Contrast-enhanced ultrasound (CEUS) and CEUS-guided biopsy in the diagnosis of lung abscess in a patient with achalasia: Case report

Contrast enhancement for ultrasound-guided interventions: when to use it and what to expect?

The use of contrast-enhanced ultrasonography (CEUS) has recently become synonymous with high-standard ultrasonography (US). From expanding the reach of US diagnostics to improving the precision of various invasive procedures, CEUS is rapidly becoming a standard in numerous niches. However, proficiency in CEUS comes with a cost, both from a learning curve and material standpoint, and as every growing field, lacks firm evidence and standardization. Therefore, in the current paper, we aim to provide an evidence-based review of available methods and to discuss the advantages and pitfalls of CEUS in interventional procedures, trying to provide strong evidence whenever available, or at least an educated expert opinion if data are lacking.

Clinical Applications of Contrast-Enhanced Thoracic Ultrasound (CETUS) Compared to Standard Reference Tests: A Systematic Review

INTRODUCTION

 Contrast-enhanced ultrasound is utilized in an increasing array of medical fields, including thoracic medicine. However, the technique is still relatively new and only sporadically mentioned in current guidelines and recommendations. The aim of this systematic review is to provide a literature overview and to critically appraise the current clinical applications of contrast-enhanced thoracic ultrasound (CETUS).

MATERIALS AND METHODS

 A systematic literature search using major electronic databases and in accordance with PRISMA guidelines was performed. Studies with a primary focus on CETUS of thoracic disorders compared to a standard reference test were included. The QUADAS-2 tool was used for quality assessment of the studies.

RESULTS

 The search identified 43 articles: 1 randomized controlled study, 6 non-randomized controlled studies, 16 non-randomized non-controlled studies, 5 case series, 10 single case reports, and 5 animal studies. The overall risk of bias was judged to be high. Diagnostic accuracy measurements of noninvasive applications of CETUS were only reported in a few studies and they were too dissimilar for meta-analysis. Six studies compared CETUS-guided versus ultrasound-guided transthoracic needle biopsy of thoracic masses. They individually reported a significant increase in diagnostic accuracy in favor of CETUS guidance but were too heterogeneous for meta-analysis.

CONCLUSION

 The current literature on CETUS is overall heterogeneous with a few high evidence level studies, small study populations and a high risk of bias. CETUS-guided biopsy is the most frequent clinical application and increases diagnostic accuracy compared to ultrasound guidance by an average of 14.6 percentage points.

Contrast-enhanced ultrasound (CEUS) guided drainage in the treatment of a patient with lung abscess secondary to hypervirulent Klebsiella pneumoniae (hvKP) infection: A case report

Hypervirulent Klebsiella pneumoniae (hvKP) can cause lung abscess, serious infection, and has a high mortality. Drainage plays a key role in the treatment of lung abscess secondary to hvKP. Contrast-enhanced ultrasound (CEUS) can identify necrotic areas within peripheral pulmonary lesions. We report a case in which thoracic CEUS using solution of sulfur hexafluoride microbubbles (SonoVue®, Bracco, Milan, Italy) was better than computed tomography (CT) in depicting lung abscess from consolidation secondary to hvKP, and its role in guiding drainage of lung abscess. CEUS is a promising imaging technique for confirming an appropriate time for drainage of lung abscess secondary to hvKP, for point-of-care application in critical patients with impaired renal function which may be aggravated by CT contrast medium.

Contrast-enhanced ultrasound of pediatric lungs

In addition to radiography, ultrasound (US) has long proved to be a valuable imaging modality to evaluate the pediatric lung and pleural cavity. Its many inherent advantages, including real-time performance, high spatial resolution, lack of ionizing radiation and lack of need for sedation make it preferable over other imaging modalities such as CT. Since the introduction of ultrasound contrast agents (UCAs), contrast-enhanced ultrasound (CEUS) has become a valuable complementary US technique, with many well-established uses in adults and evolving uses in children. Lung CEUS applications are still not licensed and are performed off-label, although the added value of CEUS in certain clinical scenarios is increasingly reported. The limited evidence of CEUS in the evaluation of pediatric lungs focuses primarily on community-acquired pneumonia and its complications. In this clinical setting, CEUS is used to confidently and accurately diagnose necrotizing pneumonia and to delineate pleural effusions and empyema. In addition to intravenous use, UCAs can be administered directly into the pleural cavity through chest catheters to improve visualization of loculations within a complex pleural effusion, which might necessitate fibrinolytic therapy. The purpose of this paper is to present the current experience on pediatric lung CEUS and to suggest potential additional uses that can be derived from adult studies.

