Contrast-enhanced ultrasonography of peripheral soft-tissue tumors: Feasibility study and preliminary results

Added value of contrast-enhanced ultrasound to conventional ultrasound for characterization of indeterminate soft-tissue tumors

OBJECTIVE

To assess the added value of contrast-enhanced ultrasound (CEUS) to conventional ultrasound in differentiating benign soft-tissue tumors from malignant ones.

METHODS

197 soft-tissue tumors underwent ultrasound examination with confirmed histopathology were retrospectively evaluated. The radiologists classified all the tumors as benign, malignant, or indeterminate according to ultrasound features. The indeterminate tumors underwent CEUS were reviewed afterwards for malignancy identification by using individual and combined CEUS features.

RESULTS

Ultrasound analysis classified 62 soft-tissue tumors as benign, 111 tumors as indeterminate and 24 tumors as malignant. There 104 indeterminate tumors were subject to CEUS. Three CEUS features including enlargement of enhancement area, infiltrative enhancement boundary, and intratumoral arrival time difference were significantly associated with the tumor nature in both univariable and multivariable analysis for the indeterminate tumors (all p < 0.05). When at least one out of the three discriminant CEUS features were present, the best sensitivity of 100% for malignancy identification was obtained with the specificity of 66.7% and the AUC of 0.833. When at least two of the three discriminant CEUS features were present, the best area under the receiver operating characteristic curve (AUC) of 0.924 for malignancy identification was obtained. The combination of at least two discriminant CEUS features showed much better diagnostic performance than the optimal combination of ultrasound features in terms of AUC (0.924 vs 0.608, p < 0.0001), sensitivity (94.0% vs 42.0%, p < 0.0001), and specificity (90.7% vs 79.6%, p = 0.210) for the indeterminate tumors.

CONCLUSION

The combination CEUS features of enlargement of enhancement area, infiltrative enhancement boundary and intratumoral arrival time difference are valuable to improve the discriminating performance for indeterminate soft-tissue tumors on conventional ultrasound.

ADVANCES IN KNOWLEDGE

The combination of peritumoral and arrival-time CEUS features can improve the discriminating performance for indeterminate soft-tissue tumors on conventional ultrasound.

Contrast-enhanced ultrasound-guided musculoskeletal biopsies: our experience and technique

OBJECTIVE

To present our experience with contrast-enhanced ultrasound (CEUS)-guided musculoskeletal soft tissue biopsies in a busy interventional clinic.

MATERIALS AND METHODS

After IRB approval was obtained and informed consent was waived, we retrospectively reviewed all CEUS-guided musculoskeletal biopsies performed from December 1, 2018 to March 2, 2020. Relevant pre-procedure imaging was reviewed. Number of samples, suspected necrosis on pre-procedure imaging, specimen adequacy for pathologic analysis, correlation with pathologic diagnosis of surgical resection specimens, and procedural complications were recorded.

RESULTS

Thirty-six CEUS-guided musculoskeletal biopsies were performed in 32 patients (mean age 57, range 26-88; 22 males, 10 females). All procedures were performed using 16-gauge biopsy needles, and all procedures provided adequate samples for pathologic analysis as per the final pathology report. Between two and seven core specimens were obtained (mean 3.7). In 30/36 cases (83%), a contrast-enhanced MRI was obtained prior to biopsy, and 10/30 (33%) of these cases showed imaging features suspicious for necrosis. In 15/36 cases, surgical resection was performed, and the core biopsy and surgical resection specimens were concordant in 14/15 cases (93%). One patient noted transient leg discomfort at the time of microbubble bursting. Otherwise, no adverse reactions or procedural complications were observed.

CONCLUSION

CEUS is an accurate way to safely target representative areas of soft tissue lesions for biopsy and can be implemented in a busy interventional clinic. Our early experience has shown this to be a promising technique, especially in targeting representative areas of heterogeneous lesions and lesions with areas of suspected necrosis on prior imaging.

