Monitoring parotid gland tumors with a new perfusion software for contrast-enhanced ultrasound

Assessment of Parotid Gland Tumors by Means of Quantitative Multiparametric Ultrasound (mpUS)

OBJECTIVE

The preoperative diagnostical differentiation of parotid gland tumor (PGT) is not always simple due to several different entities. B-mode-ultrasound (US) remains the imaging modality of choice, while histopathology serves as the gold standard for finalizing the diagnosis. We aimed to evaluate the use of multiparametric US (mpUS) in the assessment of PGT.

METHODS

We included 97 PGTs from 96 patients. A standardized mpUS protocol using B-mode-US, shear-wave elastography (SWE), and standardized contrast-enhanced ultrasound (CEUS) was performed prior to surgical intervention. SWE was assessed by real-time measurement conducting a minimum of five measurements, while quantitative CEUS parameters were assessed with a post-processing perfusion software.

RESULTS

SWE allowed differentiation between benign PGT (Warthin's Tumor (WT) paired with lymph nodes (LN) and pleomorphic adenoma (PA)), and WT and LN were softer compared to PA. WT showed lower velocities than squamous cell carcinoma (SCC): the most common malignant PGT. CEUS parameters showed significant group differences between WT and PA, WT and malignant lesions, WT and SCC, WT paired with LN versus PA, and WT paired with LN versus SCC.

CONCLUSION

MpUS seems to be beneficial in the assessment of PGT characterization, with benign PGT appearing to be softer in SWE than tumors with malignant tendencies. The quantitative CEUS parameter shows higher perfusion in WT than in PA, and malignant PGTs are less vascularized than WTs.

Contrast-Enhanced Ultrasound in the Differentiation between the Most Common Benign Parotid Gland Tumors: A Systematic Review and Meta-Analysis

Recently, contrast-enhanced ultrasound (CEUS) has become a promising tool in distinguishing benign from malignant parotid gland tumors. However, its usefulness in differentiating various benign parotid tumors has not been determined so far. This study aimed to systematically review the literature to determine the utility of CEUS in the preoperative differentiation between pleomorphic adenomas (PAs) and Warthin's tumors (WTs) of the parotid gland. PubMed, Embase, and Cochrane were searched for English-language articles published until 21 July 2022. Fifteen studies were included. On CEUS examination, a significantly greater percentage of PAs displayed heterogeneous enhancement texture compared to WTs. Contrarily, the enhanced lesion size, the enhancement margin, and the presence of the enhancement rim did not differ significantly between the entities. Significantly longer normalized mean transit time (nMTT) and time to peak (TTP) were observed in PAs. Contrarily, the mean values of area under the curve (AUC) and time from peak to one half (TPH) were significantly higher for WTs. Due to the considerable overlap among the qualitative CEUS characteristics of PAs and WTs, the reproducible, investigator-independent quantitative CEUS measurements have a greater potential to distinguish PAs from WTs, which might influence the selection of an appropriate management strategy.

Perfusion analysis of benign parotid gland tumors by contrast-enhanced ultrasonography (CEUS)

BACKGROUND

Diagnosis of parotid gland tumors is sometimes challenging due to their diversity and pleomorphic histological appearance. B-scan sonography along with color-coded duplex sonography is the gold standard in the diagnostic workup of these lesions, whereas histopathology is to date the gold standard for the final diagnosis. To date no single imaging technique provides the chance for an art-diagnosis with highly diagnostic accuracy. Contrast enhanced ultrasonography (CEUS) on the other hand provides information of the perfusion down to the capillary level. Currently there are only a few papers published with systematical examination of the perfusion in benign parotid gland tumors and its diagnostic significance.

PATIENTS AND METHODS

One hundred patients with a parotid gland tumor were examined. The examinations included conventional B-scan sonography, color-coded duplexsonography along with contrast enhanced ultrasonography (CEUS). B-scan sonographic parameters, i.e. echogenicity, shape, size, demarcation, and borders of a lesion along with vascularization estimated by color-coded-duplexsonography were analyzed. Analysis of quantitative CEUS parameters was performed using 8 regions of interest (ROI), which were standardized located throughout the entire tumors. The perfusion parameters were analyzed for particular tumor entities. Qualitative CEUS analysis with estimating the perfusion pattern was additionally performed.

