Contrast enhanced ultrasound (CEUS) to assess pleural pulmonal changes in severe COVID-19 infection: First results

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.

New International Guidelines and Consensus on the Use of Lung Ultrasound

Following the innovations and new discoveries of the last 10 years in the field of lung ultrasound (LUS), a multidisciplinary panel of international LUS experts from six countries and from different fields (clinical and technical) reviewed and updated the original international consensus for point-of-care LUS, dated 2012. As a result, a total of 20 statements have been produced. Each statement is complemented by guidelines and future developments proposals. The statements are furthermore classified based on their nature as technical (5), clinical (11), educational (3), and safety (1) statements.

The use of lung ultrasound in COVID-19

This review article addresses the role of lung ultrasound in patients with coronavirus disease 2019 (COVID-19) for diagnosis and disease management. As a simple imaging procedure, lung ultrasound contributes to the early identification of patients with clinical conditions suggestive of COVID-19, supports decisions about hospital admission and informs therapeutic strategy. It can be performed in various clinical settings (primary care facilities, emergency departments, hospital wards, intensive care units), but also in outpatient settings using portable devices. The article describes typical lung ultrasound findings for COVID-19 pneumonia (interstitial pattern, pleural abnormalities and consolidations), as one component of COVID-19 diagnostic workup that otherwise includes clinical and laboratory evaluation. Advantages and limitations of lung ultrasound use in COVID-19 are described, along with equipment requirements and training needs. To infer on the use of lung ultrasound in different regions, a literature search was performed using key words "COVID-19", "lung ultrasound" and "imaging". Lung ultrasound is a noninvasive, rapid and reproducible procedure; can be performed at the point of care; requires simple sterilisation; and involves non-ionising radiation, allowing repeated exams on the same patient, with special benefit in children and pregnant women. However, physical proximity between the patient and the ultrasound operator is a limitation in the current pandemic context, emphasising the need to implement specific infection prevention and control measures. Availability of qualified staff adequately trained to perform lung ultrasound remains a major barrier to lung ultrasound utilisation. Training, advocacy and awareness rising can help build up capacities of local providers to facilitate lung ultrasound use for COVID-19 management, in particular in low- and middle-income countries.

Intraoperative ultrasound in minimally invasive thoracic surgery for the detection of pulmonary tumors: First intrathoracic application of TE9 and laparoscopic probe Lap 13-4cs (Mindray)

AIM

To apply intraoperative ultrasound (IO-US) for the first time using a laparascopic probe to detect malignancy-susceptible solitary pulmonary nodules (SPN) and assess macrovascularization using color-coded doppler sonography or power doppler. Description of technical feasibility.

METHODS

Technical description on intrathoracic endoscopic ultrasound. A positive ethics vote from the local ethics committee and written patient consent were available. Intraoperative ultrasound was performed using a laparascopic probe (Lap 13-4cs, Mindray) on the T9 ultrasound machine (Mindray, China). B-scan was used to detect the SPN. Color-coded doppler sonography (CCS) and power doppler were used to assess macrovascularization. Primary end point was the description of the technical performance of the Io-US. Secondary endpoints were the functions of Io-US in characterizing SPN.

RESULTS

Io-US was successfully applied using (n = 2) cases in video-assisted thoracic surgery. All SPN were successfully detected intraoperatively with the intrathoracically placed laparascopy probe using B-mode and examined using CCS or power Doppler (100%). Resection was sonography-guided with marking of the tumor area in all cases without complications. Histological workup revealed malignancy in both cases.

CONCLUSION

Intrathoracic application of laparascopically guided Io-US was technically feasible. In addition to B-mode detection, Io-US using power doppler and color-coded doppler sonography provided initial evidence for characterization of SPN based on macrovascularization.

Wireless handheld focused ultrasound in student teaching during the COVID-19 pandemic: Initial results of a pilot study1

OBJECTIVE

The study aim was to investigate the use of a novel device, the Vscan Air™, for rapidly and effectively performing ultrasound in student teaching during the COVID-19 pandemic.

