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.     

Qualitative pattern classification of shear wave elastography for breast masses: How it correlates to quantitative measurements

Objective

To determine the correlation of qualitative shear wave elastography (SWE) pattern classification to quantitative SWE measurements and whether it is representative of quantitative SWE values with similar performances.

Methods

From October 2012 to January 2013, 267 breast masses of 236 women (mean age: 45.12 ± 10.54 years, range: 21–88 years) who had undergone ultrasonography (US), SWE, and subsequent biopsy were included. US BI-RADS final assessment and qualitative and quantitative SWE measurements were recorded. Correlation between pattern classification and mean elasticity, maximum elasticity, elasticity ratio and standard deviation were evaluated. Diagnostic performances of grayscale US, SWE parameters, and US combined to SWE values were calculated and compared.

Results

Of the 267 breast masses, 208 (77.9%) were benign and 59 (22.1%) were malignant. Pattern classifications significantly correlated with all quantitative SWE measurements, showing highest correlation with maximum elasticity, r = 0.721 (P < 0.001). Sensitivity was significantly decreased in US combined to SWE measurements to grayscale US: 69.5–89.8% to 100.0%, while specificity was significantly improved: 62.5–81.7% to 13.9% (P < 0.001). Area under the ROC curve (A_z) did not show significant differences between grayscale US to US combined to SWE (P > 0.05).

Conclusion

Pattern classification shows high correlation to maximum stiffness and may be representative of quantitative SWE values. When combined to grayscale US, SWE improves specificity of US.     

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.     

Does MRI help in the assessment of inflammatory breast disorders?

Objective

The aim of work is to evaluate the role of magnetic resonance imaging in the assessment of different entities of inflammatory breast disorders.

Materials and methods

Eighty-one non-lactating patients with mastitis had been evaluated by post contrast MR imaging; their ages ranged from 22 to 70 years (Average age: 41.6 years). MRI data analysis was performed regarding qualitative criteria and parametric color maps for image post processing. Diagnosis was made up regarding resolution in follow up sessions for simple mastitis and biopsy were done for cases with suspicious imaging findings.

Results

Mammary interstitial edema with no masses or abnormal enhancement was elicited in 28.4% (n = 23/81). T2-weighed and post contrast series were the sequences of choice to rely upon in evaluation. T2 had demonstrated lesions in 64.2% (n = 52/81) and contrast uptake was detected in 68% (n = 55/81). Quantitative analysis was overlapping.MR imaging had displayed sensitivity, specificity and accuracy of 87.5%, 72.3%, and 75.4% respectively in differentiating benign forms of mastitis from malignant ones.

Conclusion

In inflammatory breast disorders, MR imaging can precisely delineate disease extent and monitor response to therapy. Immediate distinction between infectious/non-infectious and malignant mastitis is difficult to be obtained.     

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.     

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.     

How to measure breast cancer tumoral size at MR imaging?

Objective

To compare the accuracy of different MR sequences to measure tumor size.

Methods

Eighty-six women (mean age: 53 years (30–78)) who underwent preoperative MRI for breast cancer were included. Maximal diameters of the index tumor (IT) and of the whole extent of the tumor (WET) were measured on T2-weighted (T2W) sequences, on dynamic contrast-enhanced (DCE) T1-weighted (T1W) sequences and on Maximal Intensity Projection (MIP) reconstructions. Agreements with pathological size were evaluated using concordance correlation coefficient (k).

Results

Median pathological size of IT was 20 mm (13–25 mm, interquartile range). Median pathological size of the WET was 29 mm (16–50 mm, interquartile range). Measurement of IT showed a good concordance with pathological size, with best results using T2W (k = 0.690) compared to MIP (k = 0.667), early-subtracted DCE frame (k = 0.630) and early-native DCE frame (k = 0.588). IT was visible on T2W in 83.7% and accurately measured within 5 mm in 69.9%. Measurement of WET was superior using early-subtracted DCE frame (k = 0.642) compared to late-native frame (k = 0.635), early-native frame (k = 0.631), late-subtracted frame (k = 0.620) and MIP (k = 0.565). However, even using early-subtracted frame, WET was accurately measured within 5 mm only 39.3%.

