Prognostic Impact of CT-Quantified Muscle and Fat Distribution before and after First-Line-Chemotherapy in Lung Cancer Patients

Introduction

Cachexia and sarcopenia are associated with poor outcome and increased chemotherapy-induced toxicity in lung cancer patients. However, the complex interplay of obesity, sarcopenia and cachexia, and its impact on survival in the context of first-line-chemotherapy is not yet understood.

Methods

In 200 consecutively recruited lung cancer patients (70 female, mean age 62y; mean BMI 25 kg/m²; median follow-up 15.97 months) with routine staging-CT before and after chemotherapy (CTX, mean interval: 4.3 months), densitometric quantification of total (TFA), visceral (VFA), and subcutaneous-fat-area (SFA), inter-muscular-fat-area (IMFA), muscle-density (MD), muscle-area (MA) and skeletal-muscle-index (SMI) was performed retrospectively to evaluate changes under chemotherapy and the impact on survival.

Results

We observed increases in TFA, VFA, SFA, VFA/SFA, and IMFA (p<0.05–0.001), while there were decreases in MA, MD and BMI (p<0.05–0.001) after chemotherapy. High pre-therapeutic VFA/SFA was a predictive factor for poor survival (HR = 1.272; p = 0.008), high pre-therapeutic MD for improved survival (HR = 0.93; p<0.05). Decrease in BMI (HR = 1.303; p<0.001), weight (HR = 1.067; p<0.001) and SMI (HR = 1.063; p<0.001) after chemotherapy were associated with poor survival. Patients with ≥4 CTX-cycles showed increased survival (17.6 vs. 9.1months), less muscle depletion (SMI_difference: p<0.05) and no BMI loss (BMI_difference: p<0.001).

Conclusions

After chemotherapy, patients exhibited sarcopenia with decreased muscle and increased adipose tissue compartments, which was not adequately mirrored by BMI and weight loss but by imaging. Particularly sarcopenic patients received less CTX-cycles and had poorer survival. As loss of BMI, weight and muscle were associated with poor survival, early detection (via imaging) and prevention (via physical exercise and nutrition) of sarcopenia may potentially improve outcome and reduce chemotherapy-induced toxicity.

Imaging of Cystic Fibrosis Lung Disease and Clinical Interpretation

Progressive lung disease in cystic fibrosis (CF) is the life-limiting factor of this autosomal recessive genetic disorder. Increasing implementation of CF newborn screening allows for a diagnosis even in pre-symptomatic stages. Improvements in therapy have led to a significant improvement in survival, the majority now being of adult age. Imaging provides detailed information on the regional distribution of CF lung disease, hence longitudinal imaging is recommended for disease monitoring in the clinical routine. Chest X-ray (CXR), computed tomography (CT) and magnetic resonance imaging (MRI) are now available as routine modalities, each with individual strengths and drawbacks, which need to be considered when choosing the optimal modality adapted to the clinical situation of the patient. CT stands out with the highest morphological detail and has often been a substitute for CXR for regular severity monitoring at specialized centers. Multidetector CT data can be post-processed with dedicated software for a detailed measurement of airway dimensions and bronchiectasis and potentially a more objective and precise grading of disease severity. However, changing to CT was inseparably accompanied by an increase in radiation exposure of CF patients, a young population with high sensitivity to ionizing radiation and lifetime accumulation of dose. MRI as a cross-sectional imaging modality free of ionizing radiation can depict morphological hallmarks of CF lung disease at lower spatial resolution but excels with comprehensive functional lung imaging, with time-resolved perfusion imaging currently being most valuable.

KEY POINTS

• Hallmarks are bronchiectasis, mucus plugging, air trapping, perfusion abnormalities, and emphysema.• Imaging is more sensitive to disease progression than lung function testing.• CT provides the highest morphological detail but is associated with radiation exposure.• MRI shows comparable sensitivity for morphology but excels with additional functional information.• MRI sensitively depicts reversible abnormalities such as mucus plugging and perfusion abnormalities. Citation Format: • Wielpütz MO, Eichinger M, Biederer J et al. Imaging of Cystic Fibrosis Lung Disease and Clinical Interpretation. Fortschr Röntgenstr 2016; 188: 834 - 845.