MATERIAL AND METHODS

As part of the ultrasound practical course with integrated hands-on activity required by the regular medical curriculum, 100 medical students were instructed in the use of the Vscan Air™, including duplex mode. They then evaluated the quality of the ultrasound images obtained by the Vscan Air™ from previously selected organs.

RESULTS

100 students were interviewed (female n = 68, male n = 32; age >18 years n = 100). The rated image quality never fell below a mean of 3 for the examined organs and portal vein flow (liver 4,58; spleen 3,99; kidneys 4,29; aorta 4,16; Douglas/rectovesical space 4,14; portal vein 4,43; pancreas 3,53; Focused Assessment with Sonography for Trauma 4,38). Scores below 3 were found sporadically in ultrasounds of the spleen (n = 4), kidneys (n = 3), Douglas/rectovesical space (n = 2), and pancreas (n = 15). The liver was rated the lowest for 59 ratings. The portal vein was evaluated in 68 cases. The hepatic artery and hepatic veins could be also visualized in all 68 examinations. The aorta was evaluated in 62 cases.

CONCLUSION

The Vscan Air™ technology offered adequate image quality and provided a new, fast and patient-oriented technique to support continuous ultrasound examinations and education of students, especially during a pandemic. Particularly noteworthy is the uncomplicated compliance with the required high level of hygiene.

Multimodal ultrasound imaging with conventional B-mode, elastography, and parametric analysis of contrast-enhanced ultrasound (CEUS): A novel approach to assess small bowel manifestation in severe COVID-19 disease

The aim was to describe the small bowel morphology with conventional B-mode and elastography and additionally to evaluate dynamic effects of COVID-19 associated small bowel microvascularization using CEUS with color coded perfusion parameters.Thirteen patients with severe COVID-19 acute respiratory distress syndrome (ARDS) were investigated. 13 patients required intensive care treatment with mechanical ventilation. Five patients required extracorporeal membrane oxygenation (ECMO). Contrast-enhanced ultrasound (CEUS) was performed by an experienced investigator as a bolus injection of up to 2.4 ml sulfur hexafluoride microbubbles via a central venous catheter. In the parametric analysis of CEUS, the flare of microbubbles over time is visualized with colors. This is the first work using parametric analysis of CEUS to detect perfusion differences in the small bowel.Parametric analysis of CEUS in the intestinal phase was carried out, using DICOM loops for 20 seconds. In 5 patients, parametric analysis revealed intraindividual differences in contrast agent behavior in the small bowel region. Analogous to the computed tomography (CT) images parametric analysis showed regions of simultaneous hyper- and hypoperfusion of the small intestine in a subgroup of patients. In 5 patients, the parametric image of transmural global contrast enhancement was visualized.Our results using CEUS to investigate small bowel affection in COVID-19 suggest that in severe COVID-19 ARDS systemic inflammation and concomitant micro embolisms may lead to disruption of the epithelial barrier of the small intestine.This is the first study using parametric analysis of CEUS to evaluate the extent of small bowel involvement in severe COVID-19 disease and to detect microemboli. In summary, we show that in COVID-19 the small bowel may also be an important interaction site. This is in line with the fact that enterocytes have been shown to a plenitude of angiotensin converting enzyme (ACE)-2 receptors as entry sites of the virus.

Blood hyperviscosity in acute and recent COVID-19 infection

BACKGROUND

Elevated estimated blood viscosity (EBV), derived from hematocrit and globulins, is associated with thrombotic complications, organ failure, and higher mortality in COVID-19 patients. Although informative, EBV does not account for cellular interactions or fibrinogen.

OBJECTIVE

Investigate whether patients with acute and recent COVID-19 have altered whole blood viscosity (WBV) when measured at both high and low shear rates using in vitro blood samples from patients.