Conclusion

If visible, IT size is best measured on T2W with a good accuracy (69%) whereas WET is best estimated on early-subtracted DCE frame. However, when adjacent additional sites exist around IT, suspected surrounding disease components need to be proved by pathological analysis.     

The impact of share wave elastography in differentiation of hepatic hemangioma from malignant liver tumors in pediatric population

Objective

In children it is crucial to differentiate malignant liver tumors from the most common benign tumor, hepatic hemangiomas since the treatment strategies are quite different. We aimed to evaluate the efficiency of shear wave elastography (SWE) technique in differentiation of malignant hepatic tumors and hepatic hemangiomas.

Methods

Twenty patients with hepatic tumor were included in our study. Two radiologists performed SWE for 13 patients with malignant hepatic tumors including hepatoblastoma (n = 7), hepatocellular carcinoma (n = 3), metastasis (n = 2), embryonal sarcoma (n = 1) and 7 patients with hepatic hemangioma. All of our patients were between the age of 1 and 192 months (mean age: 56.88 months). Receiver operating characteristic analysis was achieved to evaluate the diagnostic accuracy of SWE and to determine the optimal cut-off value in differentiation hepatic hemangioma from malignant hepatic tumors.

Results

The mean SWE values (in kPa) for the first observer were 46.94 (13.8–145) and 22.38 (6.6–49.6) and those for the second observer were 57.91 (11–237) and 23.87 (6.4–57.5), respectively for malignant hepatic tumors and hepatic hemangiomas. The SWE values of malignant hepatic tumors were significantly higher than those of hepatic hemangioma (p = 0.02). The inter-observer agreement was almost perfect (0.81). The area under the receiver operating characteristic curve of SWE for differentiating the hepatic hemangioma from malignant hepatic tumors was 0.77 with a sensitivity of 72.7% and a specificity of 66.7% at a cutoff value of 23.62 with 95% confidence interval.

Conclusion

Shear wave elastography can be helpful in differentiation of malignant hepatic tumors and hepatic hemangioma.     

Comparison of 3D turbo spin-echo SPACE sequences with conventional 2D MRI sequences to assess the shoulder joint

Purpose

To determine the accuracy and reliability of three-dimensional (3D) T1- and proton density (PD)-weighted turbo spin-echo (TSE) sampling perfection with application-optimized contrasts using different flip-angle evolution (SPACE) compared with conventional 2D sequences in assessment of the shoulder-joint.

Materials and methods

Ninety-three subjects were examined on a 3-T MRI system with both conventional 2D-TSE sequences in T1-, T2- and PD-weighting and 3D SPACE sequences in T1- and PD-weighting. All examinations were assessed independently by two reviewers for common pathologies of the shoulder-joint. Agreement between 2D- and 3D-sequences and inter-observer-agreement was evaluated using kappa-statistics.

Results

Using conventional 2D TSE sequences as standard of reference, sensitivity, specificity, and accuracy values of 3D SPACE were 81.8%, 95.1%, and 93.5% for injuries of the supraspinatus-tendon (SSP), 81.3%, 93.5%, and 91.4% for the cartilage layer and 82.4%, 98.5%, and 97.5% for the long biceps tendon. Concordance between 2D and 3D was almost perfect for tendinopathies of the SSP (κ = 0.85), osteoarthritis (κ = 1), luxation of the biceps tendon (κ = 1) and adjacent bone marrow (κ = 0.92). Inter-observer-agreement was generally higher for conventional 2D TSE sequences (κ, 0.23–1.0), when compared to 3D SPACE sequences (κ, −0.33 to 1.0) except for disorders of the long biceps tendon and supraspinatus tendon rupture.

Conclusion

Because of substantial and almost perfect concordance with conventional 2D TSE sequences for common shoulder pathologies, MRI examination-time can be reduced by nearly 40% (up to 11 min) using 3D-SPACE without loss of information.     

Diagnostic value of commercially available shear-wave elastography for breast cancers: integration into BI-RADS classification with subcategories of category 4

Objectives

To evaluate the diagnostic performance of shear-wave elastography (SWE) for breast cancer and to determine whether the integration of SWE into BI-RADS with subcategories of category 4 improves the diagnostic performance.

