elastography score was assigned based on a four-point scale according to the classification proposed by Itoh et al. with a score of 1 (low stiffness over the entire nodule) to a score of 4 (high stiffness over the entire nodule). Thyroid strain ratio (normal tissue to lesion strain ratio) was calculated. Histopathological results were the standard reference. The area under the curve (AUC) and the best cut-off point were both obtained using receiver-operating characteristic (ROC) curve analysis. The sensitivity, specificity, and accuracy of both techniques were calculated.

Results

Fifty-four of the 84 nodules had scores of 1 and 2, and 50 of these nodules were diagnosed histopathologically as benign. Thirty of the 84 nodules had a score of 3 and 4, and 21 of these nodules were diagnosed histopathologically as malignant. The scores of 1 and 2 with Itoh criteria were significantly seen in benign nodules, whereas, scores of 3 and 4 were significantly seen in malignant nodules (p < 0.05) with sensitivity 84%, specificity 84.7%, PPV 70%, NPV 92.6% and accuracy 84.5%. The mean SR for the benign nodules and malignant ones was significantly different (2.92 ± 0.96 vs. 4.53 ± 0.82, p < 0.001). With ROC analysis, the best cut-off strain ratio point was 3.5 for differentiating benign and malignant nodules with area under the curve (AUC) = 0.87 (0.8–0.95). The sensitivity of the strain ratio was 88%, while the specificity was 86.4%, PPV = 73.3%, NPV = 94.4% and accuracy = 86.9%.

Conclusions

Both the elastographic score and strain ratio are higher in malignant nodules than those in benign ones. Ultrasound elastography can provide quantitative information on thyroid nodule helping in differentiating benign and malignant ones.     

Efficacy of thyroid ultrasound elastography in differential diagnosis of small thyroid nodules

Objective

To explore the efficacy of thyroid ultrasound (US) elastography in differential diagnosis of small thyroid nodules.

Methods

This HIPAA-compliant study was approved by the Institutional Review Board and all patients provided written informed consent. Thirty-five patients with 38 small thyroid nodules as seen on transverse ultrasound image formed our study population. An US examination and a separate thyroid elastography examination with pulsation from the carotid artery used as the compression source were performed before fine-needle aspiration. Baseband US data were acquired for off-line elastography processing, where a semi-quantitative index for each nodule was calculated. The Kruskal–Wallis nonparametric rank sum test was used to assess equality of population means among the different types of thyroid nodules. Maximum likelihood estimation of the curve parameters for a binomial receiver operating characteristic (ROC) curve was performed.

Results

Elasticity contrast index calculated with elastography was effective in distinguishing between small papillary thyroid carcinomas (PTMC, n = 8) and other lesions (n = 30) in small thyroid nodules (p = 0.0036). The area under the ROC curve for diagnosing PTMCs was 0.812 with a 95% confidence interval of 0.653–0.920. The cut-off value of ECI of 3.6 led to a sensitivity of 100% and a specificity of 60% for detecting PTMCs.

Conclusion

Noninvasive evaluation of small thyroid nodules is possible using thyroid US elastography with in vivo compression to pick out the most suspicious thyroid nodules for fine-needle aspiration (FNA) and avoid FNA in benign nodules.     

Distinguishing benign from malignant thyroid nodules using thyroid ultrasonography: utility of adding superb microvascular imaging and elastography

Objective

Thyroid nodules are common; however, malignancy is less than 7%. Therefore, additional techniques such as Doppler ultrasonography or elastography are used to improve diagnostic performance of conventional ultrasonography. We want to prospectively investigate the use of additional superb microvascular imaging (SMI) and strain elastography to B-mode ultrasound in thyroid nodules in distinguishing benign from malignant thyroid nodules.

Methods

We analyzed 52 thyroid nodules (malignant = 26, benign = 26) and reviewers scored the likelihood of malignancy for three data sets (i.e., B-mode ultrasonography alone, B-mode ultrasonography + SMI, and B-mode ultrasonography + strain elastography). The area under the receiver-operating characteristic curve (Az) values, sensitivities, and specificities were compared.

Results

A comparison of the data sets revealed that area under the receiver-operating characteristic curve values were similar without statistical difference. However, on comparing sensitivity and specificity based on the management decision of whether to conduct fine-needle aspiration (FNA) after combining information from all three types of imaging (B-mode ultrasonography + SMI + strain elastography), specificity was significantly higher for the combined technique (34.6%) than for B-mode ultrasonography alone (11.5%), without decrease in sensitivity (P = 0.032).

Conclusion

Additional use of SMI and strain elastography could potentially lead to increase in specificity in thyroid ultrasonography.

     

A threshold value in Shear Wave elastography to rule out malignant thyroid nodules: A reality?

Objectives

To evaluate hability of a threshold value in ShearWave™ elastography to rule out malignant thyroid nodules while studying its pertinence in association with morphological signs.

Equipment and methods

148 patients (110 women and 38 men; 52.5 y.o. 15.8) referred for surgery of thyroid nodules underwent standard ultrasound as well as elastography. Characteristics of the morphological signs and maximum elastographic index were calculated in relation to histology. Association of morphological signs alone and then of elastography was also evaluated. One hundred and fifty one nodules were studied on a double-blind basis.

Results

297 nodules were studied. Thirty-five cancers were detected (11.6%). Elastographic index was higher in malignant nodules (115 kPa 60.4) than in benign nodules (41 kPa 25.8) (p < 0.001, Student's t-test). Cut off value of 66 kPa was the best to discriminate malignant nodules with a sensitivity of 80% (CI 95%, 62.5; 90.9) and a specificity of 90.5% (CI 95%, 86.1; 93.6) (p = 0.0001). Association of elastography and morphological ultrasound signs presented a sensitivity of 97% (CI 95%, 83.3; 99.8) and a negative predictive value of 99.5% (CI 95%, 95.6; 99.9). Interobserver reproducibility proved to be excellent with an interclass correlation of 0.97 (CI 95%, 0.96; 0.98) (p < 0.001).