METHODS

Cross-sectional study of 58 patients: 15 in the intensive care unit with acute COVID-19, 32 convalescent (9 < 8weeks [W] from acute infection, 23 > 8 W), and 11 controls without COVID-19. WBV was measured at high (300 s-1) and low (5 s-1) shear rates (HSR, LSR) using a scanning capillary viscometer.RESULTSAcute and convalescent patients < 8 W had mean WBV at LSR (16.0 centipoise [cP] and 15.1 cP) and HSR (5.1 cP and 4.7 cP). Mean WBV of convalescent > 8 W and control patients were 12.3 cP and 13.0 cP at LSR, and 4.1 cP and 4.2 cP at HSR. Acute and < 8 W patients had significantly higher WBV at both HSR and LSR compared to patients > 8 W (all p≤0.01). No significant differences in WBV were observed between acute and < 8 W patients, or between patients > 8 W and controls.

CONCLUSIONS

Hyperviscosity provides a possible explanation for thrombotic risk in acute and convalescent (< 8 W) patients. These findings have important implications for thromboprophylaxis.

Contrast-enhanced ultrasound (CEUS) - A new tool for evaluating blood supply in primary peripheral lung cancer

OBJECTIVES

To explore the feasibility of contrast-enhanced ultrasound (CEUS) as a new tool for characterizing vascularization of primary peripheral lung cancer.

METHODS

315 consecutive patients with definite primary peripheral lung cancers underwent CEUS examination from November 2016 to March 2022. CEUS parameters including time to enhancement (TE), time to peak (TP), time to wash-out (TW), distribution of vessels (DV), extent of enhancement (EE) and homogeneity of enhancement (HE) were obtained.

RESULTS

The lesions were grouped on the basis of TE which reflects tumor vascularization: early enhancement (pulmonary arterial vascularization) (n = 91) and delayed enhancement group (bronchial arterial vascularization) (n = 224). Overall, lung tumors commonly (71.1%) manifested a delayed enhancement which indicating blood supply originated from bronchial arteries, while an early enhancement was present in less than a third of the cases. Tumors with bronchial vascularization tended to show a delayed, reduced and heterogeneous enhancement. Correspondingly, it is characterized by a shorter TE, marked EE and a relatively infrequent occurrence of necrosis in tumors with pulmonary vascularization.

CONCLUSIONS

Providing micro-perfusion information, CEUS is a potentially imaging tool for evaluating blood supply in primary peripheral lung cancer.

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.

Endothelial glycocalyx damage in patients with severe COVID-19 on mechanical ventilation - a prospective observational pilot study

BACKGROUND

Coronavirus disease (COVID-19) associated endotheliopathy and microvascular dysfunction are of concern.

OBJECTIVE

The objective of the present single-center observational pilot study was to compare endothelial glycocalyx (EG) damage and endotheliopathy in patients with severe COVID-19 (COVID-19 group) with patients with bacterial pneumonia with septic shock (non-COVID group).

METHODS

Biomarkers of EG damage (syndecan-1), endothelial cells (EC) damage (thrombomodulin), and activation (P-selectin) were measured in blood on three consecutive days from admission to the intensive care unit (ICU). The sublingual microcirculation was studied by Side-stream Dark Field (SDF) imaging with automatic assessment.

RESULTS

We enrolled 13 patients in the non-COVID group (mean age 70 years, 6 women), and 15 in the COVID-19 group (64 years old, 3 women). The plasma concentrations of syndecan-1 were significantly higher in the COVID-19 group during all three days. Differences regarding other biomarkers were not statistically significant. The assessment of the sublingual microcirculation showed improvement on Day 2 in the COVID-19 group. Plasma levels of C-reactive protein (CRP) were significantly higher on the first two days in the COVID-19 group. Plasma syndecan-1 and CRP were higher in patients suffering from severe COVID-19 pneumonia compared to bacterial pneumonia patients.

CONCLUSIONS

These findings support the role of EG injury in the microvascular dysfunction in COVID-19 patients who require ICU.