In vivo monitoring of cystic fibrosis-like lung disease in mice by volumetric computed tomography

The onset and spontaneous development of cystic fibrosis (CF) lung disease remain poorly understood. In the present study, we used volumetric computed tomography (VCT) as a new method for longitudinal in vivo monitoring of early lesions and disease progression in CF-like lung disease in β-epithelial Na(+) channel (ENaC)-transgenic (TG) mice. Using a VCT scanner prototype (80 kV, 50 mA·s, scan time 19 s and spatial resolution 200 μm), βENaC-TG mice and wild-type (WT) littermates were examined longitudinally at 10 time-points from neonatal to adult ages, and VCT images were assessed by qualitative and quantitative morphological parameters. We demonstrate that VCT detected early-onset airway mucus obstruction, diffuse infiltrates, atelectasis and air trapping as characteristic abnormalities in βENaC-TG mice. Furthermore, we show that early tracheal mucus obstruction predicted mortality in βENaC-TG mice and that the density of lung parenchyma was significantly reduced at all time-points in βENaC-TG compared with WT mice (median ± sem -558 ± 8 HU in WT versus -686 ± 16 HU in βENaC-TG at 6 weeks of age; p < 0.005). Our study demonstrates that VCT is a sensitive, noninvasive technique for early detection and longitudinal monitoring of morphological abnormalities of CF-like lung disease in mice, and may thus provide a useful tool for pre-clinical in vivo evaluation of novel treatment strategies for CF.

Outracing Lung Signal Decay - Potential of Ultrashort Echo Time MRI

BACKGROUND

 Magnetic resonance imaging (MRI) of the pulmonary parenchyma is generally hampered by multiple challenges related to patient respiratory- and circulation-related motion, low proton density and extremely fast signal decay due to the structure of the lungs evolved for gas exchange.

METHODS

 Systematic literature database research as well as annual participation in conferences dedicated to pulmonary MRI for more than the past 20 years by at least one member of the author team.

RESULTS AND CONCLUSION

 The problem of motion has been addressed in the past by developments such as triggering, gating and parallel imaging. The second problem has, in part, turned out to be an advantage in those diseases that lead to an increase in lung substance and thus an increase in signal relative to the background. To reduce signal decay, ultrashort echo time (UTE) methods were developed to minimize the time between excitation and readout. Having been postulated a while ago, improved hardware and software now open up the possibility of achieving echo times shorter than 200 µs, increasing lung signal significantly by forestalling signal decay and more effectively using the few protons available. Such UTE techniques may not only improve structural imaging of the lung but also enhance functional imaging, including ventilation and perfusion imaging as well as quantitative parameter mapping. Because of accelerating progress in this field of lung MRI, the review at hand seeks to introduce some technical properties as well as to summarize the growing data from applications in humans and disease, which promise that UTE MRI will play an important role in the morphological and functional assessment of the lung in the near future.

KEY POINTS

  · Ultrashort echo time MRI is technically feasible with state-of-the-art scanner hardware.. · UTE MRI allows for CT-like image quality for structural lung imaging.. · Preliminary studies show improvements over conventional morphological imaging in lung cancer and airways diseases.. · UTE may improve sensitivity for functional processes like perfusion and tissue characterization..

CITATION FORMAT

· Wielpütz MO, Triphan SM, Ohno Y et al. Outracing Lung Signal Decay - Potential of Ultrashort Echo Time MRI. Fortschr Röntgenstr 2019; 191: 415 - 423.

Automatic lung segmentation method for MRI-based lung perfusion studies of patients with chronic obstructive pulmonary disease

PURPOSE

A novel fully automatic lung segmentation method for magnetic resonance (MR) images of patients with chronic obstructive pulmonary disease (COPD) is presented. The main goal of this work was to ease the tedious and time-consuming task of manual lung segmentation, which is required for region-based volumetric analysis of four-dimensional MR perfusion studies which goes beyond the analysis of small regions of interest.