Diagnostic Value of Contrast-Enhanced Ultrasound for Differential Diagnosis of Malignant and Benign Soft Tissue Masses: A Meta-Analysis

This meta-analysis was aimed at investigating the value of using contrast-enhanced ultrasound (CEUS) in the differential diagnosis of benign and malignant soft tissue masses (STMs). Relevant studies published before March 24, 2020 were identified through a comprehensive search of PubMed, Ovid, Cochrane and Web of Science. According to the inclusion criteria, five studies were selected comprising 746 patients. In the differential diagnosis of benign and malignant STMs, the pooled sensitivity and specificity of CEUS were 76% (95% confidence interval [CI]: 71%-81%; heterogeneity [I²] = 74.5%) and 67% (95% CI: 62%-71%; I² = 36.5%), respectively. The diagnostic odds ratio was 7.37 (95% CI: 3.78%-14.35; I² = 66.6%). The overall area under the curve was 0.77 (standard error: 0.0392). Subgroup analysis revealed that different index tests of CEUS resulted in different diagnostic performance. Importantly, CEUS is an effective method for the differential diagnosis between benign and malignant STMs.

Role of high-resolution ultrasound in detection and monitoring of peripheral nerve tumor burden in neurofibromatosis in children

PURPOSE

Peripheral nerve sheath tumors are hallmark findings in neurofibromatosis types 1 and 2. With increasing size, they typically lead to neurological symptoms, and NF1 patients have a lifetime risk of 8-13% for developing malignant peripheral nerve sheath tumors. Medical imaging is therefore highly needed for early detection and exact localization of symptomatic or potentially malignant tumors. This review will give an overview of the ultrasound characteristics of peripheral nerve sheath tumors and findings in patients with neurofibromatosis types 1 and 2.

METHODS

A systematic search of electronic databases, reference lists, and unpublished literature was conducted including the keywords "schwannoma," "neurofibroma," "neurofibromatosis," "benign and malignant peripheral nerve sheath tumor."

RESULTS

The high-resolution allows a clear analysis of tumor echotexture, definition of margins, and the relation to the parent nerve. The use of color duplex/Doppler and contrast agent adds valuable information for the differentiation of benign and malignant tumors.

CONCLUSION

High-resolution ultrasound is a well-established, non-invasive, and easily repeatable first-line tool in diagnostic procedures of soft tissue tumors.

A bump: what to do next? Ultrasound imaging of superficial soft-tissue palpable lesions

Soft-tissue palpable lesions are common in clinical practice, and ultrasound (US) represents the first imaging option in the evaluation of a patient with a soft-tissue swelling. A full and systematic US assessment is necessary, however. This includes grayscale, color- and power-Doppler, spectral-Doppler, and possibly elastography facilities, as well as a trained operator. Several lesions showing characteristic US features can be diagnosed confidently, without any further work-up, and the high spatial resolution of ultrasound in the superficial layers can be a powerful tool to discriminate their etiologies. Second-level options, to be reserved for indeterminate cases or those suspected malignant at initial ultrasound, include magnetic resonance imaging, percutaneous fine-needle aspiration or biopsy, and surgical-excision biopsy. In this article, we discuss the proper US approach for addressing superficial soft-tissue lesions.

Accuracy and role of contrast-enhanced CT in diagnosis and surgical planning in 88 soft tissue tumours of extremities

OBJECTIVES

Soft tissue tumours (STT) require accurate diagnosis in order to identify potential malignancies. Preoperative planning is fundamental to avoid inadequate treatments. The role of contrast-enhanced computed tomography (CT) for local staging remains incompletely assessed. Aims of the study were to evaluate CT accuracy in discriminating active from aggressive tumours compared to histology and evaluate the role of CT angiography (CTA) in surgical planning.

MATERIALS AND METHODS

This retrospective cohort series of 88 cases from 1200 patients (7 %) was locally studied by contrast-enhanced CT and CTA in a referral centre: 74 malignant tumours, 14 benign lesions. Contrast-enhancement patterns and relationship of the mass with major vessels and bone were compared with histology on surgically excised samples. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) were evaluated in discriminating active from aggressive tumours.

RESULTS

Sensitivity in differentiating aggressive tumours from active lesions was 89 %, specificity 84 %, PPV 90 %, NPV 82 %. The relationship between mass and major vessels/bone was fundamental for surgical strategy respectively in 40 % and in 58 % of malignant tumours.