Contrast enhanced ultrasonography (CEUS) a novel tool to detect intestinal epithelial barrier dysfunction in severe COVID-19 disease

Ten patients with confirmed COVID-19 disease were studied. Nine patients required intensive care treatment, among them four needed extracorporeal membrane oxygenation (ECMO). Contrast enhanced ultrasonography (CEUS) was performed by one experienced investigator as a bolus injection of up to 2.4 ml of sulphur hexafluoride microbubbles via a central venous catheter. B-Mode evaluation and strain elastography showed mural edema of the small bowel with a thickness of up to 10 mm in all patients. We applied color coded Doppler sonography (CCDS) and power mode with flow-adapted parameters and early, dynamic capillary arterial contrast enhancement of bowel wall structures <10 s to assess perfusion of the small bowel. In all patients, reactive hyperemia was seen in the entire small bowel. In a subgroup of seven patients microbubbles translocated into the intestinal lumen. Thus, high-grade intestinal barrier disruption secondary to SARSCoV-2 infection can be postulated in these patients. This is the first description of perfusion changes and a disruption of the small bowel epithelial barrier in COVID-19 Patients using contrast ultrasonography and elastography.

Application of dynamic contrast enhanced ultrasound in distinguishing focal-type autoimmune pancreatitis from pancreatic ductal adenocarcinoma

OBJECTIVE

To explore the value of dynamic contrast enhanced ultrasound (DCE-US) in preoperative differential diagnosis of focal-type autoimmune pancreatitis (AIP) and pancreatic ductal adenocarcinoma (PDAC).

PATIENTS AND METHODS

From May 2016 to March 2020, patients with biopsy and histopathologically confirmed focal-type AIP (n = 9) were retrospectively included. All patients received contrast enhanced ultrasound (CEUS) examinations one week before surgery/biopsy. Dynamic analysis was performed by VueBox® software (Bracco, Italy). Eighteen cases of resection and histopathologically proved PDAC lesions were also included as control group. B mode ultrasound (BMUS) features, CEUS enhancement patterns, time intensity curves (TICs) and CEUS quantitative parameters were obtained and compared between AIP and PDAC lesions.

RESULTS

After injection of ultrasound contrast agents, most focal-type AIP lesions displayed hyper-enhancement (2/9, 22.2%) or iso-enhancement (6/9, 66.7%) during arterial phase of CEUS, while most of PDAC lesions showed hypo-enhancement (88.9%) (P < 0.01). During late phase, most of AIP lesions showed iso-enhancement (8/9, 88.9%), while most of PDAC lesions showed hypo-enhancement (94.4%) (P < 0.001). Compared with PDAC lesions, TICs of AIP lesions showed delayed and higher enhancement. Among all CEUS perfusion parameters, ratio of PE (peak enhancement), WiAUC (wash-in area under the curve), WiR (wash-in rate), WiPI (wash-in perfusion index, WiPI = WiAUC/ rise time), WoAUC (wash-out area under the curve), WiWoAUC (wash-in and wash-out area under the curve) and WoR (wash-out rate) between pancreatic lesion and surrounding normal pancreatic tissue were significantly higher in AIP lesions than PDAC lesions (P < 0.05).

CONCLUSION

DCE-US with quantitative analysis has the potential to make preoperative differential diagnosis between focal-type AIP and PDAC non-invasively.

Perfusion Patterns of Peripheral Pulmonary Lesions in COVID-19 Patients Using Contrast-Enhanced Ultrasound (CEUS): A Case Series

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.

Is SARS-CoV-2 infection an emerging risk factor for splanchnic venous thrombosis?

OBJECTIVE

Thrombosis represents one of the most feared complications of the COronaVIrus Disease-2019 (COVID-19). Although pulmonary embolism and deep venous thrombosis are the most described complications, some investigations reported thrombotic localization also in the splanchnic venous district.

METHODS

We describe the case of a patient with SARS-CoV-2 infection presenting with abdominal pain and diagnosed with portal vein thrombosis. In addition, we shortly review available literature supporting the possible role of COVID-19 as leading cause of splanchnic venous thrombosis.

RESULTS

After in-depth diagnostic workup, we excluded the commonest causes of portal thrombosis and concluded that SARS-CoV-2 infection represented the main explanation of this finding.

CONCLUSIONS

Our study warns the clinicians to maintain a high index of suspicion for thrombosis in patients diagnosed with SARS-CoV-2 infection manifesting gastrointestinal symptoms. An appropriate diagnostic work-up could allow to obtain an early diagnosis and consequently improve the clinical outcome of patients.