METHODS

The first step in the automatic algorithm is the segmentation of the lungs in morphological MR images with higher spatial resolution than corresponding perfusion MR images. Subsequently, the segmentation mask of the lungs is transferred to the perfusion images via nonlinear registration. Finally, the masks for left and right lungs are subdivided into a user-defined number of partitions. Fourteen patients with two time points resulting in 28 perfusion data sets were available for the preliminary evaluation of the developed methods.

RESULTS

Resulting lung segmentation masks are compared with reference segmentations from experienced chest radiologists, as well as with total lung capacity (TLC) acquired by full-body plethysmography. TLC results were available for thirteen patients. The relevance of the presented method is indicated by an evaluation, which shows high correlation between automatically generated lung masks with corresponding ground-truth estimates.

CONCLUSION

The evaluation of the developed methods indicates good accuracy and shows that automatically generated lung masks differ from expert segmentations about as much as segmentations from different experts.

[Microvascular changes in COVID-19]

BACKGROUND

Clinically, coronavirus disease 2019 (COVID-19) is associated with a wide range of symptoms, which can range from mild complaints of an upper respiratory infection to life-threatening hypoxic respiratory insufficiency and multiorgan failure.

OBJECTIVE

The initially identified pulmonary damage patterns, such as diffuse alveolar damage in acute lung failure, are accompanied by new findings that draw a more complex scenario. These include microvascular involvement and a wide range of associated pathologies of multiple organ systems. A back-scaling of microstructural vascular changes is possible via targeted correlation of pathological autopsy results with radiological imaging.

MATERIAL AND METHODS

Radiological and pathological correlation as well as microradiological imaging to investigate microvascular involvement in fatal COVID-19.

RESULTS

The cases of two COVID-19 patients are presented. Patient 1 showed a relative hypoperfusion in lung regions that did not have typical COVID-19 infiltrates; the targeted post-mortem correlation also showed subtle signs of microvascular damage even in these lung sections. Patient 2 showed both radiologically and pathologically advanced typical COVID-19 destruction of lung structures and the case illustrates the damage patterns of the blood-air barrier. The perfusion deficit of the intestinal wall shown in computed tomography of patient 2 could not ultimately clearly be microscopically attributed to intestinal microvascular damage.

CONCLUSION

In addition to microvascular thrombosis, our results indicate a functional pulmonary vasodysregulation as part of the pathophysiology during the vascular phase of COVID-19. The clinical relevance of autopsies and the integration of radiological imaging findings into histopathological injury patterns must be emphasized for a better understanding of COVID-19.

Dephasing and diffusion on the alveolar surface

We propose a surface model of spin dephasing in lung tissue that includes both susceptibility and diffusion effects to provide a closed-form solution of the Bloch-Torrey equation on the alveolar surface. The nonlocal susceptibility effects of the model are validated against numerical simulations of spin dephasing in a realistic lung tissue geometry acquired from synchotron-based μCT data sets of mouse lung tissue, and against simulations in the well-known Wigner-Seitz model geometry. The free induction decay is obtained in dependence on microscopic tissue parameters and agrees very well with in vivo lung measurements at 1.5 Tesla to allow a quantification of the local mean alveolar radius. Our results are therefore potentially relevant for the clinical diagnosis and therapy of pulmonary diseases.

[CF Lung Disease - a German S3 Guideline: Module 2: Diagnostics and Treatment in Chronic Infection with Pseudomonas aeruginosa]

Cystic Fibrosis (CF) is the most common autosomal-recessive genetic disease affecting approximately 8000 people in Germany. The disease is caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene leading to dysfunction of CFTR, a transmembrane chloride channel. This defect causes insufficient hydration of the epithelial lining fluid which leads to chronic inflammation of the airways. Recurrent infections of the airways as well as pulmonary exacerbations aggravate chronic inflammation, lead to pulmonary fibrosis and tissue destruction up to global respiratory insufficiency, which is responsible for the mortality in over 90 % of patients. The main aim of pulmonary treatment in CF is to reduce pulmonary inflammation and chronic infection. Pseudomonas aeruginosa (Pa) is the most relevant pathogen in the course of CF lung disease. Colonization and chronic infection are leading to additional loss of pulmonary function. There are many possibilities to treat Pa-infection. This is a S3-clinical guideline which implements a definition for chronic Pa-infection and demonstrates evidence-based diagnostic methods and medical treatment for Pa-infection in order to give guidance for individual treatment options.