RESULTS

Histological examination revealed benign tumors in 92 cases, with pleomorphic adenomas and Warthin´s tumors were the most frequent entities. Malignant conditions were found in 8 cases. CEUS revealed a centripetal perfusion pattern in malignant tumors significantly more frequently than in benign tumors. CEUS showed a significant heterogenic perfusion in all tumors, with a higher perfusion in the medial parts of the tumors and in some cases also in the center. Perfusion patterns of PA and WT were different. WT displayed centrifugal, centripetal, and central diffuse perfusion more often than PA, whereas in PA perfusion often was limited to the capsule or periphery. Oncocytoma had the highest perfusion values. Intraglandular cysts showed no intralesional perfusion.

CONCLUSIONS

CEUS analysis in different parts of benign tumors revealed a significant heterogeneity in tumor perfusion. Some perfusion pattern could be identified which might be characteristic for particular lesions. Based on this, the diagnostic accuracy of CEUS in the differential diagnosis of parotid gland tumors can be increased. In particular, the perfusion analysis within the tumors using ROIs located standardized throughout the entire tumor provides additional information which are important for the art diagnosis and in differentiation of tumor entity.

[Perfusion analysis in parotid gland tumors using contrast-enhanced ultrasound (CEUS)]

OBJECTIVE

The diagnosis of parotid gland tumors is challenging due to their rarity and heterogenity. Neither conventional ultrasound nor magnetic resonance imaging (MRI) nor computed tomography (CT) allow a reliable pretherapeutic diagnosis. In addition to conventional ultrasound, contrast-enhanced ultrasound (CEUS) enables a more detailed assessment of perfusion in parotid gland tumors, thereby improving evaluation of this tumor entity. Extensive studies with analysis of perfusion characteristics in different regions of interest (ROI) in parotid gland tumors are currently lacking. This study analysed and compared perfusion parameters in different intratumoral areas of malignant and benign parotid gland tumors using CEUS.

MATERIALS AND METHODS

A total of 100 patients with tumors in the parotid gland were examined using B‑mode sonography, colour Doppler sonography and CEUS. The parameters magnitude, echogenicity, demarcation, vascularisation and in particular perfusion characteristics were measured and analysed. Analysis of quantitative CEUS parameters was performed using a specific method for perfusion analysis with certain ROI, which were allocated in a standardized manner in the entire parotid gland tumors. The perfusion parameters were compared between intratumoral ROI in the tumors and between particular tumor entities. Qualitative CEUS analysis with an estimation of perfusion patterns was additionally performed.

RESULTS

Histologically benign tumors were found in 92 cases, and malignant tumors in eight cases. CEUS analysis of perfusion patterns revealed a centripetal perfusion pattern in malignant tumors significantly more frequently than in benign tumors. In the perfusion analysis of quantitative CEUS parameters, all tumors showed higher perfusion intensities in the peripheral ROI. In benign tumors, more differences in perfusion intensity between the intratumoral ROIs were detected compared to malignant tumors.

CONCLUSION

The perfusion parameters (centripetal perfusion pattern; area under the curve) evaluated in this study have the potential to improve pretherapeutic diagnostics of parotid gland tumors in terms of differentiation of tumor entity. Further studies with larger patient cohorts are required for subsequent investigation and validation of the diagnostic accuracy of particular parameters to detect perfusion patterns potentially specific to particular tumor entities.

Contrast-enhanced ultrasound (CEUS) and perfusion imaging using VueBox®

The external perfusion software (VueBox™) for contrast-enhanced ultrasound (CEUS), enables the quantitative analysis of micro-vascularization within non-cystic lesions in terms of characterization and detection. This review summarizes our work about parathyroid gland, thyroid gland, liver, prostate and other tissues as well as original studies in the use of parametric perfusion imaging. Useful perfusion parameters are introduced.

Application of ultrasound and contrast-enhanced ultrasound to distinguish salivary focal inflammatory masses from malignant masses: A retrospective observational study

BACKGROUND

The aim was to retrospectively analyze the ultrasonographic and clinical characteristics of focal inflammatory masses and malignant masses of salivary gland by using B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) for differential analysis.

METHODS

The features of US and CEUS were retrospectively analyzed for 19 cases of focal salivary inflammatory masses and 45 cases of malignant salivary masses. All cases were confirmed by pathohistological examination.

