[Clinical, radiological, and histopathological features of pulmonary post-COVID syndrome : A form of autoimmune-mediated interstitial lung disease?] / Klinische, radiologische und histopathologische Merkmale des pulmonalen Post-COVID-Syndroms : Eine Form der autoimmunvermittelten interstitiellen Lungenerkrankung?

BACKGROUND: About 10% of patients develop persistent symptoms after mild/moderate COVID-19. We have previously reported detection of antinuclear autoantibodies/extractable nuclear antigens (ANA/ENA) in patients with severe COVID-19. OBJECTIVES: The aim of this small pilot study was to characterize long-/post-COVID and to evaluate possible similarities between lung involvement in long-/post-COVID and connective tissue disease (CTD). METHODS: We prospectively enrolled 33 previously healthy patients with persistent pulmonal symptoms after mild/moderate COVID-19 without hospitalization (median age, 39 years). We performed clinical evaluation including pulmonary function tests, computed tomography (CT), and serology for ANA/ENA. In 29 of 33 patients, transbronchial biopsies (TBBs) were taken for histopathological assessment. RESULTS: Most patients presented with disturbed oxygen pulse in spiroergometry and slight lymphocytosis in bronchoalveolar lavage (BAL) fluid. The CT pattern showed bronchial wall thickening and increased low-attenuation volume. Autoantibodies were detected in 13 of 33 patients (39.4%). Histopathological assessment showed interstitial lymphocytosis with alveolar fibrin and organizing pneumonia. Ultrastructural analyses revealed interstitial collagen deposition. CONCLUSION: While histopathology of pulmonary long-/post-COVID alone is unspecific, the combination with clinical and radiological features together with detection of autoantibodies would allow for a diagnosis of interstitial pneumonia with autoimmune features (IPAF). Since we observe interstitial collagen deposition and since IPAF/CTD-ILD might progress to fibrosis, the persistence of autoantibodies and possible fibrotic change should be closely monitored in autoantibody-positive long-/post-COVID patients.

[Cavernomas of the central nervous system : Observational study of 111 patients]. / Kavernome des Zentralnervensystems : Verlaufsbeobachtung bei 111 Patienten.

PURPOSE: The prevalence of cavernomas (cavernous hemangioma) is 0.1-0.7%. Cavernomas are often found as an incidental finding within the framework of magnetic resonance imaging (MRI) examinations in mainly young and healthy patients. In the literature, the reported risk of hemorrhage varies greatly and is sometimes higher than that of aneurysms, which is surprising given that cavernomas are part of the low blood pressure system. After the diagnosis the medical practitioner and the patient have to decide on the further therapy, either surgical removal or the strategy of watchful waiting (conservative treatment). The aim of our study was to determine the frequency of bleeding of cavernomas and the consequences and to determine the satisfaction of patients with treatment. All these aspects should make the therapeutic decision easier for medical practitioners. MATERIAL AND METHODS: The study included all patients who were treated in the military hospital in Ulm during the period 2002-2012 and with the diagnosis of one or more cavernomas of the central nervous system (CNS) detected by MRI. This resulted in a total number of 111 patients. We recorded the epidemiological data and analyzed all cavernomas with respect to the location, size, treatment, side effects, etc. Furthermore, all included patients were sent a comprehensive questionnaire about symptoms, course of the disease and the quality of life. The response rate was 38%. All the collected data were analyzed with respect to the various aspects. RESULTS: Depending on the definition of a bleeding event of a cavernoma and selection of the observational period, the probability of a hemorrhage risk ranged from 1.3% to 5.9% per patient year. This relatively high proportion is, however, put into perspective by the mostly mild consequences of a bleeding event. Many cavernomas, which were detected as an incidental finding showed signs of previous bleeding but the patients remained free of symptoms. Additionally, there was no patient in this collective who suffered serious consequences due to a bleeding event. Of the patients with temporal cavernomas 45% had symptomatic epilepsy. The results of the patient survey were heterogeneous. Some patients stated that in retrospect they would not choose surgical treatment again. CONCLUSION: As a result of our findings we think it is important to critically look at the indications for surgical removal of cavernomas and special attention must be paid to informed consent of the patient. The frequent appearance of temporal cavernomas and their propensity to epileptic seizures is an essential aspect, which certainly influences the therapeutic decision. Although cavernomas are a venous malformation in the low blood pressure system, the determined frequency of hemorrhage was 5.9%, which was higher than expected but which is confirmed by other studies. Reports on severe sequelae of cavernoma bleeding are also rare in the literature, which relativizes the resulting danger of the relatively high probability of hemorrhage.