µCT to quantify muco-obstructive lung disease and effects of neutrophil elastase knockout in mice

Muco-obstructive lung diseases are characterized by airway obstruction and hyperinflation, which can be quantified by imaging. Our aim was to evaluate µCT for longitudinal quantification of muco-obstructive lung disease in β-epithelial Na⁺ channel overexpressing (Scnn1b-TG) mice and of the effects of neutrophil elastase (NE) knockout on its progression. Lungs from wild-type (WT), NE^-/-, Scnn1b-TG, and Scnn1b-TG/NE^-/- mice were scanned with 9 µm resolution at 0, 5, 14 and 60 days of age, and airway and parenchymal disease was quantified. Mucus adhesion lesions (MAL) were persistently increased in Scnn1b-TG compared to WT mice from 0 days (20.25±6.50 vs. 9.60±2.07, P<0.05), and this effect was attenuated in Scnn1b-TG/NE^-/- mice (5.33±3.67, P<0.001). Airway wall area percentage (WA%) was increased in Scnn1b-TG mice compared to WT from 14 days onward (59.2±6.3% vs. 49.8±9.0%, P<0.001) but was similar in Scnn1b-TG/NE^-/- compared to WT at 60 days (46.4±9.2% vs. 45.4±11.5%, P=0.97). Air proportion (Air%) and mean linear intercept (Lm) were persistently increased in Scnn1b-TG compared to WT from 5 days on (53.9±4.5% vs. 30.0±5.5% and 78.82±8.44µm vs. 65.66±4.15µm, respectively, P<0.001), whereas in Scnn1b-TG/NE^-/- Air% and Lm were similar to WT from birth (27.7±5.5% vs.27.2±5.9%, P =0.92 and 61.48±9.20µm vs. 61.70±6.73µm, P=0.93, respectively). Our results suggest that µCT is sensitive to detect the onset and progression of muco-obstructive lung disease and effects of genetic deletion of NE on morphology of airways and lung parenchyma in Scnn1b-TG mice, and that it may serve as a sensitive endpoint for preclinical studies of novel therapeutic interventions for muco-obstructive lung diseases.

Spirometry-based reconstruction of real-time cardiac MRI: Motion control and quantification of heart-lung interactions

PURPOSE

To test the feasibility of cardiac real-time MRI in combination with retrospective gating by MR-compatible spirometry, to improve motion control, and to allow quantification of respiratory-induced changes during free-breathing.

METHODS

Cross-sectional real-time MRI (1.5T; 30 frames/s) using steady-state free precession contrast during free-breathing was combined with MR-compatible spirometry in healthy adult volunteers (n = 4). Retrospective binning assigned images to classes that were defined by electrocardiogram and spirometry. Left ventricular eccentricity index as an indicator of septal position and ventricular volumes in different respiratory phases were calculated to assess heart-lung interactions.

RESULTS

Real-time MRI with MR-compatible spirometry is feasible and well tolerated. Spirometry-based binning improved motion control significantly. The end-diastolic epicardial eccentricity index increased significantly during inspiration (1.04 ± 0.04 to 1.19 ± 0.05; P < .05). During inspiration, right ventricular end-diastolic volume (79 ± 17 mL/m² to 98 ± 18 mL/m² ), stroke volume (41 ± 8 mL/m² to 59 ± 11 mL/m² ) and ejection fraction (53 ± 3% to 60 ± 1%) increased significantly, whereas the end-systolic volume remained almost unchanged. Left ventricular end-diastolic volume, left ventricular stroke volume, and left ventricular ejection fraction decreased during inspiration, whereas the left ventricular end-systolic volume increased. The relationship between stroke volume and end-diastolic volume (Frank-Starling relationship) based on changes induced by respiration allowed for a slope estimate of the Frank-Starling curve to be 0.9 to 1.1.