Methods

A total of 389 breast masses (malignant 120, benign 269) in 324 women who underwent SWE before ultrasound-guided core biopsy or surgery were included. The qualitative SWE feature was assessed using a four-colour overlay pattern. Quantitative elasticity values including the lesion-to-fat elasticity ratio (E_ratio) were measured. Diagnostic performance of B-mode ultrasound, SWE, or their combined studies was compared using the area under the ROC curve (AUC).

Results

AUC of E_ratio (0.952) was the highest among elasticity values (mean, maximum, and minimum elasticity, 0.949, 0.939, and 0.928; P?=?0.04) and AUC of colour pattern was 0.947. AUC of combined studies was significantly higher than for a single study (P?<?0.0001). When adding SWE to category 4 lesions, lesions were dichotomised according to % of malignancy: 2.1 % vs. 43.2 % (category 4a) and 0 % vs. 100 % (category 4b) for E_ratio and 2.4 % vs. 25.8 % (category 4a) for colour pattern (P?<?0.05).

Conclusions

Shear-wave elastography showed a good diagnostic performance. Adding SWE features to BI-RADS improved the diagnostic performance and may be helpful to stratify category 4 lesions.

Key points

? Quantitative and qualitative shear-wave elastography provides further diagnostic information during breast ultrasound. ? The elasticity ratio (E _ratio ) showed the best diagnostic performance in SWE. ? E _ratio and four-colour overlay pattern significantly differed between benign and malignant lesions. ? SWE features allowed further stratification of BI-RADS category 4 lesions.     

Three-dimensional shear-wave elastography for differentiating benign and malignant breast lesions: comparison with two-dimensional shear-wave elastography

Objectives

To evaluate the interobserver agreement and the diagnostic performance of 3D shear-wave elastography (SWE) for breast lesions in comparison with 2D SWE.

Methods

A total of 163 breast lesions (malignant 48, benign 115) in 146 women who underwent B-mode ultrasound and SWE before biopsy were included. Two radiologists reviewed six data sets (B-mode, SWE, and a combination of both for 2D and 3D ultrasound). B-mode and SWE features were recorded. BI-RADS category was assigned for B-mode and combined sets. Interobserver variability was assessed using the κ statistic. Diagnostic performance of each data set was evaluated using the area under the ROC curve (AUC).

Results

SWE showed substantial to almost perfect agreement, with E_homo in 2D SWE being higher than in 3D SWE. The AUC of 2D SWE was higher than 3D SWE for all SWE features, significantly so for E_col (0.933 vs. 0.867, P?=?0.002) and E_max (0.961 vs. 0.874, P?=?0.006). After adding SWE to B-mode ultrasound, the AUC in 2D ultrasound increased significantly (0.968 vs. 0.912, P?=?0.008), but 3D ultrasound showed no significant difference (0.966 vs. 0.935; P?=?0.07).

Conclusion

For 3D SWE, interobserver agreement was good, but the diagnostic performance was inferior to 2D SWE even after adding to B-mode ultrasound.

Key Points

? Shear-wave elastography (SWE) provides further diagnostic information during breast ultrasound. ? 3D SWE diagnostic performance is inferior to 2D SWE. ? In 3D SWE, interobserver agreement was good. ? 2D B-mode ultrasound showed significant diagnostic improvement when combined with 2D SWE. ? 3D B-mode ultrasound performance was not significantly improved when combined with 3D SWE.     

Value of adding shear wave elastography to routine breast ultrasound examination in assessment of solid breast lesions

Purpose

To assess the additional diagnostic value of share wave elastography in combination with B-mode ultrasound versus B-mode ultrasound alone in characterization of solid breast lesions.

Normal breast tissue stiffness measured by a new ultrasound technique: Virtual touch tissue imaging quantification (VTIQ)

Objective

To evaluate normal breast tissue stiffness with virtual touch tissue imaging quantification (VTIQ) using prospectively collected data.

