Perfusion Patterns of Peripheral Organizing Pneumonia (POP) Using Contrast-Enhanced Ultrasound (CEUS) and Their Correlation with Immunohistochemically Detected Vascularization Patterns

The Value of Contrast-Enhanced Ultrasound (CEUS) in the Evaluation of Central Lung Cancer with Obstructive Atelectasis

Purpose: To assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) alongside contrast-enhanced computed tomography (CECT) in evaluating central lung cancer (CLC). Materials and Methods: From 2006 to 2022, 54 patients with CLC and obstructive atelectasis (OAT) underwent standardized examinations using CEUS in addition to CECT. The ability to differentiate CLC from atelectatic tissue in CECT and CEUS was categorized as distinguishable or indistinguishable. In CEUS, in distinguishable cases, the order of enhancement (time to enhancement) (OE; categorized as either an early pulmonary arterial [PA] pattern or a delayed bronchial arterial [BA] pattern of enhancement), the extent of enhancement (EE; marked or reduced), the homogeneity of enhancement (HE; homogeneous or inhomogeneous), and the decrease in enhancement (DE; rapid washout [<120 s] or late washout [≥120 s]) were evaluated. Results: The additional use of CEUS improved the diagnostic capability of CECT from 75.9% to 92.6% in differentiating a CLC from atelectatic tissue. The majority of CLC cases exhibited a BA pattern of enhancement (89.6%), an isoechoic reduced enhancement (91.7%), and a homogeneous enhancement (91.7%). Rapid DE was observed in 79.2% of cases. Conclusions: In cases of suspected CLC with obstructive atelectasis, the application of CEUS can be helpful in differentiating tumor from atelectatic tissue and in evaluating CLC.

B-mode ultrasound and contrast-enhanced ultrasound for evaluation of pneumonia: A pictorial essay

Due to their often peripheral pleural-based location, pneumonias can be visualised by B-mode ultrasound. Therefore, sonography can be used as an alternative imaging modality to chest X-ray in suspected cases of pneumonia. Depending on the clinical background of the patient, and various underlying pathological mechanisms, a heterogeneous pattern of pneumonia is seen in both B-mode lung ultrasound and contrast-enhanced ultrasound. Here, we describe the spectrum of sonographic manifestations of pneumonic/inflammatory consolidation on B-mode lung ultrasound and contrast-enhanced ultrasound.

Contrast-Enhanced Ultrasound in Distinguishing between Malignant and Benign Peripheral Pulmonary Consolidations: The Debated Utility of the Contrast Enhancement Arrival Time

Background. Limited studies and observations conducted on a too small number of patients prevent determining the actual clinical utility of pulmonary contrast-enhanced ultrasound (CEUS). The aim of the present study was to examine the efficacy of contrast enhancement (CE) arrival time (AT) and other dynamic CEUS findings for differentiating between malignant and benign peripheral lung lesions. Methods. 317 inpatients and outpatients (215 men, 102 women; mean age: 52 years) with peripheral pulmonary lesions were included in the study and underwent pulmonary CEUS. Patients were examined in a sitting position after receiving an intravenous injection of 4.8 mL of sulfur hexafluoride microbubbles stabilized by a phospholipid shell as ultrasound contrast agent (SonoVue-Bracco; Milan, Italy). Each lesion was observed for at least 5 min in real-time and the following temporal characteristics of enhancement were detected: the arrival time (AT) of microbubbles in the target lesion; the enhancement pattern; the wash-out time (WOT) of microbubbles. Results were then compared in light of the definitive diagnosis of community acquired pneumonia (CAP) or malignancies, which was not known at the time of CEUS examination. All malignant cases were diagnosed by histological results, while pneumonia was diagnosed on the basis of clinical and radiological follow-up, laboratory findings and, in some cases, histology. Results. CE AT has not been shown to differ between benign and malignant peripheral pulmonary lesions. The overall diagnostic accuracy and sensibility of a CE AT cut-off value < 10 s in discriminating benign lesions were low (diagnostic accuracy: 47.6%; sensibility: 5.3%). Poor results were also obtained in the sub-analysis of small (mean diameter < 3 cm) and large (mean diameter > 3 cm) lesions. No differences were recorded in the type of CE pattern showed between benign and malignant peripheral pulmonary lesions. In benign lesions we observed a higher frequency of delayed CE wash-out time (WOT) > 300 s. Anyhow, a CE WOT cut-off value > 300 s showed low diagnostic accuracy (53.6%) and sensibility (16.5%) in discriminating between pneumonias and malignancies. Similar results were also obtained in the sub-analysis by lesion size. Squamous cell carcinomas showed a more delayed CE AT compared to other histopathology subtypes. However, such a difference was statistically significant with undifferentiated lung carcinomas. Conclusions. Due to an overlap of CEUS timings and patterns, dynamic CEUS parameters cannot effectively differentiate between benign and malignant peripheral pulmonary lesions. Chest CT remains the gold standard for lesion characterization and the eventual identification of other pneumonic non-subpleural localizations. Furthermore, in the case of malignancy, a chest CT is always needed for staging purposes.