CONCLUSION

Real-time MRI during free-breathing combined with MR-compatible spirometry and retrospective binning improves image stabilization, allows quantitative image analysis, and importantly, offers unique opportunities to judge heart-lung interactions.

[Update on cystic fibrosis : From neonatal screening to causal treatment]

Cystic fibrosis (CF) is a multiorgan disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Approximately 90% of the morbidity and mortality are caused by pulmonary involvement. The mean life expectancy of patients with CF in 2020 was more than 52 years in Germany. The introduction of neonatal screening for CF and the development of a causally acting CFTR modulator treatment have clearly improved the prognosis of these patients. As an introduction, this article describes important aspects of CF in this context in order to go into details of the CF neonatal screening which was introduced in Germany in 2016.

GOLD stage-specific phenotyping of emphysema and airway disease using quantitative computed tomography

Background

In chronic obstructive pulmonary disease (COPD) abnormal lung function is related to emphysema and airway obstruction, but their relative contribution in each GOLD-stage is not fully understood. In this study, we used quantitative computed tomography (QCT) parameters for phenotyping of emphysema and airway abnormalities, and to investigate the relative contribution of QCT emphysema and airway parameters to airflow limitation specifically in each GOLD stage.

Methods

Non-contrast computed tomography (CT) of 492 patients with COPD former GOLD 0 COPD and COPD stages GOLD 1-4 were evaluated using fully automated software for quantitative CT. Total lung volume (TLV), emphysema index (EI), mean lung density (MLD), and airway wall thickness (WT), total diameter (TD), lumen area (LA), and wall percentage (WP) were calculated for the entire lung, as well as for all lung lobes separately. Results from the 3rd-8th airway generation were aggregated (WT3-8, TD3-8, LA3-8, WP3-8). All subjects underwent whole-body plethysmography (FEV1%pred, VC, RV, TLC).

Results

EI was higher with increasing GOLD stages with 1.0 ± 1.8% in GOLD 0, 4.5 ± 9.9% in GOLD 1, 19.4 ± 15.8% in GOLD 2, 32.7 ± 13.4% in GOLD 3 and 41.4 ± 10.0% in GOLD 4 subjects (p < 0.001). WP3-8 showed no essential differences between GOLD 0 and GOLD 1, tended to be higher in GOLD 2 with 52.4 ± 7.2%, and was lower in GOLD 4 with 50.6 ± 5.9% (p = 0.010 - p = 0.960). In the upper lobes WP3-8 showed no significant differences between the GOLD stages (p = 0.824), while in the lower lobes the lowest WP3-8 was found in GOLD 0/1 with 49.9 ± 6.5%, while higher values were detected in GOLD 2 with 51.9 ± 6.4% and in GOLD 3/4 with 51.0 ± 6.0% (p < 0.05). In a multilinear regression analysis, the dependent variable FEV1%pred can be predicted by a combination of both the independent variables EI (p < 0.001) and WP3-8 (p < 0.001).

Conclusion

QCT parameters showed a significant increase of emphysema from GOLD 0-4 COPD. Airway changes showed a different spatial pattern with higher values of relative wall thickness in the lower lobes until GOLD 2 and subsequent lower values in GOLD3/4, whereas there were no significant differences in the upper lobes. Both, EI and WP5-8 are independently correlated with lung function decline.

Quantification of airway wall contrast enhancement on virtual monoenergetic images from spectral computed tomography

OBJECTIVES

Quantitative computed tomography (CT) plays an increasingly important role in phenotyping airway diseases. Lung parenchyma and airway inflammation could be quantified by contrast enhancement at CT, but its investigation by multiphasic examinations is limited. We aimed to quantify lung parenchyma and airway wall attenuation in a single contrast-enhanced spectral detector CT acquisition.