CT diagnostics of pulmonary embolism: Does iodine delivery rate still affect image quality in iterative reconstruction?

BACKGROUND

Computed tomographic (CT) imaging in suspected pulmonary artery embolism represents the standard procedure. Studies without iterative reconstruction proved beneficial using increased iodine delivery rate (IDR). This study compares image quality in pulmonary arteries on iteratively reconstructed CT images of patients with suspected pulmonary embolism using different IDR.

MATERIAL AND METHODS

1065 patients were included in the study. Patients in group A (n = 493) received an iodine concentration of 40 g/100 ml (IDR 1.6 g/s) and patients in group B (n = 572) an iodine concentration of 35 g/100 ml (IDR 1.4 g/s) at a flow rate of 4 ml/s. A 80-detector spiral CT scanner with iterative reconstruction was used. We measured mean density values in truncus pulmonalis, both pulmonary arteries and segmental pulmonary arteries. Subjectively, the contrast of apical and basal pulmonary arteries was determined on a 4-point Likert scale.

RESULTS

Radiodensity was significantly higher in all measured pulmonary arteries using the increased IDR (p < 0.001). TP: 483.0 HU vs. 393.4 HU; APD: 452.1 HU vs. 372.1 HU; APS: 448.2 HU vs. 374.4 HU; ASP: 443.9 vs. 374.4 HU. Subjectively assessed contrast enhancement in apical (p = 0.077) and basal (p = 0.429) lung sections showed no significant differences.

CONCLUSION

Higher IDR improves objective image quality in all patients with significantly higher radiodensities by iterative reconstruction. Subjective contrast of apical and basal lung sections did not differ. The number of non-sufficient scans decreased with high IDR.

Generation of 2.5D lung bud organoids from human induced pluripotent stem cells

Human induced pluripotent stem cells (hiPSCs) are a promising cell source to generate the patient-specific lung organoid given their superior differentiation potential. However, the current 3D cell culture approach is tedious and time-consuming with a low success rate and high batch-to-batch variability. Here, we explored the establishment of lung bud organoids by systematically adjusting the initial confluence levels and homogeneity of cell distribution. The efficiency of single cell seeding and clump seeding was compared. Instead of the traditional 3D culture, we established a 2.5D organoid culture to enable the direct monitoring of the internal structure via microscopy. It was found that the cell confluence and distribution prior to induction were two key parameters, which strongly affected hiPSC differentiation trajectories. Lung bud organoids with positive expression of NKX 2.1, in a single-cell seeding group with homogeneously distributed hiPSCs at 70% confluence (SC_70%_hom) or a clump seeding group with heterogeneously distributed cells at 90% confluence (CL_90%_het), can be observed as early as 9 days post induction. These results suggest that a successful lung bud organoid formation with single-cell seeding of hiPSCs requires a moderate confluence and homogeneous distribution of cells, while high confluence would be a prominent factor to promote the lung organoid formation when seeding hiPSCs as clumps. 2.5D organoids generated with defined culture conditions could become a simple, efficient, and valuable tool facilitating drug screening, disease modeling and personalized medicine.

Can erythrocytes behavior in microcirculation help the understanding the physiopathology and improve prevention and treatment for covid-19?

Low plasma estrogens, vitamin D deficiency, obesity, diabetes, cardiovascular diseases, thromboembolism, and impaired microcirculation are linked to the severity of covid-19. Studies have suggested that these comorbidities also are related to erythrocyte factors linked to increased blood viscosity in microcirculation such as erythrocyte aggregation and erythrocyte deformability. Increased blood viscosity in microcirculation can lead to a decrease in oxygenation and nutrition of tissues. Therefore erythrocyte aggregation and erythrocyte deformability may be involved in covid-19 severity, leading to tissue hypoxia and a decrease of drug concentration in affected organs. If this relationship is demonstrated, erythrocytes factors can be used to monitor treatments for improve microcirculatory fluidity that may decrease covid-19 severity. Lifestyle improvement and treatments such as vitamin D and estrogens supplementation are some possible approaches to improve microcirculation and covid-19 prevention and treatment.

