Purpose: To evaluate the value of CEUS in differentiating malignant from benign pleural effusions (PEs). Methods: From 2008 to 2017, 83 patients with PEs of unknown cause were examined using B-mode thoracic ultrasound (B-TUS), CEUS, and cytological examination. The extent of enhancement of the pleural thickening, the presence of enhancement of septa or a solid mass within the PE, and the homogeneity of the enhancement in the associated lung consolidation, were examined. Subsequently, the diagnostic value of cytology, B-TUS, and CEUS in differentiating malignant from benign PEs was determined. Results: With CEUS, markedly enhanced pleural thickening and inhomogeneous enhanced lung consolidation were significantly more frequently associated with malignancy (p < 0.05). In the subgroup analysis, the use of CEUS increased the sensitivity from 69.2 to 92.3 in patients with initial negative cytology but clinical suspicion of malignant PE; it also increased the specificity from 63.0 to 90.0, the positive predictive value from 69.2 to 92.3, the negative predictive value from 63.0 to 90.0, and the diagnostic accuracy from 66.7 to 87.5, in the evaluation of PE malignancy. Conclusion: The use of clinically based B-TUS and CEUS as a complementary method to cytological evaluation may be beneficial for evaluating a PE of unknown cause. CEUS patterns of enhanced pleural thickening and inhomogeneous enhanced lung consolidation may suggest a malignant PE.

Purpose: To describe perfusion patterns of peripheral pulmonary lesions (PPLs) in COVID‐19 patients using contrast‐enhanced ultrasound (CEUS).Patients and methods: From April 2020 until July 2020, 11 consecutive patients with RT‐PCR‐confirmed COVID‐19 and PPLs sized over 5 mm were investigated by B‐mode ultrasound (B‐US) and CEUS. The homogeneity of enhancement (homogeneous and inhomogeneous) was examined retrospectively using CEUS. An inhomogeneous enhancement was defined as a perfused lesion with coexisting non‐perfused areas (NPA).Results: On B‐US, all 11 patients showed an interstitial syndrome (B‐lines) with PPLs between 0.5 and 6 cm. On CEUS, all cases showed peripheral NPA during the complete CEUS examination. One patient underwent a partial lung resection with subsequent histopathological examination. The histological examination showed vasculitis, microthrombus in the alveolar capillary, and small obliterated vessels.Conclusion: In our case series, PPLs in patients with RT‐PCR‐confirmed COVID‐19 infection presented a CEUS pattern with NPA during the complete CEUS examination. Our findings suggest a peripheral pulmonary perfusion disturbance in patients with COVID‐19 infection. In 1 case, the histopathological correlation with the perfusion disturbance in the PPL was proven.

B‐mode ultrasound (B‐US) is the standard imaging modality to evaluate pleural effusion. The value of B‐US for assessing the malignancy of a pleural effusion (PE) is limited. For this purpose, computed tomography (CT) and thoracoscopy are the methods of choice to evaluate an effusion. The aim of this Pictorial Essay is to demonstrate contrast‐enhanced ultrasound (CEUS) as a method in addition to B‐US and CT for the evaluation of PE taking into account the clinical background. The characteristic patterns of pleural pathologies, effusion morphology, and associated lung parenchymal consolidations are presented.

It is time for a change. CEUS is an established method that should be much more actively included in renal cyst monitoring strategies. This review compares the accuracies, strengths, and weaknesses of CEUS, CECT, and MRI in the classification of renal cysts. In order to avoid overstaging by CEUS, a further differentiation of classes IIF, III, and IV is required. A further development in the refinement of the CEUS-Bosniak classification aims to integrate CEUS more closely into the monitoring of renal cysts and to develop new and complex monitoring algorithms.

Purpose: To describe the perfusion patterns of peripheral pulmonary granulomatous lesions (PPGLs) by contrast‐enhanced ultrasound (CEUS) and their correlation with vascularization patterns (VPs) represented by immunohistochemical (CD34) endothelial staining.Patients and methods: From January 2007 until September 2020, 10 consecutive patients with histologically confirmed PPGLs were investigated by CEUS. The time to enhancement, classified as early pulmonary‐arterial (PA) pattern of enhancement versus delayed bronchial‐arterial (BA) pattern of enhancement, the extent of enhancement, classified as marked or reduced, the homogeneity of enhancement, classified as homogeneous or inhomogeneous, and the decrease of enhancement, classified as rapid washout (<120 seconds) or a late washout (≥120 seconds), were analyzed retrospectively. Furthermore, the tissue samples from the study patients and as a control group, 10 samples of normal lung tissue obtained by autopsy, and 10 samples of lung tissue with acute pneumonia obtained by autopsy were immunohistochemically stained with CD34 antibody. The presence of avascular areas (AAs) and the VPs were evaluated in all tissue samples.Results: On CEUS, all PPGLs showed a reduced inhomogeneous BA pattern of enhancement and a rapid washout (<120 seconds). On CD34 staining, all PPGLs showed central AAs in granulomas and a chaotic VP similar to angiogenesis in lung tumors. The lung tissue in control groups revealed on CD34 staining a regular alveolar VP.Conclusion: The PPGLs on CEUS show an identical perfusion pattern similar to those of malignant lesions. Furthermore, for the first time, neoangiogenesis was demonstrated as a histopathological correlate to BA pattern of enhancement on CEUS.

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.