Contrast-enhanced ultrasound for needle biopsy of central lung cancer with atelectasis

PURPOSE

Contrast-enhanced ultrasound (CEUS) can distinguish between central lung cancer and atelectatic lung tissue. The aim of this study was to explore the clinical value of CEUS for biopsy in patients with central lung cancer with obstructive atelectasis.

METHODS

One hundred and twelve patients were selected and CEUS was performed to display central lung cancer and atelectatic lung tissue. The front edge of central lung cancer was punctured with a needle, avoiding the necrotic area, under the guidance of CEUS.

RESULTS

All of the 112 lesions were diagnosed with a clear central lung cancer mass and atelectatic lung tissue. In 104 cases, the central lung cancer mass presented with a "slow-in and fast-out" pattern compared to atelectatic lung tissue. In eight cases, the central lung cancer mass presented with a "fast-in and fast-out" pattern compared to atelectatic lung tissue. The mean number of punctures was 2.6, and the success rate of puncture biopsy was 98%. Of the 112 patients, six cases had hemoptysis during the procedure and 10 patients had bloody sputum in the postoperative period. No complications were found in the other cases.

CONCLUSION

CEUS has important clinical value for needle biopsy of central lung cancer with atelectasis.

The feasibility of contrast enhanced ultrasonography (CEUS) in the diagnosis of non-cardiac thoracic disorders of dogs and cats

BACKGROUND

This study describes the feasibility of Contrast Enhanced Ultrasonography (CEUS) in the diagnostic work-up of non-cardiac thoracic disorders of small animals. The second aim is to assess the usefulness of CEUS as a direct guide for sample procedures.

RESULTS

Forty animals, 28 dogs and 12 cats, were included in the study. Thoracic disorders included 23 pulmonary lesions [primary carcinoma (14), lymphoma (1), sarcoma (1), histiocytic sarcoma (1), abscess (1) and pneumonia (5)] and 17 mediastinal lesions [lymphoma (8), thymoma (3), mesothelioma (1), melanoma (1), carcinomatous lymphadenopathy (1), mixsosarcoma (1), lipoma (1), and abscess (1)]. The majority of neoplastic pulmonary lesions showed an inhomogeneous distribution of contrast medium, whereas inflammatory lesions had a homogenous distribution with typical pulmonary vessels ramification. The majority of mediastinal malignant lesions showed an inhomogeneous distribution pattern. The lung and mediastinal abscesses had peripheral enhancement of the wall with an avascular center. All cytological and biopsy samples obtained after CEUS were diagnostic. Quantitative analysis, performed in 19/23 pulmonary lesions, showed a statistically significant difference (P < 0.0001) between the arrival time of the malignant (7.27 s - range 4.46-13.52 s) and benign (4.52 s - range 2.87-6.06 s) pulmonary lesions.

CONCLUSIONS

CEUS may be a useful tool for the evaluation of non-cardiac thoracic lesions. The contrast medium allows for the precise definition of lesion edges, the presence of necrotic areas, and the distribution of pulmonary vessels. Based on our preliminary results, the use of ultrasonographic contrast medium can be recommended for improving the diagnostic usefulness of cytology and biopsy sampling, because CEUS may help to define necrotic areas from viable tissue.

Thoracic ultrasound: An adjunctive and valuable imaging tool in emergency, resource-limited settings and for a sustainable monitoring of patients

Imaging workup of patients referred for elective assessment of chest disease requires an articulated approach: Imaging is asked for achieving timely diagnosis. The concurrent or subsequent use of thoracic ultrasound (TUS) with conventional (chest X-rays-) and more advanced imaging procedures (computed tomography and magnetic resonance imaging) implies advantages, limitations and actual problems. Indeed, despite TUS may provide useful imaging of pleura, lung and heart disease, emergency scenarios are currently the most warranted field of application of TUS: Pleural effusion, pneumothorax, lung consolidation. This stems from its role in limited resources subsets; actually, ultrasound is an excellent risk reducing tool, which acts by: (1) increasing diagnostic certainty; (2) shortening time to definitive therapy; and (3) decreasing problems from blind procedures that carry an inherent level of complications. In addition, paediatric and newborn disease are particularly suitable for TUS investigation, aimed at the detection of congenital or acquired chest disease avoiding, limiting or postponing radiological exposure. TUS improves the effectiveness of elective medical practice, in resource-limited settings, in small point of care facilities and particularly in poorer countries. Quality and information provided by the procedure are increased avoiding whenever possible artefacts that can prevent or mislead the achievement of the correct diagnosis. Reliable monitoring of patients is possible, taking into consideration that appropriate expertise, knowledge, skills, training, and even adequate equipment’s suitability are not always and everywhere affordable or accessible. TUS is complementary imaging procedure for the radiologist and an excellent basic diagnostic tool suitable to be shared with pneumologists, cardiologists and emergency physicians.