Interstitial lung opacities in patients with severe COVID-19 pneumonia by bedside high-resolution ultrasound in association to CO2 retention

BACKGROUND

Coronavirus disease 2019 (COVID-19) can cause acute respiratory distress syndrome (ARDS).

OBJECTIVE

This single centre cross-section study aimed to grade the severity of pneumonia by bed-side lung ultrasound (LUS).

METHODS

A scoring system discriminates 5 levels of lung opacities: A-lines (0 points),≥3 B-line (1 point), coalescent B-lines (2 points), marked pleural disruptions (3 points), consolidations (4 points). LUS (convex 1-5 MHz probe) was performed at 6 defined regions for each hemithorax either in supine or prone position. A lung aeration score (LAS, maximum 4 points) was allocated for each patient by calculating the arithmetic mean of the examined lung areas. Score levels were correlated with ventilation parameters and laboratory markers.

RESULTS

LAS of 20 patients with ARDS reached from 2.58 to 3.83 and was highest in the lateral right lobe (Mean 3.67). Ferritin levels (Mean 1885μg/l; r = 0.467; p = 0.051) showed moderate correlation in spearman roh calculation. PaCO2 level (Mean 46.75 mmHg; r = 0.632; p = 0.005) correlated significantly with LAS, while duration of ventilation, Horovitz index, CRP, LDH and IL-6 did not.

CONCUSIONS

The proposed LAS describes severity of lung opacities in COVID-19 patients and correlates with CO2 retention in patients with ARDS.

Cerebrovascular comorbidity, high blood levels of C-reactive protein and D-dimer are associated with disease outcomes in COVID-19 patients

The emerging coronavirus disease (COVID-19) swept the world, affecting more than 200 countries and territories. As of August 22, 2020, the pandemic infected more than 23,329,752 including 807,054 patients who have died. Although the main clinical features of the pandemic disease are respiratory, cerebrovascular comorbidities emerged as one of the leading causes of death associated with COVID-19. Different case reports have indicated that C-reactive protein (CRP) and D-dimer (pro-inflammatory biomarkers) were elevated in COVID-19 patients, which can significantly increase the risk of ischemic stroke. Available data on cerebrovascular complications in COVID-19 patients were collected and a meta-analysis was designed and carried out to evaluate the risk of severity and mortality associated with high levels of CRP and D-dimer levels in COVID-19 patients. In addition, we aimed to describe the overall event rate of pre-existing cerebrovascular disease in COVID-19 patients. In our analysis, 5,614 cases have been studied, out of these patients 164 cases have developed cerebrovascular comorbities. Cerebrovascular comorbidity increased the risk of disease severity (odd ratio = 4.4; 95% CI: 1.48 to 12.84) and mortality (odd ratio = 7.0; 95% CI: 2.56 to 18.99). Statistical analyses showed that CRP and D-dimer serum levels were elevated by six-folds in the severe cases of COVID-19 patients. This significant increase in these two proteins levels can serve as a vital indicator for COVID-19 patients who are at increased risk of severe COVID-19 cerebrovascular complications, such as stroke.

Characterization of lung ultrasound imaging in preterm infants with bronchopulmonary dysplasia

BACKGROUND

Lung ultrasound (LUS) is a bedside technique that can be used on diagnosis and follow-up of neonatal respiratory diseases. However, there are rare reports on the ultrasound features of bronchopulmonary dysplasia (BPD) which is one of the most common chronic lung diseases in preterm infants.

OBJECTIVE

To describe the ultrasound features of different BPD levels, and to investigate the value of ultrasound in evaluating moderate-to-severe BPD.

METHODS

In this prospective cohort study, newborns of less than 37 weeks' gestational age in neonatal intensive care unit (NICU) were included. The LUS characteristics including pleural line, alveolar-interstitial syndrome (AIS), retrodiaphragmatic hyperechogenicity and diaphragmatic morphology were observed and recorded. The reliability of LUS in evaluating moderate and severe BPD were compared and calculated.