Materials and Methods

B-mode ultrasound and VTIQ were performed in 132 breasts in 97 women. Mean values of VTIQ for parenchyma and fatty tissue were compared between those measured in healthy breasts and in the surrounding of histologically proven benign and malignant breast lesions. Moreover we reviewed VTIQ values according to breast density measured by the American College of Radiology (ACR) categories. In addition we analyzed re-test reliability of VTIQ.

Results

In 132 breasts the mean VTIQ values in parenchyma were significantly higher than in fatty tissue (3.23 m/s ± 0.74 versus 2.5 m/s ± 0.61; p < 0.0001). In healthy breasts as well as in the surrounding of a benign or malignant lesions the VTIQ values of parenchyma were similar (p = 0.12). In fatty tissue, small differences between mean VTIQ values of 2.25 m/s ± 0.51, 2.52 m/s ± 0.48 and 2.65 m/s ± 0.71 (p = 0.01) in the respective groups were observed. The comparison of mean VTIQ values of parenchyma and fatty tissue in more and less dense breasts (ACR 1 + 2 versus ACR 3 + 4 breasts) also yielded no statistically significant difference. The re-test reliability of VTIQ assessed with three independent measurements was moderate (interclass-correlation of 0.52 (p < 0.0001)).

Conclusion

VTIQ is a reliable method for measuring the stiffness of breast tissue. We propose standard values for healthy parenchyma and fatty tissues independent of the surrounding tissue or the ACR category.     

Abdominal ultrasonography in preterm necrotizing enterocolitis. Is it superior to plain radiography?

Purpose

To explore whether abdominal ultrasound (AUS) provide additional information over plain radiography in cases of necrotizing enterocolitis (NEC).

Methods

This study is a prospective study of 30 premature neonates with NEC in our neonatal intensive care unit between August 2010 and November 2011. Fifteen premature control neonates were also included in the study.

Results

Patients were classified into two groups: the first group with suspected NEC (stage I) (n = 14) and the second with definite NEC (stage II or III) (n = 16). In group I abdominal ultrasound (AUS) revealed intramural air (n = 9) and portal venous gas (PVG) (n = 1) while plain radiography showed only gaseous distension. In group II, intramural air (n = 10), PVG (n = 2), free fluid (n = 6) focal fluid (n = 1) and free air (n = 6) detected by AUS compared to pneumatosis intestinalis (PI) (n = 2) PVG (n = 1) and free air (n = 5) by plain radiography. Additionally bowel wall thinning was detected in 2 neonates of group I and 3 of group II.

Conclusion

Our results suggest AUS to be superior to plain radiography in early detection of complication as intestinal perforation by eliciting PVG and fluid collection and so early surgical management. Therefore this may decrease morbidity and mortality rates.     

Safety and efficacy of radioactive seed localization with I-125 prior to lumpectomy and/or excisional biopsy

Purpose

To evaluate the safety and efficacy of pre-operative I-125 radioactive seed localization (RSL) as an alternative to wire localization (WL).

Methods

A waiver was granted by the institutional review board for this HIPAA compliant study. Review of 356 consecutive single site nonpalpable mammographic and ultrasound guided I-125 RSLs done between November 2011 and April 2012 was conducted. Preoperative mammograms and specimen radiographs were reviewed for seed-target distance, lesion location, and target/seed removal. During a brief surgical training period, 35 of 356 women had both RSL and wire localization (WL) of the same lesion. Chi-square and single sample t-tests were used to compare margin status and duration of procedures.

Results

Of the 356 RSLs, 303 (85.1%) were performed ≥1 day before surgery. Mammographic guidance was used in 330 (93%) and ultrasound in 26 (7%). Mean seed to target distance was 1 mm (range 0–20 mm); all targeted lesions were retrieved. In 31 women in whom mammographic guidance was used for both RSL and WL, median procedure time was not significantly different (RSL 9.0 min; WL 7.0 min; p = 0.91), and median seed migration distance was <1 mm (range 0–15 mm). No difference was detected between margin status with RSL alone versus WL (p = 0.40 and p = 0.65 for positive and <1 mm margins, respectively). Two adverse events occurred requiring an additional wire/surgery.