RESULTS

On B-mode US, the incidence of expansive growth patterns of malignant salivary masses (44.4%, 20/45) was significantly higher than that of focal salivary inflammatory masses (15.8%, 3/19) (p = 0.029). The rate of lymphadenopathy surrounding salivary glands of malignant salivary masses (42.2%, 19/45) was significantly higher than that of focal salivary inflammatory masses (15.8%, 3/19) (p = 0.042). On CEUS, clear enhancement margins were more common in malignant salivary masses (44.4%, 20/45) compared to focal salivary inflammatory masses (15.8%, 3/19) (p = 0.029); Rapid washout was more common in malignant salivary masses (82.2%, 37/45) than focal salivary inflammatory masses (31.6%, 6/19) (p <  0.001). Rapid washout on CEUS and craniocaudal diameter were independent predictive factors in differentiating salivary inflammatory masses and malignant masses according to binary logistic regression analysis. US and CEUS achieved a sensitivity of 80.0%, a specificity of 78.9%and an accuracy of 80.0%for discrimination between salivary inflammatory masses and malignant masses.

CONCLUSION

Therefore, a multimodal ultrasonographic pathway combining clinical manifestations, B-mode US and CEUS was needed to differentiate between salivary focal inflammatory masses and malignancies to avoid unnecessary biopsies.

Narrative review of multiparametric ultrasound in parotid gland evaluation

Disorders affecting parotid gland represent a heterogeneous group comprising congenital, inflammatory and neoplastic diseases which show a focal or diffuse pattern of appearance. The differentiation of neoplastic from non-neoplastic conditions of parotid glands is pivotal for the diagnostic imaging. Frequently there is evidence of overlapping between the clinical and the imaging appearance of the various pathologies. The parotid gland is also often object of study with the combination of different techniques [ultrasound-computed tomography-magnetic resonance imaging (US-CT-MRI), ex.]. Compared to other dominant methods of medical imaging, US has several advantages providing images in real-time at lower cost, and without harmful use of ionizing radiation and of contrast enhancement. B-mode US, and the microvascular pattern color Doppler are usually used as first step evaluation of parotid lesions. Elastography and contrast-enhanced US (CEUS) has opened further possible perspectives to improve the differentiation between benign and malignant parotid lesions. The characterization of the parotid tumors plays a crucial role for their treatment planning and for the prediction of possible surgical complications. We present, here an updated review of the most recurrent pathologies of parotid gland focusing on the diagnostic power of multiparametric US including CEUS and ultrasound elastography (USE); limitations, advantages and the main key-points will be presented.

ACR Appropriateness Criteria® Neck Mass-Adenopathy

A palpable neck mass may be the result of neoplastic, congenital, or inflammatory disease. Older age suggests neoplasia, and a congenital etiology is more prevalent in the pediatric population. The imaging approach is based on the patient age, mass location, and clinical pulsatility. Underlying human papillomavirus-related malignancy should be considered in all age groups. Although the imaging appearance of some processes in the head and neck overlap, choosing the appropriate imaging examination may allow a specific diagnosis, or a limited differential diagnosis. Tissue sampling is indicated to confirm suspected malignancy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Predicting Malignancy Risk in Gastrointestinal Subepithelial Tumors with Contrast-Enhanced Harmonic Endoscopic Ultrasonography Using Perfusion Analysis Software

Background/Aims

Contrast-enhanced harmonic endoscopic ultrasonography (CEH-EUS) is a promising imaging modality that can differentiate subepithelial tumors (SETs) by detecting the degree of enhancement. However, whether CEH-EUS alone can predict the malignancy risk of gastrointestinal stromal tumors (GISTs) remains unclear. This study aimed to evaluate the feasibility of CEH-EUS by using perfusion analysis software for distinguishing among SETs and predicting the malignancy risk of GISTs.

Methods

We retrospectively included patients with SETs who underwent preoperative CEH-EUS. In this study, 44 patients with histologically proven GISTs and benign SETs were enrolled. Perfusion analysis was performed using perfusion quantification software. Peak enhancement (PE), wash-in rate (WiR), wash-in perfusion index (WiPI), and wash-in and wash-out areas under the time-intensity curve (WiWoAUC) were calculated and compared between the GISTs and benign SETs.