METHODS

For this cross-sectional retrospective study, 234 lung-healthy patients who underwent spectral CT in four different contrast phases (non-enhanced, pulmonary arterial, systemic arterial, and venous phase) were recruited. Virtual monoenergetic images were reconstructed from 40-160 keV, on which attenuations of segmented lung parenchyma and airway walls combined for 5th-10th subsegmental generations were assessed in Hounsfield Units (HU) by an in-house software. The spectral attenuation curve slope between 40 and 100 keV (λHU) was calculated.

RESULTS

Mean lung density was higher at 40 keV compared to that at 100 keV in all groups (p < 0.001). λHU of lung attenuation was significantly higher in the systemic (1.7 HU/keV) and pulmonary arterial phase (1.3 HU/keV) compared to that in the venous phase (0.5 HU/keV) and non-enhanced (0.2 HU/keV) spectral CT (p < 0.001). Wall thickness and wall attenuation were higher at 40 keV compared to those at 100 keV for the pulmonary and systemic arterial phase (p ≤ 0.001). λHU for wall attenuation was significantly higher in the pulmonary arterial (1.8 HU/keV) and systemic arterial (2.0 HU/keV) compared to that in the venous (0.7 HU/keV) and non-enhanced (0.3 HU/keV) phase (p ≤ 0.002).

CONCLUSIONS

Spectral CT may quantify lung parenchyma and airway wall enhancement with a single contrast phase acquisition, and may separate arterial and venous enhancement. Further studies are warranted to analyze spectral CT for inflammatory airway diseases.

KEY POINTS

• Spectral CT may quantify lung parenchyma and airway wall enhancement with a single contrast phase acquisition. • Spectral CT may separate arterial and venous enhancement of lung parenchyma and airway wall. • The contrast enhancement can be quantified by calculating the spectral attenuation curve slope from virtual monoenergetic images.

Acquisition of a Dose Management System with Consideration of Medico-Legal and Economic Aspects

BACKGROUND

 New radiation protection regulation encompassing additional obligations for monitoring, reporting and recording of radiation exposure, was enacted on December 31, 2018. As a consequence, dose management systems (DMS) are necessary to fulfill the requirements. The process of selection, acquisition and implementation of a suitable IT solution for this purpose is a challenge that all X-ray-applying facilities, including hospitals and private practices, are currently facing.

METHOD

 A target/actual-analysis as well as a cost-utility analysis is presented for this specific case as a foundation for the acquisition decision-making process.

RESULT

 An actual analysis is necessary in order to record the current status of dose documentation. An interdivisional approach is recommended to include all imaging modalities and devices. An interdisciplinary steering committee can be helpful in enabling consensus and rapid action. A target analysis includes additional criteria with respect to ease of operation, technical feasibility, process optimization and research opportunities to consider in addition to the statutory requirements. By means of a cost-benefit analysis, considerations between costs and the individually weighted advantages and disadvantages of eligible DMS result in a ranking of preference for the available solutions.

CONCLUSION

 Requirements of a DMS can be summarized in a specification sheet. Deploying an actual condition analysis, target state analysis and cost-utility analysis can help to identify a suitable DMS to achieve rapid commissioning and highest possible user acceptance while optimizing costs at the same time.

KEY POINTS

· An actual analysis reveals optimization and standardization needs in examination protocols and technical coding of dose data that can be addressed before or during the acquisition process.. · A specification sheet covers all functional, technical, and financial aspects of a target analysis.. · A cost-utility analysis is useful for exploring an appropriate dose management system with high user acceptance, rapid implementation, and low cost.. · An interdisciplinary steering committee can be helpful to enable early consensus building and fast action..

CITATION FORMAT

· Do TD, Melzig C, Kauczor H et al. Acquisition of a Dose Management System with Consideration of Medico-Legal and Economic Aspects. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1710-3529.

Aliado - A design concept of AI for decision support in oncological liver surgery

BACKGROUND

The interest in artificial intelligence (AI) is increasing. Systematic reviews suggest that there are many machine learning algorithms in surgery, however, only a minority of the studies integrate AI applications in clinical workflows. Our objective was to design and evaluate a concept to use different kinds of AI for decision support in oncological liver surgery along the treatment path.