Validating a Four-gene Set for H-ARS Severity Prediction in Peripheral Blood Samples of Irradiated Rhesus Macaques.

Increased radiological and nuclear threats require preparedness. Our earlier work identified a set of four genes (DDB2, FDXR, POU2AF1 and WNT3), which predicts severity of the hematological acute radiation syndrome (H-ARS) within the first three days postirradiation In this study of 41 Rhesus macaques (Macaca mulatta, 27 males, 14 females) irradiated with 5.8-7.2 Gy (LD29-50/60), including some treated with gamma-tocotrienol (GT3, a radiation countermeasure) we independently validated these genes as predictors in both sexes and examined them after three days. At the Armed Forces Radiobiology Research Institute/Uniformed Services University of the Health Sciences, peripheral whole blood (1 ml) of Rhesus macaques was collected into PAXgene® Blood RNA tubes pre-irradiation after 1, 2, 3, 35 and 60 days postirradiation, stored at -80°C for internal experimental analyses. Leftover tubes from these already ongoing studies were kindly provided to Bundeswehr Institute of Radiobiology. RNA was isolated (QIAsymphony), converted into cDNA, and for further gene expression (GE) studies quantitative RT-PCR was performed. Differential gene expression (DGE) was measured relative to the pre-irradiation Rhesus macaques samples. Within the first three days postirradiation, we found similar results to human data: 1. FDXR and DDB2 were up-regulated, FDXR up to 3.5-fold, and DDB2 up to 13.5-fold in the median; 2. POU2AF1 appeared down regulated around tenfold in nearly all Rhesus macaques; 3. Contrary to human data, DDB2 was more up-regulated than FDXR, and the difference of the fold change (FC) ranged between 2.4 and 10, while the median fold changes of WNT3, except days 1 and 35, were close to 1. Nevertheless, 46% of the Rhesus macaques showed down-regulated WNT3 on day one postirradiation, which decreased to 12.2% on day 3 postirradiation. Considering the extended phase, there was a trend towards decreased fold changes at day 35, with median-fold changes ranging from 0.7 for DDB2 to 0.1 for POU2AF1, and on day 60 postirradiation, DGE in surviving animals was close to pre-exposure values for all four genes. In conclusion, the diagnostic significance for radiation-induced H-ARS severity prediction of FDXR, DDB2, and POU2AF1 was confirmed in this Rhesus macaques model. However, DDB2 showed higher GE values than FDXR. As shown in previous studies, the diagnostic significance of WNT3 could not be reproduced in Rhesus macaques; this could be due to the choice of animal model and methodological challenges.

[Hypoxic and hypoglycemic brain damage as a result of an adrenal cortex crisis-An important differential diagnosis in cases of unspecific symptoms]. / Hypoxisch-hypoglykämischer Hirnschaden infolge einer Nebennierenrindenkrise ­ eine wichtige Differenzialdiagnose bei unspezifischer Symptomatik.

Acute adrenal cortex insufficiency is a rare disease, which is hard to diagnose because of its diffuse symptoms. Symptoms, such as general weakness, nausea or vomiting, fatigue, hyponatremia, hyperkalemia, hypoglycemia and pronounced hypotension up to shock can be crucial in the diagnosis of an adrenal cortex crisis. The underlying disease of adrenal cortex insufficiency is also characterized by not always obvious symptoms, which are differently expressed depending on whether it is the primary or secondary type.After the diagnosis is made it is important to educate the patients, determine the optimal dosage of the substitution and ensure the compliance of the patients to optimize the further process and avoid an adrenal crisis. An adrenal crisis is one of the reasons for a higher mortality of these patients, which is well-described in the current literature. Descriptions of fatal courses and their reasons are rare; however, knowledge of the disease and the importance of rapid intervention is very important, especially for physicians who work in the emergency room or intensive care unit (ICU).This article reports about a female patient with a known secondary adrenal cortex insufficiency who developed the complete picture of an adrenal crisis. Despite rapid diagnosis and initiation of treatment massive brain damage could not be averted due to hypoxia and hypoglycemia. This case report demonstrates the potential symptoms, in particular a massive hypoglycemia and an initial shock refractory to catecholamine. It also shows the severity of that disease and the importance of rapid treatment even though it is difficult to make the diagnosis.