CONCLUSION

Contrast-enhanced CT and CTA are effective in differentiating aggressive masses from active lesions in soft tissue and in depicting the relationship between tumour and adjacent bones and major vessels.

KEY POINTS

• Accurate delineation of vascular and bony involvement preoperatively is fundamental for a correct resection. • CT plays a critical role in differential diagnosis of soft tissue masses. • Contrast-enhanced CT and CT angiography are helpful in depicting tumoral vascular involvement. • CT is optimal for characterization of bone involvement in soft tissue malignancies.

Contrast-enhanced ultrasonography in differential diagnosis of benign and malignant ovarian tumors

Objective

To evaluate the accuracy of contrast-enhanced ultrasonography (CEUS) in differential diagnosis of benign and malignant ovarian tumors.

Methods

The scientific literature databases PubMed, Cochrane Library and CNKI were comprehensively searched for studies relevant to the use of CEUS technique for differential diagnosis of benign and malignant ovarian cancer. Pooled summary statistics for specificity (Spe), sensitivity (Sen), positive and negative likelihood ratios (LR⁺/LR⁻), and diagnostic odds ratio (DOR) and their 95%CIs were calculated. Software for statistical analysis included STATA version 12.0 (Stata Corp, College Station, TX, USA) and Meta-Disc version 1.4 (Universidad Complutense, Madrid, Spain).

Results

Following a stringent selection process, seven high quality clinical trials were found suitable for inclusion in the present meta-analysis. The 7 studies contained a combined total of 375 ovarian cancer patients (198 malignant and 177 benign). Statistical analysis revealed that CEUS was associated with the following performance measures in differential diagnosis of ovarian tumors: pooled Sen was 0.96 (95%CI = 0.92∼0.98); the summary Spe was 0.91 (95%CI = 0.86∼0.94); the pooled LR⁺ was 10.63 (95%CI = 6.59∼17.17); the pooled LR− was 0.04 (95%CI = 0.02∼0.09); and the pooled DOR was 241.04 (95% CI = 92.61∼627.37). The area under the SROC curve was 0.98 (95% CI = 0.20∼1.00). Lastly, publication bias was not detected (t = −0.52, P = 0.626) in the meta-analysis.

Conclusions

Our results revealed the high clinical value of CEUS in differential diagnosis of benign and malignant ovarian tumors. Further, CEUS may also prove to be useful in differential diagnosis at early stages of this disease.

Perfusion pattern and time of vascularisation with CEUS increase accuracy in differentiating between benign and malignant tumours in 216 musculoskeletal soft tissue masses

INTRODUCTION

Musculoskeletal Soft Tissue Tumours (STT) are frequent heterogeneous lesions. Guidelines consider a mass larger than 5 cm and deep with respect to the deep fascia potentially malignant. Contrast Enhanced Ultrasound (CEUS) can detect both vascularity and tumour neoangiogenesis. We hypothesised that perfusion patterns and vascularisation time could improve the accuracy of CEUS in discriminating malignant tumours from benign lesions.

MATERIALS AND METHODS

216 STT were studied: 40% benign lesions, 60% malignant tumours, 56% in the lower limbs. Seven CEUS perfusion patterns and three types of vascularisation (arterial-venous uptake, absence of uptake) were applied. Accuracy was evaluated by comparing imaging with the histological diagnosis. Univariate and multivariate analysis, Chi-square test and t-test for independent variables were applied; significance was set at p<0.05 level, 95% computed CI.

RESULTS

CEUS pattern 6 (inhomogeneous perfusion), arterial uptake and location in the lower limb were associated with high risk of malignancy. CEUS pattern has PPV 77%, rapidity of vascularisation PPV 69%; location in the limbs is the most sensitive indicator, but NPV 52%, PPV 65%. The combination of CEUS-pattern and vascularisation has 74% PPV, 60% NPV, 70% sensitivity. No correlation with size and location in relation to the deep fascia was found.

CONCLUSION

US with CEUS qualitative analysis could be an accurate technique to identify potentially malignant STT, for which second line imaging and biopsy are indicated in Referral Centers. Intense inhomogeneous enhancement with avascular areas and rapid vascularisation time could be useful in discriminating benign from malignant SST, overall when the lower limbs are involved.