Peripheral Pulmonary Lesions in Confirmed Pulmonary Arterial Embolism: Follow-up Study of B-Mode Ultrasound and of Perfusion Patterns Using Contrast-Enhanced Ultrasound (CEUS)

PURPOSE

This retrospective study aimed to describe the B-mode lung ultrasound (B-LUS) and contrast-enhanced ultrasound (CEUS) follow-up patterns of peripheral pulmonary lesions (PPLs) in patients with confirmed pulmonary embolism (PE).

PATIENTS AND METHODS

Data from 27 patients with a confirmed diagnosis of PE and PPLs over 5 mm from October 2009 to November 2018 were included retrospectively in the study. The inclusion criteria were performance of a baseline CEUS examination, a short-term B-LUS and CEUS follow-up, and a long-term B-LUS follow-up of PPLs. The homogeneity of enhancement of PPLs (homogeneous/inhomogeneous/absent) on CEUS and the presence and size of PPLs on B-LUS were evaluated.

RESULTS

A total of n = 25/27 (92.6%) lesions showed absent or inhomogeneous enhancement during baseline examination or short-term follow-up, indicating impaired perfusion. On short-term CEUS follow-up, 9/27 cases (33.3%) showed a pattern shift. On B-LUS long-term follow-up, 26/27 lesions (96.3%) were detectable for an average of 10 weeks (range 3-32 weeks). The size of reference lesions was significantly reduced at the time of the final follow-up examination (P < .05).

CONCLUSION

B-LUS follow-up showed that, in patients with confirmed PE, PPLs had a delayed regression. On CEUS follow-up examination, various perfusion patterns of PPLs were observed, indicating the different ages and the variable reparative processes of pulmonary infarction. In PPLs independent of the underlying signs and symptoms, follow-up B-LUS and CEUS examinations may be helpful for a possible retrospective diagnosis of peripheral pulmonary infarction suggestive of PE.

WFUMB Technological Review: How to Perform Contrast-Enhanced Ultrasound of the Lung

The use of ultrasound has revolutionized the evaluation of pulmonary complaints and pathology. Historically, most lung ultrasound uses described are limited to B-mode, M-mode and occasionally color Doppler. However, the use of contrast can significantly expand the diagnostic capabilities of lung ultrasound. Ultrasound contrast enables significant expansion of therapeutic and intervention capabilities. We provide a detailed description of contrast administration, phases and uses in lung ultrasound. Additionally provided are example contrast use cases and illustrative examples of contrast use in a wide range of lung ultrasound applications including pneumonia, atelectasis, pulmonary embolism and neoplasms. Clinical practice examples will help providers incorporate contrast use into their lung ultrasound practice.

Diagnostic Performance of Point Shear Wave Elastography (pSWE) Using Acoustic Radiation Force Impulse (ARFI) Technology in Mesenteric Masses: A Feasibility Study

Purpose: To evaluate the diagnostic performance of ultrasound point shear wave elastography (pSWE) using acoustic radiation force impulse (ARFI) technology in different benign and malignant mesenteric masses (MMs). Methods: A total of 69 patients with MMs diagnosed from September 2018 to November 2021 were included retrospectively in the study. The inclusion criteria were (1) an MM over 1 cm; (2) valid ARFI measurements; and (3) confirmation of the diagnosis of an MM by histological examination and/or clinical and radiological follow-up. To examine the mean ARFI velocities (MAVs) for potential cut-off values between benign and malignant MMs, a receiver operating characteristics analysis was implemented. Results: In total, 37/69 of the MMs were benign (53.6%) and 32/69 malignant (46.4%). Benign MMs demonstrated significantly lower MAVs than mMMs (1.59 ± 0.93 vs. 2.76 ± 1.01 m/s; p < 0.001). Selecting 2.05 m/s as a cut-off value yielded a sensitivity and specificity of 75.0% and 70.3%, respectively, in diagnosing malignant MMs (area under the curve = 0.802, 95% confidence interval 0.699–0.904). Conclusion: ARFI elastography may represent an additional non-invasive tool for differentiating benign from malignant MMs. However, to validate the results of this study, further prospective randomized studies are required.

Contrast-enhanced ultrasound is helpful for differentiating benign from malignant parietal pleural lesions

INTRODUCTION

To describe the value of contrast-enhanced ultrasound (CEUS) for the differentiation of malignant from benign parietal pleural lesions (PPLs).

MATERIALS AND METHODS

From November 2005 to June 2019, 63 patients with histologically/cytologically confirmed PPLs were investigated by CEUS. On CEUS, the extent of enhancement (EE; marked or reduced/absent) and the homogeneity of enhancement (HE; homogeneous or inhomogeneous) were analyzed retrospectively.

RESULTS

In total, 24/63 lesions were benign, and 39/63 lesions were malignant. On CEUS, 11/24 benign and 36/39 malignant lesions showed a marked enhancement. A marked enhancement was significantly more frequently associated with malignancy compared with benign lesions (p < 0.001). In five cases, due to the absence of enhancement, it was not possible to determine the HE. In the remaining cases, 9/20 benign and 19/38 malignant lesions showed an inhomogeneous enhancement (p = 0.79).

CONCLUSION

On CEUS, marked enhancement was significantly more frequently associated with malignant compared with benign lesions. However, some benign lesions, such as chronic inflammatory processes, may also show a marked enhancement. Therefore, the interpretation of perfusion patterns in these lesions must always take into account the clinical background of the patient.