Conclusion

RSL ≥ 1 day before surgery is a safe effective procedure for pre-operative localization, with few adverse events and surgical outcomes comparable to those achieved with wire localization.     

Shear wave elastography for breast masses is highly reproducible

Objectives

To evaluate intra- and interobserver reproducibility of shear wave elastography (SWE) for breast masses.

Methods

For intraobserver reproducibility, each observer obtained three consecutive SWE images of 758 masses that were visible on ultrasound. 144 (19%) were malignant. Weighted kappa was used to assess the agreement of qualitative elastographic features; the reliability of quantitative measurements was assessed by intraclass correlation coefficients (ICC). For the interobserver reproducibility, a blinded observer reviewed images and agreement on features was determined.

Results

Mean age was 50 years; mean mass size was 13 mm. Qualitatively, SWE images were at least reasonably similar for 666/758 (87.9%). Intraclass correlation for SWE diameter, area and perimeter was almost perfect (ICC?≥?0.94). Intraobserver reliability for maximum and mean elasticity was almost perfect (ICC?=?0.84 and 0.87) and was substantial for the ratio of mass-to-fat elasticity (ICC?=?0.77). Interobserver agreement was moderate for SWE homogeneity (κ?=?0.57), substantial for qualitative colour assessment of maximum elasticity (κ?=?0.66), fair for SWE shape (κ?=?0.40), fair for B-mode mass margins (κ?=?0.38), and moderate for B-mode mass shape (κ?=?0.58), orientation (κ?=?0.53) and BI-RADS assessment (κ?=?0.59).

Conclusions

SWE is highly reproducible for assessing elastographic features of breast masses within and across observers. SWE interpretation is at least as consistent as that of BI-RADS ultrasound B-mode features.

Key Points

? Shear wave ultrasound elastography can measure the stiffness of breast tissue ? It provides a qualitatively and quantitatively interpretable colour-coded map of tissue stiffness ? Intraobserver reproducibility of SWE is almost perfect while intraobserver reproducibility of SWE proved to be moderate to substantial ? The most reproducible SWE features between observers were SWE image homogeneity and maximum elasticity

     

Combined sonoelastographic scoring and strain ratio in evaluation of breast masses

Aim of the work

To detect the diagnostic performance of the combined use of sonoelastographic scoring and strain ratio in differentiation of benign and malignant breast masses with the histopathology is the standard reference.

Patients and methods

One hundred and seventy-two women with 190 breast masses were enrolled in this prospective study. Conventional US (B-mode and color Doppler US) and sonoelastography (elasticity score “ES” and calculation of strain ratio “SR”) were performed. B-mode images were classified according to the Breast Imaging Recording and Data System. The hardness was determined with 5-point scoring method and SRs of the lesions were calculated. Receiver operating characteristic (ROC) curves were performed and the cutoff point for differentiation of benign and malignant masses was detected.

Results

There was a significant difference (P = 0.02) in the mean SRs between benign and malignant breast masses. The area under the curve (AUC) for combination of ES and SR (0.964) was higher than for ES alone (0.852) and B-mode US (0.823). A cutoff value of 3.6 for the SR allowed the best differentiation of benign and malignant breast lesions.

Conclusion

The combined use of elasticity score and strain ratio of sonoelastography increased the diagnostic performance in distinguishing benign from malignant breast masses.     

Differentiation of benign from malignant solid breast masses: comparison of two-dimensional and three-dimensional shear-wave elastography

Objectives

To prospectively compare the diagnostic performances of two-dimensional (2D) and three-dimensional (3D) shear-wave elastography (SWE) for differentiating benign from malignant breast masses.

Methods

B-mode ultrasound and SWE were performed for 134 consecutive women with 144 breast masses before biopsy. Quantitative elasticity values (maximum and mean elasticity in the stiffest portion of mass, E_max and E_mean; lesion-to-fat elasticity ratio, E_rat) were measured with both 2D and 3D SWE. The area under the receiver operating characteristic curve (AUC), sensitivity and specificity of B-mode, 2D, 3D SWE and combined data of B-mode and SWE were compared.