RESULTS

A total of 108 infants were enrolled in our study: 39, 24, 29, 16 infants had non, mild, moderate and severe BPD. The median(IQR) pleura thickness in the moderate-to-severe BPD group was 1.7(1.6-1.85) mm, which was thicker than that in the none-to-mild BPD infants (P <  0.001), meanwhile the proportions of rough pleural lines, diffuse AIS, retrodiaphragmatic hyperechogenicity, small cysts above the diaphragm and rough diaphragm in the moderate-to-severe BPD group were also higher than those in none-to-mild BPD group (86.7% vs 36.5, 57.8% vs 7.9%, 37.8% vs 0, 33.3% vs 0, P <  0.001). In evaluating moderate-to-severe BPD, rough pleura had 91.1% (95% confidence interval [CI]: 0.793-0.965) in sensitivity, 91.3% (95% CI: 0.797-0.966) in negative predictive value (NPV), and 66.7% (95% CI: 0.544-0.771) in specificity. Small cysts had 100% (95% CI: 0.941-1) in specificity, 100% (95% CI: 0.816-1) in PPV, and 37.8% in sensitivity (95% CI: 0.251-0.524). Rough diaphragm had 100% (95% CI: 0.943-1) in sensitivity, 100% (95% CI: 0.796-1) in PPV and 33.3% (95% CI: 0.211-0.478) in specificity.

CONCLUSIONS

Depending on its unique advantages such as convenient, no radiation and repeatable, LUS is a valuable imaging method in assessing the severity of BPD, especially in moderate and severe BPD.

Elevated fibrinogen and fibrin degradation product are associated with poor outcome in COVID-19 patients: A meta-analysis

INTRODUCTION

COVID-19 is a systemic infection with a significant impact on coagulation which manifests in thromboembolism. There is an unknown relationship of which coagulation profile parameter at presentation has an association with poor outcome in COVID-19.

OBJECTIVE

This meta-analysis aimed to determine the relationship between fibrinogen and FDP with poor outcome in COVID-19 patients.

METHODS

A systematic search of all observational studies or trials involving adult patients with COVID-19 that had any data fibrinogen or FDP on admission was carried out using the PubMed, Science Direct, Scopus, ProQuest, and MedRxiv databases. We assessed the methodological quality assessment using the NIH Quality Assessment Tool. We performed random-effects inverse-variance weighting analysis using mean difference (MD).

RESULTS

A total of 17 studies (1,654 patients) were included in this meta-analysis. It revealed a higher mean of fibrinogen levels on admission in patients with severe case compared to those with non-severe case (MD = 0.69, [95% CI: 0.44 to 0.94], p < 0.05; I2 = 72%, p < 0.05). Non-survivor group had a pooled higher mean difference of fibrinogen values on admission (MD = 0.48 [95% CI: 0.13 to 0.83], p < 0.05; I2 = 38%, p = 0.18). Higher FDP on admission was found in poor outcome (composite of severity, critically ill, and mortality) compared to good outcome (4 studies, MD = 4.84 [95% CI: 0.75 to 8.93], p < 0.05; I2 = 86%, p < 0.05).

CONCLUSION

Elevated fibrinogen and FDP level on admission were associated with an increase risk of poor outcome in COVID-19 patients.

Functional micro/nanobubbles for ultrasound medicine and visualizable guidance

Chemically functionalized gas-filled bubbles with a versatile micro/nano-sized scale have witnessed a long history of developments and emerging applications in disease diagnosis and treatments. In combination with ultrasound and image-guidance, micro/nanobubbles have been endowed with the capabilities of biomedical imaging, drug delivery, gene transfection and disease-oriented therapy. As an external stimulus, ultrasound (US)-mediated targeting treatments have been achieving unprecedented efficiency. Nowadays, US is playing a crucial role in visualizing biological/pathological changes in lives as a reliable imaging technique and a powerful therapeutic tool. This review retrospects the history of ultrasound, the chemistry of functionalized agents and summarizes recent advancements of functional micro/nanobubbles as US contrast agents in preclinical and trans-clinical research. Latest ultrasound-based treatment modalities in association with functional micro/nanobubbles have been highlighted as their great potentials for disease precision therapy. It is believed that these state-of-the-art micro/nanobubbles will become a booster for ultrasound medicine and visualizable guidance to serve future human healthcare in a more comprehensive and practical manner.