Results

When we allocated the enrolled patients into the leiomyoma group and low- and high-grade malignancy GIST groups, significant statistical differences in PE (p<0.001), WiR (p=0.009), WiPI (p<0.001), and WiWoAUC (p<0.001) were identified in the high-grade malignancy group compared with the leiomyoma group.

Conclusions

CEH-EUS with perfusion analysis using perfusion analysis software could be a quantitative and independent method for predicting malignancy risk in gastrointestinal SETs.

Volumetric Growth Rate of Recurrent Pleomorphic Adenoma

Objectives:

Surgery for recurrent pleomorphic adenoma (PA) can be challenging and may increase the risk of operative complications, particularly facial nerve weakness. As observation may be a viable alternative to surgery for slow-growing tumors, our objective was to assess the growth rate of recurrent PAs.

Study Design:

This study is a case series of patients at our tertiary academic medical center with recurrent PA. Two magnetic resonance images (MRI) were compared; total volume (TV) of recurrent tumor on both studies was calculated to obtain our main outcomes of percent change in TV and tumor growth rate.

Results:

Fourteen patients with recurrent PA had a median interval time between MRI of 12.8 months. Though growth rates were variable, the median continuous compound growth per year was 10.2%. Notably, 3 patients (21%) had no growth, and 2 patients (14%) had a reduction in TV.

Conclusions:

The median growth rate for enlarging tumors is estimated at 10.2% per year. Due to variability, tumor growth rate should be estimated on an individual patient basis. For slow-growing tumors, physicians may weigh the risk of this slow growth with the morbidity of reoperation.

Analysis of arterial dynamic micro-vascularization with contrast-enhanced ultrasound (CEUS) in thyroid lesions using external perfusion software: First results

AIM

To determine different perfusion characteristics of histo-pathologically proven adenomas and carcinomas of the thyroid gland with CEUS and perfusion software.

MATERIAL AND METHODS

Retrospective perfusion analysis of 25 patients with carcinomas and 41 cases of adenomas of the thyroid gland (30 males, 36 females; aged 18 - 85 years, mean 56 years). All cases were histologically analyzed. Perfusion analysis was independently performed using external perfusion software (VueBox®). TTP, mTT, Peak and Rise time were calculated.

RESULTS

Lesions' sizes ranged from 0.2 to 10.2 cm in carcinomas (mean 2.18 cm), and from 0.6 to 5.0 cm in adenomas (mean 2.25 cm). In 20 out of 25 carcinomas that were evaluated with CEUS, a complete wash-out in the late venous phase was found. Adenomas showed wash-out at the border.Perfusion analysis in VueBox® revealed some parameters which tend to show differences between adenomas and carcinomas, however did not reach the level of significance.Median Peak in carcinomas was highest at the margins (2945 rU), and lowest in the surroundings (1110 rU). Mean Transit Time (mTT) values showed no differences between center, margin and surrounding.In adenomas healthy tissue showed higher mTT values compared to the center (24.6 vs. 20.7 sec). Median Peak was highest in the surrounding tissue and lowest in the margins (1999 vs. 1129 rU). No statistical differences could be found in the comparisons.

CONCLUSION

CEUS with perfusion analysis offers new possibilities for the dynamic evaluation of micro-vascularization in thyroid adenomas and carcinomas. Using VueBox® the perfusion analysis of the arterial phase provides new parameters that help determine a lesion's malignancy or benignity. However a final assessment regarding malignancy and benignity of thyroid lesions using only CEUS and perfusion analysis of the arterial phase is not yet possible.

Contrast-enhanced ultrasound in the evaluation of parotid gland lesions: an update of the literature

High-resolution ultrasound is the first line examination for parotid gland diffuse disease and focal lesions, normally using grey-scale and colour-Doppler ultrasound. Unfortunately, grey-scale and colour-Doppler ultrasound features of benign and malignant salivary gland lesions may overlap, particularly with benign tumors, where pleomorphic adenomas are often indistinguishable from malignant lesions. With atypical lesions, contrast-enhanced magnetic resonance imaging is usually the second level imaging modality requested. The introduction of ultrasound contrast agents has opened further possible perspectives to improve the interpretation of parotid diseases, particularly the differentiation between benign and malignant lesions. We present a review of the current literature on contrast-enhanced ultrasound for the assessment of parotid gland lesions, considering all characteristics of the technique, evidence of usefulness, future perspectives and limitations.