Metal artefact reduction in low-dose computed tomography: Benefits of tin prefiltration versus postprocessing of dual-energy datasets over conventional CT imaging.

INTRODUCTION: The purpose of this study was to determine the potential for metal artefact reduction in low-dose multidetector CT as these pose a frequent challenge in clinical routine. Investigations focused on whether spectral shaping via tin prefiltration, virtual monoenergetic imaging or virtual blend imaging (VBI) offers superior image quality in comparison with conventional CT imaging. METHODS: Using a third-generation dual-source CT scanner, two cadaveric specimens with different metal implants (dental, cervical spine, hip, knee) were examined with acquisition protocols matched for radiation dose with regards to tube voltage and current. In order to allow for precise comparison, and due to the relatively short scan lengths, automatic tube current modulation was disabled. Specifically, the following scan protocals were examined: conventional CT protocols (100/120 kVp), tin prefiltration (Sn 100/Sn 150 kVp), VBI and virtual monoenergetic imaging (VME 100/120/150 keV). Mean attenuation and image noise were measured in hyperdense and hypodense artefacts, in artefact-impaired and artefact-free soft tissue. Subjective image quality was rated independently by three radiologists. RESULTS: Objectively, Sn 150 kVp allowed for the best reduction of hyperdense streak artefacts (p < 0.001), while VME 150 keV and Sn 150 kVp protocols facilitated equally good reduction of hypodense artefacts (p = 0.173). Artefact-impaired soft tissue attenuation was lowest in Sn 150 kVp protocols (p ≤ 0.011), whereas all VME showed significantly less image noise compared to conventional or tin-filtered protocols (p ≤ 0.001). Subjective assessment favoured Sn 150 kVp regarding hyperdense streak artefacts and delineation of cortical bone (p ≤ 0.005). The intraclass correlation coefficient was 0.776 (95% confidence interval: 0.712-0.831; p < 0.001) indicating good interrater reliability. CONCLUSION: In the presence of metal implants in our cadaveric study, tin prefiltration with 150 kVp offers superior artefact reduction for low-dose CT imaging of osseous tissue compared with virtual monoenergetic images of dual-energy datasets. The delineation of cortical boundaries seems to benefit particularly from spectral shaping. IMPLICATIONS FOR PRACTICE: Low-dose CT imaging of osseous tissue in combination with tin prefiltration allows for superior metal artefact reduction when compared to virtual monoenergetic images of dual-energy datasets. Employing this technique ought to be considered in daily routine when metal implants are present within the scan volume as findings suggest it allows for radiation dose reduction and facilitates diagnosis relevant to further treatment.

Magnetic resonance imaging in the presence of projectiles and projectile fragments: Artefacts, image quality, rotation and movement.

BACKGROUND AND PURPOSE: Gunshot injuries have been considered a contraindication for MRI because of the risk of secondary dislodgement of retained metallic foreign bodies. The objective of our study was to provide a systematic overview of the behaviour of projectiles and fragments in order to aid decision-making regarding the use of MRI in clinical practice. MATERIALS AND METHODS: Ferromagnetic (n = 2) and non-ferromagnetic (n = 5) projectiles and fragments that were lodged in soft tissue (porcine masseter muscles) were examined using standard protocols at 1, 1.5 and 3 T, to simulate clinical situations as realistically as possible. CT was performed before and after every MRI to assess rotation and movement. Artefacts and image quality were analysed using Likert-type scales. RESULTS: Ferromagnetic projectiles were of poorer quality and showed larger artefacts and did not provide benefit for clinical practice compared to images of non-ferromagnetic material. Image quality of non-ferromagnetic projectiles varied widely (from very good to moderate) depending on the composition of the projectiles. Field strength (1 T to 3 T) had no relevant influence on image quality. CONCLUSIONS: Non-ferromagnetic projectiles are not a contraindication for MR imaging since there is no potential risk of secondary dislodgement. Image quality and the extent of artefacts, however, strongly depend on the type of ammunition used. The presence of ferromagnetic projectiles in or near vital anatomic structures is a contraindication for MRI because these objects may exhibit movement in response to magnetic fields. Knowledge of the type of projectile used appears to be important in order to guide patient management before an examination is performed. So, the production and use of projectiles suitable for MRI should be favored in the future, knowing that this will be hard to fulfil.