D-dimer daily continuous tendency predicts the short-term prognosis for COVID-19 independently: A retrospective study from Northeast China

BACKGROUND AND OBJECTIVE

To study whether D-dimer daily continuous tendency could predict the short-term prognosis of COVID-19.

PATIENTS AND METHODES

According to the short-term prognosis, 81 COVID-19 patients were divided into two groups, one of worse prognosis (Group W) and the other of better prognosis (Group B). The slope of D-dimer linear regression during hospitalization (SLOPE) was calculated as an indicator of D-dimer daily continuous tendency. The SLOPE difference between Group W and Group B was compared. The difference between the discharge results and the 3-month follow-up results was also compared. COX regression analysis was used to analyze the relationship between SLOPE and short-term prognosis of COVID-19.

RESULTS

There were 16 patients in Group W and 65 patients in Group B. Group W had more critical proportion (p <  0.0001), indicating that the symptoms of its patients were more severe during hospitalization. ARDS, the most visible cause of worse prognosis, accounted for up to 68.75%, and many symptoms merged and resulted in worse prognosis. The D-dimer levels of Group W not only were significantly higher (p <  0.0001), but also showed an increasing trend. In addition, the D-dimer levels at discharge were significantly higher than those at follow-up (p = 0.0261), and the mean difference was as high as 0.7474. SLOPE significantly correlated with the short-term prognosis of COVID-19 independently (RR: 1.687, 95% CI: 1.345-2.116, P <  0.0001). The worst prognosis occurred most likely during the first month after COVID-19 diagnosis.

CONCLUSION

Our study found that D-dimer daily continuous tendency independently correlates with worse prognosis and can be used as an independent predictor of the short-term prognosis for COVID-19.

Functional ultrasound imaging of the venous valve of the great saphenous vein in the area around the crosse using the novel vector flow technique

PURPOSE: The aim of our pilot study is to consider if the new flow presentation of the vector flow (V-flow) allows an assessment of the valve morphology of the crosses with respect to an insufficiency. MATERIAL AND METHODS: We performed a total of 50 investigations in which we documented a complete valve closure at the so called “crosse” at the valve of the large saphenous vein, a delayed valve closure or an incomplete valve closure with consecutive insufficiency at the crosse. The valve function of the crosse is crucial for the development of varicosis. For our study we recorded age and gender of the patients. One patient in the study was suffering from Covid19. For the examinations we used a 3–9 MHz probe and a high-end ultrasound device. The examination was performed in a lying position and under quiet conditions. Before examination we practiced inhalation and exhalation as well as “pressing” or coughing with the patients, which resulted in a physiological closure of the venous valves. To rule out thrombosis, we carried out compression sonography on the legs. During the examination we documented the B-scan, the Color-Coded Duplex Sonography, the HR-flow and the V-flow for 3 seconds at the estuary of the crosses and incorporated these parameters into our measurements. Via V-flow, vectors can be imaged by representing the flow of erythrocytes and visually indicate a possible insufficiency due to delayed or incomplete valve closure. RESULTS: 31 of 50 patients (age 19–81years) showed a complete valve closure of the crosses, three of them suffered from thrombosis. In eight of the 50 study participants (age 45–79 years) a delayed valve closure could be diagnosed by V-flow within 1–2 seconds. None of them had a thrombosis, but six of them suffered from cancer. In eleven patients we derived an incomplete valve closure with insufficiency (age 51–88 years). With reflux it took >2 seconds to close the valve. The patient with Covid19 also showed an incomplete valve closure with insufficiency. At the same time this patient showed a Covid19-associated deep vein thrombosis. Eight additional patients also had a thrombosis. Six of them suffered from cancer. Overall, the results were best visualized by V-Flow. CONCLUSION: The crosse as a significant venous structure can be well investigated by V-flow with respect to hemodynamic changes and a resulted reflux. Also associated changes close to the valve can be visualized well.