Results

Sixty-seven of the 144 breast masses (47 %) were malignant. Overall, higher elasticity values of 3D SWE than 2D SWE were noted for both benign and malignant masses. The AUC for 2D and 3D SWE were not significantly different: E_mean, 0.938 vs 0.928; E_max, 0.939 vs 0.930; E_rat, 0.907 vs 0.871. Either 2D or 3D SWE significantly improved the specificity of B-mode ultrasound from 29.9 % (23 of 77) up to 71.4 % (55 of 77) and 63.6 % (49 of 77) without a significant change in sensitivity.

Conclusion

Two-dimensional and 3D SWE performed equally in distinguishing benign from malignant masses and both techniques improved the specificity of B-mode ultrasound.

Key Points

? Shear-wave elastography (SWE) is increasingly used during ultrasound of the breast ? 2D and 3D SWE performed equally in distinguishing benign from malignant masses ? Either SWE method, combined with B-mode, outperformed B-mode ultrasound alone ? Quantitative elasticity was greater for 3D than 2D SWE for all masses     

Characterization and staging of central bile duct stenosis—Evaluation of the hepatocyte specific contrast agent gadoxetate disodium

Objective

To assess the value of gadoxetate disodium for characterization and staging of central bile duct stenosis (CBDS).

Materials and methods

This prospective HIPAA-compliant study was IRB approved. 14 patients (8 male, 6 female; 36–80 years) with clinical suspicion of CBDS underwent preoperative MRI. To estimate the value of hepatocyte phase images (10, 20, 120 min p.i.), only T2w images (T2), only post-contrast images (CM), or both image datasets were assessed in three reading sessions by 3 readers. Agreement of each reading session with the intraoperative findings in terms of CBDS etiology and tumor extension (weighted kappa statistic) was calculated.

Results

CBDS was caused by hilar cholangiocarcinoma (n = 9), gallbladder carcinoma (n = 4) and pancreatic carcinoma (n = 1). Characterization of CBDS etiology was correct by use of: T2w images in 57%, 64%, 50%; CM images in 64%, 57%, 50%; both in 71%, 64%, 64%. Agreement comparing reading sessions and intraoperative findings regarding tumor extension was fair up to moderate (κ-range = 0.21–0.54) as a result of common underestimation. Interobserver agreement for tumor extension was fair (κ-range = 0.31–0.33).

Conclusions

By means of combined evaluation of T2 and CM images a more reliable characterization of CBDS was possible. Even though CBDS tended to be underestimated assessment of exact tumor extension was improved by contrast administration.     

Quantitative assessment of shear-wave ultrasound elastography in thyroid nodules: diagnostic performance for predicting malignancy

Objectives

To evaluate the predictability of shear-wave ultrasound elastography (SWE) for thyroid malignancy and to compare the diagnostic performances of SWE and B-mode US.

Methods

Retrospective review of 99 patients who underwent SWE before US-guided fine-needle aspiration of thyroid nodules was performed. SWE elasticity indices of the mean (E_mean ), maximum (E_max), and minimum (E_min) of nodules were measured. Diagnostic performance of SWE was compared with that of B-mode US.

Results

Among a total of 99 nodules, 21 were papillary thyroid carcinoma (PTC) and 78 were benign. E_mean, E_max, and E_min were significantly higher in PTCs than in benign nodules (P?<?0.001). Sensitivity and specificity for predicting malignancy were 76.1 %, 64.1 % with E_max (65 kPa), 61.9 %, 76.1 % with E_min (53 kPa), and 66.6 %, 71.6 % with E_mean (62 kPa). Areas under the ROC curves (Az) of SWE values were not significantly different from those of US categories on B-mode US. However, combining E_mean and E_min with B-mode US of probably benign lesions improved the specificity (P?=?0.02, 0.007) for predicting PTC.

Conclusions

The quantitative parameter of SWE was significantly higher in PTC than in benign nodules, and combined use of quantitative SWE and B-mode US provided higher specificity for predicting malignancy.

Key Points

? Quantitative shear-wave elastography (SWE) helps differentiate benign from malignant nodules ? SWE and conventional ultrasound have comparable diagnostic performance for predicting thyroid malignancy ? Combined quantitative SWE and B-mode ultrasound is highly specific for thyroid malignancy