Conclusion

The 66 kPa threshold in Shear Wave elastography is the best ultrasound sign to rule out malignant thyroid nodules. The method is simple, quantitative, reproducible and usable in the study of nodules larger than 3 cm. Progress must still be made in the study of calcified nodules and follicular tumors.     

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.     

The value of strain ratio in differential diagnosis of thyroid solid nodules

Objective

To assess the clinical value of strain ratio in differentiating thyroid solid nodules and explore its distribution characters based on pathological results.

Materials and methods

The study was approved by the ethic committee and the informed consents were signed. Ninety nine solid thyroid nodules (67 benign and 32 malignant) from 71 female (mean age 46.3 ± 9.8 years) and 28 male (mean age 54.9 ± 11.7 years) patients were evaluated. Five radiologists evaluated the nodules based on a four-degree elastography score system. Strain ratio was calculated on-line. Diagnostic performances of the two evaluations were compared using Receiver Operating Characteristic (ROC) curves. Values of different pathological nodules were compared by one-way ANOVA.

Results

Areas under the ROC curve (AUC) of the five readers were 0.82, 0.81, 0.79, 0.73 and 0.83, respectively. The AUC of strain ratio evaluation was higher (0.88 vs. 0.79, p < 0.001) than that of the ES score evaluation. Best cut-off points of the two evaluations were 3.5 (82% sensitivity, 72% specificity) and 4.225 (81% sensitivity, 83% specificity), respectively. Both the ES score and strain ratio were higher for malignant nodules than that for benign ones (p < 0.001).

Conclusions

Strain ratio was a useful index in differential diagnosis of thyroid solid nodules. It can provide quantitative information on thyroid nodule characterization and improve diagnostic confidence. The best cut-off point for benign and malignant nodules was 4.2.     

The value of acoustic radiation force impulse (ARFI) in the differential diagnosis of thyroid nodules

Objectives

The aim of this study was to investigate the value of shear wave velocity value (SWV) and shear wave velocity ratio (SWR) in differentiating between malignant and benign thyroid nodules using virtual touch tissue quantification (VTQ) of acoustic radiation force impulse (ARFI) technology.

Methods

The SWV and SWR were analyzed in 155 thyroid nodules in 155 patients (93 benign and 62 malignant) and eighty normal thyroid glands. The diagnostic performance of SWV and SWR were compared.

Results

The mean value of SWV of malignant nodules differed significantly from those of the benign nodules (6.34 ± 2.58 m/s vs. 2.15 ± 0.59 m/s, P < 0.05) and the normal thyroid (1.96 ± 0.31 m/s, P < 0.05). There was no statistically significant difference between the mean value of SWV of benign nodules and normal thyroid (P > 0.05). The mean value of SWR of malignant nodules differed significantly from those of the benign nodules (2.99 ± 1.45 vs. 1.07 ± 0.34, P < 0.05). The sensitivity, specificity, positive predictive values, negative predictive values and accuracy of SWV in differentiating between malignant and benign nodules were 96.80%, 95.70%, 93.75%, 97.80% and 96.13% respectively based on the cutoff point as 2.84 m/s. Those of SWR were 91.90%, 81.70%, 77.03%, 93.83% and 85.83% based on the cutoff point as 1.32. The diagnostic accuracy rate of SWV was statistically higher than that of SWR (P < 0.05).

Conclusion

VTQ of ARFI technology provides the quantitative information of thyroid tissue elasticity and has high accuracy rate in differentiating between malignant and benign nodules. It is a useful complement for conventional ultrasonography.     

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.     

"Focal thyroid inferno" on color Doppler ultrasonography: A specific feature of focal Hashimoto's thyroiditis

Purpose

To evaluate color-Doppler features predictive of focal Hashimoto's thyroiditis.

Materials and methods

A total of 521 patients with 561 thyroid nodules that underwent surgeries or gun biopsies were included in this study. These nodules were divided into three groups: focal Hashimoto's thyroiditis (104 nodules in 101 patients), benignity other than focal Hashimoto's thyroiditis (73 nodules in 70 patients), and malignancy (358 nodules in 350 patients). On color Doppler sonography, four vascularity types were determined as: hypovascularity, marked internal flow, marked peripheral flow and focal thyroid inferno. The χ² test was performed to seek the potential vascularity type with the predictive ability of certain thyroid pathology. Furthermore, the gray-scale features of each nodule were also studied.

Results

The vascularity type I (hypovascularity) was more often seen in focal Hashimoto's thyroiditis than other benignity and malignancy (46% vs. 20.5% and 19%). While the type II (marked internal flow) showed the opposite tendency (26.9% [focal Hashimoto's thyroiditis] vs. 45.2% [other benignity] and 52.8% [malignancy]). However, type III (marked peripheral flow) was unable to predict any thyroid pathology. Importantly, type IV (focal thyroid inferno) was exclusive to focal Hashimoto's thyroiditis. All 8 type IV nodules appeared to be solid, hypoechoic, and well-defined. Using “focal thyroid inferno” as an indicator of FHT, the diagnostic sensitivity and specificity were 7.7% and 100% respectively.

Conclusions

The vascularity type of “focal thyroid inferno” is specific for focal Hashimoto thyroiditis. Recognition of this particular feature may avoid unnecessary interventional procedures for some solid hypoechoic thyroid nodules suspicious of malignancy.