Enhancing the role of paediatric ultrasound with microbubbles: a review of intravenous applications

Contrast-enhanced ultrasound (CEUS) represents a complementary technique to greyscale and colour Doppler ultrasonography which allows for real-time visualization and characterization of tissue perfusion. Its inherent advantages in the child makes ultrasonography an ideal imaging modality; repeatability and good tolerance along with the avoidance of CT, a source of ionizing radiation, renders ultrasonography imaging desirable. Although currently paediatric CEUS is principally used in an "off-label" manner, ultrasonography contrast agents have received regulatory approval for assessment of paediatric focal liver lesions (FLL) in the USA. The safety of ultrasound contrast-agents is well documented in adults, as safe as or even surpassing the safety profile of CT and MR contrast agents. Except for the established intracavitary use of CEUS in voiding urosonography, i.v. paediatric applications have been introduced with promising results in the abdominal trauma initial diagnosis and follow-up, characterization and differential diagnosis of FLL and characterization of lung, pleura, renal and splenic pathology. CEUS has also been used to detect complications after paediatric transplantation, evaluate inflammatory bowel disease activity and assess tumour response to antiangiogenic therapy. The purpose of this review was to present these novel i.v. paediatric applications of CEUS and discuss their value.

Utility of contrast-enhanced ultrasound with SonoVue in biopsy of small subpleural nodules

OBJECTIVES

This study aimed to evaluate the diagnostic accuracy and complication rates of contrast-enhanced ultrasound (CEUS)-guided biopsy of small subpleural nodules with SonoVue.

METHODS

CEUS-guided biopsies with SonoVue and conventional ultrasound were performed to determine nodule size, texture and biopsy route. After baseline ultrasonography, all patients received an intravenous injection of 4 mL of SonoVue, followed by 5 mL of saline flush. CEUS was obtained using a convex probe and contrast-specific imaging software. The lesion was observed using a contrast agent. Biopsies were performed during real-time visualisation of the target lesion.

RESULTS

A total of 51 patients (34 males and 17 females; average age, 54.8 ± 5.8 years) with subpleural nodules were enrolled. The median nodule size was 1.92 ± 0.75 cm (0.9-2.5 cm). Forty-eight of 51 procedures (94.1%) provided adequate material for histological analysis. Thirty patients (62.5%) were malignant and 18 patients (37.5%) were benign at the definitive diagnosis. The true positive and true negative result were 28 (58.3%) and 18 (37.5%), no false positive result was seen and two (4.2%) provided a false negative result. The sensitivity, specificity, positive and negative predictive values for the malignant diagnosis were 93.3, 100, 100 and 90%, respectively. The diagnostic accuracy was 95.8% (46/48), the standard error and the 95% CI were 2.8% and 86%-99%. An asymptomatic pneumothorax was present in one patient with no chest tube placement required. A small amount of hemoptysis was observed in another patient, which stopped spontaneously without treatment.

CONCLUSIONS

CEUS-guided biopsy with SonoVue exhibits high diagnostic accuracy and low complication rates. It is especially advantageous for biopsies of small subpleural nodules.

The Role of Contrast-Enhanced Ultrasound in Selection Indication and Improveing Diagnosis for Transthoracic Biopsy in Peripheral Pulmonary and Mediastinal Lesions

Objective. To investigate the value of contrast-enhanced ultrasound (CEUS) in transthoracic biopsy of peripheral lung and mediastinal lesions. Methods. Of 142 patients, 82 patients received CEUS before biopsy and were defined as CEUS group. The remaining 60 patients only underwent conventional ultrasound (US) before biopsy and were served as US group. The information of CEUS was used for selecting indication and instructing biopsy. The imaging features, number of punctures, diagnostic successful rate, and complication rate between the two groups were compared. Results. Necrosis was demonstrated in 43.9% of the lesions in CEUS group and in 6.7% of US group (P < 0.001). Detection rate of lesion hidden in pulmonary atelectasis in CEUS group was 13.4%, which was statistically higher than 1.7% of US group (P = 0.013). The diagnostic success rate was 96.3% for CEUS group and 80% for US group, respectively (P = 0.002). The average number of punctures was 2.5 ± 0.7 and 2.6 ± 0.6, respectively. There was no significant difference in complications between CEUS group and US group. Conclusions. CEUS could play an important role in selecting proper indication and improving diagnostic accuracy rate of lung biopsy.