METHODS

In an exploratory co-creation between design experts, surgeons, and data scientists, pain points along the treatment path were identified. Potential designs for AI-assisted solutions were developed and iteratively refined. Finally, an evaluation of the design concept was performed with n = 20 surgeons to get feedback on the different functionalities and evaluate the usability with the System Usability Scale (SUS). Participating surgeons had a mean of 14.0 ± 5.0 years of experience after graduation.

RESULTS

The design concept was named "Aliado". Five different scenarios were identified where AI could support surgeons. Mean score of SUS was 68.2 ( ± 13.6 SD). The highest valued functionalities were "individualized prediction of survival, short-term mortality and morbidity", and "individualized recommendation of surgical strategy".

CONCLUSION

Aliado is a design prototype that shows how AI could be integrated into the clinical workflow. Even without a fleshed out user interface, the SUS already yielded borderline good results. Expert surgeons rated the functionalities favorably, and most of them expressed their willingness to work with a similar application in the future. Thus, Aliado can serve as a surgical vision of how an ideal AI-based assistance could look like.

Right-to-left-shunts in patients scheduled for neurosurgical intervention in semi-sitting position - a literature review based on two case scenarios

BACKGROUND

Neurosurgery performed in the semi-sitting position provides advantages for certain procedures. However, this approach is associated with potential complications, particularly venous air embolism. Due to typically negative venous pressure at the wound site, air can be drawn into the veins. This risk is especially high in patients presenting with an intra- or extracardiac right-to-left-shunt. Transoesophageal echocardiography can be used to detect a patent foramen ovale or other possible pulmonary-systemic shunt before placing the patient in the sitting position.

CASE PRESENTATION

In this report, we present two young patients undergoing scheduled microsurgical vestibular schwannoma removal in a semi-sitting position who were diagnosed with congenital heart defects during routine perioperative assessment to detect possible intracardiac right-to-left shunts, using pre- and intraoperative transesophageal echocardiography (TEE) and additionally conducting an agitated saline bubble study under Valsalva manoeuvre. Patient A was diagnosed with a persistent left superior vena cava and Patient B with an unroofed coronary sinus (UCS). These findings confronted the anesthesiological and surgical teams with difficult individual decisions regarding further perioperative management.

CONCLUSIONS

Perioperative transesophageal echocardiography is a diagnostic tool to both detect intraoperative position-related air embolisms and to rule out intracardiac right-to-left shunts, e.g. a patent foramen ovale, in order to decide for or against a (semi-)sitting position. Depending on the surgical circumstances a semi-sitting positioning of patients presenting with an intracardiac right-to-left-shunt, e.g. a PFO, can be feasible in individual cases if there is an implemented therapeutic algorithm to immediately terminate significant venous air entry. However, since certain other intra- or extracardiac right-to-left-shunts, such as here presented PLSVC or UCS, are rare, there is no definitive way of estimating the amount of entered air through detected shunts or anomalous vessels. Therefore, it is recommended to avoid a (semi-)sitting position in favour of a lateral or prone position for a patient undergoing intracranial surgery, once the perioperative TEE shows air bubbles in the left atrium or ventricle whose origins cannot be defined solely through TEE for certain in order to ensure patient safety by minimizing the risk of intraoperative paradoxical air embolisms.

Simultaneous presence of the "bullseye" and "reversed halo" sign at CT of COVID-19 pneumonia: A case report

The "bullseye" sign has been exclusively reported in patients suffering from coronavirus disease 2019 (COVID-19) pneumonia. It is theorized that this newly recognized computed tomography (CT) feature represents a sign of organizing pneumonia. Well established signs of organizing pneumonia also reported in COVID-19 patients include linear opacities, the "reversed halo" sign (or "atoll" sign), and a perilobular distribution of abnormalities. These findings are usually present on imaging in the intermediate and late stage of the disease. This is a case of simultaneous presence of the "bullseye" and the "reversed halo" sign on chest CT images of a COVID-19 patient examined 22 days after symptom onset.